chapter 9 homeostatsis

Question 1

What are the steps in the homeostatic pathway

Answer 1

Stimulus —-> sensor —–> control ——> effector

Question 2

Sensor and effector

Answer 2

Sensor is the thing that picks up the change in homeostasis (something like Nerve cells) and effectors are things that vary the condition (sweat glands when were too hot)

Question 3

Purpose of the negative feedback loop

Answer 3

Prevent the body from over correcting a change from homeostasis to the other direction

Question 4

What happens when the body in cold temperatures

Answer 4

Dip in temperature activates hypothalamus heat center ——-> blood vessels shrink and blood is drawn deeper into body

Question 5

What happens to the body in hot temperatures

Answer 5

pre optic area of hypothalamus responds to the higher temperatures which activates sweat glands and dilates blood vessels

Question 6

thyrotropin releasing hormone (TRH)

Answer 6

secreted by the hypothalamus when homeostatic temperature changes, acts on the anterior pituitary

Question 7

thyroid stimulating hormone (TSH)

Answer 7

released by the anterior pituitary when TRH stimulates it, TSH then acts on the thyroid

Question 8

Thyroid hormone(TH)

Answer 8

released by the thyroid, stimulates target cells in order to cause an increase metabolic activities, also has inhibitory effects on the release of TSH by blocking TRH

Question 9

Hyponatremia

Answer 9

sodium levels in your extracellular fluid is abnormally low which causes your cells to swell with fluid

Question 10

What stimulates thirst

Answer 10

lack of fluids (hypovolemic)
increase in certain solutes (osmotic thirst)

Question 11

Role of antidiuretic hormones in context of fluid levels

Answer 11

tells body to promote fluid retention

Question 12

Ghrelin

Answer 12

Most of its actions take place in the stomach, higher ghrelin means higher food cravings

Question 13

Leptin

Answer 13

Made in fat tissue, drops when fat is low, tells hypothalamus that we can stop eating

Question 14

Insulin

Answer 14

Takes up sugar that is absorbed into blood stream, inhibits NPY neurons which has an overall inhibitory affect on appetite

Question 15

Neuropeptide y

Answer 15

Has an overall excitatory effect on appetite

Question 16

Homeostatic control

Answer 16

Essential nutrients are missing and our stomach is empty (hardwired response)

Question 17

Hedonic control

Answer 17

Hedonic has to do with external cues that are mainly social and learned (when were out with friends we usually eat something)