Endocrine Histology and Embryology Flashcards Preview

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Flashcards in Endocrine Histology and Embryology Deck (82):
1

What is the primary function of the endocrine system

aid in establishment and maintenance of homeostasis

2

What is the main difference between endocine and exocrine glands

endocrine glands release their products directly into the bloodstream (ductless Glands), Exocrine glands release their products through ducts to an external environment (duct glands)

3

What are endocrine cells called

??

4

What is the chemical signal of the endocrine system

hormones

5

what determines cell response with the endocrine system

??

6

How fast is the speed of onset of the endocrine system

??

7

What is the duration of action of the endocrine system

??

8

What are the 9 main endocrine glands of the endocrine system

Pituitary (anterior and posterior)
Hypothalamus
Pineal
Thyroid
Parathyroid
Thymus
Adrenal glands
pancreatic islets
ovaries/testes

9

What is a hormone

a long distance chemical mediator produced by an endocrine gland, released into the bloodstream and transported to its target cells where it interacts with specific cells and affects cell function

10

What are the three main types of hormones

protein/peptide hormones
steroids (cholesterol based)
Eicosanoids

11

Where is the hypothalamus located, what is it made of, and what does it secrete

it is located at the base of the brian
it is made of brain tissue
It secretes ADH (anti-diuretic hormone) and Oxytocin
as well as hypothalamic-releasing and inhibiting hormones

12

What part of the brain in development develops into the hypothalamus, pituitary, and pineal gland

the Diencephalon

13

What cells of the hypothalamus secrete ADH and Oxytocin, and what happens to them once they are secreted

the neurosecretory cells secrete ADH and Oxytocin, once they are secreted they go to the posterior pituitary for storage, until they are released into the bloodstream

14

What is another name for the hypophysis

pituitary gland

15

where is the pituitary gland found

at the base of the hypothalamus

16

what are the two parts of the pituitary gland

the anterior and posterior pituitary

17

what tissue is the anterior pituitary made of

glandular epithelium

18

what tissue is the posterior pituitary made of

neural tissue

19

What are the steps in development of the pituitary gland

1. infundibulum extends from the diencephalon toward the stomodeum
2. Rathke's pouch evaginates up from the stomodeum up towards the infundibulum
3. Rathke's pouch loses connection with the stomodeum, and lies anteriorly to the infundibulum
4. Rathke's pouch develops into adenhypophysis
5. infundibulum develops into neurohypophysis

20

What are the three parts of the adenohypophysis

anterior lobe (pars distalis)
pars tuberalis (surrounds infundibulum)
Pars intermedia (cells that form between ant. and post. pituitary)

21

What are the three parts of the neurohypophysis

pars nervosa (posterior lobe)
pituitary stalk
infundibuluar recess

22

what is found in the pars nervosa

lots of non-myelinated axons and nerve endings

23

what are herring bodies

where the non-myelinated axons in the pars nervosa terminate

24

what is found in the infundibulum

nerve tracts from the hypothalamus to the pars nervosa

25

Where does the hypothalamus release its hormones

into the interstitial fluid of the median eminence

26

what kind of capillaries are found in the median eminence of the pituitary gland

fenestrated

27

what is the blood vessel system like in the pituitary gland

it is a portal system
there is a superior hypophyseal artery which enters the pituitary at the median eminence, where it picks up the hypothalamic hormones and takes them to the anterior pituitary through portal vessels.
there is an inferior hypophyseal artery which enters the posteior pituitary, picks up those hormones.
all the vessels leave as hypophyseal veins

28

which neurons of the hypothalamus send their hormones to the anterior pituitary, via the superior hypophyseal artery, after releasing them to the median eminence

neurosecretory neurons

29

which neurons of the hypothalamus send their hormones to the posterior pituitary

the supraoptic nuclei, and the paraventricular nuclei

30

What are the three ways in which the hypothalamus regulates the body

direct control by nervous system
direct release of hormones
indirect release of hormones

31

what body tissues does the hypothalamus directly control by the nervous system

the adrenal medulla, which secretes epinephrine and norepinephrine

32

what body tissues does the hypothalamus directly control by hormones

the posterior pituitary, which secretes ADH (kidneys) and Oxytocin (prostate and uterine smooth muscle and mammary glands)

33

what body tissues does the hypothalamus indirectly control through hormones

the anterior pituitary, the hypothalamus tells it to secrete its hormones

34

what are the 7 hormones of the anterior pituitary

ACTH (adrenal corticotropic hormone)
TSH (thyroid stimulating hormone)
GH (growth hormone)
PRL (prolactin)
FSH (follicle stimulating hormone)
LH (leutinizing hormone)
MSH (melanocyte stimulating hormone)

35

what is the action of ACTH

it causes the adrenal cortex to secrete glucocorticoids

36

what is the action of TSH

it causes the thyroid to secrete thyroid hormones

37

what is the action of GH

it causes the liver to secrete somatomedins, which affect bone, muscle and other tissues

38

what is the action of PRL

it causes milk production from the mammary glands

39

what is the action of FSH and LH

they cause the testes to produce inhibin and testosterone
they cause the ovaries to produce estrogen, progesterone, and inhibin

40

what is the action of MSH

it goes to the melanocytes, action is uncertain

41

what are the three disorders of GH

hyposecretion = pituitary dwarfism
hypersecretion before growth plates fuse = gigantism
hypersecretion after growth plates fuse = acromegaly

42

What are the pharyngeal arches, pouches, and grooves derived from

arches = mesoderm
pouches = endoderm
grooves = ectoderm

43

how many pairs of pharyngeal pouch pairs are there

4 (the 5th goes away)

44

What develops from the 1st pharyngeal pouch

the tympanic cavity and pharyngotympanic tube

45

what develops from the 2nd pharyngeal pouch

the palatine tonsil

46

what develops from the 3rd pharyngeal pouch

the inferior parathyroid and they thymus

47

what develops from the 4th pharyngeal pouch

the superior parathyroid and the ultimopharyngeal body

48

what is the fate of the ultimopharyngeal body, and what does it secrete

it becomes the parafollicular cells (C-cells), and they secrete calcitonin

49

what is the function of calcitonin

decreases blood calcium (opposition to the parathyroid hormone)

50

What are the steps in the development of the thyroid gland

1. thyroid primordium forms at the foramen cecum
2. thyroid primordium moves down the thyroglossal duct
3. thyroglossal duct dissapears
4. two thyroid lobes connect via an isthmus
5. thyroid descends to inferior of the cricoid cartilage

51

what forms if the thyroglossal duct persists

a thyroglossal cyst or sinus

52

What stimulates the thyroid to secrete its hormones, what are its hormones

thyroid stimulating hormone stimulates the thyroid to secrete Calcitonin, Triiodothyronine(T3), and thyroxin (T4)

53

What are the teo types of cells in the thyroid

follicular cells
parafollicular cells

54

what are the follicular cells and parafollicular cells like histologically

follicular cells are simple cuboidal epithelium
parafollicular cells are cuboidal

55

What are the functions of T3 and T4

increase metabolism and assist in growth and development

56

what is required for synthesis of T3 and T4

iodine

57

what causes a goiter

too little iodine

58

what are the symptoms of hypothyroidism (Myxedemia)

fatigue
weakness
weight gain
hair loss
depression
decreased libido

59

what are the symptoms of hyperthyroidism (graves disease)

palpitations
nervousness
heat intolerance
insomnia
fatigue
fast heart rate
weight loss
bulging eyes

60

what causes the secretion of cacitonin

high blood calcium levels

61

what is caused when the thyroid fails to develop properly

cretinism

62

what is the parathyroid gland

4 bean shaped glands embedded in the fascial sheath of the thyroid that secrete parathyroid hormone

63

what is the function of parathyroid hormone

causes calcium to be moved into the blood from the bones (brakes down bones)

64

What are the two divisions of the adrenal gland

the adrenal cortex (outside) and the adrenal medulla (inside)

65

what are the three layers of the adrenal cortex from superficial to deep

glomerulosa
fasciculata
reticularis

66

what does the adrenal medulla secrete

catecholectamines (epinephrine and norepineprhine)

67

Where do the medulla and cortex originate from

medulla originates from the ectoderm
cortex originates from the mesoderm

68

what are the steps in the development of the adrenal glands

1. mesothelial cells penetrate underlying mesencyhme
2. these cells differentiate into cortex
3. mesothelial cells penetrate mesenchyme again
4. these 2nd cells surround the first cells, and most of the first cells regress, except the reticularis zone
5. neural crest cells invade the medial aspect of the cortex
6. these neural crest cells invade and arrange in clumps and cords = adrenal medulla

69

what are chromaffin cells

the neural crest cells that invade the primitive cortex and form the adrenal medulla

70

what are the types of hormones (and specific hormones) secreted from the three layers of the adrenal cortex

Glomerulosa = mineralocorticoids (aldosterone)
Fasciculata = glucocorticoids (cortisol)
reticularis = sex hormones

71

what is the function of aldosterone, and what causes it to be secreted

it causes sodium reabsorption into the blood in the kidneys, which causes water retention and assists in maintaining blood pressure.
blood pressure and electolyte balance regulate it by angiotensin 2

72

what is the function of cortisol and what causes it to be secreted

it causes increase blood glucose, and decreases antibodies
it is regulated by ACTH (but caused by stress)

73

what is the function of the sex hormones from the adrenal cortex and what regulates their secretion

they supplement the sex hormones from the gonads, and they are regulated by ACTH

74

What is the disease with excessive ACTH

cushing syndrome
- hyperglycemia and glucosuria
- fat in the face, mid section, and above the shoulders
- muscle tissue breakdown

75

what is the disease with insufficient ACTH

addison disease
- weight loss
- fatigue
- hypotension
- skin darkening

76

What are the two hormones secreted from the chromaffin cells of the adrenal medulla, what is their function, and what regulates them

epinephrine, norepinephrine (small amounts of dopamine)
they are important in fight or flight
they are regulated by the nervous system

77

What is the pancreas

an organ with endocrine and exocrine function that lies below the stomach, and is attached to the duodenum, and is 90% acinar (exocrine) cells

78

What are the steps in the development of the pancreas

1. dorsal and ventral pancreatic buds grow off of the duodenum
2. the ventral bud moves around the duodenum and joins with the dorsal bud
3. the dorsal bud makes the head, body, and tail. the ventral bud makes the ucinate process and the main pancreatic duct

79

What occurs when the ventral buds of the pancreas migrate in opposite directions around the duodenum

you have an annular pancreas, with which the duodenum will be constricted by the pancreas that has formed around it

80

most of the pancrease if composed of ductal and exocrine glands, what is the remaining part of the pancreas made of

islets

81

what are pancreatic islets? and why do they get most of the blood supply to the pancreas

the islets are where alpha, beta and delta cells are located. They get most of the blood supply to the pancreas because they are the endocrine portion of the pancreas (thus they secrete hormones into the blood)

82

What do alpha, beta, and delta pancreatic cells produce

alpha cells produce glucagon
beta cells produce insulin
delta cells produce somatostatin