Lab 2

Question 1

homeostasis 2 definitions

Answer 1

• dynamic constancy (NOT absolute constancy or constantly dynamic)
• set of mechanisms that aims to maintain internal state

Question 2

set point

Answer 2

• average of a range attempted to be maintained by homeostasis

Question 3

sensitivity

Answer 3

how much deviation from set point is needed before homeostatic mechanisms kick in

Question 4

sensors

Answer 4

sense changes in internal state and send information to integrating centers

Question 5

integrating center

Answer 5

combine information from multiple sensors and sends commands to effectors

Question 6

effectors

Answer 6

receives and carries out commands from integrating center

Question 7

negative feedback

Answer 7

cycle where effect decreases the initial stimulus

Question 8

antagonistic effectors and ex for blood glucose

Answer 8

• antagonistc = opposite effect on an internal state

- insulin and glucagon are antagonistic

Question 9

resting pulse rate

Answer 9

60-90 bpm

Question 10

arterial blood pH

Answer 10

7.35-7.45 very narrow

Question 11

bicarbonate pH

Answer 11

24-28 mEq/L

Question 12

sodium

Answer 12

135-145 mEq/L

Question 13

glucose

Answer 13

75-100

Question 14

positive feedback and 2 examples

Answer 14

• effect of stimulus increases the stimulus - there is always an event that stops break the positive feedback
• ex: oxytocin from posterior pituitary –> uterine contraction –> more oxytocin
• birth causes sensory information to stop being sent
• ex: blood clotting, event is stopping of blood

Question 15

intrinsic regulation and example

Answer 15

• regulation of an organ’s state done by an organ aka autoregulation
• ex: brain and kidney regulate their own blood pressure

Question 16

extrinsic regulation and mechanisms

Answer 16

• nerves and endocrine system regulate state of teh ssytem (para/sympathetic nerves and hormones)

Question 17

athletes bradycardia

Answer 17

decreased resting heart rate due to endurance training - heart muscle is stronger and has increased contractility so needs to do less work at rest

Question 18

why does lying –> standing cause decreased blood pressure

Answer 18

gravity causes pooling of blood in veins of lower body –> less blood returning in veins –> less blood pumped and going into arteries –> detection by baroreceptors in aortic arch

Question 19

effects of drop in blood pressure

Answer 19

dizziness, fainting, coma, death

Question 20

2 paths to effect heart and blood vessel

Answer 20

• neural by direct innervation of sympathetic system

- endocrine via adrenal medulla releasing epinephrine and norepinephrine

Question 21

full mechanism of blood pressure restabalization (neural endocrine)

Answer 21

blood pressure decrease –> detection by baroreceptors in aortic arch and carotid arteries –> medulla oblongata –> paraysmpathetic decrease, sympathetic increased, and adrenal gland secretes norepi and epi –> heart rate increases and vasoconstriction