Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

b&b > task 7 - homeostasis > Flashcards

task 7 - homeostasis Flashcards

1
Q

regulatory mechanisms

A

maintain the organisms homeostasis in the face of variability environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

4 parts of the system

A

system variable, set point, detector, correctional mechanism/effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

system variable

A

the characteristic that is regulated by the mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

set point

A

the optimal value of the system variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

detector

A

an entity that monitors the value of the system variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

correctional mechanism/effect

A

an entity that restores the system variable to the set point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

negative feedback

A

a process whereby the effect produced by an action serves to diminish/terminate the action, regulates the regulatory system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

ingestive behaviors

A

eating and drinking) to replenish the body’s depleted stores of water in nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

satiety mechanism

A

physiological mechanisms that reduce hunger/thirst and thus produce the motivation to stop eating/drinking. makes for adequate intake of nutrients

  • delay the ingestion and replenishment of depleted stores. they are NOT detectors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

osmosis

A

low to high concentration movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

osmometric thirst

A

→ motivation to drink caused by loss of water from the intracellular fluid (fluid in the cell)

→ caused by the increase of solutes (makes the cells smaller and draws liquid out the cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

osmoreceptors

A

neurons whose firing rate is affected by their level of hydration. they detect change in the cell’s volume and transform those changes into membrane potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

activation of the osmoreceptors

A
  1. activation in the anterior cingulate cortexand hypothalamus corresponding to a sensation of thirst
  2. activation in the lamina terminals (location of the osmoreceptors)
  3. the median preoptic nucleus of the lamina terminalis receives input from both OVLT and SFO. integrates info. and control drinking in the brain through connections to other brain parts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

osmotic thrist: correctional devices

A

cortex, vasopressin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

osmotic thrist: what do the correctional devices do?

A
  1. create thirst
  2. constrict vessels
  3. conserve water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

osmotic thrist: system variable? set point?

A

osmotic pressure
0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

osmotic thrist: is positive or negative feedback?

A

decreased osmotic pressure post the correctional devices work

negative feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

volumetric thirst

A

motivation to drink caused by reduction of the volume of the blood plasma

  • leads to a salt appetite because of loss of sodium from hypovolemia (causes loss of blood volume without depleting the intracellular fluid)
  • the atria of the heart contains baroreceptor cells; a second set of receptors for volumetric thirst, produces volumetric thirst after a reduction in blood flow to the heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

hypovolemic thirst: correctional devices?

A

baroreceptor reflex
vasopressin
RA system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

hypovolemic thirst: what do the correctional devices do?

A
  1. create thirst
  2. constrict vessels
  3. conserve water
  4. conserve salt
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

hypovolemic thirst: system variable? set point?

A

blood pressure
120/80

21
Q

hypovolemic thirst: positive or negative feedback?

A

increased blood volume

negative feedback

22
Q

angiotensin

A

a hormone produced at the kidneys when cells inside them detect releases in blood flow - initiates volumetric thirst which in turn causes the kidneys to conserve water and salt, and increases blood pressure

  • doesn’t cross blood barrier
23
Q

digestion

A

the gastrointestinal process of breaking down food and absorbing its constituents into the body

24
Q

energy delievered?

A
  1. lipids from fat
  2. amino acids from proteins
  3. glucose from complex carbohydrates
25
Q

energy stored?

A
  1. triglycerides, glycerol and 3 fatty acids (FATS)
  2. glycogen; complex insoluble carbohydrate
  3. proteins (chain of amino acids)
26
Q

phases of energy metabolism

A
  1. cephalic phase
  2. absorptive phase
  3. fasting phase
27
Q

cephalic phase

A

the preparatory phase that begins with the sight/smell/thought of food and ends when the food starts being absorbed in the bloodstream

28
Q

absorptive phase

A

the period during which the energy absorbed into the bloodstream from the meal is meeting the bodys immediate energy needs

29
Q

fasting phase

A

the period during which all of the non-stored energy from the previous meal has been used and the body is withdrawing energy from its reserves to meet its immediate energy requirements lasts till next cephalic phase

30
Q

the flow of energy in the metabolic phase is controlled by 2 pancreatic hormones?

A

isulin and glucagon

31
Q

insulin functions

A
  • promotes the use of glucose as the primary source of energy. since glucose can’t pass through cell membrane it needs to be taken in the cell by glucose transporters
  • promotes the conversion of bloodborne fuels (carried by the blood) to forms that can be stored
  • promotes the storage of glycogen in the liver, muscle and fats in adipose tissue and proteins in muscle
32
Q

set-point assumption

A

hunger is caused by the presence of an energy deficit, and eating is the means by which the energy resources of the body are returned to their optimal level (energy set point)

  • all set-point systems are negative feedback systems
33
Q

glucostatic theory

A

the set point is defined by a specific level of blood glucose levels

34
Q

lipostatic theory

A

the set point is defined by a specific level of body fat

35
Q

glucoprivic hunger

A

hunger that is provoked by glucose deprived cells

36
Q

lipoprivic hunger

A

hunger that is provoked by lipid deprivation of cells

37
Q

the brain receives signals through the vagus nerve from the liver receptors that detect lipid and glucose deprivation of cells and this causes?

A

cause immediate eating

cutting the vagus abolishes the two types of hunger

38
Q

problems with the set-point theories?

A

the set point theories are inconsistent with evolutionary pressures. ancestors needed to eat large quantities when it was available

they also do not recognize major influences such as taste, learning and societal influences

39
Q

positive-incentive theory

A

animals are not normally driven to eat by internal energy deficits but by the anticipated pleasure of eating (the anticipated pleasure of a behavior is called its positive-incentive value)

  • formed from the evolutionary pressures of unexpected food shortages have shaped warm-blooded animals to take advantage of food when it is present and eat it
  • the degree of hunger felt depends on the interaction of all the factors that influence the positive-incentive value of eating
40
Q

blood glucose levels

A

the intention to start eating triggers a decline in blood glucose (the glucostatic theory)

41
Q

brain stem

A

the area postrema and the nucleus of the solitary tract (AP/NST) located in the dorsal medulla receive taste information from the tongue and a variety of sensory information from internal organs

42
Q

hypothalamus

A

melanin-concentrating hormone (MCH) and orexin are neuropeptides that are produced by neurons in the lateral hypothalamus

  • activity of these neurons increases food intake and decreases metabolic rate
  • the axons of these neurons travel to many brain structures that are involved in motivation and movement
43
Q

vasopressin

A
  1. constricts blood vessels
  2. conserves water
44
Q

serotonin and satiety

A

→ serotonin agonists reduce hunger and eating in some people who overeat under some conditions

→ serotonin agonists seem to increase short-term satiety signals associated with the consumption of a meal unlike the signals from leptin and insulin which produce long-term satiety signals based on fat stores

45
Q

cholecystokinin (CCK)

A

produced in the gastrointestinal system, suppression of eating

secreted when fat or protein is detected by receptors mainly in walls of duodenum

46
Q

peptide YY (PYY)

A

secreted proportional to amount of calories consumed, mainly in the ileum and colon

47
Q

insulin

A

→ serves as a negative feedback signal in the regulation of body fat

  • positively correlated with levels of bodyfat
  • correlated with visceral fat (stored around the internal organs of the body cavity
48
Q

leptin

A

fat releases this peptide hormone. it is believed to be a negative feedback signal normally released from fat stores to decrease appetite and increase fat metabolism

  • levels of leptin are correlated with subcutaneous fat (stored under the skin)
  • have an inhibitory effect on the NPY/ARGP neurons when activation of leptin on the receptors occur

more fat > higher leptin > higher satiety > less food intake > reduction of fat mass

49
Q

ghrelin

A

a peptide hormone that is released from the gastrointestinal system when a person is in the fasting phase and the digestive system is empty, binds to receptors in the hypothalamus to help stimulate eating behavior

  • reduced after a meal and increase with fasting
  • blocking the signal inhibits eating
  • increasing the levels can cause weight gain by increasing food intake and decreasing metabolism of fats
50
Q

neurons of the arcuate nucleus

A
  • neuropeptide Y (NPY); stimulates food intake
  • agouti-related protein (AGRP); released by NPY and also acts together with it

b&b (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions