Brainscape's Knowledge GenomeTM

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


See full index

Physiology > ENDO II - Pituitary Hormones > Flashcards

ENDO II - Pituitary Hormones Flashcards

1
Q

what is the anterior pituitary gland made of

A

a true endocrine gland with endocrine cells

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

what is the posterior pituitary made of

A

axon terminals of hypothalamic neurons containing neurons and synaptic terminals

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

where is the pituitary gland located

A

in the sella turcica ventral to the diaphragma sella

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

what hormones do they anterior and posterior pituitary secrete?

A

-anterior: GH, ACTH, TSH, FSH,LH, prolactin
-posterior: ADH/vasopressin, oxytocin

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

what do adenomas cause in children and adults and what cells are involved

A

involves somatotropic cells, causes gigantism in children before closure of long bones epiphyseal plate or acromegaly in adults

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

what cells secrete GH

A

somatotrophs

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

what cells secrete ACTH

A

corticotrophs

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

what cells secrete TSH

A

thyrotrophs

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

what cells secrete LH and FSH

A

gonadotrophs

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

what cells secrete prolactin

A

mammotrophs

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

what is the order of most secreted to least secreted hormones in the anterior pituitary

A

GH > ACTH > TSH > LH AND FSH > prolactin

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

where are hypothalamic hormones released into

A

the primary capillary plexus in the median eminence

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

what do the blood vessels in the hypothalamic-hypophyseal portal carry hypothalamic hormones to

A

sinuses of the anterior pituitary gland

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

what does the hypothalamic-hypophyseal portal system connect

A

hypothalamus to anterior pituitary

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

what is the effect of TRH and what does it act on

A

activating, TSH

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

what is the effect of GnRH and what does it act on

A

activator, LH and FSH

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

what effect does CRH have and on what

A

activating, ACTH

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

what is the effect of GHIH and on what

A

inhibiting, GH

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

what is the effect of GHRH and on what

A

activating, GH

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

what is the effect of PIH and on what

A

inhibiting, Prolactin

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

what is the effect of PRH and on what

A

activating, prolactin

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

how do hypothalamic regulatory hormones signal anterior pituitary cells

A

the hormones bind to GPCRs then through generation of second messengers they either stimulate or inhibit AP hormone secretion

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

what second messengers do hypothalamus and anterior pituitary signaling

A

cAMP via adenylate cyclase and IP3 and DAG via phospholipase C

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

what does GH act on

A

target tissues and as a tropic hormone to the liver which releases IGF1

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

what is the normal concentration of GH in adults and children

A

1.6-3 ng/ml and higher in children

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

what happens to GH during starvation

A

increases

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

what does IGF1 act back on in a long negative feedback loop

A

hypothalamus and anterior pituitary

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

what does GH act back on in a short negative feedback loop

A

hypothalamus

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

what factors activate GHRH and inhibit SS

A

sleep, hypoglycemia and stress

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

what factors inhibit GHRH and stimulate SS

A

aging, disease, glucose

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

how does GH and IGF1 act in the skeleton

A

increases AA uptake, increases protein synthesis, necessary for linear growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

how does GH and IGF1 act on mucscle

A

increased protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

when is growth hormone highest and lowest

A

highest a few hours after sleep and during strenuous exercise and lowest during the day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is GH stimulated by

A

fasting (hypoglycemia), starvation (protein deficiency), stress, exercise and excitement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

when are the highest and lowest levels of GH throughout our lifetime

A

high during neonatal period but decreases in childhood, peak in puberty and then declines with age

36
Q

what hormones stimulate GH release

A

GHRH, dopamine, catecholamines, excitatory amino acids, thyroid hormone

37
Q

what hormones inhibit GH release

A

somatostatin
IGF1
high glucose
high FFA

38
Q

many of the growth and metabolic effects of GH are mainly produced by ____

A

IGFs

39
Q

how does IGF act on neighboring cells

A

in a paracrine manner

40
Q

what is the major site of IGF1 synthesis

A

liver

41
Q

what happens in osteocyte derived IGF1 in mechanotransduction between osteocytes and osteoblasts

A

osteocyte responds to mechanical sensors that releases IGF-1 which binds to the osteoblast resulting in bone formation

42
Q

what is the mechanism of action of GH and IGF1

A

-growth in nearly all tissues in the body ( increased size of cells, mitosis, and differentiation of bone and muscle cells) via IGF1. increased organ size, increased organ function, increased linear growth
-AA uptake and protein synthesis in most cells
- reduced glucose utilization- decreased uptake, increased hepatic glucose production and increased insulin secretion
- mobilization of fatty acids from adipose tissue resulting in increase in FFA in blood and use of FFA for energy

43
Q

what do GH and IGF1 do before fusion of the epiphyseal plates

A

stimulate chondrogenesis and widening of the epiphyseal plates followed by bone matrix deposition stimulating linear growth

44
Q

what do GH and IGF1 do in adults

A

regulate normal physiology of bone formation by increasing bone turnover via activation of osteoblasts and also increasing bone resorption via activation of osteoclasts

45
Q

how does GH contribute to insulin resistance

A

GH decreases uptake of glucose, increasing blood glucose, leading to insulin resistance

46
Q

what does an MRI show in acromegalic patients

A

a pituitary tumor in 90%

47
Q

what are the features of growth hormone excess in adults

A

-coarse facial features, large fleshy nose, frontal bossing, jaw malocclusion
-somatotropic adenoma of pituitary
-coronary heart disease
-barrel chest
-DM
-kyphosis
-increased size of hands and feet
- arthritis
-paresthesias
-hyperhidrosis and oily skin
- enlarged frontal sinuses and pituitary fossa

48
Q

what is the treatment for a pituitary microadenoma

A

surgical resection of the tumor via transphenoidal approach followed by medication GHIH receptor ligand or GH receptor antagonist

49
Q

what is another name for GHIH

A

somatostatin

50
Q

what are oral manifestation of GH excess

A

-thick rubbery skin, enlarged nose and thick lips
-macrocephaly
-macrognathia
- mandibular prognathism
- diastemata
- anterior open bite and malocclusion
- macroglossia, dyspnea, dysphagia, dysphonia, sialorrhea
-hypertrophy of pharyngeal and laryngeal tissues -> sleep apnea

51
Q

what are the causes of GH deficiency

A

-hypothalamic disorders
- mutations: GHRH receptor, GH gene, GH receptor, IGF1 receptor
-combined pituitary hormone deficiencies
- radiation
-psychosocial deprivation

52
Q

what are the clinical manifestations of GH deficiency

A

-slow linear growth rates
-normal skeletal proportions
-pudgy youthful appearance (decreased lipolysis)
-in the setting of cortisol deficiency -> hypoglycemia

53
Q

what do clinical manifestationf of GH deficiency depend on

A

time and onset and severity of hormone deficiency

54
Q

what is the most common form of dwarfism

A

achondroplasia

55
Q

what type of inheritence pattern in achrondroplasia

A

autosomal dominant

56
Q

what causes achondroplasia

A

a mutation of FGF3 receptor in cartilage and brain that makes the receptor overly active and inhibits cartilage growth at growth plates so limb growth is reduced

57
Q

what are oral manifestations of GH deficiency

A

-disproportionate delayed growth of the skull and facial skeleton -> small facial appearance
-tooth formation and growth of the alveolar regions of the jaws abnormal and may be disproportionately smaller than adjacent anatomic structures
-solitary median maxillary central incisor
- eruption of primary and secondary dentition and shedding of deciduous teeth are delayed

58
Q

how are tooth formation and growth of the alveolar regions of jaws abnormal in GH deficiency

A

-tooth crowding and malocculsion
-a high tendency for plaque accumulation
-difficulty maintaining good oral hygiene
- prone to gingivitis and periodontal disease

59
Q

what dentition is solitary median maxillary central incisor seen in with GH deficiency

A

both primary and permanent

60
Q

how are oral manifestations of GH deficiency managed

A

correct dental and skeletal malocclusions

61
Q

what does the posterior pituitary contain

A

100,000 unmyelinated axons of neurons whose cell bodies are in the hypothalamus- paraventricular nucleus and supraoptic nucleus

62
Q

what does the posterior pituitary secrete

A

ADH/vasopressin and oxytocin

63
Q

how many amino acids make up the posterior pituitary hormones

A

9

64
Q

does each nucleus in the posterior pituitary only secrete one hormone

A

predominately one neurohormone but it can synthesize and secrete some of the other

65
Q

what hormone does the paraventricular nucleus secrete

A

oxytocin

66
Q

what hormone does the supraoptic nucleus secrete

A

ADH

67
Q

what does ADH do in blood vessels

A

contraction of vascular smooth muscle via V1 receptors

68
Q

what does ADH do in renal tubules

A

-binds to V2 receptors in the late distal tubule and collecting duct
-aquaporin 2 proteins are then inserted into the apical membrane of tubular epithelial cells, allowing for water reabsorption (and AQP-3 and AQP-4 on the basolateral membrane)

69
Q

what are the stimuli for ADH secretion

A

-decreased blood volume
- increased osmolarity
-decreased blood pressure

70
Q

what is hypodipsia and what does it result in

A

decreased or absent feeling of thirst which results in reduced intake of water and can cause hypernatremia

71
Q

what can hypodipsia trigger

A

osmolarity change that would stimulate ADH secretion by posterior pituitary

72
Q

when is hypodipsia seen

A

in eldery people, lesions in hypothalamus, head trauma,hydrocephalus or subarachnoid hemorrhage

73
Q

what levels of ADH are associated with diabetes insipidus? syndrome of inappropriate ADH?

A

-DI: decreased ADH
-SIADH: increased ADH

74
Q

what is diabetes insipidus due to

A

insufficient production or lack of kidney response to ADH

75
Q

what does diabetes insipidus present as

A

polyuria

76
Q

what is polyuria

A

excretion of large volumes of urine that is hypotonic and tasteless

77
Q

what is a diagnositic test of diabetes insipidus

A

dehydration test

78
Q

what are the other causes of polyuria

A

-primary ingestion of excess fluid : primary polydispia
- increased metabolism of ADH (pregnancy)

79
Q

what is SIADH

A

increased and uncontrolled secretion of ADH that causes volume expansion and hyponatremia

80
Q

what causes SIADH

A

surgery, pain, stress

81
Q

what does oxytocin do

A

-stimulates contraction of the uterus towards the end of gestation
- causes milk ejection from the breasts in lactation

82
Q

what does prolactin do

A

causes milk production

83
Q

describe the relationship between prolactin and oxytocin

A

permissive

84
Q

what is a sign and give example

A

objective evidence of disease that can be seen or measured
ex: polyuria, tachycardia

85
Q

what is a symptom and give example

A

cannot be measured, they are subjective and reported by the person
ex: headache, numbness

Physiology (41 decks)

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