Review #6 Presentation

Question 1

atria

Answer 1

• receiving chambers

- pump blood into the ventricles at the same time

Question 2

ventricles

Answer 2

• pumping chambers
• highly muscular
• left ventricle has the thickest walls
• pump blood out of the heart into the arteries at the same time

Question 3

coronary arteries

Answer 3

• supply oxygen and glucose to heart muscles (aerobic respiration) for pumping action
• if a coronary artery is blocked, it could result in a heart attack*

Question 4

flow of blood into, through, and out of the heart

Answer 4

1) vena cava delivers deoxygenated blood from body to right atrium
2) blood passes through right atrioventricular (AV) valve into the right ventricle - pumps it through the right semilunar valve into the pulmonary arteries - takes blood to the lungs to lungs to be oxygenated (pulmonary circulation)
3) oxygenated blood returns to the left atrium of the heart through the pulmonary veins
4) blood passes through left AV valve into left ventricle, which pumps it through left semilunar valve into the aorta which takes it to the body (systemic circulation)

Question 5

what do heart valves and valves in veins maintain

Answer 5

one-way blood flow

Question 6

what builds pressure and opens AV valves so blood can flow into the ventricles

Answer 6

atrial contraction

Question 7

what closes AV valves and opens semilunar valves so that blood flows into arteries

Answer 7

ventricle contraction

Question 8

as arterial pressure increases…

Answer 8

semilunar valves close

Question 9

myogenic

Answer 9

signal for cardiac contraction arises in heat muscle itself

Question 10

SA node

Answer 10

• pacemaker
• specialized collection of nerves
• generates impulse in right atrium stimulating the atria to contract from top to bottom
• impulse reaches junction btw atria and ventricles and activates the AV node

Question 11

AV node (atrioventricular)

Answer 11

• waits 0.1 seconds then sends a signal
• causes ventricles to contract - from the bottom - apex - up so that blood is pushed up and out of ventricles to arteries

Question 12

what does the myogenic sequence ensure

Answer 12

delay between atrial and ventricular contraction

- maximizing blood flow

Question 13

what is your resting heart rate

Answer 13

the rate at which the myogenic sequence of events happens

Question 14

what does the medulla oblongata of brainstem/autonomic nervous system control

Answer 14

SA node

Question 15

what happens if CO2 levels increase (myogenic)

Answer 15

medulla sends signals to SA node through cardiac nerve to cause SA node to fire more frequently
- increases heart rate

Question 16

as CO2 levels decrease (myogenic)

Answer 16

medulla sends signal to SA node through vagus nerve to cause SA node to fire less frequently
- decreases heart rate to resting rate

Question 17

how can the adrenal gland affect the heart rate

Answer 17

speed up the heart rate by releasing adrenaline into the bloodstream

Question 18

arteries: pressure (p), diameter and vessel wall thickness (d), vessel wall features (vw), addition features (af)

Answer 18

P: high (80-120 mm Hg)
D: narrow lumen (maintain high pressure); thick wall (3 layers - prevents rupturing and withstands high pressure
vw: 3 layers; middle layer = thick elastic fibers to maintain pressure btw beats - can stretch to pump blood; high elasticity - elastic recoil to help push blood
af: outer layer of wall contains collagen to prevent artery from rupturing under high pressure