Term
| What is the primary function of the digestive system? |
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Definition
| To transfer nutrients, water, and electrolytes from ingested food into body's internal environment |
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Term
| What are the other four functions of the digestive system? |
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Definition
1) Motility
2) Secretion
3) Digestion
4) Absorption |
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Term
| In regards to digestion, what is motility? What are the two types? |
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Definition
Muscular contractions that mix and move forward the contents of the digestive tract
1) Propulsive movements - push contents forward through the digestive tract
2) Mixing movements - serve two functions a) mixing food with digestive juices promotes digestion of foods. b)facilitates absorption by exposing all parts of intestinal contents to absorbing surfaces of digestive tract. |
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Term
| Digestive secretions consists of what three things? |
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Definition
1) Water
2) Electrolytes
3) specific organic constituents |
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Term
| Secretions are released into the digestive tract lumen on appropriate ______ or ________ stimulation. |
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Definition
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Term
| Secretions are normally __________ in one form or another back into the blood after their participation in digestion. |
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Definition
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Term
| What is digestion defined? how is digestion accomplished? |
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Definition
Biochemical breakdown of structurally complex foodstuffs into smaller, absorbable units.
Accomplished by enzymatic hydrolysis |
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Term
What are the absorbable units of the following foodstuffs?
1) Carbohydrates ->
2) Proteins ->
3) Fat -> |
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Definition
1) Carbohydrates -> monosaccharides
2) Proteins -> amino acids
3) Fats -> glycerol and fatty acids |
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Term
| Explain absorption in regards to digestion. |
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Definition
| When small units resulting from digestion, along with water, vitamins, and electrolytes are transferred from the digestive tract lumen into the blood or lymph. |
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Term
| The digestive tract is continuous from the _____ to the ____. |
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Definition
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Term
| The digestive tract consists of what 7 things? |
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Definition
1) Mouth
2) Pharynx
3) Esophagus
4) Stomach
5) Small intestine - duodenum, jejunum, and the ileum
6) Large intestine - Cecum, appendix, colon, and the rectum
7) Anus |
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Term
| List the three accessory digestive organs: |
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Definition
1) Salivary glands
2) Exocrine pancreas
3) Bilary system - liver, gallbladder |
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Term
| True or False - The wall has the same general structure throughout length from esophagus to anus |
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Definition
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Term
| List the four major tissue layers from innermost layer to outermost layer. |
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Definition
1) Mucosa - innermost layer
2) Submucosa
3) Muscularis externa
4) Serosa - outer layer |
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Term
| Characterize the mucosa layer. |
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Definition
-Lines the luminal surface of digestive tract
- Highly folded surface greatly increases absorptive area
3 layers:
1) mucous membrane - serves as protective surface and modified for secretion and absorption. Contains: a) exocrine gland cells - secrete digestive juices b) endocrine gland cells - secrete blood-borne gastrointestinal hormones c) epithelial cells - specialize for absorbing digestive nutrients.
2) Lamina propria - Houses gut associated lymphoid tissue (GALT) - important in defense against disease-causing intestinal bacteria
3) Muscularis mucosa - sparse layer of smooth muscle |
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Term
| Characterize the submucosa: |
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Definition
-Thick layer of connective tissue
-provides digestive tract with distensibility and elasticity
-contains larger blood and lymph vessels
-contains nerve network known as the submucosal plexus. |
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Term
| Characterize the muscularis externa: |
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Definition
-Major smooth muscle coat of digestive tube
-In most areas consist of two layers:
1) Circular layer - inner layer, contraction decreases diameter of lumen.
2) Longitudinal layer - outer layer, contraction shortens the tube.
-Contractile activity produces propulsive and mixing movements.
-Myenterix plexus - lies between the two muscle layers. |
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Term
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Definition
-Secretes serous fluid which lubricates and prevents friction between digestive organs and surrounding viscera
-Continuous with mesentery throughout much of the tract - this attachment provides relative fixation while also supporting digestive organs in proper place while allowing them freedom for mixing and propulsive movements. |
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Term
| Digestive motility and secretion are regulated by what four things? |
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Definition
1) Autonomous smooth muscle function
2) Intrinsic nerve plexuses
3) Extrinsic nerves
4) Gastrointestinal hormones |
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Term
| What four things do the lips do? |
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Definition
-Form opening
-Help procure, guide, and contain food in the mouth
-Important in speech
-Well-developed tactile sensation |
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Term
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Definition
-Forms roof of oral cavity (separates mouth from nasal passages)
-Uvula |
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Term
| What seals off the nasal passages during swallowing? |
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Definition
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Term
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Definition
-Forms floor of oral cavity
-Composed of skeletal muscle
-Movements aid in chewing and swallowing
-Plays important role in speech
-Taste buds |
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Term
| What is the cavity at the rear of the throat which is a common passageway for digestive and respiratory systems? What else is there in this cavity? |
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Definition
| The pharynx - also has the tonsils within the side walls of the pharynx and lymphoid tissue |
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Term
| What is the first step in the digestive process? What is responsible for it? |
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Definition
| First step is chewing or mastication using your teeth fool |
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Term
| What are the three functions of chewing? |
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Definition
1) Grind and break food into smaller pieces to make swallowing easier and increase food surface area on which salivary enzymes can act
2) Mix food with saliva
3) Stimulate taste buds |
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Term
| Saliva is largely produced by what? What is its composition? |
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Definition
Produced largely by three major pairs of salivary glands.
-99.5% H2O
-0.5% electrolytes and protein (amylase, mucus, lysozyme) |
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Term
| About how much saliva do we produce in a day? |
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Definition
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Term
| There are 8 functions of saliva, try and list them all. |
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Definition
1) Salivary amylase begins digestion of carbohydrates
2) Facilitates swallowing by moistening food
3) Mucus provides lubrication
4) Antibacterial action - lysozyme destroys bacteria - saliva rinses away material that could serve as food source for bacteria
5)Solvent for molecules that stimulate taste buds
6)Aids speech by facilitating movements of lips and tongue
7)Helps keep mouth and teeth clean
8)Rich in bicarbonate buffers |
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Term
| _______ stimulates saliva production. |
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Definition
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Term
| ______ is the only secretion that is under nervous system control. |
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Definition
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Term
| Explain the process of swallowing. |
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Definition
1) Motility associated with pharynx and esophagus
2) Sequentially programmed all-or-none reflex
3) Initiated when bolus is voluntarily forced by tongue to rear of mouth into pharynx
4) Most complex reflex in the body
5) Can be initiated voluntarily but cannot be stopped once it has begun |
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Term
| What are the two stages of swallowing? |
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Definition
1) Oropharyngeal stage - oral to pharyngeal
2) Esophageal stage - moves bolus from mouth through pharynx and into esophagus |
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Term
| How long does it take for food to get from the back of the throat to the stomach? |
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Definition
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Term
| What is characterized by a fairly straight muscular tube that extends between pharynx and stomach? |
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Definition
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Term
| What are the two sphincters associated with the esophagus? |
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Definition
1) Pharynogoesophageal sphincter - keeps entrance closed to prevent large volumes of air from entering esophagus and stomach during breathing
2) Gastroesophageal sphincter - prevents reflux of gastric contents |
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Term
| ___________ _____ push food through esophagus and _________ are entirely protective. |
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Definition
peristaltic waves
secretions (mucus) |
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Term
| What is the stomach shaped as and where is it located? |
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Definition
| J-shaped sac-like chamber lying between esophagus and small intestine. |
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Term
| What are the three sections of the stomach and what are the three main functions of the stomach? |
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Definition
Sections:
1) Fundus
2) Body
3) Antrum
Functions
1) Store ingested food until it can be emptied into small intestine
2) Secretes hydrochloric acid (HCL) and enzymes that begin protein digestion
3) Mixing movements convert pulverized food to chyme |
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Term
| What is the job of the pyloric sphincter? |
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Definition
| Serves as a barrier between the stomach and upper part of the small intestine |
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Term
| List and describe the four aspects of gastric motility. |
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Definition
1) Filling - Involves receptive relaxation - enhances stomach's ability to accommodate the extra volume of food with little rise in stomach pressure. Triggered by act of eating. Mediated by the vagus nerve.
2) Storage - Takes place in the body of the stomach
3) Mixing - takes place in the antrum of the stomach
4) Emptying - largely controlled by factors in the duodenum |
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Term
| What factor in the stomach influences the strength of contraction during gastric emptying? |
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Definition
| The amount of chyme in the stomach |
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Term
| Explain the four factors in the duodenum which influence gastric emptying. |
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Definition
1) Fat - fat digestion and absorption takes place only within the lumen of the small intestine. When fat is already in the duodenum, further gastric emptying of additional fatty stomach contents is prevented (slows down motility)
2) Acid - unneutraliezed acid in the duodenum inhibits further emptying of acidic gastric contents until neutralization can be accomplished
3) Hypertonicity - Gastric emptying is reflexly inhibited when the osmolarity of the duodenal contents starts to rise
4) Distention - Too much chyme in the duodenum inhibits emptying of even more gastric contents. |
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Term
| What two types of responses do these factors trigger? |
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Definition
1) Neural response - Mediated through both intrinsic nerve plexuses (short reflex) and autonomic nerves (long reflex).
2) Hormonal response - involves release of hormones from duodenal mucosa collectively known as enterogastrones - secreten and cholecystokinin (CCK)-bile bladder contraction |
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Term
| What three additional factors that influence gastric motility? |
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Definition
1) Emotions - sadness and fear - tend to decrease motility
2) Anger and aggression - tend to increase motility
3) Intense pain - tends to inhibit motility |
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Term
| List two distinct areas of gastric mucosa that secrete gastric juice: |
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Definition
1) Oxyntic mucosa - lines body and fundus
2) pyloric gland area (PGA) - lines the antrum
Gastric pits at the base of gastric glands |
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Term
| List three types of gastric exocrine secretory cells: |
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Definition
1) Mucous cells - line gastric pits and entrance of glands and secrete thin, watery mucus
2) Chief cells - secrete enzyme precursor, pepsinogen
3) Parietal (oxyntic) cells - secrete HCL and intrinsic factor |
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Term
In regards to the orientation in the stomach,
1) Fundus =
2) Body =
3) Tandrum = |
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Definition
1) Fundus = Top
2) Body = Middle
3) Tandrum = Bottom |
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Term
| What are the four functions of HCl? |
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Definition
1) Activates pepsinogen to active enzyme pepsin and provides acid medium for optimal pepsin activity
2) Aids in breakdown of connective tissue and muscle fibers
3) Denatures protein
4) Along with salivary lysozyme, kills most of the microorganisms ingested with food. |
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Term
| List and explain the three phases of gastric secretion: |
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Definition
1) Cephalic phase: refers to increases secretion of HCl and pepsinogen that occurs in response to stimuli acting in the head before food reaches stomach - chewing (food entering mouth)
2) Gastric phase (stomach) - begins when food actually reaches the stomach
3) Intestinal phase - (decrease in gastric secretion) - helps shut off flow of gastric juices as chyme begins to empty into small intestine |
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Term
| The _______ _______ barrier enables the stomach to contain acid without destroying the walls. |
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Definition
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Term
| _____ _________ in the stomach with the mucus coating makes the stomach impermeable to HCl. |
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Definition
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Term
| If acid eats away at the lining of the stomach what happens? |
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Definition
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Term
| The ________ is a mixture of exocrine and endocrine tissues. |
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Definition
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Term
| Where is the pancreas located and what is its endocrine function and exocrine function? |
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Definition
Elongated gland located behind and below the stomach
Endocrine function: Islets of Langerhans - found throughout pancreas and they secrete insulin and glucagon
Exocrine function: Secretes pancreatic juice consisting of a) pancreatic enzymes actively secreted by acinar cells that form the acini b) aqueous alkaline solution actively secreted by duct cells that line pancreatic ducts |
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Term
| Pancreatic exocrine secretion is regulated by what two hormones? |
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Definition
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Term
| What do proteolytic enzymes do? List three of them |
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Definition
Digest protein
1) Trypsinogen - converted to active form trypsin
2) Chymotrypsinogen - converted to active form chymotrypsin
3) Procarboxypeptidase - converted to active form carboxypeptidase |
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Term
| What does pancreatic amylase do? |
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Definition
| Converts polysaccharides into the disaccharide amylase |
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Term
| What is the only enzyme secreted throughout the entire digestive system that can digest fat? |
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Definition
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Term
The _____ is the largest and most important metabolic organ in the body. It is also the body's major _________ factory.
Why is it important for the digestive system? |
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Definition
liver
biochemical
important due to secretion of bile salts (detergent) - breaks down grease |
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Term
| List 7 functions of the liver which are not related to digestion. |
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Definition
1) Metabolic processing of the major categories of nutrients (proteins, carbs, fats)
2) Detoxifying or degrading body wastes and hormones, drugs, and other foreign compounds
3) Synthesizes plasma proteins - responsible for blood clotting
4) Stores glycogen, fats, iron, copper, and many vitamins.
5) Activates vitamin D - calcium (bone growth)
6) Removes bacteria and worn-out red blood cells
7) Excretes cholesterol and bilirubin - end product of hemoglobin breakdown. |
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Term
| Bile is actively secreted by the _____ and actively diverted to the __________ between meals. |
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Definition
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Term
| Bile consists of what four things? |
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Definition
1) Bile salts
2) Cholesterol
3) Lecithin
4) Bilirubin |
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Term
| After a meal, bile enters the ________ through ____ _____. |
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Definition
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Term
| Bile salts are derivatives of ___________. They convert large fat globules into a ______ emulsion. After participation in fat digestion and absorption, most are __________ into the blood |
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Definition
cholesterol
liquid
reabsorbed |
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Term
| What is the site where most digestion and absorption takes place? |
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Definition
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Term
| List the three segments of the small intestine. |
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Definition
1)Duodenum
2)Jejunum
3)Ileum |
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Term
| Motility includes what two things? |
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Definition
1) Segmentation
2) Migrating motility complex |
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Term
| What characterizes segmentation? |
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Definition
Primary method of motility in the small intestine.
-Consists of ringlike contractions along length of the small intestine
-Within seconds, contracted segments relax and previously relaxed areas contract
-Action mixes chyme throughout small intestine lumen |
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Term
| What is segmentation initiated by? What are the two functions of it? |
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Definition
initiated by pacemaker cells in the small intestine which produce basic electrical rhythm (BER)
-Circular smooth muscle responsiveness is influenced by distensions of intestine, gastrin, and extrinsic nerve activity
Functions:
1) Mixing chyme with digestive juices secreted into small intestine lumen (from pancreas and liver)
2) Exposing all chyme to absorptive surfaces of small intestine mucosa |
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Term
| What does the migrating motility complex do? |
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Definition
| sweeps intestines clean between meals |
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Term
| Juice secreted by the small intestine does not contain any _______ ________. |
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Definition
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Term
___________ enzymes act within brush-border membrane of epithelial cells.
List three of these types of enzymes. |
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Definition
Synthesized enzymes
1) Enterokinase - activates trypsinogen (breaks down proteins)
2) Disaccharidases - sugars (breaks down)
3) Aminopeptidases - amino acids (breaks down) |
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Term
| What is digested entirely within the small intestine lumen by _________ ______? |
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Definition
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Term
| Explain absorption in the small intestine. |
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Definition
1) Absorbs almost everything presented to it
2) Most occurs in duodenum and jejunum
3) Adaptations that increase small intestine's surface area a) inner surface has permanent circular folds b) microscopic finger-like projections called villi c) Brush border (microvilli) arise from the luminal surface of epithelial cells
4) Lining is replaced about ever three days
5) Products of fat digestion undergo transformations that enable them to be passively absorbed - eventually enter lymph |
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Term
| Explain the large intestine. What four things does it consist of? |
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Definition
Primarily a drying and storage organ
Consists of
1) Colon
2) Cecum
3) Appendix
4) Rectum
Contents received from small intestine consists of indigestible food residues, unabsorbed biliary components, and remaining fluid
-Colon - extracts more water and salt from contents - feces is what remains to be eliminated. |
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Term
What are taeniae coli?
Haustra?
Haustral contractions? |
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Definition
Taeniae coli - Longitudinal bands of muscle in the large intestine
Haustra - pouches or sacs that actively change location as a result of contraction of circular smooth muscle layer
Haustral contractions - main motility initiated by autonomous rhythmicity of colonic smooth muscle cells. |
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Term
What are mass movements?
Gastrocolic reflex?
Defecation reflex? |
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Definition
Mass movements - massive contractions which moves colonic contents into distal part of large intestine
Gastrocolic reflex - Mediated from stomach to colon by gastrin and by autonomic nerves. Most evident after first meal of the day and often followed by urge to defecate
Defecation reflex - Initiated when stretch receptors in the rectal wall are stimulated by distensions. Causes internal anal sphincter to relax and rectum and sigmoid colon to contract more vigorously. If external anal sphincter (skeletal muscle under voluntary control) is also relaxed, defecation occurs - learned |
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Term
|
Definition
1) Gastrin
2) Secretin
3) CCK |
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Term
| Explain how gastrin works. |
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Definition
Release is stimulated by presence of protein in stomach.
-Secretion inhibited by accumulation of acid in stomach
Functions
1) Acts in several ways to increase secretion of HCl and pepsinogen
2) Enhances gastric motility, stimulates ileal motility, relaxes ileocecal sphincter, induces mass movements in colon, and helps maintain well-developed, functionally viable digestive tract lining. |
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Term
| How is secretin simulated and what are the functions of it? |
|
Definition
presence of acid in duodenum stimulates release
functions:
1) Inhibits gastric emptying in order to prevent further acid from entering duodenum until acid already present is neutralized
2) Inhibits gastric secretion to reduce amount of acid being produced
3) Stimulates pancreatic duct cells to produce large volume of aqueous NaHCO3 secretion
4) Stimulates liver to secrete NaCO3 rich bile which assists in neutralization process
5) Along with CCK, is trophic to exocrine pancreas |
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Term
| List the functions of CCK |
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Definition
1) Inhibits gastric motility
2) Stimulates pancreatic acinar cells to increase secretion of pancreatic enzymes
3) Causes contraction of gallbladder and relaxation of sphincter of Oddi
4) Along with secretin, is trophic to exocrine pancreas
5) Implicated in long-term adaptive changes in proportion of pancreatic enzymes in response to prolonged diet changes
6) Important regulator of food intake |
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Term
| What does Glucose-dependent insulinotrophic peptide (GIP) do? |
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Definition
| Stimulates insulin release by pancreas |
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Term
| The reproductive system includes what three main things? |
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Definition
1) Gonads
2) Reproductive tract
3) accessory sex glands |
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Term
| Reproduction depends on what? |
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Definition
Depends on union of male and female gametes to form new individual
Male and female reproductive systems designed to enable union of genetic material |
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Term
| The primary reproductive organs are ______. They consist of a pair of ______ in the male and a pair of _______ in the female. |
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Definition
|
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Term
| What are the two main functions of mature gonads? |
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Definition
1) Producing gametes (gametogenesis)- Spermatozoa (sperm) in male and Ova (eggs) in female
2) Secreting sex hormones - Testosterone in males and Estrogen and progesterone in females |
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Term
| What is the reproductive tract? |
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Definition
| System of specialized ducts that transport or house gametes after they are produced. |
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Term
What are accessory sex glands?
External genitalia?
Secondary sexual characteristics? |
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Definition
Accessory sex glands - Empty supportive secretions into reproductive tract
External Genitalia - externally visible portions of reproductive system
Secondary sexual characteristics - external characteristics not directly involved in reproduction that distinguish males and females - body configuration and hair distribution |
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|
Term
| What are the two functions and four organs of the male reproductive organs? |
|
Definition
Functions:
1) Production of sperm (spermatogenesis)
2) Delivery of sperm to female
Organs:
1) Testes - sperm-producing organs. Suspended outside abdominal tract in skin covered sac (scrotum)
2) Accessory sex glands - seminal vesicles, prostate gland, bulbourethral glands. Secretions provide bulk of semen (liquid substance that is conductive to sperm viability)
3) Penis - organ used to deposit semen into female
4) Male reproductive tract - epididymis, ductus (vas) deferens, ejaculatory duct empty into urethra (canal running length of penis that empties into exterior) |
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Term
| List and describe 6 functions of the female Reproductive organs. |
|
Definition
1) Production of ova (oogenesis)
2) Reception of sperm
3) Transport of sperm and ovum to common site for union (fertilization or conception) - product of fertilization is known as an embryo - after first two months of intrauterine development, embryo is known as fetus.
4) Maintenance of the developing fetus until it can survive in the outside world (gestation or pregnancy) - formation of placenta (exchange organ between mother and fetus)
5) Giving birth to the baby (parturition)
6) Nourishing infant after birth by milk production (lactation) |
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|
Term
| List and describe the 3 main female reproductive organs: |
|
Definition
Female Reproductive Tract
1) Oviducts (uterine or Fallopian tubes)
-in close association with ovaries
-pick up ova on ovulation
-serve as site for fertilization
2) Uterus
-responsible for maintenance of fetus during development
-Responsible for expelling fetus at the end of pregnancy
3) Vagina
-muscular, expandable tube that connects uterus to external environment
-Lower portion is cervix - cervical canal, single, small opening that serves as pathway for sperm, serves as passageway for delivery of baby from uterus |
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|
Term
| The vagina consists of what three parts? |
|
Definition
1) Vaginal opening - located in perineal region between urethral opening and anal opening. Partially covered by thin mucous membrane, hymen (typically disrupted by first sexual intercourse)
2) Labia minora and labia majora - skin folds that surround vaginal and urethral openings
3) Clitoris - Small erotic structure located at the anterior end of folds of the labia minora |
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Term
|
Definition
| Collective term for female external genitalia |
|
|
Term
| List and describe the four types of reproductive cells. |
|
Definition
1) Body (somatic) cells - contain 46 chromosomes (diploid number). Can be sorted into 23 homologous pairs
2) Gametes (sperm and egg) - Have 23 chromosomes (haploid number). Contains only one member of each homologous pair of chromosomes. Gametogenesis is accomplished by meiosis
3)Autosomes - 22 pairs which code for general human characteristics and specific traits such as eye color
4) Sex chromosomes - remaining pair of chromosomes. Two genetically different types - a) larger X chromosome and b) Smaller Y chromosome |
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Term
Sex determination depends on the combination of what?
Genetic Female = ?
Genetic Male = ? |
|
Definition
Sex chromosomes.
Female = 2 X chromosomes
Male = X and a Y chromosome |
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Term
| What is the Y chromosome responsible for? When is the genetic sex determined and what does it depend on? |
|
Definition
Y chromosome is responsible for all the anatomic and functional distinctions between males and females
Genetic sex is determined at the time of conception and depends on which type of sex chromosome is contained within the fertilizing sperm |
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|
Term
| List and describe the three levels of differences between males and females: |
|
Definition
1) Genetic - depends on combination of sex chromosomes at time of conception
2) Gonadal - Whether testes or ovaries develop. Presence or absence of Y chromosome determines gonadal differentiation.
3) Phenotypic - Apparent anatomic sex of individual. Determined by gonadal sex |
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Term
| In the testes, descent is usually complete by the _______ month of gestation. Why do the testes descend into the scrotum? |
|
Definition
seventh
The testes descend into the scrotum because this location provides cooler environment essential for spermatogenesis |
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|
Term
| What is the dual function of the testes? |
|
Definition
1) Produce Sperm - occurs within seminiferous tubules
2) Secrete testosterone - Produced by leydig (interstitial) cells that lie in connective tissue between seminiferous tubules |
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|
Term
What is testosterone and what is it derived from?
List the five categories of testosterone effects: |
|
Definition
Testosterone is a steroid hormone derived from cholesterol precursor molecule
1) Reproductive system before birth
2) Sex-specific tissues after birth
3) Other reproductive-related effects
4) Secondary sexual characteristics
5) Non-reproductive actions |
|
|
Term
| What is spermatogenesis? What results from it? |
|
Definition
Complex process by which undifferentiated diploid primordial germ cells (spermatogonia) are converted into haploid spermatozoa (sperm).
Results in many highly specialized, mobile sperm. |
|
|
Term
| List and describe the three major stages of spermatogenesis. |
|
Definition
1) Mitotic proliferation - sperm-forming daughter cell divides mitotically twice more to form four identical primary spermatocytes
2) Meiosis - Each primary spermatocyte forms two secondary spermatocytes yielding four spermatids after the second meiotic division. Theoretically, sixteen spermatozoa result from each spermatogonium that goes through process.
3) Packaging - spermiogenesis |
|
|
Term
Spermatozoan remains closely associate with what throughout development?
List the four parts of sperm. |
|
Definition
Sertoli cells
1) Head - consists primarily of the nucleus (contains DNA)
2) Acrosome -
-enzyme-filled vesicle that caps tip of the head.
-Used to penetrate ovum.
-Formed by endoplasmic reticulum and Golgi complex before these organelles are discarded.
3) Midpiece - area where mitochondria are concentrated
4) Tail - Provides mobility for spermatozoan |
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Term
| Spermatogenesis is a function of _______ ____ located in the ____________ _______. |
|
Definition
| sertoli cells located in seminiferous tubules. |
|
|
Term
| What are 6 functions of sertoli cells? |
|
Definition
1) Form blood-testes barrier
2) Provide nourishment
3) Phagocytic function
4) Secrete seminiferous tubule fluid which flushes released sperm from tubule into epididymis for storage and additional processing
5) Secrete androgen-binding protein
6) Site of action to control spermatogenesis - release inhibin and acts in negative feedback fashion to regulate FSH secretion |
|
|
Term
| What are the two jobs of the epididymis and the ductus (vas)defernes? |
|
Definition
1) Store and concentrate sperm
2) increase sperm motility and fertility prior to ejaculation |
|
|
Term
| What happens during ejaculation? |
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Definition
| 1) Sperm are mixed with secretions released by accessory glands |
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Term
| List and describe three accessory glands and their secretions which mix with sperm during ejaculation. |
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Definition
1) Seminal vesicles - supply fructose for energy. Supply prostaglandins which promote smooth muscle motility in both male and female reproductive tracts (enhances sperm transport). Provides more than half the semen and secretes fibrinogen.
2) Prostate gland - contributes alkaline fluid that neutralizes acidic vaginal secretions. Provides clotting enzymes and fibrinolysin.
3) Bulbourethral glands - release lubricating mucus |
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Term
| Female reproductive physiology is characterized by complex _______. |
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Definition
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Term
What are the two functions of the ovaries?
List and describe the two female sex hormones? |
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Definition
1) Produce ova (oogenesis)
2) Secrete female sex hormone
a) Estrogen - essential for ova maturation and release. Establishment of female secondary sexual characteristics. Essential for transport of sperm from vagina to fertilization site in oviduct. Contributes to breast development in anticipation of lactation
b)Progesterone - important in preparing suitable environment for nourishing a developing embryo/fetus. Contributes to breasts ability to produce milk |
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Term
| True or False - There are identical steps of chromosome replication and division during gamete production in both sexes. |
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Definition
| True! The timing and end result however, are very different. |
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Term
| What are oogonia? how do they divide? How many are initially produced? |
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Definition
An undifferentiated primordial germ cell in the fetal ovaries.
Divide mitotically to give rise to 6 million to 7 million oogonia by the fifth month of gestation. |
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Term
| When do the early steps of the first meiotic division occur and when are they completed? |
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Definition
| During last part of fetal life, there begins the early steps of first meiotic division but will not be complete until just before ovulation. |
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Term
| After the first meiotic division, what are the oogonia now known as? |
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Definition
| now known as primary oocytes which contain diploid number of 46 replicated chromosomes. Remain in meiotic arrest for years until they are prepared for ovulation. |
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Term
| What percentage of eggs do not mature? So about how many eggs will reach maturity? |
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Definition
99.8% of all eggs don't mature.
Around 400 eggs will reach maturity |
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Term
| What is the site of fertilization? |
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Definition
| The oviduct (fallopian tube) |
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Term
What is a primary oocyte surrounded by?
Oocyte + _______ _____ = primary follicle! |
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Definition
Primary oocyte is surrounded by a single layer of granulosa cells
Oocyte + granulosa cells = primary follicle |
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Term
| In regards to the primary follicle, after development starts, what are the two possible fates? |
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Definition
1) Reach maturity and ovulate
2) Degenerate to form scar tissue (atresia) |
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Term
| What occurs with the follicles between puberty and menopause? |
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Definition
| Follicles develop into secondary (antral) follicles on cyclic basis. |
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Term
| We know that just before ovulation occurs, the primary oocyte completes its first meiotic division yielding what? |
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Definition
1) First polar body
2) Secondary oocyte - ovulated |
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Term
| What triggers the second meiotic division? What is produced because of this? |
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Definition
Sperm entry triggers second meiotic division which produces
1) Secondary polar body (haploid)
2) Mature haploid ovum which unites with haploid sperm cell during fertilization |
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Term
| The average ovarian cycle lasts how long? What is it only normal interrupted by? What is it finally terminated by? List and describe the two alternating phases of the ovarian cycle. |
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Definition
28 days
normally interrupted only by pregnancy
Finally terminated by menopause
Two phases:
1) Follicular phase - dominated by presence of maturing follicles
2) Luteal phase - Characterized by presence of corpus luteum. |
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Term
| In more depth, explain the follicular phase. |
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Definition
1) Operates first half of cycle (first 14 days)
2) Granulosa cells of some primary follicles proliferate
3) Oocyte inside each follicle enlarges
4) Theca cells in follicle secrete increased amounts of estrogen - estrogen secreting cells
5) Rapid follicular growth continues during follicular phase. |
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Term
| What happens when one follicle usually grows more rapidly and matures about 14 days after onset of follicular development? What is this even called? |
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Definition
1) Follicle ruptures to release oocyte form ovary.
2) Event is called ovulation
3) Released oocyte enters oviduct where it may or may not be fertilized |
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Term
| Theca cells secrete what? |
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Definition
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Term
| Explain the luteal phase. |
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Definition
-Last 14 days of ovarian cycle
-Old follicular cells undergo structural transformation to form corpus luteum
-Becomes highly vascularized
-Becomes fully functional within four days after ovulation
-Continues to increase in size for another four or five days
-If released ovum is not fertilized and does not implant, corpus luteum degenerates within about 14 days after its formation |
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Term
Put the following phases in order.
ovulation, luteal phase, follicular phase
When does the luteal phase begin? |
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Definition
1)Follicular Phase
2)Ovulation
3)Luteal Phase
Luteal phase begins when the egg is released. |
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Term
1) During follicular phase, a rise in ___ signals ovarian follicle to secrete more estrogen
2) This rise in estrogen feeds back to inhibit ___ secretion which declines as follicular phase proceeds
3) __ rises in the follicular phase. As it peaks in mid-cycle, it triggers ovulation and causes egg to be released (day 14)
4) When the estrogen output decreases, the mature follicle is converted to a ______ ______.
5) The corpus luteum secretes ___________ and ________ during the luteal phase.
6) Progesterone output inhibits the release of ___ and __.
7) Low __ causes the corpus luteum to degenerate. and progesterone levels decline.
8)___ can start to rise again, initiating a new cycle. |
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Definition
1)FSH
2)FSH
3)LH
4)corpus luteum
5)progesterone and estrogen
6)FSH and LH
7)LH
8)FSH |
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Term
| The menstrual cycle is also known as the _______ _____. How long does this usually last? |
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Definition
| uterine cycle. 28 days. It reflects hormonal changes during the ovarian cycle. |
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Term
| What is the outward manifestation of cyclic changes in the uterus? What are the three phases? |
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Definition
Menstrual bleeding once during each cycle
1) Menstrual phase
2) Proliferative phase
3) Secretory or progestational phase |
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Term
| Explain the Menstrual phase. |
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Definition
-Characterized by discharge of blood and endometrial debris from the vagina
-First day of menstruation is considered the start of a new cycle
-Coincides with the end of ovarian luteal phase and onset of follicular phase
-Release of uterine prostaglandin - pain
-Causes vasoconstriction of endometrial vessels - disrupts blood supply and causes death of endometrium.
-Stimulates mild rhythmic contractions of uterine myometrium which helps expel the blood and endometrial debris from the uterine cavity out through the vagina (menstrual flow) |
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Term
| Explain the proliferative phase. |
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Definition
-Begins concurrent with last portion of ovarian follicular phase - endometrium starts to repair itself and proliferate under influence of estrogen from newly growing follicles
-Estrogen-dominant proliferative phase lasts from end of menstruation to ovulation
-Peak estrogen levels trigger LH surge responsible for ovulation |
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Term
| Explain the Secretory or progestational phase. |
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Definition
-Uterus enters this phase after ovulation when new corpus luteum is formed
-Corpus luteum secretes large amounts of progesterone and estrogen
-Progesterone converts endometrium to highly vascularized, glycogen-filled tissue
-Endometrial glands actively secrete glycogen
-If fertilization and implantation do not occur then the corpus luteum degenerates and new follicular phase and menstrual phase begin once again. |
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Term
| Explain what menopause is. When it occurs. |
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Definition
Cessation of woman's menstrual cycle
-Usually occurs between ages of 45 and 55
-Midlife hypothalamic change may trigger onset of menopause
-Preceded by period of progressive ovarian failure - increasingly irregular cycles, dwindling estrogen levels. Loss of estrogen primarily affects skeleton and cardiovascular system
-Period of transition called the climacteric. |
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Term
| Where is the site of fertilization? What is the time limit in which it must occur? What three ways does the female reproductive tract aid in sperm migration? |
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Definition
Normally occurs in upper third of oviduct(ampulla)
-Must occur within 24 hours after ovulation - sperm usually survive about 48 hours but can survive up to 5 days in female reproductive tract.
-Sperm deposited in the vagina travel through cervical canal, uterus, and to upper third of oviduct.
Female reproductive tract aids sperm migration:
1) Contractions of myometrium
2) Upward contractions of oviduct smooth muscle
3) Allurin released by mature eggs |
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Term
| What happens when fertilization occurs? |
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Definition
1) First sperm to reach ovum penetrates it
2) Fuses with plasma membrane of ovum
3) Triggers chemical change in ovum's surrounding membrane that makes outer layer impermeable to entry of any more sperm
4) Head of fused sperm gradually pulled into ovum's cytoplasm
5) Within hour, sperm and egg nuclei fuse - fertilized ovum now called a zygote. |
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Term
| How does the fertilized egg divide? What does it become after it divides? |
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Definition
| mitotically - within a week it grows and differentiates into blastocyst capable of implantation. |
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Term
| Where does the blastocyst implant itself and how does it do it? |
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Definition
Blastocyst implants in endometrial lining of the uterus by means of enzymes released by trophoblasts. Enzymes digest endometrial tissue and carve hole in the endometrium for implantation of the blastocyst.
-Release of nutrients from the endometiral cells for use by developing embryo. |
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