Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Metabolism > Endocrinology > Flashcards

Endocrinology Flashcards

0
Q

What are the two main forms of communication for a control system?

A
  • Hormones

- Nervous system

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

What are the 4 features of a control system?

A
  • Communication
  • Control centre
  • Receptor
  • Effector
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two pathways within a control system?

A
  • Afferent (receptor-> control)

- Efferent (control-> effector

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

What is the result of negative feedback?

A

-The response opposes the stimulus

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

What is the result for positive feedback?

A

-The response enhances the effect, often leading to major changes

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

Give two examples of positive feedback

A
  • Labour

- Ovulation

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

What is a circadian rhythm?

A

-Levels higher on a morning and low on an evening

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

How is melatonin released controlled?

A
  • Light/dark cycle

- Light to the retina inhibits melatonin production

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

The menstrual cycle is an example of a…

A

-Biological rhythm

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

What controls biological rhythms?

A

-Superchiasmatic nucleus in the hypothalamus

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

Define hormone

A

-Chemical signals produced in endocrine glands or tissues that travel in the bloodstream to cause an effect on other tissues

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

What are the 4 general categories of hormones?

A
  • Peptide
  • Glycoprotein
  • a’a derivatives
  • Steroid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give an example of a peptide hormone

A
  • GH
  • Insulin
  • Thyrotropin releasing hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Give an example of glycprotein hormones

A
  • LH
  • TSH
  • FSH
  • human Chorionic Gonadotrophin (hCG)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Give an example of a’a derivative hormones

A
  • Tyrosine-> adrenaline and T3+T4

- Histidine-> Histamine

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

What are the 3 classes of steroid hormones?

A
  • Glucocorticoids
  • Mineralocorticoids
  • Sex hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are steroid hormones derived from?

A

-Cholesterol

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

Which classes of hormones are water-soluble?

A

-Peptide and some a’a derivatives

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

Which hormones are lipid soluble?

A
  • Steroid hormones

- Thyroid hormones

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

How are water-soluble proteins transported?

A

-Dissolved in the blood at low concentrations

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

How are lipid-soluble hormones transported?

A

-Bound to a protein carrier in the blood

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

What effects do protein carriers have on hormones?

A
  • Increase solubility
  • Increase half-life
  • Act as a readily available reserve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What proteins bind to steroid and thyroid hormones for transport?

A
  • Steroid-> steroid binding globulin

- Thyroid-> thyroxine binding globulin

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

Which is the biologically active form of hormone bound or unbound?

A

-Unbound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Is there an equilibrium between bound and unbound forms of hormone?
-Yes
25
Describe the action of water-soluble hormones
- Travel in the bloodstream to target tissue - Bind with receptor - Activates a second messenger, causing a signal cascade within the cell - Biological response generated
26
What does the magnitude of a response to hormone binding depend on?
- The conc of hormone present at active tissue - Receptor number - Receptor affinity for substrate - Degree of signal amplification
27
How do lipid-soluble hormones (ie, steroids) cause a response?
-Cross pm -Bind to receptor, bound to a hsp for stability, located in cytosol -Receptor:hormone complex translocated to the nucleus OR -Hormone passes into nucleus and binds to a nucleus-located receptor -Receptor:hormone complex binds to DNA, either increasing/decreasing transcription -Thus controlling protein synthesis
28
What is the general structure of a feedback system?
- Hypothalmus releases releasing factors into hypothalamic pituitary axis portal - Anterior pituitary produces a response and releases trophic hormones into main circulation - Signal recieved by endocrone glands which release hormone - Hormone levels regulate the hypothalamic release of releasing factors and also pituitary release of trophic hormones
29
What controls negative feedback?
- Change in parameter which the hormone regulates | - Change in hormone levels itself or a hormone which regulates it
30
What type of gland is the pancreas?
-Both endocrine and exocrine
31
Which part of the pancreas is endocrine?
-The islets of langerhans which are scattered throughout the pancreas
32
What type of cells are in the islets of langerhans and what do they secrete?
- a-glucagon | - b-insulin
33
How do the cells in the islets of langerhans store their hormones?
-Intracellularly in membrane bound vesicles (storage granules)
34
How many storage vesicles can each cell contain?
-Upto 13000
35
How are b-cells adapted to insulin synthesis?
- Extensive rough endoplasmic reticulum - Well define golgi apparatus - Many mitochondria
36
What is the structure of insulin?
-Two polypeptide chains covalently linked by 3 DSB
37
What is insulin synthesised as?
-Preproinsulin
38
What is the "pre" part of immature insulin?
-A signal peptide which ensures the newly synthesised protein enters the cisternal space of the ER
39
When is the signal peptide of preproinsulin cleaved?
-Once preproinsulin has entered the ER
40
What happens to proinsulin once in the ER?
-Folds to ensure correct DSB formation
41
What happens to proinsulin once it has folded?
-Transported to the trans golgi
42
How is proinsulin packaged in the trans golgi?
-Into secretory vesicles
43
What happens to proinsulin once it has been packaged into secretory vesicles?
-Protelysis removing C peptide, creating two peptides held together by DSB, i.e. mature insulin
44
What can C peptide be used for?
-A marker for endogenous insulin production as it will be in equimolar amounts to insulin
45
How is insulin secreted?
-Through the regulatory secretory pathway
46
How is insulin transported around the body?
-As free hormone in plasma
47
What are the major target tissue for insulin?
- Liver - Skeletal Muscle - Adipose tissue
48
In what form is glucagon synthesised?
-Preproglucagon
49
How is mature glucagon formed?
-Post-translational modification
50
What happens when glucagon binds to receptor?
-Lacks DSB so has flexible 3D structure that takes up active conformation upon binding to receptor on target surface
51
Which substrate metabolism does insulin have an effect on?
- Carbohydrate - Lipid - Amino acid
52
Is insulin anabolic or catabolic?
-Largely anabolic
53
How are changes brought about in response to high insulin concentration in the circulation?
-Rapid response using pre-existing proteins (enzymes and transporters)
54
What effects does insulin have on glucose transport?
-Increases uptake into adipose tissue and skeletal muscle
55
What effect does insulin have on glycogen metabolism?
-Increases glycogenesis and decreases glycogenolysis in adipose tissue and skeletal muscle
56
What effect does insulin have on gluconeogenesis?
-Inhibits gluconeogenesis in the liver
57
What effect does insulin have on glycolysis?
-Increases glycolysis in the liver and skeletal muscle
58
What effect does insulin have on lipolysis?
-Decreases lipolysis in adipose tissue
59
What effect does insulin have on ketogenesis?
-Decreases ketogenesis in the liver through inhibiting lyase and activating HMG-CoA reductase so cholesterol is produced instead
60
What effect does insulin have on lipoprotein lipase activity?
-Increases
61
What effect does insulin have on protein synthesis?
-Increases a'a uptake and protein synthesis in the liver, skeletal muscle and adipose tissue
62
What effect does insulin have on proteolysis?
-Decreases proteolysis in the liver, skeletal muscle and adipose tissue
63
What controls insulin secretion?
-Levels of metabolites in the blood (glucose,FAs, a'a), levels of GI tract hormones (gastrin, secretin) and neurotransmitters (noradrenaline and acetylcholine)
64
What effect does adrenaline have on insulin?
-Decreases secretion
65
What effect does glucagon have on glycogenolysis?
-Increases in liver and skeletal muscle
66
What effect does glucagon have on glycogenesis?
-Decreases in the liver
67
What effect does glucagon have on gluconeogenesis?
-Increases in the liver
68
What effect does glucagon have on ketogenesis?
-Increases in the liver
69
What effect does glucagon have on lipolysis?
-Increases in the liver, skeletal muscle and adipose tissue
70
What is the major factor which stimulates glucagon secretion?
-Low glucose concentrations in the blood

Metabolism (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions