Coronary Circulation/Temp Regulation

Question 1

What period of cardiac cycle has coronary blood flow in the L ventricle the lowest

Answer 1

isovolumertric contraction

Question 2

Why is coronary perfusion of the left ventricular myocardium is low during systolic periods and higher during diastolic periods

Answer 2

this is an effect of the pressure gradient, since the aortic pressure is highest in diastole

Question 3

What is the effect of cardiac dilation of ventricular wall tension and mycoardial perfusion

Answer 3

larger the ventricle, higher the tension and myocardial perfusion is reduced

Question 4

Most frequent location of MI

Answer 4

subendocardial arterial plexus

Question 5

Why is subendocardial arterial plexus most senstivie to compressive forces and damage

Answer 5

due to variation in perfusion during cardiac cycle

Question 6

Effect of increased heart rate on mycocardial perfusion

Answer 6

increase HR results in increased perfusion because the pressure is higher in CBF, and the demand of O2 from the heart would be higher

Question 7

Sublingual body temp

Answer 7

approximately normal - 37 C

Question 8

rectal temp

Answer 8

closer to actual core temp - 36.1 to 37.8 C

Question 9

axillary temp

Answer 9

about 1 F less than oral

Question 10

3 causes for normal variation in body temp

Answer 10

diurnal variability
estrous cycle
exercise

Question 11

How does diurnal variablity affect normal body temp

Answer 11

lower in morning, higher in evening

Question 12

How does estrous cycle affect normal body temp

Answer 12

luteal phase elicits an abrupt increase in temperature

Question 13

How does exercise affect normal body temp

Answer 13

metabolic rate

Question 14

Core temperature

Answer 14

temp inside the thoracic, abdominal, and brain/spinal cord

Question 15

Shell temperature

Answer 15

skin

Question 16

Radation

Answer 16

heart leaves/enters the body when it’s colder/warmer outside

Question 17

Condition

Answer 17

heart flows down thermal gradient with DIRECT contact

Question 18

Evaporation

Answer 18

sweat evaporates from our skin, takes heat with it

Question 19

Convection

Answer 19

heart dissipated by current/movement (air/water)

Question 20

What does cutatneous/core thermoreceptors do when temp rises

Answer 20

activates sweating and cutaneous vasodilation

Question 21

What does cutaneous/core thermoreceptors do when temp drops

Answer 21

initiates shivering, cutaneous vasoconstrction, inhibits sweating

Question 22

What changes in the body when temp increase

Answer 22

vasodilation, sweating

shivering, thermogenesis and piloerection inhibited

Question 23

What changes in the body when temp decreases

Answer 23

vasconstrction, shivering, thermogenesis, pilorection

Question 24

What does epinephrine do when body temp decreases

Answer 24

increase thermogensis

Question 25

What does NE do when the body temp decreases

Answer 25

cutaneous vasoconstriction

Question 26

How do vasodilation and sweating get inhibited

Answer 26

PANS innervation results in the hypothalamus releasing TRH, which causes anterior pititarty to release TSH, which causes thyroid gland to release thyoxine which increases metabolitic thermogensis