Brainscape's Knowledge GenomeTM

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


See full index

HUBS191 > lecture 25 > Flashcards

lecture 25 Flashcards

1
Q

What is synaptic communication?

A

Action potentials in axons and neurotransmitter release at synapse- it is the fastest transmission speed to minimise response delays and good for brief responses

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

What is endocrine communication?

A

Hormones released into the blood- relatively slow but long lasting action and is good for widespread and sustained responses

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

What does the endocrine system consist of?

A

Endocrine glands cells, that secretes hormones, then carried into the blood stream and the hormones act on the target cells.

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

What are the major endocrine glands?

A

Hypothalamus, pineal gland, parathyroid glands, pituitary gland, thyroid gland, adrenal glands and pancreas

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

What is a paracrine system?

A

Chemicals released such as paracrine through extracellular fluid, and it is primarily limited to the local area, where paracrine

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

What is an

autocrine system?

A

It transmission through extracellular fluid which releases a chemical signal called autocrines and is limited to the cell that secretes the chemical signal

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

What is a true hormone?

A

They are chemical messengers produced in one location and transported via the bloodstream to a second location (target cells) where they cause a response in those cells.

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

What is the endocrine system?

A

It transmits through the bloodstream and sends chemical signals called hormones that target cells are mainly in other distant tissues and organs and must have appropriate receptors.

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

Can hormones affect all cells?

A

No they can only affect cells with that specific receptor

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

What are the cell receptors made out of?

A

Proteins

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

Where can you find the receptors?

A

In or outside the cell.

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

What is the most common hormone?

A

75% of hormones are peptides ( chains of amino acids)

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

How does a peptide travel around the body?

A

Travels in the blood by dissolving in

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

Are peptide hormones stored or released straight away?

A

Stored and released when required through exocytosis

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

Are peptide hormones lipid soluble or water soluble?

A

Water soluble

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

What are the two most important water-soluble hormones?

A

Adrenaline and noradrenaline

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

What hormones are lipid-soluble?

A

Steroids and thyroid hormones

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

Can you store steroid and thyroid hormones?

A

You cannot store steroids as they are released straight away and thyroid hormones are made and stored until required

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

Where are steroids and thyroid hormones made?

A

Steroids are made from cholesterol and thyroid hormones are made in the thyroid.

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

How do lipid soluble hormones travel around?

A

They travel in the blood, bound to a carrier protein.

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

Can water soluble hormones cross the cell membrane?

A

No

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

If the hormone cannot travel throughout the cell where does the receptor lie?

A

On the outside of the cell, so in the plasma membrane

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

Can lipid soluble hormones cross the cell membrane?

A

Yes

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

If the hormone can travel through the cell where does the receptor lie?

A

The receptors are found in the cytoplasm and a nucleus

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

What does hormone binding allow activation of?

A

G-protein!

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

What does G-protein activate/inhibits?

A

It inhibits/activates adenylyl cyclase or increases intracellular Ca2+

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

Describe the steps that lipid-soluble hormone has to go through to activate in the cell

A
  1. Dissociates from carrier protein
  2. the hormone then diffuses across the cell membrane
  3. Hormone must then bind to the intracellular receptor
  4. Hormone-receptor complex acts as a specific transcription factor
  5. Target gene is activated
  6. New mRNA is generated
  7. New protein is generated by translation of mRNA
  8. New protein mediates cell specific response (SLOW PROCESS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where are the receptors found for a water-soluble hormone?

A

On the cell surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where are the receptors for a lipid-soluble hormone found?

A

Intracellular receptors in cytoplasm or nucleus

30
Q

What is the mechanism of action in a lipid-soluble hormone?

A

By altering gene transcription

31
Q

What is the mechanism of action in a water-soluble hormone?

A

Through 2nd messengers

32
Q

What is the speed of response for a lipid-soluble hormone

A

Hours to days

33
Q

What is the speed of response for a water-soluble hormone

A

Milliseconds to minutes

34
Q

What does the amount of hormone in blood depend on?

A

Rate of hormone secretion and rate of removal from blood.

35
Q

How is removal of hormones controlled?

A

Removal is controlled by enzymes in blood or in target cells

36
Q

How is secretion controlled?

A

Secretion is controlled by negative feedback loops USUALLY, NOT ALL THE TIME

37
Q

How does negative feedback occur?

A
  • It occurs in a System and is detected by a receptor/sensor recognised by a control centre.
  • A mechanism is activated to bring the variable back to the set point, the change then occurs in the effectors.
38
Q

How does positive feedback occur?

A

When you have an outcome you need to complete such as child birth because you need the baby to come out.

39
Q

What is the overall goal of hormones?

A

To maintain homeostasis

40
Q

What happens if you have too much or too little of hormone? levels

A

Can lead to endocrine disorders

41
Q

What is homeostasis?

A

The presence of a stable internal environment.

42
Q

What is the feedback loop? describe it

A

Receptors detect change, control centre compares to set point and signals, effectors are the organs or tissues, they respond with various effects: localised or effects throughout the body then it is restored to homeostasis.

43
Q

Can the receptor and control centre be the same organ/ tissue?

A

Yes

44
Q

Is the pancreas an exocrine or endocrine gland?

A

It is both

45
Q

What does the exocrine gland secrete?

A

Cells of the pancreatic acini secrete digestive enzymes

46
Q

What does the endocrine gland do?

A

Endocrine gland has two types of cells: beta and alpha and also has pancreatic islets

47
Q

What does alpha cells secrete?

A

They secrete glucagon

48
Q

What does beta cells secrete?

A

They secrete insulin

49
Q

Why must our blood glucose concentration be maintained?

A

If it gets too high for too long you get diabetes and if it gets too low for too long you get hypoglycaemia.

50
Q

What is the only fuel source the brain uses?

A

The brain only uses glucose

51
Q

What are the two metabolic states?

A

Fed state and fasting state

52
Q

What is the fed state?

A

Cellular uptake of nutrients and anabolic metabolism

53
Q

What is the fasting state?

A

Mobilisation of nutrients and catabolic metabolism

54
Q

How is blood glucose concentration regulated?

A

Hormonal regulation

55
Q

What hormones maintain blood glucose?

A

Glucagon and insulin between 70-100 Dl-1 concentration

56
Q

What are the target cells when the beta cell releases insulin?

A

Muscles and adipose cells, they increase their uptake in glucose and in liver cells glucose output stops and the net glucose uptake increases

57
Q

What occurs when the glucose uptake in liver cells, muscles and adipose cells increases?

A

The overall blood glucose concentration decreases.

58
Q

Insulin is the only hormone to decrease blood glucose concentration. True or false?

A

True

59
Q

Do the target cells for insulin have membrane or internal receptors?

A

Membrane receptors

60
Q

What does glucagon do?

A

Increases fuel release

61
Q

Describe the effects of the glucagon hormone

A

A decrease in glucose concentration causes pancreatic islet alpha cells secrete glucagon, the target cells are liver cells- which increases the breakdown of glycogen, glucose synthesis and ketone synthesis therefore increases blood glucose concentration and blood ketones concentration.

62
Q

What is it called when the liver cell increases its breakdown of glycogen?

A

Glycogenolysis

63
Q

What is it called when the liver increases its glucose synthesis?

A

Gluconeogenesis

64
Q

what other hormones can increase blood glucose?

A

Growth hormone, adrenaline and cortisol.

65
Q

What type of feedback is glucagon?

A

Negative feedback

66
Q

Where is the receptor found for the glucagon hormone?

A

Membrane receptors

67
Q

What is hypo-secretion?

A

too little hormone

68
Q

What is hypersecretion

A

Too much hormone

69
Q

What is hyposensitive?

A

Little or no response to hormone

70
Q

What is hypersensitive?

A

Responds too much to hormone

71
Q

What can problems with hormone signalling cause?

A

Autoimmunity- destruction of receptors
genetic mutation
Tumors and many other things

HUBS191 (28 decks)

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