Homeostasis

A. definition

B. mechanisms of operation 

A. Maintinance of a relatively constant internal environment; ex. blood sugar, pH, temp, etc

B. Functions through negative feedback; uses

1. Receptors: moniter internal environment/detect stimuli, and send messages to:

2. Control center (brain, usually), which establishes ideal 'range'. Send messages to:

3. Effectors, typically glands/muscles, which create changes to move system back into equilibrium

^This negates changes made away from equilibrium; thus negative feedback

~Body Cavaties from lateral view~

(6, from superior to inferior)

Cranial

A. Oral Cavity

B. Nasal cav

C. Orbital cavs

D. Middle ear cavs 

Vetrebral Canal 

Thoracic

 A.Right pleural cavity

B. Left pleural cavity

C. Mediastinum - middle top 

D. Pericardial cavity - middle lower

Diaphragm

-seperates thoracic and abdominopelvic 

Abdominalpelvic:

A. Abdominal

B. Pelvic 

~Membranes and cavaties~

Cavaties lined by membranes (parietal; visceral lines organ surface), act as barriers.

Serous membranes: constant fluid production for lubrication (heart and lung contractions)

Heart: pericardial membranes

A. Visceral pericardium - covers surface

B. Parietal pericardium - folds back on A., to create pericardial cavity between both folds

C. Fibrous pericardium - Thicker, covers B.

D. Parietal and visceral pleura: v.p. covers lungs as serous membrane; p.v. folds back and lines cavity. Potential space between called:

E. Pleural cavity 

Abdominopelvic: peritoneal cavaties

A. Visceral peritoneum - covers organs

B. Parietal peritoneum - folds over and covers A; creates potential space between folds which is C. 

C. Peritoneal cavity 

1. Food

2.Water

3. Air

4. Heat

5. Hydrostatic 

~Organ Systems~

11 of em 

1. Integumentary - skin+accessory organs

2. Skeletal - bones, ligaments, cartliges

3. Muscular

4. Nervous - brain, spine, peripheral nerves, sense organs

5. Endocrine - hormone secretion; pituitary, thyroid, parathyroid, adrenal; pancreas, testes, pineal,m thymus

(integration/coordination) 

6. Cardio - heart, arteries, capillaries, veins, blood

7. Lymphatic - lymph nodes/glands; part of cardio, tissue fluid and immune support

(6+7=transport) 

8. Digestive - mouth, tongue, salivary, pharynx, esophogus, stomach, intestines

9. Respiratory - nasal cavity, passages, phar/larynx, trachea, bronchi, lungs

(8+9 are absorbption/excretion) 

10. Urinary - kidneys, urethra, ureters

11. Reproductive

Sagittal - seperates into right/left

Midsagittal - directly through middle

Transverse - seperates horizontally into superior/inferior

Coronal - anterior/posterior (think coronal suture)

Tube section termionology:

Cross-section: transverse or across circumfrence; as a pipe would get cut with a miter saw.

Longitudal: perpindicular to direction of tube.

Oblique: diagonal across; split between former two.

4: RUQ, RLQ, LUQ, LLQ

12, by layer, left to right:

Right hypochondriac, epigastric, left hypochondriac

Right lumbar, umbilical, l lumbar

R iliac, hypogastric, l iliac 

260 varieties, 70 trillion in body

3 major parts: nucleus, cytoplasm, cell membrane

-Composed of cytoplasmic organelles suspended in cytosol; contains abundant rods/tubes of protein forming cytoskeleton

Components: phosphlipid, glycolipid, proteins, glycolipids, cholesterol

-Selectively permeable

-communicates through signal transduction

-composed of phospholipid bilayer;

Permeable to: 

• o2, co2, steroroids, h20

Impermeable to:

- proteins, amino acids, sugars, small ions (Na+, K+)

-long protein molecules span membrane and act as transport or receptors 

Cell Membrane Proteins

• Transport 

Integral: Span membrane, 

Peripheral: attach to intra/extracellular sides

Anchoring:  attach to cell membranes to one another, or to interal/external structures (CAMS)

Recognition proteins: ident cell, prevent attack by immune system. glycolipids, glycoproteins

Enzyme proteins: catalyze intra/extyracellular reactions. small intestine

Receptor proteins: bind to specific ligands in extracellular fluid. insulin receptor

Carrier proteins: bind/transx molecules across membrane, ie glucose

Leak channels: permit continuous passive movement of h20 and ions; open to movement of certina shaped molecules.

Gated channels: open/close to regulate ion movement 

Aquaporins: pores which allow water to pass

CAMS:

Intercellular junctures: tight, nothing shall pass

Desmosomes: spot welded; skin cells

Gap Junc't: channel between cells; pericardial cells bound this way 

~Tissues~

~Histology~

Tissues are cells organized together with common function

4 major types:

Epithelial

Connective

Muscle

Nervous 

~Organelles~

~Ribosomes~ 

Protein and RNA; glycoproteins (amino acid chains).

Structure+enzymatic support to cell. Abundant on outside of Rough Endoplasmic Reticulum; they make it 'rough'.

 Some ribos wander in bloodstream, and produce enzymatic proteins for cytoplasm.

Some ribos are fixed and produce proteins intended to leave cell (i.e. insulin in the pancreas).

~Organelles~

~ER~ 

Sheets of folded membrane.

 Both Smooth and Rough ER.

Smooth: Lipid synth (phospho), cholesterol, steroid hormones, trigycerides (fats), outer cell membrane particles. Also produces glycogen; glucose chians. Fucntions to detox certain things like alcohol (in liver)  

Rough: 'Rough because of ribosomes'

Sends proteins to Golgi for further processing.

~Organelles~

~Golgi~ 

Folded membranes form cistern sacs. 

Reciveves (in transx vesicles), processes (adds value!), and sends out proteins to cell. Three types of products for shipment:

A. Secretory vesicle: contains hormones and enzymes (like proinsulin), which Golgi intakes, processes into insulin, packages into vesicle, and secretes outside cell.

B. Membrane Renewal vesicle: fuses to and incorporates into cell membrane. Contains protein components of cell membrane.

C. Lysosomes

~Organelles~

~Mitochondria~ 

-Contain DNA for creation of new DNA/RNA

-Double membrane layers (outer and inner)

-Controls chem reax which derive e! from sugars; produces ATP from breakdown of carbs, fats, proteins, powerhouse. 

VERY abundant in muscle cells (they need lots of e!)

~Organelles~

~Lysosome~

-"Garbage disposal"; scas of 'digestive' enzymes.

-Enzymatic brkdwn of cellular wast, and release back into cytoplasm.

-WBCs utilize lysosomes to kill bacteria.

-Think lysol

~Organelles~

~Peroxisomes~ 

-Resemble lysosomes

-Catalyze metabolic reax; oxidize nutes, release h202;"peroxide". Breakdown alcohol; abundant in liver.

- But also breakdown h202 as to prevent cell damage 

~Organelles~

~Centrosome~ 

-Located near nucleus; houses centrioles (therefore many microtubules) used in mitosis/cell replication

NON MEMBRANEOUS!

~Organelles~

~Cilia/microvilli/flagellum~ 

Cilia = hairlike, used to evacuate shit from throat, lungs, or push eggs through ovary tubes, etc. Wavey action!

Microvilli: stationary, bolster surface area (aids in digestive tract).

Flagellum = sperm tail. 

~Organelles~

~Microfilaments~

~Microtubules~ 

Threadlike structures in cytoplsm; comprise cytoskeleton. microfilaments used in muscle fibers; microtubule action used in cilia +flagella, and moving  organelle structures around in cell

Microtubules: longs chains of tubulin, a protein. Provide mechanical support and intercellular transport. Aid in cell division by seperating proteins (funtion of centrosome).

Microfilaments: Long chains of actin, a protein. Provide mechanical support (muscle cells). 

THESE FORM CYTOSKELETON

~Organelles~

~Inclusions~ 

"Inclusions (Cytoplasmic) are chemical substances that may or may not be present in a cell, depending on the cell type. Inclusions are stored nutrients, secretory products, and pigment granules. Examples of inclusions are; glycogen granules in the liver and muscle cells; lipid droplets in fat cells; pigment granules in certain cells of skin and hair; water containing vacuoles; and crystals of various types."

from wiki 

~Nucleus~

• Nuclear Structures 

-Houses DNA in chromatin fibers (visible as chromosomes)

- Encased in dbl layer nuclear envelope (inner+outer lipid bilayer mem). Nuclear pores allow passage of certain substances between cytoplasm and nucleus.

Structures:

Nucleolus - small, dense, comprised of RNA+protein. Produces ribosomes

Chromatin: (actin?) fibers composed of continuous DNA stanrands wrapped in histones. 

Nuclear membrane opens on nuclear envelope.

-Ions moving from areas of higher concentration to that of lower; movement towards equlibrium.

-Only possble if membrane is substance-permeable and uneven concentrations exist on either side. 

~Cellular movement~ 

~Osmosis~

H20 diffusion

-osmotic pressure can lift water level it diffuses to.

-water tends to diffuse towards concentrations of greater osmotic pressure/greater solute levels

Isotonic- solution w/ same osmotic pressure/solute level as that which is beyond membrane (such as cell membrane and blood)

Hypertonic- greater osmotic concentration on outside

Hypotonic- greater concentration of solute is in cell; movement therefore into cell. This can cause lysis and ___?; bursting of cell. Bathtub pruning.

~Cellular movement~

~Filtration~ 

~Cellular movement~

~Active transx~ 

-Movement against concentration gradient

-Requires e! from cell

-Uses pumping action from carrier molecules:

When ligands bind to carrier molecules, trigger is released, e! is used, and particle is pumped into cytoplasm.

-Important to homeostasis; calcium is moved through this process

~Cellular movement~

~Endocytosis~ 

Endo; molecules/large particles pass through vesicles forming sections of cell membrane.

3 types:

1. Pinocytosis:cell drinking;bubble forms from membrane, surrounding extracellular thing/stuff, enclosing it, and resealing membrane/dropping off bubble inside cell.

2. Phagocytosis: Solids, cell eating. WBCs and cleanup/bacteria eating.

3. Receptor-mediated endocytosis: Receptors pick up particles to which they are specific; LDL=ligand.

~Cellular movement~

~Exocytosis~

~Cellular movement~

~Transcytosis~ 

~Tissues~

~Epithelial~

-Covers body (skin), organs+cavaties; one side exposed to surface.

-Connected to connective tissue by basement layer

-Avascular; uses diffusion for nutes

Closely packed, forming barriers (skin) 

Don't forget these membarne types:

A. Serous: line cavaties, does not open to outside,like inner abdominal lining.

B. Mucous: lines cavaties opening to outside of body, oral, nasal, respiratory, digestive, etc. Goblets! 

C. Cutaneous (skin)

D. Synovial (line joints)

~Tissues~

~Epithelial Classifications~ 

-Squamous: thin, flat; diffusion/filtration

examples

A. -.simple: lung sacs, capillaries

B. -.strat: flat on top; gradually become more cubod. epidermis (outer layer is keratinized)

-Cuboidal: cube like - secretion of glandular produx

A.-.simple: Secretion+absorption; kidneys, tubules, glands

B. -.strat: ducts of glands (salivary)

-Columnar - tall, narrow; cilia+goblets; secrete digestive fluid, microvilli bolster surface area for absorption of nutes (intestines)

A. -.simple: secretion/absorp, stomach/intestines, sprinkled with GOBLETS!

B. -.strat:  urethra; uncommon

C.-.psuedostrat: often w/ cilia +goblets; looks stacked but isn't.

Further classified into:

Simple - single layer

Psuedostratified: looks multi-layer, but not

Stratified - mx layers

Also transitional epithelium:

Changs in response to increased tension, such as in bladder or uterus. Tranitions between cubodial and squamous as it's stretched.

~Epithelium~

~Glandular classifications~ 

Glandular epithelial cells are specilaized to secrete substances into ducts/body fluid. One or more = a gland.

Exocrine gland: Secrete into ducts or onto surfaces

Endocrine glands: secrete into tissue fluid or blood

These are further classified into:

Simple: relationship to surface through non-branching (can branch once) tube or duct

Compound: Duct to surface branches multiple times

Exocrine glands further classified by their secretion method (see next slide)

~Tissues: epithelium~

 ~Exocrine gland classifications~

Merocrine (gland): predominant: exocytosis. Further divided into serous cells, which secrete watery shit, and mucous cells. "Merry Exit"

Apocrine: small portions of cell (glandular bodies) are cast into ether. APo = A Portion

Holocrine: entire cell is cast away  

~Tissues: Connective~

~General info~ 

Most abundant tissue by weight; bind and support structures, protect, fill space, store fat, produce blood cells, repair tissue damage.

-Large ECM, varies from liquid to solid.

Major Cell Types:

Fixed

Wandering 

~~~

Fibroblasts - large, starlike; produce fibers for ECM

Macrophages- originate as WBCs, attached to fibers but can move; migratory, phagocytic

Mast Cells- large and widely distributed. Release herapin, an anti-coagulant (anti clotting agent), and histamine, an inflammatorty agent.

~Tissues: Connective Fibers~

~Collagenous~ 

-Thick, woven fibers comprised of collagen, strong; forms tendons and ligaments. Abundant in skin

Dense connect. tissue=abundant in collagen; loose conn. tiss. opposite 

~Tissues: Connective Fibers~

~Elastic~ 

~Tissues: Connective Fibers~

~Reticular Fibers~ 

~Tissues: Connective Fibers~

Adipose

Adipocytes store fat in cytoplasm. Crowd out other cell types and form adipose tissue; which stores fat, insulates, cushioning.

Relase cytokines,which have negative effects such as insulin resistance (bind to receptors)

~Tissue Type: Dense~

A. Regular - fibers all run in same direction;ie tendons and ligaments.

B. Irregular - fibers run in star-like projection, strecth in mx directions; ie. dermis of skin

-Cells called chondrocytes; surrounded by lacuna

-Avascular; rely on diffusion, which limits cell size and slows healing.

-ECM protein+liquid; flexible

Structures surrounded by perichondrium

~Types of cartilage~

A. Hyline - most common, costal, articular. Embryonic skeleton, supporting rings of repiratory tract, etc.

B. Elastic; more flexible than former. i.e. outer-ear and larynx.

C. Fibrocartilage - between vertebral disks and knee 

Cells called Osteocytes, surrounded by lacuna as cartilage is. Osteocytes 

ECM is mineral-based (lamellae) and therefore sturdy; formed in concentric patterns which surround capillaries. Therefore bones are well-supplied with blood.

Uber collagenous to shore up strength, store/release Ca and Phosphorus.

3 Types of Cells:

A. RBCs, erythrocytes. Formed in bone marrow. Gas exchange. Only RBCs function exclusively in plasma.

B. WBCs; leukocytes. Immune system

C. Platlets; thrombocytes. Clotting.

Elongated cells called muscle fibers shorten and lengthen by shortening and thickeing using microtubules.

~Several Types~

Skeletal- attaches to ends of bones, controlled by conscious effort. Threadlike cells w/ lateral striations. MxNuclear. protein filaments slide across eachother for movement. 

Smooth: Lack striations (smooth), shorter, spindle shaped, uninuclear, involuntary muscle action (digestive, urinary, etc)

Cardiac: Unique to heart, striated and branched, connected end2end which forms webby matrix, uninuclear, intercellular juncture known as intercalated disk (unqique to cardiac muscle). Involuntary - doesn't even need nerve impulse (heart will beat if someone rips it out of you).

Brain, spine, sense organs, peripheral nerves.

 Cells called neurons sense environmental changes and send impulses to other cells. Coordinate, regulate, and integrate many body functions.

Nervous tissue abundant in neroglial cells, which bind/support nervous tissue components, perform phagocytosis, help supply neurons w/ nutes. Role in cell-cell comm, provide neural stem cells.