Arrange muscle structures in order of size

Fiber --> Fibril --> Sarcomere --> Filaments

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Actin - thin

Myosin - thick

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Ca²⁺

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Sarcoplasmic reticulum

1. Troponin     2. Tropomyosin

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Ach or Acetylcholine

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The thick and thin filaments slide over each other. The Z lines come closer together, but the A bands size do not change. The H & I bands also get more narrow and may vanish completely.

Youtube video about sarcomere contraction http://www.youtube.com/watch?v=U2TSaz8-yNQ

Ach binds to receptors in the sarcolemma, which causes action potentials to take place, then this causes the voltage gated Ca²⁺ channels in the transverse tubules to make the Ca²⁺ release channels in the sarcoplasmic reticulum, which leads to diffusion of Ca²⁺ into the sarcoplasm. 

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Once the Ca²⁺ has entered the sarcoplasm, it binds to the troponin, then the tropomyosin shifts its position and reveals the actin binding sites to which the myosin cross bridges attach. Once the crossbridge attaches, it can undergo a power stroke, which consists of the filaments sliding.

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If action of ACh-ase was blocked, the muscle would constantly contract - spastic paralysis.

If the ACh receptors were blocked, this would cause muscle flaccid paralysis.

This diagram does not include fatigue.

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1. tetany

2. hypocalcemia

3. alkalosis

How we produced summated contractions with the isolated muscle and how we produced a tetanus contraction. Explain how summation of twitches is accomplished in vivo and how a sustained, complete tetanus contraction is produced.

We stimulated the muscle with rapid manual pulses of electricity so that the muscle was quickly contracting and twitching. To produce tetanus, we set the machine to automatically stimulate the muscle, and raised the frequency, until the twitches appeared to vanish and turned into a continuous muscle contraction.

Summation in vivo is caused by the fiber twitches of different motor units which occurs rapidly and successively and causes a synchronous activation of multiple fibers. Stronger muscle contraction occurs by the recruitment of more motor units.

Tetanus occurs in vivo when succesive motor units twitch rapidly enough that the muscle contraction is sustained and smooth.

How can you increase the strength of the contraction with isolated muscle, and explain how this is accomplished in vivo.

The strength of the contraction could be increased if multiple places on the frogs muscles were stimulated at the same time, so the contractions could combine.

In vivo, this occurs by more motor units being recruited to cause more summated contractions and an overall increase in the strength of the contraction.

We kept a continuous stimulation on the frog's muscle until the muscle appeared to become limp and no longer contracted and the physiograph recorder line had a downward curve.

The fatigue is produced by an increase in extracellular K⁺ , which causes the muscle to depolarize and makes action potentials not occur. Also, the muscle glycogen gets depleted and the sarcoplasmic reticulum does not release Ca²⁺ , which makes excitation/contraction coupling not occur.

Suppose you had a 10-lb weight in your hand and a constant contraction was kept. you would feel pain and it would get hard to hold the weight up. Why?

Suppose your hand starts shaking, why?

because the muscle is kept in constant tetanus/contraction, after an extended period of time, muscle fatigue will occur pain will be felt because lactic acid is built up.

The hand shakes because the muscle is becoming fatigued. Action potentials can't occur, the muscle fibers start to not remain contracted because there is not enough calcium to bind to troponin, so the myosin heads start releasing from the actin.

4

Oxygen

erythropoietin

kidneys

Old RBC's are destroyed by the _____________ system, which includes these three organs:

(a) ______

(b) ______

(c) ______

reticuloendothelial

spleen

liver

bone marrow

bilirubin

jaundice

name the antigens present and absent on the surface of a RBC if the person is:

(a) type A negative(RH) ___________

(b) type O positive(RH) ____________

(c) type AB negative(RH) __________

(a) Contains type A antigens. Because RH is negative, there are no Rh antigens. Does not contain B antigens either.

(b) No type A or B antigens. Has Rh antigens because it is positive.

(c) Has both A & B antigens, but no Rh antigens.

AA, AO, BB, BO, AB, OO

Phenotypes are antigen A, antigen B, or no antigen (O).

Lack of an antigen is a recessive trait, so an individual with type O blood must have genotype OO. There is no dominance between A & B.

Conc. unknown = (12g/dL x 0.32)/0.24 = 16 g/dL

Calculate mean corpuscular volume (MCV) given the following

Hematocrit = 52, rbc count = 4.6 million

Calculate MCVconcentration

hematocrit = 52, hemoglobin conc. = 13 g/dL

BP = 168/112

Systolic =

Diastolic =

168

112

 ------Systolic --------Diastolic

Normal Under 120mmHg    Under 80mmHg

Prehypertension      120-139            80-89

Stage 1Hypertension 140-159             90-99

State 2 Hypertension  160 or greater  100 or greater

Laminar flow is when blood flows smoothly and in same direction, blood in central axial stream flows faster than blood close to artery wall.

Turbulent flow is when some of the blood moves in circumferential and radial directions and causes vibrations.

Pulse pressure calculation and how value relates to pulse.

Mean arterial pressure calculation and significance.

Pulse pressure is the difference b/t systolic and diastolic pressure. The value pulse p is when hydrostatic pressure against the artery wall expands and is the pressure head that drives blood through the arterial tree.

Mean arterial pressure is calculated as dia. + 1/3 p pressure. mean arterial p. is combined systolic and diastolic pressure head which forces blood from arterial tree into blood capillaries.

Hint: Pulse p. =tree

Hint: Mean art. p. = art tree --> blood cap.

For people who are not phys. fit, their bp and pr will increase more than phys. fit person, and it will take longer time for their values to return to baseline.

A phys. fit person will increase their levels some, but will quickly return to baseline levels after.

Carboxyhemoglobin would be increased, and oxyhemoglobin would be lower.

Danger is because oxyhemoglobin concentration decreases, not enough oxygen gets delivered to body and person can die.

(a) reason for this is because muscles use up oxygen that arteries carry and by time it reaches veins to go back to heart, oxygen has been used up.

(b) arterial % oxyhemoglobin would be high first coming out of the heart, then, as it moved through body, it would decrease as muscles used it up.

In babies with resp. distr. syndrome, the measurements allow medical proff. to determine of babies lungs are working prop. and taking in enough oxy. Even if babies have plenty of blood flowing, enough oxy may not be delivered.

In patients under general anesthesia, body functions are shut down, so they are artificially respirated. By monitoring, medical prof. knows how much oxygen to deliver.

Theory is that C02 will be exhaled into bag and reinhaled.

Because paper bags are not air tight, fresh O2 will also be inhaled.  Also, the bag opening and closing has a psychological effect.

Why bicarbonate helps patients with acidosis. What would happen if too much were given.

Prospector, decreased urine volume and Na+ and Cl- content. Increased specfic gravity.

Partygoer, increased urine volume and Na+ and Cl- content. Decreased specific gravity.

Why?

Desert prosp. has a higher secretion of ADH that the partygoer because he is dehydrated. The pg has become overly hydrated and alcohol also inhibits ADH secretion. The pg would excrete larger volume of diluted urine. The more dilute urine would have a lower specific gravity.

Since the prosp. is dehydrated and has smaller circulating blood volume, he would have  higher secretion of aldosterone that the partygoer. In this case, aldosterone would stimulate increased reabsorption of Na and Cl, so that less of these ions is secreted in urine.

Study diagram 9.1 Q 11

Many diuretic drugs inhibit Na+ reabsorption in the loop of henle. Predict effect of drugs on urinary excretion of Cl and K.

Calculate mEq/L of Ca²⁺ in the plasma (weight Ca is 40)

Ca= 0.1g/L

(0.1g/L) x (1mol/40g) = (2.5 ^{^-3}mol/L) x (1000mM/M) = 2.5 mM

2.5 mM x 2 = mEq/L

Identify cells of the gastric mucosa that secrete:

(a) HCl _________

(b) pepsinogen ___________

(c) histamine _____________

(a) parietal cells

(b) chief cells

(c) entero chromaffin-like cells. (ECL's)

Surface area is increased by :  plicae circulares --> villi --> microvilli.

Rate is increased because of these structures and brust border enzymes in the microvilli.

Consists of hepatic sinusoids, a central vein, bile ductules, branch of the hepatic artery.

(a) blood drains from the cappillaries of the intestine through the hepatic portal vein. This blood travels through the sinusoids in the liver tissue before returning to the heart. Also, blood from the hepatic artery mixes with blood in the sinusoids of the liver and this modifies the composition.

(b) The blood is kept separate from the bile because bile never enters the sinusoids, but instead, hepatocytes secrete bile into bile canaliculi and the bile is drained into bile ducts within the liver.

Tube with H2O, because starch was not digested by saliva.

Tube with warm saliva caused amylase to work faster and dissolved more starch, thus leaving more maltose.

For pepsin, HCl actually helps digest the protein because optimal is pH below 2.

For starch, HCl makes it to acidic. A pH of 6.7 is optimum for amylase.

Glucose and amino acids are digested by amylase and are absorbed as monomers.

Fat is digested in small intestine by pancreatic lipase when bile salts are present. Then, fatty acids form micelles and are absorbed by the intestinal epi.  Then these are formed into triglycerides which attach to carrier proteins and form chylomicrons which secrete into the lacteals, and onto the lymph in veins.

Because there is a lining of stable gel of mucous which contains alkaline bicarbonate buffer. This also protects against damage that could be caused by pepsin.

Because the duodenum is covered in an adherent layer of mucous on its epi. The cells of the duod.secrete bicarbonate in this mucus. Also, brunners glands secrete bicarbonate. The acidic chyme is neutralized by the alkaline pancreatic juice, so this doesn't harm duodenum.