AOS 4 sac

Question 1

what is homeostasis

Answer 1

the (relatively) constant physiological state of the body despite changes (fluctuations) in the external environment

Question 2

what are the most important systems involved in homeostasis

Answer 2

nervous system and endocrine system

Question 3

what is the endocrine system

Answer 3

system of ductless glands that produce hormones and release them directly into the bloodstream

Question 4

are exocrine glands considered part of the endocrine system. If no why not

Answer 4

no, they do not produce hormones so aren’t considered part of the system

Question 5

What are the two types of stimulus response models

Answer 5

open stimulus-response model and closed homeostatic stimulus-response model

Question 6

what are the 5 components of the stimulus response models

Answer 6

stimulus, receptor, control center, effector, response

Question 7

what happens in the stimulus stage

Answer 7

a change, either increase or decrease, in the level of an internal variable

Question 8

what happens is the receptor

Answer 8

the structure detects the change and send signals to the control centre

Question 9

what is the control centre

Answer 9

the structure (central nervous system) that evaluates the change against the set point for that variable and sends signals to the effector about the correction needed

Question 10

what is the effector

Answer 10

the structure that adjusts its output to make the required correction

Question 11

what happens in the response stage

Answer 11

the corrective action is taken

Question 12

what are the two types of feedback

Answer 12

negative and positive

Question 13

what happens in negative feedback

Answer 13

maintains the body’s internal environment at a relatively steady state

Question 14

what happens in positive feedback

Answer 14

amplify (increase) a response in order to achieve a particular result (pooping, birth)

Question 15

what is the term for how body temperature is regulated

Answer 15

thermoregulation

Question 16

what is thermoregulation controlled by?

Answer 16

hypothalamus

Question 17

what is the hypothalamus

Answer 17

a region of the brain that has thermoreceptors that monitor the core temperature

Question 18

what does the hypothalamus do to maintain homeostasis

Answer 18

it registers change in the temperature and then it coordinates nervous and hormonal responses to counteract the changes and restore homeostasis

Question 19

what happens in the stimulus stage of decreased body temperatures

Answer 19

the body temperature decreases below normal ranges (set point ranges)

Question 20

what happens in the receptor stage of decreased body temperatures

Answer 20

the decrease in temperature is detected in the thermoreceptors in the skin, organs and hypothalamus

Question 21

what happens in the control centre stage of decreased body temperatures

Answer 21

the hypothalamus will send signals via the nervous and hormonal systems to effectors

Question 22

what are the effectors of decreased body temperatures

Answer 22

blood vessels in skin, skeletal muscles and brown adipose tissue (BAT)

Question 23

what happens in the response stage of decreased body temperatures

Answer 23

reduced blood flow to the skin vessels (vasoconstriction) , shivering, BAT heat production and increased metabolic heat from BAT

Question 24

what behaivourial changes occur when your core temperature is below average

Answer 24

having a hot drink, standing in front of a heater and rubbing your hands together

Question 25

what happens in the stimulus stage after high body temperatures

Answer 25

the increase in body temperature is above normal

Question 26

what happens in the receptor stage after high body temperatures

Answer 26

increase detected by thermoreceptors in skin, organs and hypothalamus

Question 27

what happens in the control centre stage after high body temperatures

Answer 27

hypothalamus sends signal via nerves to effectors

Question 28

what are the effector after high body temperatures

Answer 28

blood vessels in skin, sweat glands

Question 29

what happens in the response stage after high body temperatures

Answer 29

vasodilation of skin vessels, initiation of sweating

Question 30

what are some behaivourial changes for increased body temperature

Answer 30

removing layer of clothing, using an ice pack and resting in the shade

Question 31

what are hormones

Answer 31

chemicals that coordinate different functions in your body by carrying messages through your blood to organs, skin, muscles and other tissues

Question 32

what are 3 types of hormones

Answer 32

thyroxine, insulin and glucagon

Question 33

what does thyroxine (T4) do

Answer 33

T4 can speed up metabolic activity in cells causing heat to be produced

Question 34

how is T4 supplied to the target cells

Answer 34

thyroid stimulating hormones (TSH) acts on the thyroid gland, causing it to produces thyroid hormones including T4

Question 35

what does insulin do

Answer 35

pancreas will release insulin and this instructs the target cells to absorb glucose

Question 36

what does glucagon do

Answer 36

pancreas will release glucagon and this instructs the target cells to release glucose

Question 37

summary of glucagon and insulin

Answer 37

insulin lowers blood glucose, glucagon increases blood glucose

Question 38

what are alpha cells

Answer 38

cells that secrete the hormone glucagon

Question 39

what are beta cells

Answer 39

cells that produces insulin

Question 40

what is happening in the stimulus stage of decreased blood glucose

Answer 40

decrease in blood glucose

Question 41

what is happening in the receptor stage of decreased blood glucose

Answer 41

alpha cells of pancreas

Question 42

what is happening in the control centre stage of decreased blood glucose

Answer 42

alpha cells of the pancreas secrete the hormone glucagon

Question 43

what is happening in the effector stage of decreased blood glucose

Answer 43

liver cells, body cells

Question 44

what is happening in the response stage of decreased blood glucose

Answer 44

increase in blood glucose by the release of glucose into the blood from the liver

Question 45

what is the stimulus in increased blood glucose levels

Answer 45

increase in blood glucose

Question 46

what is the receptor in increased blood glucose levels

Answer 46

beta cells of pancreas

Question 47

what is the control centre in increased blood glucose levels

Answer 47

beta cells of pancreas secrete the hormone insulin

Question 48

what is the effector in increased blood glucose levels

Answer 48

skeletal muscle, adipose tissue, liver

Question 49

what is the response in increased blood glucose levels

Answer 49

decrease in blood glucose by: uptake by muscle and adipose tissue and glycogen formation in liver

Question 50

what is diabetes

Answer 50

a condition where blood glucose is too high because the body's cells cannot take up glucose in the normal way

Question 51

why isn't there enough insulin with people with diabetes

Answer 51

the beta cells in the pancreas are destroyed so cannot produce insulin

Question 52

what do people with diabetes have to do to restore insulin levels

Answer 52

inject themselves with insulin