BSNC 3000 FINAL QUESTIONS ANSWERS 2026 UPDATE
WITH COMPLETE SOLUTION.
Does blood perfuse the coronary circulation during systole or diastole? Answer
- Diastole
What happens to myocardial blood flow when heart rate increases? Answer -
When heart rate increases, the cardiac cycle is shortened in duration; less time
is spent in diastole, which decreases the time available for coronary perfusion.
70% of oxygen in coronary blood is extracted by the myocardium at rest. This
means that there is little oxygen reserve when myocardial demand increases.
What must happen when oxygen demands of the heart increase to ensure
adequate oxygen supply? Answer - If oxygen demands of the heart increase,
coronary blood flow must increase (e.g. v/d d/t NO)
which portion of the heart is first affected by MI? Answer - the first inner third
(furthest away from the coronary artery and subject to higher pressures from
the inside of the heart)
subendocardial infarct Answer - sudden reperfusion of coronary artery
following an MI, where only the inner third of the ventricle wall is irreversibly
damaged (infarct)
N-STEMI
,can also be caused by conditions that dec perfusion:
- severe atherosclerosis
- hypotension
sources of heat gain Answer - external sources
- cell metabolism
- muscle activity
- ingestion of food
sources of heat loss Answer - - evaporation of sweat
- through the skin
- breathing
What regulates body temperature? Answer - hypothalamus - determines set
point
why are older adults at risk for hypothermia? Answer - less heat gain:
- smaller meals
- mobilize less (less muscle activity)
- less cellular metabolism
more heat loss:
- less fat -> more heat loss
why does stress inc body temp? Answer - PSR -> inc metabolism
inc muscle tension
vasoconstricton -> less heat loss
,fever definition Answer - increase in core body temperature d/t resetting of
thermodynamic set point in response to pyrogens
is PSR the cause of fever? Answer - alone, no.
if underlying cause of PSR causes the release of pyrogens (infection), then yes
general causes of fever (2) Answer - infection
inflammation
causes of hyperthermia Answer - malignant hyperthermia
PSR
malignant hyperthermia Answer - A hereditary condition of uncontrolled heat
production that occurs when susceptible people receive certain anesthetic
drugs.
causes of hypothermia Answer - heat loss during sx (open body cavity,
anesthesia, cold OR)
therapeutic hypothermia (dec metabolic demand)
exogenous pyrogens Answer - e.g. from bacteria cells walls; act indirectly by
stimulating the release of endogenous pyrogens (cytokines)
endogenous pyrogens Answer - cytokines released by macrophages and
leukocytes
, IL-1, TNF-alpha
physiology of fever Answer - 1. endogenous pyrogens enter circulation -> brain
2. synthesis of PGE2 by endothelial cells close to the hypothalamus
3. PGE2 acts on hypothalamus -> resets thermoregulatory set point (higher)
stages of fever Answer - - chill phase (baselines temp below new set point)
- fever
- defervescence phase (pyrogens cease to act; mechanisms to dec temp to
normal)
what autonomic responses help to increase temp to new set point? Answer -
epinephrine released
v/c - diverts blood to the core so less heat is lost
skeletal muscle contraction (shivering)
behavioural responses in order to increase body temp Answer - external heat
sources: fire, sweaters etc (inc heat gain and decreases heat loss)
how does thyroid hormone play a role in thermoregulation? Answer -
increases heat gain during prolonged periods of cold (e.g. winter)
not acutely responsible during chill-phase of a fever
WITH COMPLETE SOLUTION.
Does blood perfuse the coronary circulation during systole or diastole? Answer
- Diastole
What happens to myocardial blood flow when heart rate increases? Answer -
When heart rate increases, the cardiac cycle is shortened in duration; less time
is spent in diastole, which decreases the time available for coronary perfusion.
70% of oxygen in coronary blood is extracted by the myocardium at rest. This
means that there is little oxygen reserve when myocardial demand increases.
What must happen when oxygen demands of the heart increase to ensure
adequate oxygen supply? Answer - If oxygen demands of the heart increase,
coronary blood flow must increase (e.g. v/d d/t NO)
which portion of the heart is first affected by MI? Answer - the first inner third
(furthest away from the coronary artery and subject to higher pressures from
the inside of the heart)
subendocardial infarct Answer - sudden reperfusion of coronary artery
following an MI, where only the inner third of the ventricle wall is irreversibly
damaged (infarct)
N-STEMI
,can also be caused by conditions that dec perfusion:
- severe atherosclerosis
- hypotension
sources of heat gain Answer - external sources
- cell metabolism
- muscle activity
- ingestion of food
sources of heat loss Answer - - evaporation of sweat
- through the skin
- breathing
What regulates body temperature? Answer - hypothalamus - determines set
point
why are older adults at risk for hypothermia? Answer - less heat gain:
- smaller meals
- mobilize less (less muscle activity)
- less cellular metabolism
more heat loss:
- less fat -> more heat loss
why does stress inc body temp? Answer - PSR -> inc metabolism
inc muscle tension
vasoconstricton -> less heat loss
,fever definition Answer - increase in core body temperature d/t resetting of
thermodynamic set point in response to pyrogens
is PSR the cause of fever? Answer - alone, no.
if underlying cause of PSR causes the release of pyrogens (infection), then yes
general causes of fever (2) Answer - infection
inflammation
causes of hyperthermia Answer - malignant hyperthermia
PSR
malignant hyperthermia Answer - A hereditary condition of uncontrolled heat
production that occurs when susceptible people receive certain anesthetic
drugs.
causes of hypothermia Answer - heat loss during sx (open body cavity,
anesthesia, cold OR)
therapeutic hypothermia (dec metabolic demand)
exogenous pyrogens Answer - e.g. from bacteria cells walls; act indirectly by
stimulating the release of endogenous pyrogens (cytokines)
endogenous pyrogens Answer - cytokines released by macrophages and
leukocytes
, IL-1, TNF-alpha
physiology of fever Answer - 1. endogenous pyrogens enter circulation -> brain
2. synthesis of PGE2 by endothelial cells close to the hypothalamus
3. PGE2 acts on hypothalamus -> resets thermoregulatory set point (higher)
stages of fever Answer - - chill phase (baselines temp below new set point)
- fever
- defervescence phase (pyrogens cease to act; mechanisms to dec temp to
normal)
what autonomic responses help to increase temp to new set point? Answer -
epinephrine released
v/c - diverts blood to the core so less heat is lost
skeletal muscle contraction (shivering)
behavioural responses in order to increase body temp Answer - external heat
sources: fire, sweaters etc (inc heat gain and decreases heat loss)
how does thyroid hormone play a role in thermoregulation? Answer -
increases heat gain during prolonged periods of cold (e.g. winter)
not acutely responsible during chill-phase of a fever
