hormones and homeostasis Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what is a hormone

A

chemical substance produced by one of 8 endocrine glands, carried by blood, and altering the activity of one or more target organs

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

what does the pituitary gland do and secrete

A

most of the hormones the pituitary glands secrete are stimulants for other glands to secrete their hormones:
Produces:
FSH
GH
Luteinizing Hormone - stimulates ovulation in females and testosterone production in males.
Thyroid-stimulating hormone - helps manage metabolism, energy levels and nervous system

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

what does FSH do and where is it produced

A

produced in the pituitary gland:
FSH (follicle stimulating hormone) stimulates sperm production in male babies and stimulates the ovaries to stimulate estrogen, which helps in egg development in females.

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

what does the growth hormone do and where is it produced

A

produced in the pituitary gland:
helps children grow and adults strengthen their muscles and bones

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

what is the luteinising hormone and where is it secreted

A

secreted in the pituitary gland:
stimulates ovulation in females and testosterone production in males

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

what is a thyroid stimulating hormone and where is it produced

A

produced in the pituitary gland:
as the name suggests the hormone stimulates thyroids to create thyroxine, also helps manage metabolism, energy levels and nervous system

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

what is the the thyroid gland and what does it do

A

the thyroid gland produces thyroxine
thyroxine increases the metabolic rate and hence regulating growth and development.

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

what are the pancreas and what do they do

A

the pancrease secrete many digestive enzymes (amylase, trypsin, lipase) but also play a major role in blood glucose level maintainence.

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

what is insulin

A

insulin is a hormone that is produced by the pancreas.
insulin acts in response to the blood glucose being too high. Insulin promotes glucose –> glycogen which reduces blood sugar levels.
glucose to glycogen conversion occurs in the liver and glucose once converted to glycogen is stored in the liver and muscles.
Inslulin is produced by beta cells

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

what is glucagon

A

produced by the pancreas, glucagon acts in response to the blood glucose level being too low.
glucagon promotes glycogen —> glucose which increases the glucose level in the blood.
glucagon is produced by alpha cells

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

what is the adrenal gland and what does it do

A

the adrenal gland produces adrenaline.

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

what is adrenaline and where is it produced

A

adrenaline is a hormone which is secreted in fight or flight situations.
major part of the sympathetic nervous system.
adrenaline stimulates increase in metabolism, heart rate, respiration, pupil dilation and blood glucose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is noradrenaline

A

noradrenaline is the main NEUROTRANSMITTER of the sympathetic nerves in the cardiovascular system. Noradrenaline can constrict blood vessels increasing blood pressure.

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

what is adrenaline used to treat

A

asthma attacks
cardiac arrest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is noradrenaline used to treat

A

ADHD
septic shock

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

what are the testes and what do they do

A

testes produce testosterone (male sex hormone)

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

what are the ovaries and what do they do

A

produce estrogen (female sex hormone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why does adrenaline increase pulse and breathing rate

A

so that in fight or flight situations glucose and oxygen can be delivered easily to the muscles

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

why does adrenaline increase blood glucose

A

for increased respiration in muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

why does adrenaline dilate the pupils

A

so that more information can be processed by the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is homeostasis

A

maintainence of a constant internal environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the “internal environments” that is being referred to

A

Temperature
blood glucose concentration
water concentration
blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is negative feedback

A

Negative feedback occurs when conditions change from the ideal or set point and returns conditions to this set point

24
Q

how does negative feedback work

A

if the level of something rises, control systems are switched on to reduce it again
if the level of something falls, control systems are switched on to raise it again

25
Q

what is the problem in patients with type-1 diabetes and how is it treated.

A

blood glucose is far too high as insulin secreting cells in the pancreas are not secreting enough insulin.
treated with insulin shots

26
Q

how does the body regulate heat, when there is an increase in body temp

A

increase in body temp -> thermoreceptors in the hypothalamus and skin detect change -> increased sweating, vasodilation, hairs lie flat on skin -> decrease in body temp to normal temp (37C)

27
Q

how does the body regulate heat, when there is a decrease in body temperature

A

decrease in body temp -> thermoreceptors in the hypothalamus and skin detect change -> vasoconstriction, shivering, hair on skin erect -> increase in body temp to regular temp (37C)

28
Q

how does sweat help cool the body

A

sweat secreted by sweat glands evaporates off the skins surface leaving a cooling effect on the skin

29
Q

how does shivering help heat up the body

A

skeletal muscles contract rapidly, the contractions need energy from respiration some of this energy is transferred as heat.

30
Q

what is the effect of strenuous exercise on the volume of water lost by the skin and the kidneys

A

volume of water lost by the skin:- increases
volume of water lost by the kidney:- decreases

31
Q

why does vasoconstriction make us feel warmer

A

capilaries get narrower, less blood flow to the surface of the skin, less heat lost by radiaton from blood travel

32
Q

why does vasodilation make us feel colder

A

arterioles relax, more blood is flown to the surface of the skin, more heat is lost by radiation making us feel cooler.

33
Q

what is gravitropism
+ve response
-ve response

A

growth in plants towards/away from gravity
positive response: growth towars gravity (towards the ground)
negative response: growth away from gravity (away from the ground)

34
Q

what is phototropism
+ve response
-ve response

A

growth towards/away from light
positive response: growth towards light (towards shoot)
negative response: growth away from light (towards root)

35
Q

what are shoots photopic and gravitropic

A

positively phototropic
negatively gravitropic

36
Q

what is a clinostat

A

a device that revolves slowly and repeatedly so the shoots are evenly exposed to light. Allows all the sides of the seedlings to get an equal amount of light so they dont curve towards the light but grow straight up

37
Q

What is auxin

A

growth hormone in plants which controls the direction of the plant growth

38
Q

how do plants control their growth

A

chemically

39
Q

where is auxin made
and how does it spread

A

in the tips of growing stems and roots, diffuses to the other parts of the stem/roots spreading from high concentration to low concentration

40
Q

what does auxin stimulate

A

auxin stimulates the cell behind the tip to elongate. the more auxin present the more they will grow

41
Q

How does auxin affect phototropism

A

if light is shone all around the tip then auxin is distributed evenly and equally and the cells in the meristem grow at the same rate.

when light shines on the shoot predominantly from one side then the auxin produced in the tip concentrates on the shaded side (side with no light), making cells on the shaded side elongate and grow faster than the side facing the light.

42
Q

how does auxin affect gravitropism

A

Auxin collects on the lower side of the plant making it grow faster than the upper side causing it to curve upwards

43
Q

where does auxin collect in plants exposed to light and plants under the force of gravity
how does the plant grow accordingly

A

gravity: bottom. grows upwards
light: shaded side. grows towards the light

44
Q

in which organ do the breakdown of hormones first appear

A

liver

45
Q

which target organ releases glucose into the blood as a result of adrenaline

A

liver

46
Q

what part of the eye prevents total internal reflection

A

choroid

47
Q

explain how a decrease in water potential of the blood may damage the red blood cells

A

water diffuses out of the rbc
through a partially permeable membrane
down the water potential gradient

48
Q

which part of the brain is key in maintaining homeostasis

A

hypothalamus

49
Q

why must internal body temperatures remain below 37 degrees C

A

If body temperature increases over this temperature, enzymes will denature and become less effective at catalysing reactions such as respiration

50
Q

Describe how the nervous system coordinates the response of the skin to cold weather.

A

change in temperature acts as a stimulus
thermo receptors in the hypothalamus and skin detect change
electric impulse travels through sensory neurone to brain
relay neurone to motor neurone to effector (eg arteriole)

51
Q

Explain how negative feedback is involved in the control of body temperature.

A

change in temperature is detected and acts as a stimulus
to keep temperature constant
corrective action by body is taken
body temperature returns back to normal (37 deg C)
homeostasis is maintained

52
Q

Explain how the liver lowers blood glucose concentration when it is too high.

A

responds to insulin (from the pancreas)
increased uptake of glucose
glucose converted to glycogen
insoluble glycogen is stored in the liver

53
Q

Explain how an increase in glucose concentration is controlled in the body.

A

pancreas detect increase in glucose concentration
pancreas secrete insulin
liver converts glucose to glycogen
stores in liver
homeostasis maintained

54
Q

Explain how a decrease in water potential of the blood may damage red blood cells.

A

water, diffuses out of red blood cells
through partially permeable membrane
by osmosis
down water potential gradient
red cells decrease in volume

55
Q

The organs of the human body are coordinated by the nervous system.
Outline one other way in which these organs are coordinated.

A

hormones
secreted in the blood
stimulate target organ