L24. Endocrine System 2 Flashcards

(40 cards)

1
Q

What happens to the pituitary gland at 4 weeks after fertilization

A

the oral ectoderm starts to collapse

the neural ectoderm invaginates and descends towards the oral ectoderm

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

What happens to the pituitary gland at 5 weeks after fertilization

A

The neural ectoderm that starts to descend forms the neurohypophyseal pouch
The oral ectoderm forms the Rathke’s pouch

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

Identify the Neurohypophyseal bud, oral ectoderm and Rathe’s pouch on pg 6 of L 24

A

pg 6 lecture 24

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

Describe what happens to the pituitary gland at 8 weeks after fertilization

A

The neurohypophyseal bud from the neural ectoderm forms the pituitary stalk
the oral ectoderm forms the Rathke’s pouch which then ‘breaks off’ from the oral ectoderm, the remnants form a regressing hypophyseal stalk

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

Where does the anterior pituitary derive from?

A

It is derived from the oral ectoderm

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

Where does the posterior pituitary derive from ?

A

Posterior Pituitary is derived from the neural ectoderm

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

What is the sella turcica

A

orchestration of different materials ( nervous tissue, blood supply, bone, non-nervous tissue)
Sella turcica is the bone that supports the pituitary gland

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

What is the pituitary stalk interruption syndrome?

A

truncated or absent pituitary stalk ( derived from the oral ectoderm) which implies that hormone concentration associated with the anterior pituitary decreases.
- growth failure and pituitary hormone deficiencies

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

What is the pars distalis ? Where does it develop from? What does it contain

A

anterior lobe of the pituitary
derived from the oral ectoderm
contains non-nervous tissue

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

What is the pas nervosa? Where does it develop from? What does it contain

A

posterior lobe of the pituitary
derived from the neural ectoderm
contains nervous tissue

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

How can HE be used to categorize cells

A

Can differentiate between hormone secreting and non-hormone secreting cells
marks cells that have secretory granules

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

Why do endocrine cells have secretory granules?

A

needed for hormone storage and release

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

Draw the anterior pituitary components ( pg 10 L 24)

A

pg 10 b L 24

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

What predominates in the anterior pituitary

A

cell bodies

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

What are chromophobic cells and what are their characteristics?

A

stain lightly in HE
no secretory granules
could be immature secretory cells
have a supportive function

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

What are chromophlic cells, what are their characteristics

A

stain intensely in HE
contains secretory granules
acidophilic ( means they attract acidic dyes stain red but are basic themselves)
basophilic ( means they attract basic dyes will appear blue and are acidic themselves)

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

What are gonadotropes

A

One of the unique cell type in the anterior pituitary gland

  • ruled by GnRH
  • makes FSH and LH
  • chromophilic
  • contains secretory granules
18
Q

What are folliculostellate?

A
  • support cells of gonadotropes
  • have a paracrine function
  • no secretory granules ( stains lightly: chromophobic)
19
Q

What are the limitations in HE staining?

A

cannot reflect cell phenotype or cell identity

20
Q

What is the product of somatotropes , acidophilic or basophilic

A

GH , acidophilic

21
Q

What is the product of lactotrope, acidophilic or basophilic

A

prolactin , acidophilic

22
Q

What is the product of thyrotropes, acidophilic or basophilic

A

TSH , basophilic

23
Q

What is the product of corticotropes, acidophilic or basophilic

A

ACTH, basophilic

24
Q

What is the product of gonadortropes, acidophilic or basophilic

A

FSH, TH , basophilic

25
Draw the posterior pituitary components ( pg 14b L 24)
pg 14b L 24
26
Describe the components in the posterior pituitary
- nerve terminals - - swellings and Herring bodies ( contains hormones) , packed with secretory granules - pituicytes - - provides physical and nutritive support - - cell body and nucleus present - - neuroglial in nature
27
Describe the components in the anterior pituitary
- predominently filled with cell bodies - has chromophils - has chromophobs
28
Which of anterior / posterior sections would look like there are more cells
anterior portion
29
What is the function of the intermediate lobe of the pituitary
-secretes melanocyte-stimulating hormones which changes the skin colour
30
What are the 2 hormones released by the thyroid gland
- thyroid hormone | - calcitonin
31
What is the pathway for thyroid hormone production
- hypothalamus cells secrete the 1 hormone ( Thyroid releasing hormone in the paraventricular neuron) - the neuron travels down the hypophyseal artery and the TSH (thyroid stimulating hormone ) is secreted in teh anterior pituitary gland which enters the hypophyseal vein - the follicular cells in the thyroid upon receiving 2 hormone (TSH) releases the thyroid horone
32
What is the pathway for calcitonin hormone secretion
- elevated Ca2+ level in blood | - stimulates parafollicular cells to secrete calcitonin
33
Describe the relation between the follicular cell and paracfollicular cell
* act as separate units* - follicular unit: contains follicular cell and synthesizes TH , responds to TSH from anterior pituitary - parafollicular unit: contains chromophilic, synthesizes calcitonin, responds to changes in blood calcium
34
Describe calcitonin
- made by parafollicular cells - 32 amino acid , linear polypeptide - release is stimulated by increase in circulating Ca2+ levels - inhibits Ca2+ action ( osteoclasts inhibited?)
35
What are the 2 cell types in the parathyroid gland
1. chief cells | 2. oxyphil cells
36
Describe the chief cells in the parathyroid gland
- dense cytoplasm - has secretory granules, chromophilic - secretes parathyroid hormones
37
Describe the oxyphil cells in the parathyroid gland
- could be inactive chief cells - clear cytoplasm - chromophobic
38
Describe the parathyroid hormones
- 84 amino acid polypeptide - secretion is stimulated by decreases in the blood calcium levels - enhances Ca2+ release in the bone, absorption in intestines and reabsorption in the kidneys
39
Describe the parathyroid gland
- 4 glands within the posterior part of the thyroid - regulation is independent of the thyroid - chief cells regulate PTH secretion
40
Describe the role of parathyroid and calcitonin in calcium homeostasis
- PTH increases the calcium levels | - calcitonin decreases the level of calcium