Brainscape's Knowledge GenomeTM

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


See full index

Histology 2 > Endocrine System > Flashcards

Endocrine System Flashcards

1
Q

What are the functions of the endocrine system?

A
  1. Maintain homeostasis
  2. Stress reactions
  3. Regulate growth and development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is the secretion of endocrine hormones controlled?

A

Feedback loops

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

Define paracrine secretion.

A

Some endocrine cells produce hormones that act very quickly at only a short distance

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

What is the name for when endocrine cells may produce molecules that act on themselves or on cells of the same type?

A

Autocrine secretion

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

What is the typical structure of endocrine glands?

A

Cords of parenchymal cells closely associated with a very rich vascular supply composed of a network of fenestrated capillaries and a relatively small amount of stroma

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

List the 6 major endocrine organs.

A
  1. Pituitary
  2. Hypothalamus
  3. Thyroid
  4. Parathyroid
  5. Adrenals
  6. Pineal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Within other solid organs, there are important endocrine components. What organs contain these?

A
  1. Pancreas
  2. Ovary
  3. Testis
  4. Kidneys
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the diffuse endocrine system?

A

Scattered individual hormone cells (or clumps of cells)

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

Where are cells of the diffuse endocrine system typically found?

A

Within extensive epithelial

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

Most, but not all, endocrine tissue are of epithelial origin. Which tissues aren’t?

A
  1. Adrenal medulla
  2. Hypothalamus
  3. Posterior pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What do the glands and tissues of the endocrine system do?

A
  1. Synthesis and secretion of hormones
  2. Regulate, control and coordinate organ and tissue activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe what a hormone is.

A

Chemical messengers typically released into the blood to act at specific distance receptors

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

What are the 4 types of hormones?

A
  1. Protein and glycoprotein
  2. Small peptide
  3. Derivatives of amino acids
  4. Steroids derived from cholesterol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is the pituitary gland called the master endocrine gland?

A

Its hormones regulate physiological activities of many other endocrine glands and tissues

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

What is the morphology of the pituitary gland?

A

Size of a flat pea
500-900 mg in adults
Composed of anterior and posterior part

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

What is the name of the fossa that the pituitary gland is found in?

A

Sella turcica

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

What covers the superior aspect of the pituitary gland?

A

A thickened extension of the dura mater called the diaphragmatic sella

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

What 2 endocrine organs make up a complex neuroendocrine circuit?

A

Pituitary and hypothalamus

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

What 2 parts of a developing embryo does the pituitary gland develop from?

A

Oral ectoderm
Developing brain

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

What does the oral ectoderm form during development of the pituitary gland?

A

The hypophyseal (Rathke’s) pouch which becomes the anterior pituitary (adenohypophysis)

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

What is the neurohypophyseal bud in the development of the pituitary gland?

A

A bud from the diencephalon that becomes the posterior pituitary (neurohypophysis)

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

What is the pars nervosa of the pituitary gland?

A

Expanded portion of the posterior part that is continuous with the infundibulum

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

True or False: The infundibulum is a stalk attached to the hypothalamus above.

A

True

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

What is the name for the anterior part of the pituitary gland located around the infundibulum stem like a collar?

A

Pars tuberalis

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

What is the pars intermedia?

A

A narrow band of tissue that lies between the pars nervosa and pars distalis

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

Describe the pars distalis.

A

Part of the anterior pituitary
Contains a variety of cell types

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

Why is the staining of the pars distalis of the pituitary variable in regions?

A

The cells aren’t uniformly distributed so don’t stain evenly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What percentage of the adenohypophysis is the pars distalis?

A

75%

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

What are the 2 cell groups in the pars distalis?

A

Chromophils and chromophobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are chromophils?

A

Secretory cells in which hormones are found in cytoplasmic granules and can be further distinguished into basophils and acidophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

List examples of basophilic endocrine cells.

A

Gonadotropic: oval cells with round nuclei that secrete FSH and LH
Corticotropic: polygonal cells with round eccentric nucleus and secretes ACTH
Thyrotropic: large oval cells with round eccentric nucleus and basophilic small granules and secrete TSH

32
Q

What are mammotropic and somatotropic cells examples of?

A

Acidophilic endocrine cells

33
Q

What are the hypothalamic hormones that regulate the anterior pituitary?

A
  1. Growth hormone-releasing
  2. Somatostatin
  3. Thyrotropin-releasing
  4. Corticotropin-releasing
  5. Dopamine
  6. Gonadotropin-releasing
34
Q

What segment of the pituitary gland has colloid filled follicles?

A

Pars intermedia

35
Q

What cells are present in the neurohypophysis?

A

Pituicytes
Unmyelinated nerve fibres axons

36
Q

What are Herring bodies?

A

Swellings in the terminal portion of the axons containing basophilic, large accumulations of neurosecretory material

37
Q

What does the neurosecretory material in Herring bodies contain?

A

Aggregations of oxytocin and/or antidiuretic hormone (vasopressin)

38
Q

True or False: Axons from the supraoptic nuclei are mainly concerned with oxytocin secretion while fibres from paraventricular nuclei are concerned with vasopressin secretion.

A

False

39
Q

Describe the thyroid gland.

A

Located anterior the the larynx
Dense irregular C.T. capsule encloses the 2 lobes and the connecting isthmus
Aymmetric (right lobe twice as big as left)

40
Q

What is the thyroid gland’s function?

A

Synthesis of thyroxine and tri-iodothyronine (important for growth, cell differentiation and control of basal metabolic rate and oxygenconsumption)

41
Q

When does thyroid development begin in embryological development?

A

Fourth week

42
Q

What is the capsule of the thyroid gland derived from?

A

Cervical fascia

43
Q

Describe the contents of the thyroid’s glandular parenchyma.

A

Spherical, cyst-like follicles filed with gelatinous colloid made of thyroglobulin

44
Q

How many follicles are in the thyroid’s glandular parenchyma?

A

20-30 million

45
Q

What is the purpose of the colloid material within thyroid follicles?

A

Temporary storage form and precursor to main thyroid hormones

46
Q

What is the lining epithelium of thyroid follicles?

A

Simple cuboidal epithelium (squamous to low cuboidal = inactive while nearly columnar = active)

47
Q

Describe follicular epithelial cells.

A

Central round nucleus with prominent nucleoli
Lightly basophilic cytoplasm
Apical Surface: junctional complexes, microvilli, secretory granules, phagosomes and lysosomes, Golgi apparatus
Basal Surface: abundant RER

48
Q

What are parafollicular/C cells?

A

Individual scattered, large pale cells in the follicle basal lamina that secrete calcotonin

49
Q

What does calcotonin do?

A
  1. Lowers plasma calcium levels
  2. Inhibits bone reabsorption
  3. Antagonist to parathyroid hormone
50
Q

Describe the parathyroid glands.

A

4 small oval masses
Located on posterior of the thyroid
Fibrous capsule with septa conveying vessels
Synthesises and secretes parathyroid hormone

51
Q

What is the role of parathyroid hormone?

A

Maintains serum calcium levels

52
Q

What cells are present in the parathyroid gland parenchyma?

A

Chief/principal cells
Oxyphil cells
Adipose cells

53
Q

Describe the ultrastructure and function of chief cells.

A

Small, lightly stained cells with dark central nuclei
Secrete parathyroid hormone

54
Q

True or False: Oxyphil cells are large eosinophilic cells with abundant mitochondria.

A

True

55
Q

What happens to oxyphil cells and adipose cells with age?

A

They become more numerous

56
Q

Where are the adrenal glands located?

A

Superior pole of each kidney

57
Q

What is the adrenal gland morphology?

A

Thick, dense C.T. capsule with trabeculae
Yellow, peripheral cortex
Red-brown, central medulla

58
Q

What embryological tissues are the adrenal medulla and cortex derived from?

A

Medulla: neural crest cells
Cortex: mesoderm

59
Q

True or False: The adrenal cortex is about 10% of the gland.

A

False, the medulla is about 10%

60
Q

What are the 3 distinct zones of the adrenal cortex and their percentages?

A

Zona glomerulosa - 15%
Zona fasciculata - 80%
Zona reticularis - 5-7%

61
Q

What is the contents of each of the distinct regions in the adrenal cortex?

A

ZG: Contains columnar/pyramidal cells arranged in rounded clusters
ZF: Consists of parallel cords of secretory cells disposed at right angles to capsule
ZR: Adjacent to the medulla, consists of small closely-packed cells arranged in irregular cords

62
Q

What does zona glomerulosa secrete?

A

Mineralcorticoids and aldosterone

63
Q

Which region of the adrenal cortex secretes glucocorticoids e.g. cortisol?

A

Zona fasciculata

64
Q

What is the hormonal secretions of the zona reticularis?

A

Glucocorticoids
Androgens
Dehydroepiandrosterone (converted to testosterone)

65
Q

Describe the composition of the adrenal medulla.

A

Cords/clumps of large, pale-staining polyhedral slightly basophilic cells, supported by a reticular fibre network

66
Q

What are the products of the adrenal medullary parenchymal cells, Chromaffin cells?

A

Adrenaline and noradrenaline

67
Q

How to differentiate adrenaline vesicles from noradrenaline vesicles in Chromaffin cells?

A

Adrenaline is stored in smaller vesicles with a light/moderately dense core
Noradrenaline is stored in larger vesicles with a high density core

68
Q

What regulates the secretion of products from Chromaffin cells?

A

Preganglionic sympathetic neurons

69
Q

What organ is a mixed exocrine-endocrine gland that produces both digestive enzymes and hormones?

A

Pancreas

70
Q

What does the endocrine portion of the pancreas consist of?

A

About 1 million small, scattered islands of tissue called islets of Langerhans

71
Q

How much of the pancreas is constituted by islets of Langerhans?

A

1-2%

72
Q

Does the exocrine or endocrine portion of the pancreas stain darkly basophilic?

A

Exocrine pancreas stains dark purple while the endocrine portion stains more lightly

73
Q

Name the 4 principal cell types in the pancreatic islets.

A
  1. B cells (secrete insulin) - 70%
  2. A cells (secrete glucagon) - 20%
  3. D cells (secrete somatostatin)
  4. F/PP cells (secrete pancreatic polypeptide)
74
Q

What is the name of the cells in the testes that produces testosterone?

A

Leydig cells

75
Q

True or False: The theca externa of the ovum in the ovaries produces hormone precursors which is converted to oestrogen by granulosa cells.

A

False, theca interna produces precursors

Histology 2 (6 decks)

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