Jackson- Endocrine System Lecture 1 Flashcards Preview

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Flashcards in Jackson- Endocrine System Lecture 1 Deck (39)
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1
Q

What are two ways in which the endocrine system communication differs from the nervous system?

A

Route of communication (blood)

Onset and duration of effects

2
Q

T/F- Hormones work because target cells express specific receptors to that hormone.

A

True

3
Q

What are the three classes of hormones?

A

Peptide/protein hormones
Steroid hormones
Amine hormones

4
Q

What is one way to increase variability in peptide hormones?

A

Glycosylation

5
Q

T/F some peptides function as both hormones and neurotransmitters?

A

True

6
Q

The preprohormones are synthesized where?

A

On the ribosomes

7
Q

How is the pro hormone formed?

A

By cleaving off extra amino acids in RER. Then it’s packaged into secretory vesicles in the Golgi

8
Q

T/F the final hormone can be made before packaging into the vesicle or after more cleavage occurs within the vesicle?

A

True

9
Q

Can hormones be stored?

A

Yes, they’re stored in vesicles so that they’re available for rapid release

10
Q

What are the glandular/major sources of steroid hormones?

A

Gonads, adrenal cortex and placenta

11
Q

All steroid hormones come from the precursor molecule _______.

A

Cholesterol

12
Q

What determines which steroid hormone is produced?

A

Enzymes

13
Q

T/F Some cholesterol is produced by de novo synthesis?

A

True

14
Q

T/F all cells have the capacity to synthesize cholesterol

A

True

15
Q

Most of the cholesterol used for synthesis of steroid hormones is derived from what?

A

Low density lipoproteins (LDLs)

16
Q

What releases cholesterol from its stores?

A

Cholesterol esterase

17
Q

After cholesterol is released from its stores, it needs to be transferred to the mitochondria so it can be made into a steroid hormone. What facilitates the transport?

A

Steroid acute regulator protein (StAR) helps cholesterol cross both the outer and inner membranes

18
Q

Cholesterol is converted to steroid by which enzymes and where does this happen?

A

Converted by P450 enzymes in the mitochondria

19
Q

Amine hormones are all derived from which amino acid?

A

Tyrosine

20
Q

T/F amine hormones have limited but important effects?

A

False. widespread and important effects

21
Q

Thyroid hormones (triiodothyronine and thyroxine) are produced by iodination of tyrosine at one or two carbons

A

Truth

22
Q

Where are catecholamines synthesized?

A

The adrenal medulla and hypothalamus

23
Q

What are the three catecholamines?

A

Norepinephrine
Epinephrine
Dopamine

24
Q

What three things can control patterns of hormone secretion?

A
  1. Plasma concentrations of a nutrient
  2. Neural control
  3. Hormonal control
25
Q

What type of hormones readily dissolve in plasma?

A

Hydrophilic

26
Q

T/F- Lipophilic hormones require carrier or binding proteins to increase their solubility in the blood plasma

A

True

27
Q

If a hormone is circulating in the blood, how is it inactivated so that its response is cut off?

A

The liver and kidneys are important for metabolism and excretion of hormones. They contain enzymes that break down or inactive a hormone by hydrolysis or sulfation

28
Q

T/F binding hormones do not protect lipophilic hormones from circulating blood enzymes?

A

False. They most definitely do.

29
Q

For peptides and catecholamines, what is their mechanism of action when a hormone binds to a receptor?

A

Because both of these are hydrophilic, the receptors are on the cell surface or in the plasma membrane.
Receptor activatio ntrigegers a signal transduction pathway that facilitates a response within the cell to an extracellular signal.
Inotropic responses open ion channels
Metabotropic response alter cell activity
Rapid and delayed responses are possible

30
Q

For steroid and thyroid hormones, what is their mechanism of action?

A

The receptors are intracellular and/or nuclear. A receptor/ligand forms a DNA binding protein which regulates transcription. Responses like this are delayed ones because transcription and protein synthesis takes time.
Some membrane receptors for steroid hormons control rapid, non-genomic processe as well.

31
Q

What are the two main components of central control for endocrine function?

A

Hypothalamus and pituitary gland

32
Q

The anterior pituitary gland develops from where?

A

an out pocketing of the oral ectoderm that pinches off from the roof of the mouth

33
Q

The posterior pituitary gland develops from where?

A

It buds off the floor of the hypothalamus

34
Q

Which two hormones are released from the posterior pituitary? Are they made there? Where are they made?

A

Oxytocin
Vasopressin
Not made in the posterior pituitary, but are made in the supraoptic and paraventricular nuclei

35
Q

What does oxytocin do?

A

Stimulates smooth muscle contraction

36
Q

What does vasopressin or ADH do?

A

Helps regulate blood pressure (ADH- anti diuretic-hormone helps you retain water)

37
Q

The anterior pituitary gland is regulated by what?

A

Hormones secreted by hypothalamic neurons

38
Q

Capillaries are at the base of the median eminence and that’s where axon terminals for hypothalamic nuclei are found. The hypothalamic hormones go into the capillaries. The hypothalamic hormones travel down to the anterior pituitary via the blood stream. Then the anterior pituitary releases the indicated hormone back into the blood supply which is then sent out into the body.

A

mmhmm.

39
Q

The anterior pituitary secretes at least 8 hormones. What are the most important 6?

A
  1. follicle stimulating hormone (FSH)
  2. luteinizing hormone (LH)
  3. growth hormone (GH) (somatotropin)
  4. thyroid stimulating hormone (TSH or thyrotropin)
  5. prolactin (PRL)
  6. adrenocorticotropic hormone (ACTH or corticotropin)