Physiology Exam 2 Review Guide

4 major groups of plasma proteins and site of production

-albumins -> liver (osmotic pressure)

-globulins -> liver, lymph tissue (clotting factors, enzymes, antibodies)

-fibrinogens -> liver (threads for blood clotting)

-transferrin -> liver and other tissues (iron transport -> hemoglobin -> oxygen)

3 major types of blood cells

-red blood cells (erythrocytes)

- white blood cells (leukocytes)

-platelets (split from megakaryocytes)

5 types of leukocytes

neutrophils, eosinophils, basophils, monocytes, lymphocytes

definition of hematocrit

ratio of red blood cells to plasma (%)

first step of platelet plug formation

exposed collagen binds and activates platelets (vasoconstriction -> swelling)

second step of platelet plug formation

activation begins clotting process

third step of platelet plug formation

factors attract more and more platelets

fourth step of platelet plug formation

platelets aggregate into platelet plug (loose plug)

what are the 2 major functions of pleural fluid

-attach lung to wall of thoracic cage

-allows lungs to move in the thorax

what does the conducting zone do

brings air into respiratory zone and warms and filters the air

what parts of the body does the conducting zone include

trachea, bronchial tree, and bronchioles

what does the respiratory zone do

exchange of gasses between air and blood

what parts of the body does the respiratory zone include

respiratory bronchioles and alveolar sacs

3 ways to classify muscles

location, contraction pattern, and communication with neighboring cells

examples of classifying smooth muscle by location

vascular, gastrointestinal, urinary, respiratory, reproductive, and ocul

contraction patterns of smooth muscle

phasic and tonic

Examples of phasic muscles

-esophagus (propel food)

-intestine (mix food)

examples of tonic muscles

-a sphincter that when relaxed allows material to pass (excrete urine)

-vascular smooth muscle (regulate blood flow)

Can single-unit smooth muscles communicate with neighboring cells (read carefully, not a duplicate)

yes

Can multi-unit smooth muscles communicate with neighboring cells (read carefully, not a duplicate)

yes

features of smooth muscle

-must operate over a range of lengths

-layers may run in several directions

-contracts and relaxes much more slowly

-sustains contractions for extended periods

-small, spindle-shaped cells with one nucleus

-contraction initiated by electrical OR chemical signals OR both

speed of smooth muscle contraction/relaxation vs skeletal or cardiac muscle

smooth muscle contraction and relaxation are SLOWER than skeletal or cardiac muscle

size of smooth muscle fibers vs skeletal muscle fibers

smaller

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actin and myosin in smooth muscle vs skeletal muscle

longer actin and myosin

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how is actin different in smooth muscle

has tropomyosin, but not troponin

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what are 3 major ways to control smooth muscle contraction

-stretch-activated calcium channels

-hormones and paracrines

-antagonistic control by both sympathetic and parasympathetic neurons

how do stretch-activated calcium channels work in smooth muscle

-open when pressure or other force distorts cell membrane

-myogenic contraction

how do hormones and paracrines help control smooth muscle conctraction

-histamine constricts smooth muscle of airways

-nitric oxide affects regulation of diameter of blood vessels

what is an exception during antagonistic control by both sympathetic and parasympathetic neurons for smooth muscle contraction

arterioles and veins

rank the order of highest pressure to lowest

-aorta

-arteries

-arterioles

-capillaries

-venules

-veins

-venae cavae

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function of the aorta

Pumps blood out of the heart to the rest of the body

function of the arteries

-carry blood away from the heart

-high pressure

-low volume

-maintains blood flow during ventricular relaxation

function of the arterioles

-transport blood from arteries to capillaries

-regulate blood flow and pressure by altering their diameter

function of the capillaries

exchange between blood and cells

function of the venules

drain capillary beds and merge to form veins

function of the veins

-carry blood back to the heart

-low pressure

-high volume

function of the venae cavae

pump blood from veins back into the heart

why is it important for blood flow velocity to change in the capillaries

they're thin and have lots of area so we don't want the blood to blow through and damage them

what are the 2 determinants of blood flow (double check me on this please)

flow rate and flow velocity

how is flow rate measured

the volume of blood which passes along a blood vessel per unit time (L/s or L/min)

how is flow velocity measured

distance traveled by an object relative to time (meters per second)

where is the base of the heart

superior portion of the heart (top)

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where is the apex of the heart

inferior portion of the heart (bottom)

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the heart is encased in a fluid-filled sac, what is it called

pericardium

where do the arteries and veins attach

base of the heart

What do the atrioventricular valves do?

prevent backflow into atria when ventricles contract

what makes up the atrioventricular valves

-tricuspid

-bicuspid

-chordae tendineae

what makes up the semilunar valves

-pulmonary and aortic valve

-3 cuplike leaflets

when do the 3 cuplike leaflets push together in the semilunar valve

artery pressure is higher than ventricle pressure

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characteristics of myocardial cells

-99% contractile, 1% pacemaker

-striated and arranged in sarcomeres

-shorter and smaller than skeletal muscle cells

-single nucleus per fiber

-branched

-1/3 of cell volume is mitochondria

-pacemaker cells -> autorhythmicity

what is the heart mostly composed of

myocardium

what is the first step of excitation-contraction coupling

action potentials travel along the sarcolemma and down into the transverse tubule (T-tubule) system; depolarizing the cell membrane

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what is the second step of excitation-contraction coupling

voltage-sensitive calcium channels (DHP) open to permit calcium entry into the cell

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what is the third step of excitation-contraction coupling

calcium influx triggers a subsequent release of calcium that is stored in the sarcoplasmic reticulum (SR) through calcium-release channels ("ryanodine receptors"), and increases intracellular calcium concentration

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what is the fourth step of excitation-contraction coupling

free calcium binds to troponin to expose the myosin head binding site and the cross bridge cycle occurs

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what is the fifth step of excitation-contraction coupling

relaxation occurs when calcium is pumped back into the SR by and ATP-dependent calcium pump (SERCA), thus lowering cytosolic calcium concentration and removing calcium from the troponin

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Influx of Na+

voltage-gated ion channels open

Na+ channels close

Slow Ca2+ channels open

Slow Ca2+ channels close

K+ channels close

Why is the timing of action potential and contraction important?

long refractory period in cardiac muscle prevents tetanus; allows muscle to fully relax

action potentials in autorhythmic cells:

-have unstable resting membrane potential

-are autorhythmic

-I-funny channels are permeable to both K+ and Na+

-Output can be modified by the ANS

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first step in electrical conduction pathway in the heart

SA node depolarizes

second step in electrical conduction pathway in the heart

electrical activity goes rapidly to AV node via internodal pathways

third step in electrical conduction pathway in the heart

depolarization spreads more slowly across atria; conduction slows through AV node

fourth step in electrical conduction pathway in the heart

depolarization moves rapidly though ventricular conducting system to the apex of the heart

fifth step in electrical conduction pathway in the heart

depolarization wave spreads upward from the apex

P wave

R complex

Q complex

S complex

T wave

what is sinus rhythm

60-100 bpm (regular rhythm)

what is bradycardia

less than 60 bpm (slow rhythm)

what is tachycardia

more than 100 bpm (fast rhythm)

what is heart block

electrical signal from AV node is partially or completely blocked from reaching the ventricles

what aids in ventricular filling and how much does it fill

gravity fills ~80% of the ventricle

what fills the last little bit of blood in the ventricles

atrial contraction fills the last ~20% of the ventricles

what is isovolumetric contraction

the valves aren't open quite yet, so the pressure is building up the ventricles (like squeezing a water bottle with the cap on)

in ventricular ejection, do the atrials or ventricles have greater presssure

ventricles

What is ventricular ejection

enough pressure is generated in the ventricles to open the valves and eject the blood (squeezing the water bottle enough to blow the cap off)

What is isovolumetric relaxation

when the blood has been ejected from the ventricles and the muscle relaxes to be filled with blood again

what are the consequences of hypertension

the risk of developing a CV disease doubles with each 20/10 mmHg increase

Why might risk of pulmonary edema and congestive heart failure increase with hypertension

extra work is put on the heart to maintain stroke volume

what is atherosclerosis

narrowing of arteries due to build up of plaque

what is atherosclerosis comprised of

mainly cholesterol/fat deposits

does atherosclerosis have increased or decreased blood cholesterol and triglycerides

increased

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HDL: good or bad

good

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LDL: good or bad

bad

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what is myocardial infarction

major blockage of coronary arteries results in lack of oxygen to the heart muscle and the tissues die

what does Q stand for when talking about the cardiovascular system

cardiac output, or how well the heart is working

What does SV stand for when talking about the cardiovascular system

stroke volume, or amount of blood pumped by one ventricle during a contraction

how to calculate cardiac output

Q = Heart Rate x Stroke Volume

what is the average cardiac output

about 5 L/min

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how to calculate stroke volume

end diastolic volume (EDV) - end systolic volume (ESV)

will the ESV ever be larger than EDV

no, not all of the blood gets ejected

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AV valves open

AV valves close