Brainscape's Knowledge GenomeTM

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


See full index

HMS302 Endocrine System > Endocrine System Overview > Flashcards

Endocrine System Overview Flashcards

1
Q

Body contains 2 kinds of glands:

A
  • Exocrine glands
  • Endocrine glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Exocrine glands
(exo - outside)

A

Secrete their products into ducts that carry the secretions into body cavities, into a lumen of an organ, or to other surfaces of the body.

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

Endocrine glands
(endo - within)

A

Secrete their products (hormones) into the interstitial fluid surrounding the secretory cells rather than into the ducts.

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

Endocrine gland + Hormone secreting cells =

A

Endocrine System

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

Classical endocrine glands - definition

A

Glands that have one function, which is to synthesize & release hormones into the bloodstream.

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

Classical endocrine glands - examples

A
  • Pituitary
  • Thyroid
  • Parathyroid
  • Adrenal glands
  • Pineal glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The 2 major regulatory systems in the body

A
  • Neural system
  • Endocrine system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hormones released from nerve endings

A

Neuro-hormones

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

Similarities between Neural & Endocrine systems

A
  • Both react to stimuli
  • Both help maintain homeostasis
  • Both are systems of the body than send messages
  • Hypothalamus is a link between the 2 systems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Differences between Neural & Endocrine system

A

Nervous System
- Mediator molecules = neurotransmitters released locally in response to nerve impulses.
- Site of mediator action = localized, binds to receptors in post-synaptic membranes.
- Types of target cells = muscle cells, gland cells, & other neurons.
- Onset of action = typically within milliseconds
- Duration of action = milliseconds

Endocrine System
- Mediator molecules = hormones delivered to tissues throughout the body by the blood.
- Site of mediator action = widespread, binds to receptors on or in target cells.
- Types of target cells = cells throughout the body
- Onset of action = seconds to hours to days
- Duration of action = generally longer

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

Hormones like _______ influence their ______ _________ by chemically bindings to specific ___ _______.

A

Neurotransmitter, target cells, protein receptors.

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

Only the _______ cells for a given hormone have ______ that bind & recognize this hormone.

A

target, receptors

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

Target cells has _______ to _______ receptors for a particular hormone.

A

2,000 to 100,000 receptors

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

Down-regulation

A

It is when the number of receptors decreases in response to high levels of a hormone, making the target cell less sensitive to the hormone.
- decreases cellular activity

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

Up-regulation

A

It is when the number of receptors increases in response to low levels of a hormone, making the target cell more sensitive to the hormone.
- increases cellular activity

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

Most endocrine hormones are _________ hormones

A

circulating

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

Circulating hormones

A
  • Hormones that travel in the blood & act on distant target cells.
  • Endocrines
  • Inactivated by the liver & excreted by the kidneys.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Local hormones

A

Hormones that act locally (neighboring or same cells) without first entering the bloodstream.
- affect target cells close to their release site.
- Paracrine & Autocrines
- inactivated quickly

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

In cases of liver & kidney failure, hormones may?

A

Build up in the blood

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

Paracrine
(Para = beside or near)

A

Hormones that act on neighboring cells

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

Autocrine
(Auto = self)

A

Hormones that act on the same cell that secreted them.

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

Functions of hormones

A

(1) Help regulated:
- chemical composition & interstitial fluid
- metabolism & energy balance
- contraction of smooth & cardiac muscle fibers
- glandular secretions
- some immune system activities
(2) Control growth & development
(3) Regulate the operation of reproductive systems
(4) Help establish circadian rhythms.

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

2 types of chemical classes of hormones

A
  1. Lipid-soluble hormones
  2. Water-soluble hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Lipid-soluble hormones

A
  • steroid hormones
  • thyroid hormones
  • nitric oxide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Water-soluble hormones

A
  • amine hormones
  • peptide hormones
  • protein hormones
  • eicosanoid hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Steroid hormones

A
  • derived from cholesterol
  • each steroid hormone is unique due to the presence of different chemical groups attached at various sites on the 4 rings at the core of it’s structure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Thyroid hormones

A
  • T3 & T4
  • the presence of the 2 benzene rings makes these molecules very lipid soluble.
28
Q

Nitric Oxide (NO)

A
  • both a hormone & neurotransmitter
  • produced by endothelial cells that lines blood vessels & causes vasodilation.
29
Q

Amine hormones

A
  • called amines because they retain an amino group (-NH3+).
30
Q

Peptide & Protein Hormones

A
  • amino acid polymers
  • smaller peptide hormones consist of chains of 3 - 49 amino acids.
  • larger protein hormones include 50 - 200 amino acids.
31
Q

Eicosanoid hormones

A
  • Eicos = 20 forms oid = resembling
  • derived from arachidonic acid (20-carbon fatty acid).
  • circulating & local hormones
  • 2 major kinds:
    1. Prostaglandins (PGs)
    2. Leukotrienes (LTs)
32
Q

Hormone transport in the blood

A
  • Water-soluble hormones = circulate in the watery blood plasma in a free form.
  • most Lipid-soluble hormones = are bound to transport proteins.
33
Q

Transport proteins are synthesized by?

A

cells in the liver

34
Q

Transport proteins have 3 functions:

A
  1. They make lipid-soluble hormones temporarily water-soluble, thus increasing their solubility in blood.
  2. They delay the passage of small hormone molecules through the filtering mechanism in the kidneys —— this slows down the rate of hormone loss in the urine.
  3. They provide a ready reserve of hormones, already present in the bloodstream.
35
Q

___________ of the molecules of a lipid-soluble hormone aren’t bound to a transport protein.

A

0.1 - 10%

36
Q

What happens to the free fraction (0.1 - 10%) of a lipid-soluble hormone?

A

It diffuses out of capillaries, binds to receptors, & triggers responses.
- afterwards, transport proteins release new ones to replenish (fill) the free fraction.

37
Q

Why are steroids & thyroid hormones effective when taken by mouth?

A

This is because they aren’t split apart during digestion & they easily cross the intestinal lining.

38
Q

Why are peptide & protein hormones not effective when taken orally?

A

This is because digestive enzymes will destroy them by breaking their peptide bonds. Instead they are taken by injection.

39
Q

The response to a hormone depends on both the _________ itself & the _______ cell.

A

hormone, target

40
Q

Hormonal effects (4)

A
  • Changes the permeability of the plasma membrane
  • Stimulates the transport of a substance into or out of the target cells
  • Alters the rate of specific metabolic reactions.
  • Causes contraction of smooth muscle or cardiac muscle.
41
Q

Receptors for lipid-soluble hormones

A

inside target cells

42
Q

Receptors for water-soluble hormones

A

outside the target cells = part of the plasma membrane of target cells

43
Q

Action of lipid-soluble hormone (4)
- 1st

A

(1) A free lipid-soluble hormone molecule diffuses from the blood, through the lipid bilayer of the plasma membrane into a cell.

44
Q

Action of lipid-soluble hormone (4)
- 2nd

A

(2) If the cell is a target cell, the hormone binds to & activates receptors located within the cytosol or nucleus. The activated receptor-hormone complex then alters gene expression = which turns specific genes of the nuclear DNA on or off.

45
Q

Action of lipid-soluble hormone (4)
- 3rd

A

As the DNA is transcribed, new mRNA forms, leaves the nucleus, & enters the cytosol. There it directs synthesis of a new protein, often an enzyme, on the ribosome.

46
Q

Action of lipid-soluble hormone (4)
- 4th

A

The new proteins alter the cell’s activity & causes the responses typical of that hormone.

47
Q

Action of water-soluble hormones (6)
- 1st

A

(1) Binding of hormone (1st messenger) to its receptor (outside the cell) activates G protein, which activates adenylate cyclase.

48
Q

Action of water-soluble hormones (6)
- 2nd

A

(2) Activated adenylate cyclase converts ATP to cAMP.

49
Q

Action of water-soluble hormones (6)
- 3rd

A

(3) cAMP serves as a 2nd messenger to activate protein kinases.

50
Q

Action of water-soluble hormones (6)
- 4th

A

(4) Activated protein kinases phosphorylate cellular proteins.

51
Q

Action of water-soluble hormones (6)
- 5th

A

Millions of phosphorylated proteins cause reactions that produce physiological responses.

52
Q

Action of water-soluble hormones (6)
- 6th

A

Phosphodiesterase inactivates cAMP

53
Q

Protein Kinases

A

Are intracellular enzymes that:
- regulate cell growth & proliferation
- triggering & regulating immune responses.

54
Q

Protein kinases are important therapeutic targets in cancer because?

A

Of their critical role in signaling mechanisms that drive malignant cell characteristics.

55
Q

Explain the statement - different protein kinases exist within different target cells & within different organelles of the same target cell.

A

Meaning - 1 protein kinase might trigger glycogen synthesis, a 2nd might cause the breakdown of triglyceride, & a 3rd may promote protein synthesis, & so forth.

56
Q

Examples of second messengers

A
  • Calcium ions (Ca2+)
  • CGMP = cyclic guanosine monophosphate
  • IP3 = inositol triphosphate
  • DAG = diacylglycerol
57
Q

Hormones that bind to plasma membrane receptors can?
Give an example

A

induce their effects at very low concentrations, & initiate a cascade or chain reaction where each step amplifies the initial effect.

Example = the binding of a single molecule of epinephrine to its receptor on a liver cell may activate a hundred or so G proteins, each of which activates an adenylate cyclase molecule.

58
Q

The responsiveness of a target cell to a hormone depends on:
(3)

A
  • the hormone’s concentration in the blood
  • abundance of the target cell’s hormone receptors.
  • influences exerted by other hormones
59
Q

A target cell responds more vigorously when:
(3)

A
  • level of a hormone rises
  • has more receptors (up-regulation)
  • simultaneous or recent exposure to a 2nd hormone.
60
Q

Permissive effect
- define & example

A
  • The presence of one hormone is required in order for another hormone to exert its full effects on a target cell. (increases the # of receptors for the other hormone)
  • e.g. epinephrine alone only weakly stimulates lipolysis but when small amounts of thyroid hormones are present, the same amount of epinephrine stimulates lipolysis much more powerfully.
61
Q

Synergistic effect
- define & example

A

When the effect of 2 hormones acting together is greater than the effect of each hormone acting alone.
- e.g. normal development of oocytes in the ovaries requires both FSH (from the anterior pituitary) & estrogens (from the ovaries). Neither hormone alone is sufficient.

62
Q

Antagonistic effect
- define & example

A

When one hormone opposes the actions of another hormone.
- e.g. insulin & glucagon
- insulin = promotes synthesis of glycogen by liver cells.
- glucagon = stimulates breakdown of glycogen in the liver.

63
Q

The release of most hormones occurs in _____ ____ with _____ or _____ secretion between ______.

A

short bursts, little, no, bursts.

64
Q

When stimulated, an endocrine gland will release its hormone in more _____ _____, _____ the concentration of the hormone in the blood.

A

frequent bursts, increasing

65
Q

Hormone secretion is regulated by?
(3)

A
  • signals from the nervous system
  • chemical changes in the blood
  • other hormones
66
Q

If the response reverses the stimulus, a system is operating by?

A

negative feedback

67
Q

If the response enhances or intensifies the stimulus, a system is operating by?

A

positive feedback

HMS302 Endocrine System (14 decks)

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