lab 7

Question 1

cardiac cycle

Answer 1

involves sequential contraciton of atria and ventricles

Question 2

hearts rhythmical contraction sequence

Answer 2

triggered from action potentials from myocardial cells

Question 3

body fluids are

Answer 3

good conductors of electricity and able to be easily recorded at the surface

Question 4

electrocardiogram

Answer 4

electrical currents associated with depolarization and repolarization of the heart that are measured as electrical potential across the body surface by placing electrodes on opposing sides of the heart

Question 5

myocardial cells

Answer 5

where electrical signals to initiate vertebrate heart contraction originate

Question 6

excitation and inhibition of the heart accomplished by

Answer 6

changes to contraction rate and various other parameters associated with myocardial contraction

Question 7

T-P interval

Answer 7

time between beats

Question 8

P-T interval

Answer 8

overall time that a complete depolarization/repolarization occurs

Question 9

arterial system

Answer 9

receives blood from the heart and distributes it throughout the body

Question 10

pressure resevoir for arteries

Answer 10

the amount of blood flood is directly related to the pressure difference along an artery

Question 11

increased heart function

Answer 11

increases centralized blood pressure

Question 12

signals from autonomic nervous system control

Answer 12

the degree of contraction of smooth muscles found in walls of arteries

Question 13

vasoconstriction

Answer 13

increase centralized blood pressure

Question 14

vasolidation

Answer 14

decrease centralized blood pressure

Question 15

autonomic nervous system effects alter

Answer 15

how much blood goes to various organs

Question 16

Fight or Flight

Answer 16

autonomic nervous system releases epinephrine from adrenal glands which bind to heart and cause it to be faster

Question 17

after fight or flight

Answer 17

parasympathetic system releases acetylcholine from vagus nerve that binds to receptors on heart causing it to beat slower

Question 18

peripheral feedback loops

Answer 18

simultaneously coordinate heart activity, arterial blood pressure and overall blood flow in the body

Question 19

baroreceptor reflex

Answer 19

ensures central arterial blood pressure is maintained but not so high that arterial blood vessels are ruptured and there is excess fluid leakage

Question 20

diving bradycardia

Answer 20

heart rate is substantially reduced to ensure blood pressure in central arteries does not exceed safe levels

Question 21

diving causes

Answer 21

selective peripheral vasoconstriction (significant increase in blood pressure to central arteries
and sharply reduced blood flow to limbs gut and skin
(sensures blood is deliverd to organs with highest need for blood)