Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Endocrinology > Flashcards

Endocrinology Flashcards

1
Q

7 hormone facts

A

More than one produced in one endocrine gland

More then one tissue secrets the same hormone

More than one target cell type for a signal hormone

A single target cell can be influenced by more than one hormone

Secretion varies over time and will be effected by changes in the environment

Hormones can be blood borne or neuronally driven

Some hormones are excreted from tissues that have other functions

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

Synthesis and secretion post translational modification of peptide hormones

A

1) peptide cleavage
2) glycosylation
3) phosphorylation
4) sulfation
5) amidation
6) acetylation
7) subunit aggregation

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

Describe hormone release feedback control

A

This is predominantly negative
But can also be positive

Ie) output counteracts input and is frequently seen in the trophic hormones

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

Hormone release neuroendocrine reflexes

A

Combination of neural and hormonal processes

Not the same as neuromodulation

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

Hormone release rhythms

A

Release of hormones is entrained to environmental cycles which vary in interval length and duration

Melatonin secretion peaks at night
Cortisol secretion has two predominant phases

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

Explain carrier proteins with hormone delivery

A

Carrier proteins can be general or specific to the hormone in question dictated by binding affinity

Specific carries - corticosteroid binding globulin to corticosteroids thyroid hormone binding globulin and transthyretin to thyroid hormones

General carrier - albumin

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

Hormone activation

A

Metabolism of the precursor or release from the carrier protein will activate the hormone that will then have a half life in the blood

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

The length of time for hormone half life follows the general pattern

A

1) single amino acid derivatives = minutes
2) peptide hormones = mins to hours
3) steroid hormones = hours

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

Hormone inactivation

A

Enzyme degradation

Hormone receptor complex endocytosis

Conjugation

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

Endocrine dysfunction types

A

Hyposecretion

Hypersecretion

Target cell

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

Describe hyposecretion of endocrine dysfunction

A

Primary or secondary usually the result of atrophy of the endocrine gland and normally treated through replacement therapy

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

Describe hypersecretion of endocrine dysfunction

A

Primary or secondary usually the result of a benign tumour (adenoma) normally treated through inhibition or removal

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

Describe target cell endocrine dysfunction

A

Lack of receptors or biomechanics machinery at the target cell
Ie) hyperinsulinemia

Target cell responsiveness is also altered naturally

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

Response at target cell

A

Up and down regulation

Permissiveness

Synergism

Antagonism

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

Up and down regulation response at target cells

A

Receptors at the target cell are themselves regulated in response to hormone levels influencing abundance and affinity

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

Measurement of binding kinetics for hormone/receptor complexes relies heavily on the

A

Chemical law of mass action

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

Do all hormone receptor complexes adhere to the law of mass action

A

Non-cooperative = law of mass action is upheld

Positively cooperative = ligand binding increases receptor affinity of vacant receptors

Negatively cooperative = ligand binding decreases receptor affinity of vacant receptors

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

Permissiveness response at target cell

A

One hormone cannot fully exert its effect without the other being present

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

Synergism response at target cell

A

The combined effect is greater then the sum of the parts

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

Antagonism response at target cells

A

The actions of one hormone reduces the effectiveness of the second can be direct or indirect

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

What are the two types of hormone receptors

A

Membrane bound

Nuclear receptors

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

Membrane bound hormone receptors

A

Ligand gated
Enzyme linked
Guanylyl cyclase and G protein linked receptors

Second messenger system includes

  • adenylate cyclase
  • guanylate cyclase
  • inositol phosphate and diacyl glycerol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Nuclear receptors

A

Most lipophilic hormones act through nuclear receptors and many genes will have responsive elements

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

Nomenclature of

Anterior pituitary

Posterior pituitary

A

Pars distalis
Adenohypophysis

Pars nervosa
Neurohypophysis

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

The hypothalamus and posterior pituitary form a

A

neuroendocine system with cell bodies based in the hypothalamus

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

Posterior pituitary hormones are synthesized in the

A

Hypothalamus

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

Cell bodies then extend down the ___ and terminate in the ____

A

Infundibulum and terminate in the posterior pituitary

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

Describe neurohypophysial peptides

A

Two nonapeptides = OT and AVP

Precursor peptides produced in the hypothalamus - neurophysins

Closely related but one can work within the other

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

AVP and OT neurophysins + proteolytic enzymes are packages in ___ and begun to migrate down the axon to the ___ where the nerve terminals are located

A

Secretory Granules

Neurohypophysis

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

Vasopressin, arginine vasopressin, and antidiuretic hormone release and action

A

Release
- reduced ECFV which increases plasma osmolaitiy which increases osmorecpetor activity which increases vasopressin release

Action

  • increases h2o reabsorption in renal tubules
  • vasoconstriction of vascular smooth muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Oxytocin release and action

A

Release
- birth canal distension increases oxytocin release

  • infant suckling increases oxytocin release

Action

  • increases utrine muscle contraction during parturition
  • increases milk ejection from breast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe behavioural aspects of OT

A

Increases maternal behaviour in rats but estrogens need to be present

Plasma OT levels increase during sexual arousal in both sexes

Act as neuromodulators in the brain to influence social recognition memory and affiliative behaviours such as paid bonding

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

Describe behavioural aspects of AVP

A

Stimulates release of ACTH that is synergistic with CRH

Seems to play a greater role in males rather then females in regard to social recognition and consolidation of social memory

Aggression courtship scent marking and learning

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

Adenohypophysial cells

A

Histological and cytological methods have provided definitive evidence on the cellular source for each hormone release from the adenohypophysis

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

Hypothalamic anterior pituitary axis

A

Hormones synthesized and release from the anterior pituitary are under control of the hypophysiotropic hormones that can be stimulatory or inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the hormones of the glycoprotein family

A

Follicle stimulating hormone
Leutinizing hormone
Thyroid stimulating hormone
Human chorionic gonadotropin

Each has a A and B subunit the amino acid sequence of the A subunit is similar but the B subunit varies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Explain pars intermedia

A

Many animals have an anatomically separate pars intermedia

The predominant endocrine product is alphaMSH

In humans this is also the case during development

As adults these cells are not anatomically distinct but still synthesize and secrete aMSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Normal growth means

A

1) Protein, Fat, Cartilage synthesis
2) cell proliferation
3) bone lengthening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Normal growth is influenced by

A

1) generic resolve
2) diet and nutrient transfer
3) disease and stress
4) multiple layers of hormonal control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Growth rate

A

GH levels increase during puberty

In makes testicular androgens are v. Important and increase dramatically during puberty

Adrenal androgens also increase and may be more important in females

Testosterone and estrogen both ultimately put brakes on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Growth hormone (GH) production and inhibition

A

Production stimulated by GHRH

Inhibited by GHIH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the most abundant adenohypophysial hormone

A

Growth hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Spontaneous secretion of GH over a 24 hour period usually peaks when

A

In the first 90 mins of sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The somatomedin hypothesis

A

Growth hormone does not have a direct effect on growth of any given tissue but rather acts indirectly through somatomedins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Somatomedins hypothesis

There are two main somatomedins

A

Insulin like growth factors 1 and 2

They are 70 and 67 amino acids respectively and share many similarities with insulin

IgF 2 is more abundant in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Circulating levels of IGF 1 increase massively during ___ but ____ increases moderately by comparison

A

Pubertal growth spurt

GH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The __ is the mature bone shaft with the ___ at either end

A

Diaphysis

Epiphysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

In a growing bone the ___ is separated from the ___ by the ___

A

Epiphysial

Diaphysis

Epiphysial plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

___ produce enzymes collagen and proteins to provide framework for hydroxyapatite crystals. They deposit new bone on the outer edges of old bone to increase width

A

Osteoblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Osteoblasts will ultimately turn into mature bone cells ___

A

Osteocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Bone length grow is regulated by cartilage cells ___ located in the epiphyseal plates

A

Chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Thyroid hormones are

A

Involved in energy homeostasis

Hypothyroidism = reduced growth TH is largely permissive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Insulin is involved in

A

Carbohydrate metabolism

Deficiency can block growth and excess can promote growth potential cross reactivity with IGF receptors

54
Q

Androgens and estrogens arrest

A

Long bone length increase by closure of the epiphyseal plate

55
Q

Prolactin belongs to the ___ family and influenced

A

GH

Mammary gland growth as well as aspects of the immune system

56
Q

Placental lactogen belongs to the __ family and influences

A

GH

Neonatal development maternal glucose and amino acid supply
Peaks around mid pregnancy until full term

57
Q

Neurotrophic factors are

A

Nerve growth factors

58
Q

Erythropoietin are

A

Red blood cell growth factor

59
Q

Platelet derived growth factors are

A

Vascular injury repair but also involved in the development of artherosclerosis

60
Q

Epidermal growth factors enhanced proliferation of

A

Epidermis
Gut lining
Pulmonary lining

61
Q

Tumour derived growth factors angiogenesis

A

Fibroblast growth factors

Transforming growth factors

62
Q

Why regulate calcium

A

Calcium is perhaps the most tightly regulated ion in circulation

  • 99% of the bodies calcium is calcified structures
  • 0.9% is intracellular
  • 0.1% exists in the ECF half is bound to proteins or negatively charged ions and the rest is free from Ca2

Cell-cell integrity of tight junctions
Cofactor for clotting blood
Required for structural form of bone and teeth

63
Q

Neuromuscular excitability

A

Reduced calcium leads to tetanic muscle contraction and high levels lead to reduced muscular contraction

64
Q

Stimulus secretion coupling (calcium importance)

A

Many cells willl require calcium to enter the cell to stimulate the secretion of a given substance

65
Q

Regulation of calcium ____ impacts phosphate concentrations

A

ALWAYS

66
Q

Bone remodelling requires deposition and resorption using
Osteocytes =
Osteoblasts =
Osteoblasts =

A

Osteocytes = mature bone cells

Osteoblasts = bone builders responsible for depositing the collagen matrix

Osteoclasts = bone breakers

67
Q

Hormones involved in calcium regulation

A

Parathyroid hormone

Vitamin D3

Calcitonin

68
Q

Describe parathyroid hormone

A

Negative relationship between plasma concentration and plasma (Ca2) that is extremely sensitive

69
Q

Vitamin D3 (cholecalciferol) describe

A

Needs to be converted to 1,25-OH2)-vitamin D3 (calcritol)

70
Q

Calcitonin is

A

The only hyocalcaemic hormone

71
Q

Parathyroid hormone and bone

A

1) fast homeostatic regulation of Ca from bone fluid space

2) slower balancing of total body calcium from resorptive processes

72
Q

What does parathyroid hormone do for the kidneys

A

PTH increases and decreases phosphate reabsorption

73
Q

What does parathyroid hormone do for the intestine

A

Actions are indirect through stimulation of vitamin D3 production

74
Q

Why is vitamin D considered a hormone

A

Because it can be produced in the skin from 7-dehydrocholesterol

75
Q

Two important enzymatic steps that involve the sequential addition of hydroxyl groups

A

1) activation of 1alpha hydroxylase is the most important step and this enzyme is regulated by PTH

76
Q

Target sites for vitamin D3

A

The gut is the best documented area of vitamin D3 action

Where both fast and slow components are initiated

77
Q

Explain calcitonin

A

Not involved in day to day regulation but may be involved during the absorptive state and also during pregnancy

Calcitonin has both hypocalccaemic and hypophosphatemic effects

78
Q

For the most part bone resorption and bone disposition balance each other out but

A

There are times when this is not the case

79
Q

Osteoblasts are derived from ____

Osteoclasts are derived from___

A

Stromal cells in the bone marrow

Macrophages in the bone marrow

80
Q

Osteoblasts and its precursor cells produce two main messengers __

A

RANKL (receptor activator of NFkB ligand)

Osteoprotegerin

81
Q

Estradiol stimulates the production of

A

Osteoprotegerin

82
Q

Osteoporosis is

A

Reduced bone mineral density

Prevalent in pre and post menopausal woman

Onset of osteoporosis and about 1% of bone mass is lost every year

83
Q

Osteoporosis therapy

A

Exercise

Ca supplements

HRT

Calcitonin

SERMS and ANGELS

84
Q

Tetraiodothyronine (T4) and triiodothyronine (T3) are both derived from _____ and synthesized in the ___ of the thyroid gland

A

Thyroglogulin

Follicular cells and the colloid of the thyroid gland

85
Q

T4 and T3 are collectively referred to as the ___ hormones and are involved in the regulation of ____ and are key during ___

A

Thyroid hormones

Regulation of metabolic rate

Key during development

86
Q

What are thyroid hormones basic ingredients

A

The amino acid tyrosine and the element iodine

Tyrosine can be made in the body whereas iodine is an essential component of our diet

87
Q

Thyroid hormone deiodination

A

Deiodinases can have a strong preference for specific THs

Type 1 has a strong preference for reverse T3

Type 2 deiodinates only the outer ring

Type 3 deiodinates only the inner ring

These enzymes can be tissue specific

88
Q

Actions of thyroid hormone

Calorigenic

A

TH is the most important regulator of basal metabolic rate

89
Q

Actions of thyroid hormone

Sympathomimetic effect

A

Action is similar to the sympathetic nervous system

Increases target response to catecholamines

90
Q

Actions of thyroid hormones

Cardiovascular

A

Largely as a result of the increase in catecholamine receptors and calorigenic effects

91
Q

Actions of thyroid hormones

growth

A

Synergistic actions with both GH and IGFs

TH is essential for normal growth and neural development

92
Q

Thyroid hormone abnormalities

A

This is one of the most common endocrine disorders and is very prevalent in young adult women

Includes both hypothyroidism and hyperthyroidism either of which are characterized by goiter

93
Q

Goiter is

A

An over stimulation of the thyroid gland and not necessarily related to the capacity of the gland to synthesize and release TH

94
Q

Exophthalmos is a thyroid hormone abnormality that is

A

A common feature of Graves’ disease which is an autoimmune disease

95
Q

Melatonin is

A

The primary hormone released from the pineal gland and is synthesized from the amino acid tryptophan

96
Q

Melatonin is synthesized and released in a rhythmical fashion that is closely related to ____

A

Circadian rhythms

Scotophase = dark

Photophase = light

97
Q

Darkness is a universal stimulus for the synthesis and release of ___ from the ___ suggesting a strong link between the pineal and the optic tract

A

Melatonin

Pineal gland

98
Q

The melatonin link comes in the form of the _____ which is our major biological clock

A

Suprachiasmatic nucleus (SCN)

99
Q

Our major biological clock is where the ____

A

Interaction between PER genes and CLOCK proteins cycle at a remarkably constant rate that shifts depending on light cues

100
Q

Melatonin release peaks in humans usually __

A

In the middle of the night

101
Q

___ involved in melatonin synthesis also follows a rhythm

A

Enzymes

102
Q

___ follows cycles so there is a link between melatonin and ____ hormones and ___

A

Reproduction

Sex

Reproduction

103
Q

Adrenal hormones

A

Mineralocorticoids
Glucocorticoids
Sex hormones

Epinephrine
Norepinephrine

104
Q

What are the adrenal steroids released from the adrenal cortex

A

Mineralocorticoids = aldosterone

Glucocorticoids = cortisol

Sex hormones = dehydroepiandrosterone and androstenedione (androgens) and estrogens

105
Q

Catecholamines released from the adrenal medulla

A

Epinephrine - about 80%

Norepinephrine - about 20%

106
Q

Cholesterol as a precursor three main parent molecules

A

C21- pregnane

C19- androstane

C18- estrane

107
Q

Mineralocorticoids:

Aldosterone acts on distal and collecting tubules of the ____ in the ___

A

Nephron

Kidney

108
Q

Mineralocorticoids regulates ____ which has implications on the ___ and the ___ systems

A

Body fluid volume

Renal

Cardiovascular

109
Q

Mineralocorticoids steroid is essential for life it promotes ___ retention and ___ excretion in the kidney

A

Na

K

110
Q

Secretion of mineralocorticoids is regulated by the ____ system and also directly by circulating __ concentrations

A

Renin angiotensin system

K

111
Q

Aldosterone regulation is largely independent of the ___

A

Pituitary gland

112
Q

Hyperaldosteronism can be either ___ or ___ symptoms present as hypernatremia hypokalemia and usually hypertension

A

Primary (Conns syndrome)

Secondary

113
Q

The adrenal gland produces small amounts of both male and female sex steroids as ____ in an ____

A

DHEA

Adrenal androgen

114
Q

Why are estrogens considered female sec steroids and androgens considered male sex steroids

A

In males testosterone overpowers the actions of DHEA however as females otherwise lack androgens DHEA plays a role in the pubertal growth spurt hair growth and the female sex drive

115
Q

Adrenogenital syndrome

A

Symptoms are dependent on sex and age of hyperactivity onset

Adult females - masculinity, fascial hair deepening of voice ect.

Newborn females - pseudohermaphroditism

Adult males - no effect

Pubertal males - precocious pseudopuberty

116
Q

Glucocorticoids direct actions

A

Stimulates gluconeogenesis
- generation of glucose from non carbohydrate substrates (amino acids pyruvates and glycerol)

Inhibits glucose uptake by many peripheral tissues

Stimulates protein degradation in muscle

Stimulates lipolysis mobilising fatty acids as an alternative energy source

117
Q

Glucocorticoids permissive actions

A

Vascular collapse during stressful events in the absence of glucocorticoids

118
Q

Glucocorticoids anti-inflammatory and immunosuppressive

A

This anti inflammatory effects are seen following administration of supra physiologic or pharmacologic levels

Prevention of leucocytes infiltration into the wound site

Atrophy of lymphatic system

119
Q

Cortisol hyper/hypo secretion issues

A

Cushing’s syndrome (hyper)

Addison’s disease (hypo)

120
Q

Cushing’s syndrome

A

Hypersecretion

Increased amounts of CRH or ACTH
Adrenal tumours
Ectopic ACTH release

Symptoms
- excess glucose, fat deposition in the face and abdomen thin legs and arms and facial hair excess

121
Q

Addison’s disease

A

Hyposecretion

General name for bilateral damage to the adrenals
Can also be primary or secondary in nature

Symptoms
- increased integument pigmentation, weakness, weight loss, hypotension, salt craving and hypoglycaemia

122
Q

General adaptation to stress

A

1) primary alarm response
2) secondary resistance response
3) tertiary exhaustion response

123
Q

Describe primary alarm response for the adaptation to stress

A

Catecholamine surge into the system

Increase BMR
Increase Blood flow to required organs
Hepatic glycogenolysis

124
Q

Secondary resistance response to Stress

A

Described actions of cortisol on metabolism

Continued mobilisation of glucose for central organs

Continued breakdown of alternative energy stores (lipids and proteins)

125
Q

Tertiary exhaustion response to stress

A

Muscle wasting, hyperglycaemia (diabetes)

Atrophy of the immune system gastric ulcers

Vascular derangements

126
Q

The adrenal medulla essentially acts as an extension of the ____

A

Sympathetic nervous system

127
Q

Catecholamine release from the adrenal medulla is largely under the control of the ___

A

SNS

128
Q

Both catecholamines are stored in ____

A

Chromaffin granules

129
Q

Epinephrine and norepinephrine are both the active Ligands in the ____ system and they will bind to one of the 4 ____ receptors (which are)

A

Adrenergic system

Adrenergic receptors

Alpha 1,2 beta 1,2

130
Q

Describe epinephrine

A

Rapid mobilisation of the bodies energy reserves

Increase cardiac output and total peripheral resistance

Increase coronary and skeletal muscle arteriolar dilation

Reduce gut motility

Increases glycogenolysis in liver and muscle

Increased CNS alertness

Dilates pupils and flattens theblens

Increases sweating

Physiology (15 decks)

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