Brainscape's Knowledge GenomeTM

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


See full index

Biology > Communication and Homeostasis - Module 5 > Flashcards

Communication and Homeostasis - Module 5 Flashcards

1
Q

cell signalling

A

the release of a chemical by one cell that is detected by another using a receptor
The 2nd cell carries out a response
This occours in the endocrine and nervous system

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

define Homeostasis

A

the maintenance of a constant internal environment

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

What has to be maintained theough homeostasis

A

-Body temp
-Blood glucose conc.
-Blood salt conc.
-Water potential of blood
-Blood pressure
-Carbon dioxide concentration

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

What in their environment to animals respond to

A

external + internal stimuli

E.g: Temp, glucose

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

What in their environment to plants respond to

A

external + internal stimuli

E.g: light intensity

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

stimuli =

A

internal + external changes in an environment

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

Receptors

A

-Detect stimuli
-specific to one particular stimulus
-Can be cells e.g: photoreceptors connected to nervous system or can be proteins on cells surface membranes

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

Effectors

A

Cells that bring about a response to a stimulus. Include muscles cells and cells found in glands

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

Negative feedback=

A

keeps things around normal level
a system reacts to a change in a way that pushes it back to its stable state

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

Process of negative feedback [mechanism]

A

-Receptors detect when a level (e.g glucose or temperature) is too high / low.
-This information is communicated by the nervous system or the hormonal system to effectors.
-The effecters respond to counteract the change, bringing the level down to normal

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

Positive feedback mechanism=

A

they react to a change in a way which amplifies it from a stable state

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

proces of positive feedback mechanism

A

-Receptors detect the change and the effectors respond by further increasing the level away from the normal level

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

is positive feedback involved in homeostasis

A

no as it doesn’t keep he internal environment at a constant

It is useful to rapidly activate bodily processes

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

2 examples of positive feedback and their basic description

A

1)Blood clotting- during formation of blood clot, platelets become active and release a chemical that triggers more platelets to be released

2) During childbirth - when head of baby presses against cervix, release of oxycotin is stimulated. Oxycotin stimulates uterus to contract, pushing the head of the baby harder towards the cervix, .: more oxycotin is released

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

what is an Ectotherm

A

Animals that can’t control their body temperature internally.

This means their body temperature depends on their surroundings.

They control their temperature by changing their behaviour

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

What is an Endotherm?

A

Animals that can control their body temperature internally by homeostasis

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

example of an endotherm

A

Mammals and birds

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

example of ecotherm

A

invertebrate, fish, reptiles, amphibians

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

Name 3 behavioural ways ecotherms warm up

A

Bask in sun

Conduction

exothermic metabolic activity

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

How do ecotherms bask in the sun

A

-orientate body so that max SA exposed to sun

Also extend areas of body- to absorb more radiation from the sun

eg: liards bask in sun long enough to be fast enough to catch prey
locusts spread wings

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

How do ecotherms use Conduction to warm up

A

Press body against warm ground

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

Example of ecotherm using exothermic metabolic activity to warm up

A

Galapagos Iguanas contract muscles to vibrate, increasing cellular metabolism

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

name 2 physiological ways ectotherms regulate temperature

A

-alter skin colour
-alter heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

advantages of being an ectotherm

A

Don’t need to use as much energy on regulating body temperature, so don’t ae to eat as much and can use energy for growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Disadvantages of being an ectotherm

A

May be not capable of activity in winter so need to hibernate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How to Ectotherms cool down (behavioural)

A

-Shaellter from sun, sometimes using mud or water
-press body agains cold stones
-minimise SA to sun
-Minimise body movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

name 5 ways in which endotherms Cool down (physiologically)

A

-vasodilation
-Increased sweating
-large SA:V ratio
-Pilorelaxation (hair relax)
-Animals panting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

name 5 ways in which endotherms Warm up (physiologically)

A

-vasoconstriction
-piloerection ( traps insulating layer of air)
-Shivering
-Raising feathers
- Release hormones such as adrenaline, require homeostatic system receptors to detect change

29
Q

Bhehavioural responses to a change in temperature for endotherms

A

-Wear clothes

-live in house

30
Q

disadvantage and a advantage of being an endotherm

A

(-) need more food

(+) Can survive without shelter

31
Q

Endocrine Gland

A

gland that secretes hormones directly into the blood

32
Q

Exocrine Gland

A

Gland that secretes substances into a duct which carries the molecule to where it is needed

33
Q

Pathway of hormonal control

A

Stimulus - Receptors - Hormone - Effectors - Response

34
Q

Different types of hormones

A

-Protein + peptide hormones (non-steroid)

-Steroid hormones

35
Q

Steroid hormones

properties, examples,

A

-Lipid soluble
-Can pass through membrane into cells and act directly on the DNA

-Testosterone, oestrogen, Progesterone

36
Q

Protein + peptide hormones (non-steroid)
properties, examples

A

-Derivatives of amino acids
-Not soluble so do not enter cell

-Adrenaline, insulin, glucagon, HGH, FSH, LH

37
Q

Process of thermoregulation after a rise in core body temperature caused by external temperature or exercise

A

-This is detected by the thermoregulatory centre in the hypothalamus and the peripheral temperature receptors in the skin
-Hypothalamus sends impulses to effectors which respond by causing Vasodilation of arterioles , sweating or panting,
-Core body temperature returns to normal

38
Q

what is a hormone

A

Molecule released by endocrine gland into the blood. Act as chemical messengers sending signals to a target/tissue cell

39
Q

when is Adrenaline released and where from

A

-Secreted from Adrenal gland when theres a low concentration of glucose in the blood, when you’re stressed or when you’re exercising

40
Q

how does Adrenaline cause a Response in Target tissue?

A

-Adrenaline = 1st messenger
-binds to specific receptors in cell membrane of many cells
-when adrenaline binds, it activates an enzyme in the membrane called adenylyl cyclase.
-Activated adenylyl cyclase catalyses production of secondary messenger = cyclic AMP (cAMP) from ATP
-cAMP activates a cascade of enzyme reactions

41
Q

what does the cortex of the adrenal gland do

A

uses cholesterol to make steroid hormones =
-mineralocorticoids (ALDOSTERONE) control sodium + potassium in blood
-Glucocorticoids (CORTISOL) help control the metabolism of proteins + carbohydrates in the liver

42
Q

What does the Adrenal medulla do

A

secretes Catecholamine hormones (modified amino acids) E.g: noradrenaline and adrenaline

43
Q

Effects of Adrenaline and Noradrenaline

A

Make energy available in the short term:
-Increase heart rate + stroke volume
-general vasoconstriction to raise blood pressure
-dilation of pupils
-increased mental awareness
-inhibits gut action
-body hair stands on end
-relaxes smooth muscle in bronchioles

-Cause cells to break down glucagon into glucose
-constricts some blood vessels so that blood is diverted to the brain and muscles

44
Q

\effects of cortisol and aldosterone

A

-Stimulates breakdown of fats and proteins into glucose
= increased energy available so brain and muscles can respond to situation

  • Increased blood volume and pressure by increased uptake op sodium ions and water into kidney

-Supress immune system

45
Q

What type of gland is the pancreas

A

acts as both an endocrine and exocrine gland

46
Q

when does the pancreas act as an endocrine gland?

A

in the regulation of blood glucose concentration, makes insulin and glucagon and releases them into the bloodstream

47
Q

when does the pancreas act as an exocrine gland?

A

in digestive system,

produces enzymes and releases them into the small intestines via a duct

48
Q

Islets of Langerhans

A

areas of the pancreas that contains endocrine tissue. Found in clusters around blood capillaries -> secretes hormones directly into blood

49
Q

properties of alpha cells and their role

A

-Secrete GlucAgon

-Larger and more numerous than Beta cells

50
Q

what di Beta cells secrete

A

Insulin

51
Q

what are the normal blood glucose levels

A
  • 90mg 100cm^-3
  • 4-6 mmol dm^-3
52
Q

how do alpha and beta cells react to a rise in blood glucose concentration above the normal value

A

Beta cells detect this
-alpha cells stop secreting glucagon and the beta cells secrete insulin into the blood plasma

53
Q

After insulin is secreted into the blood plasma, what does it bind to?

A

complementary receptors on the plasma membrane of hepatocytes and muscle cells

54
Q

after insulin binds to receptors on cells , what happens

A

This activates adenylyl cyclase enzyme, causing ATP to be converted into cAMP, the second messenger.

This causes a series of enzyme controlled reactions to start taking place inside the cell

55
Q

What enzyme controlled reactions to start taking place inside the cell due to Insulin ?

A

-higher uptake of glucose by the cells,
Due to glucose Channel proteins being inserted into the membrane
-glycogenesis (formation of glycogen)
-More glucose converted to fats
-more glucose used in respiration

56
Q

how do beta and alpha cells react to a fall in blood glucose concentration below the normal value

A

-alpha cells start secreting glucagon
-beta cells stop secreting insulin into the blood plasma

57
Q

After being secreted into the blood, what does Glucagon do?

A

binds to complementary receptors on plasma membrane of hepatocytes

58
Q

after glucagon binds to receptors, what happens

A

Liver cells respond by activating :
-Gluconeogenesis (formation of glucose from fatty acids or amino acids)
-Glycogenolysis (Breakdown of glycogen into glucose)
-less respiration of glucose

59
Q

name for diabetes

A

diabetes Mellitus

60
Q

what does Type 1 diabetes cause

A

-unable to produce insulin
-B cells in the Islets of Langerhans do not produce insulin

61
Q

what does type 2 diabetes cause

A

-Cannot effectively use insulin

either because:
-B cells don’t produce enough Insulin
-person’s body cells don’t respond properly to Insulin

62
Q

when is type 1 diabetes usually developed, why

A

in childhood

possibly due to autoimmune response where white blood cells attack Beta cells

possibly a genetic link

63
Q

Treatment of type one diabetes

A

-regular insulin injections
-test blood glucose levels (hyperglycemia = high blood sugar vs hypo)
-

64
Q

where did and now where do we get insulin to treat diabetes

A

-From pigs and cows

-Now from GM bacteria

65
Q

Cures for type 1 diabetes [Potential]

A

-pancreas transplant
-Injected totipotent stem cells, stimulated to create B cells

66
Q

Explain why person with Diabetes type 2 not responding to Insulin

A

-usually glycoprotein insulin receptor on cell membrane not working properly
=Cells lose responsiveness to Insulin so glucose stays in bloodstream

67
Q

Treatment for Diabetes type 2

A

-monitor diet, regulate carb and glucose levels
-Monitor exercise levels

If these don’t work:
-Metformin = usually first medicine to be perscribed,
-sulfonylureas
-Thiazolidinediones

68
Q

what do the blood insulin and blood glucose levels of a diabetic person look like ?

A

B Insulin = very low
B glucose = very High

69
Q

anticoagulant

A

medicines that help prevent blood clots.

Biology (45 decks)

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