Exam 2 Study Guide

Question 1

Why are the chordae tendinae important for pumping blood?

Answer 1

they prevent the valve flaps from everting into the atria; helps so blood doesn’t go back up

Question 2

Why are gap junctions important to the heart?

Answer 2

they allow ions to pass from cell to cell in order to behave as a single coordinated unit; they electrically couple adjacent cells

Question 3

What can happen if gap junctions close?

Answer 3

fatal arrhythmias, heart would not beat properly

Question 4

Why are sodium channels important for cardiac muscle contraction?

Answer 4

they do depolarization

Question 5

What is the cardiac conduction system?

Answer 5

network of noncontractile cells that initiate and distribute impulses

Question 6

How does electrical activity produce a coordinated heartbeat?

Answer 6

through gap junctions

Question 7

What two factors determine cardiac output?

Answer 7

heart rate and stroke volume

Question 8

What is resting membrane potential?

Answer 8

separation of oppositely charged particles across membrane in all cells

Question 9

What is heart rate?

Answer 9

number of beats per minute

Question 10

What is stroke volume?

Answer 10

volume of blood pumped out by one ventricle with each beat

Question 11

Why do gap junction make the heart independent of the nervous system?

Answer 11

Either all fibers contract together(via gap junctions) or they do not contract at all. Unlike skeletal muscle, which is controlled by the nervous system

Question 12

Discuss the sinoatrial node

Answer 12

located in the right atrial wall; sets the pace for the heart; it is the heart’s pacemaker

Question 13

Discuss the atrioventricular node

Answer 13

from the SA node, the depolarization wave spreads(via gap junctions) throughout atria via internodal pathway to the atrioventricular node; AV node conducts impulses slower than other parts of system

Question 14

What happens when the SA node is defective?

Answer 14

ectopic focus may appear and take over pacing of heart rate; or the AV node may become the pacemaker

Question 15

Why is sodium important for action potentials and cardiac muscle contraction?

Answer 15

depolarization; voltage gated Na channels open up, so all Na previously pumped outside leaks back in; voltage gated Na channels allow depolarization to happen

Question 16

Why is calcium important for action potentials and cardiac muscle contraction?(plateau phase)

Answer 16

need Ca for contraction to happen; Ca comes in via Ca channels, generating contraction

Question 17

Why are potassium channels important for action potentials and cardiac muscle contraction?(repolarization)

Answer 17

K lets muscle relax; K channels open & K that was pumped in, is pumped out, which is what resets the whole thing back to rest

Question 18

Arteries have a higher blood pressure than veins. T/F

Answer 18

true

Question 19

What are the three important sources of resistance?

Answer 19

blood viscosity, total blood vessel length, blood vessel diameter

Question 20

Smaller vessels have ______ resistance.

Answer 20

greater

Question 21

Blood pressure can be regulated by:

Answer 21

cardiac output

Question 22

Why doesn’t blood flow backwards in the veins?

Answer 22

one way valves prevent blood from flowing backwards

Question 23

What does systole mean?

Answer 23

contraction

Question 24

What does diastole mean?

Answer 24

relaxation

Question 25

What are baroreceptors?

Answer 25

nerve endings that sense pressure

Question 26

Where does blood flow fastest?

Answer 26

the aorta

Question 27

Where is blood flow slowest?

Answer 27

in capillaries, allowing time for exchange between blood and tissues

Question 28

Why is the brain different than other tissues in its vascular needs?

Answer 28

neurons are intolerant of ischemia(inadequate blood supply); can cause a stroke

Question 29

Why does blood flow to skin?

Answer 29

to help get rid of heat

Question 30

What is hydrostatic pressure?

Answer 30

pushes fluid out of capillary

Question 31

What is osmotic pressure?

Answer 31

pulls fluid into capillary

Question 32

Why are plasma proteins like albumin important for osmotic pressure?

Answer 32

albumin is like rice sucking up water; pulls water into blood vessels

Question 33

What is hypovolemic shock?

Answer 33

results from large scale blood loss

Question 34

What is vascular shock?

Answer 34

results from extreme vasodilation and decreased peripheral resistance; system wide vasodilation ex: not enough oxygen getting to tissues

Question 35

What is cardiogenic shock?

Answer 35

results when an inefficient heart cannot sustain adequate circulation; what happens if heart is not pumping enough blood into system

Question 36

What is filtration?

Answer 36

net fluid flow OUT at arterial end

Question 37

What is reabsorption?

Answer 37

net fluid flow IN at venous end

Question 38

How do phagocytes destroy pathogens?

Answer 38

must adhere to particle, phagocyte forms a pseudopod that engulfs the particle forming a phagosome, lysosome fuses w the phagocytic vesicle forming a phagolysosome, enzymes digest it leaving residual body, exocytosis is performed to throw out trash

Question 39

How do natural killer cells attack?

Answer 39

death whisperers; secrete signal to target to program apoptosis

Question 40

What is the inflammatory response?

Answer 40

triggered when body tissue is injured; sets stage for repair, stops spread of damaging agent

Question 41

How do interferons provide antiviral death?

Answer 41

protect against viruses by warning other cells to protect themselves

Question 42

How does the complement system destroy pathogens?

Answer 42

kills things that have been marked for destruction; proteins circulate in inactive form in blood; kills bacteria and other cell types by cell lysis

Question 43

What is the membrane attack complex and how does it kill?

Answer 43

it is the insertion of complement proteins into a cell's membrane; if CP's see antibodies, they hogpile

Question 44

Complement activation: classical pathway

Answer 44

activated by antibodies coating target cell

Question 45

Complement activation: lectin pathway

Answer 45

activated by lectins binding to specific sugars on microorganisms surface

Question 46

Complement activation: alternative pathway

Answer 46

activated spontaneously

Question 47

Why is fever beneficial?

Answer 47

controlled hyperthermia; discourages growth of bacteria allowing body to kill them off faster than they can grow

Question 48

What are pyrogens?

Answer 48

chemicals that raise the body's temperature

Question 49

What do lymphocytes do?

Answer 49

mediate adaptive immunity; B&T

Question 50

B lymphocytes

Answer 50

humoral(antibody based)

Question 51

T lymphocytes

Answer 51

cellular(cell recognition and destruction)

Question 52

Why are antibodies important?

Answer 52

they fight infection

Question 53

humoral immunity

Answer 53

antibodies mark pathogens for destruction; seen it before; carried out by B lymphocytes

Question 54

cellular immunity

Answer 54

T lymphocytes act against infected cells

Question 55

Immunocompetence

Answer 55

has the ability to recognize antigen by binding to it

Question 56

Where do B cells mature?

Answer 56

red bone marrow

Question 57

Where do T cells mature?

Answer 57

thymus

Question 58

What are naive cells?

Answer 58

immunocompetent B and T cells not yet exposed to antigen

Question 59

plasma cells are _______ cells that produce _______.

Answer 59

effector; antibodies

Question 60

What is titer?

Answer 60

measure of how big of immune response; level of antibody in blood plasma

Question 61

Is titer higher after a primary or secondary infection?

Answer 61

secondary bc of memory cells