Endocrine System Flashcards

1
Q

Hypothalamic-hypophyseal tract

A

Bundle of axons that runs through infundibulum and connects the posterior pituitary to the hypothalamus

Arises from neurons in paraventricular and supraoptic nuclei of hypothalamus

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

Glandular anterior lobe origin

A

Epithelial tissue

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

Anterior lobe and hypothalamus connection

A

No direct neural connection

Vascular connection 👍
-primary capillary plexus in infundibulum communicates inferiority via small hypophyseal portal veins with a secondary capillary plexus in anterior lobe

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

Hypophyseal portal system

A

Primary and secondary capillary plexuses + intervening hypophyseal portal veins

Arrangement of blood vessels in which a capillary bed feeds into veins which in turn feed into a second capillary bed

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

Hypophyseal portal system ensures…

A

That the min. Quantities of hormones released by the hypothalamus arrive rapidly at the anterior pituitary w/o being diluted by the systemic circulation

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

Paraventricular neurons (of hypothalamus) primarily make

A

Oxytocin

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

Supraoptic neurons (of hypothalamus) mainly produce..

A

Antidiuretic hormone (ADH)

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

Oxytocin

A

Peptide from neurons in paraventricular nucleus of hypothalamus

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

Oxytocin regulation of release

A

Stimulated by impulses from hypothalamic neurons in response to stretching of uterine cervix or suckling of infant at breast

Inhibited by lack of appropriate neural tissue

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

Oxytocin target organs and effects

A

Uterus: stimulates uterine contractions; initiates labor

Breast: initiates milk ejection

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

Antidiuretic hormone (ADH)

A

“Vasopressin”

Peptide

From neurons in supraoptic nucleus of hypothalamus

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

ADH Regulation of release

A

Stimulated by impulses from hypothalamic neurons in response to increased blood solutes concentration of decreased blood volume; also stimulated by pain, some drugs and low blood pressure

Inhibited by adequate hydration of the body and by alcohol

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

ADH Regulation of release

A

Stimulated by impulses from hypothalamic neurons in response to increased blood solutes concentration of decreased blood volume; also stimulated by pain, some drugs and low blood pressure

Inhibited by adequate hydration of the body and by alcohol

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

ADH target organs and effects

A

Kidneys: stimulate kidney tubule cells to reabsorb water from the forming urine back into blood

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

ADH target organs and effects

A

Kidneys: stimulate kidney tubule cells to reabsorb water from the forming urine back into blood

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

ADH effects of hypo-secretion and hyper-secretion

A

Hypo: diabetes insipidus (intense thirst and huge urine output)

Hyper: Syndrome of inappropriate ADH secretion (SIADH)

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

ADH effects of hypo-secretion and hyper-secretion

A

Hypo: diabetes insipidus (intense thirst and huge urine output)

Hyper: Syndrome of inappropriate ADH secretion (SIADH)

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

Tropic hormone

A

“Tropin”

Regulates secretory action of other endocrine glands

-TSH
-ACTH
-FSH
-LH

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

Tropic hormone

A

“Tropin”

Regulates secretory action of other endocrine glands

-TSH
-ACTH
-FSH
-LH

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

Growth Hormone (GH)

A

“Somatotropin”

Protein

Produced by Somatotropic cells of anterior lobe

Anabolic (tissue building) hormone

Has metabolic and growth-promoting actions

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

GH direct actions on metabolism

A

-metabolizes fats from fat depots for transport to cells, increasing blood levels of fatty acids and encouraging their use for fuel
-decreases rate of glucose uptake and metabolism, conserving glucose
-anti-insulin effect of GH
-increases amino acid uptake into cells and their incorporation into proteins

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

Anti-insulin effect of GH

A

In the liver, it encourages glycogen breakdown and release of glucose to the blood

Raises blood glucose levels

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

GH indirect actions on growth

A

Indirectly via family of growth-promoting proteins= insulin-like growth factors (IGFs)

Liver, skeletal muscle, bone, and other tissues produce IGFs in response to GH
-IGFs produced by liver act as hormones, while IGFs made in other tissues act locally w/in those tissues (as paracrines)

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

IGFs stimulate actions required for growth

A

-uptake of nutrients from the blood and their incorporation into proteins and DNA, allowing growth by cell division
-formation of collagen and deposition of bone matrix

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

GH regulation of release

A

Stimulated by GHRH release, which is triggered by low blood levels of GH as well as by a # of secondary triggers including deep sleep, hypoglycemia, increases in blood levels of amino acids, low levels of fatty acids, exercise, and other types of stressors

Inhibited by feed back inhibition exerted by GH and insulin-like growth factors (IGFs), and by hyperglycemia, hyperlipidemia, obesity, and emotional deprivation via increased GHIH (somatostatin) or decreased GHRH release

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

GH target organ and effects

A

Liver, muscle , bone, cartilage, and other tissues: anabolic hormone; stimulates somatic growth; metabolizes fats; spares glucose

Growth-promoting effects mediated indirectly by IGFS

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

GH effects of hyposecretion and hypersecretion

A

Hypo: pituitary dwarfism in children

Hyper: gigantism in children; acromegaly in adults

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

Thyroid-stimulating hormone (TSH)

A

“Thyrotropin”

Glycoprotein

Tropic hormone that stimulates normal development of thyroid gland

Thyrotropic cells

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

TSH regulation of release

A

Stimulated by TRH and in infants indirectly by cold temp

Inhibited by feedback inhibition exerted by thyroid hormones on anterior pituitary hypothalamus and by GHIH

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

TSH target organ and effects

A

Thyroid gland: stimulates thyroid gland to release thyroid hormones

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

TSH effects of hyposecretion and hypersectretion

A

Hypo: hypothyroidism, may cause myxedema

Hyper: effects similar to those of Graves’ disease (antibodies mimic TSH)

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

Adrenocorticotropic hormone (ACTH)

A

“Corticotropin”

Peptide

Secreted by corticotropic cells

It is split from prohormone (large precursor molecule) with pro-opiomelanocotrin (POMC)

Stimulates the adrenal cortex to release corticosteroid hormones

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

ACTH regulation of release

A

Stimulated by corticotropin-releasing hormone (CRH); stimuli that increase CRH release include: fever, hypoglycemia, and other stressors

Inhibited by feedback inhibition exerted by glucocorticoids (block secretion of CRH and ACTH release)

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

ACTH target organs and effects

A

Adrenal cortex: promotes release of glucorticoids and androgens (mineralocorticoids to a lesser extent)

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

ACTH Effects of hyposecretion and hypersecretion

A

Hypo: rare

Hyper: Cushing’s disease

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

Gonadotropins

A

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

Regulate function of gonads

FSH stimulates production of gametes (sperm or egg)

LH promotes production of gonadal hormones

Almost absent from blood of prepubertal

During puberty, gonadotropic cells are activated and gonadotropin levels rise, causing gonad to mature

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

Follicle-stimulating hormone (FSH)

A

Glycoprotein

By gonadotropic cells

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

FSH regulation of release

A

Stimulated by gobadotropin-releasing hormone (GnRH)

Inhibited by feedback inhibition exerted by estrogens in females abdominal testosterone in males

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

FSH regulation of release

A

Stimulated by gobadotropin-releasing hormone (GnRH)

Inhibited by feedback inhibition exerted by inhibin, and estrogens in females and testosterone in males

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

FSH target organ and effects

A

Ovaries and testes

Females: stimulates ovarian follicle maturation and production of estrogens

Males: stimulates sperm production

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

FSH target organ and effects

A

Ovaries and testes

Females: stimulates ovarian follicle maturation and production of estrogens

Males: stimulates sperm production

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

FSH and LH effects of hyposecretion

A

Failure of sexual maturation

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

Luteinizing hormone (LH)

A

Chemical structure: Glycoprotein

Cell type: Gonadotropic cells

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

Luteinizing hormone (LH)

A

Chemical structure: Glycoprotein

Cell type: Gonadotropic cells

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

LH regulation of release

A

Stimulated by gonadotropin-releasing hormone (GnRH)

Inhibited by feedback inhibition exerted by estrogens and progesterone in females and testosterone in males

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

LH target organs and effects

A

Ovaries and testes

Females: triggers ovulation and stimulates ovarian production of estrogens and progesterone

Males: promotes testosterone production

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

Prolactin (PRL)

A

Chemical structure: protein

Cell type: prolactin cells

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

PRL target organ and effects

A

Breast secretory tissue: promotes lactation

49
Q

PRL effects of hyposecretion and hypersecretion

A

Hypo: poor milk production in nursing women

Hyper: inappropriate milk production (galactorrhea); cessation of menses in female; impotence in males

50
Q

What is the key difference between the way the hypothalamus communicates with the anterior pituitary and the way it communicates with the posterior pituitary?

A

Hypothalamus communicates with ANTERIOR pituitary via hormones releases into a special portal system of blood vessels

It communicates with posterior pituitary via action potentials traveling down axons that connect the hypothalamus to the posterior pituitary

51
Q

Zoe drank too much alcohol one night and suffered from a headache and nausea the next morning. What caused these “hangover” effects?

A

Alcohol inhibits ADH secretion from the posterior pituitary and causes copious urine output and dehydration

52
Q

Describe structural and functional relationships between the hypothalamus and pituitary gland.

A

The pituitary gland hangs from the base of the brain and is enclosed by bone. It consists of a hormone-producing glandular portion ( anterior pituitary/adenohypophysis) and a neural portion (posterior pituitary or neurohypophysis) which is an extension of hypothalamus. The neurohypophysis includes: infundibulum and posterior pituitary

53
Q

Describe structural and functional relationships between the hypothalamus and pituitary gland.

A

The pituitary gland hangs from the base of the brain and is enclosed by bone. It consists of a hormone-producing glandular portion ( anterior pituitary/adenohypophysis) and a neural portion (posterior pituitary or neurohypophysis) which is an extension of hypothalamus. The neurohypophysis includes: infundibulum and posterior pituitary

54
Q

Comparison of NS and ES

A

NS:
Initiates responses RAPIDLY
SHORT-Duration responses
Acts via APs and NEUROTRANSMITTERS
Acts as SPECIFIC LOCATIONS determined by axon pathways
Neurotransmitters act over very SHORT DISTANCES

ES:
Initiates responses SLOWLY
LONG-DURATION responses
Acts via HORMONES released into the blood
Acts as DIFFUSE LOCATIONS- targets can be anywhere blood reaches
Hormones act over LONG DISTANCES

55
Q

Major process that hormones control and integrate

A

-reproduction
-growth and development
-maintaining electrolyte, water, and nutrient balance of the blood
-regulating cellular metabolism and energy balance
-mobilizing body defense

56
Q

Endocrine glands

A

-ductless
-well-vascularized
-Release hormones directly into blood or lymph

-pituitary
-thyroid
-parathyroid
-adrenal
-pineal

57
Q

Autocrine

A

Short-distance chemical signal that exert their effects on the same cells that secrete them

Ex. Prostaglandins released by smooth muscle cells cause this smooth muscle cells to contract

58
Q

Hormones

A

Long-distance chemical signals that travel in blood or lymph throughout the body

59
Q

Hormones

A

Long-distance chemical signals that travel in blood or lymph throughout the body

60
Q

Paracrines

A

Short-distance chemical signals

Act locally (w/in the same tissue) but affect cell types other than those releasing the paracrine chemicals

Ex. Somatostatin released by one pop. of pancreatic cells inhibits the release of insulin by a different pop. If pancreatic cells

61
Q

Steroid hormones

A

Lipid soluble

62
Q

Amino acid-based hormones

A

Water soluble except thyroid hormone

63
Q

Where in the cell are steroid hormones synthesized? Where are peptide hormones synthesized? Which of these 2 type of hormone could be stored in vesicles and released exocytosis?

A

(A)Steroid hormones are synthesized on the membrane of smooth ER

(B)Peptide hormones are synthesized on rough ER

(C)Peptide hormones

64
Q

Corpus-

A

Body (corpus callosum)

65
Q

Corpus-

A

Body (corpus callosum)

66
Q

Describe the 2 major mechanisms by which hormones bring about their effects on their target tissues.

A

Cell-surface receptor activation: hormone binds to a receptor protein on outside of cell membrane, which then activates intracellular processes. Used by amino acid based- can’t pass through cell membrane

Intracellular receptor recognition: hormone enters the cell and binds to a receptor, which changes cell’s protein synthesis. Used by steroid hormones, slower b/c involves protein synthesis

67
Q

Cell responses to hormone stimulation may involve changes in…

A

-Membrane permeability
-enzyme synthesis, activation, or inhibition
-secretory activity
-Mitosis

68
Q

Cyclic AMP system: 2nd messenger mechanisms employing G proteins and intracellular messenger: amino acid-based hormones interacting with target cells

A

1) hormone brands to a plasma membrane receptor that couples to a G protein
2)G protein is activated, then it couples to adenylate cyclase, which catalyzes the synthesis of cyclic AMP from ATP
3)adenylate cyclase converts ATO to cAMP (2nd messenger)
4) cAMP activates protein kinases
5) cellular response

69
Q

Steroid hormones (and thyroid hormones) effecting responses: intracellular receptors and direct gene activation

A

Enter their target cells and effect responses by activating DNA, which initial messenger RNA formation (transcription) leading to protein synthesis

70
Q

Which class of hormones consists entirely of lipid-soluble hormones? Name the only hormone in the other chemical class that is lipid soluble.

A

Steroids are all lipid soluble. Thyroid hormones are the only amino acid-based hormones that are lipid soluble

71
Q

Hurmoral stimulus

A

Hormone release caused by altered levels of certain crustal ions or nutrients

Ex.
Stimulus: low concentration of Ca2+ in capillary blood
Response: parathyroid glands secrete parathyroid hormone (PTH), which increases blood Ca2+

72
Q

Neural Stimulus

A

Hormone release caused by neural input

Ex.
Stimulus: APs in rehanging sympathetic fiber to adrenal medulla
Response: Adrenal medulla cells secrete epi and norepinephrine

73
Q

Hormonal Stimulus

A

Hormone release caused by another hormones (a tropic hormone)

Ex.
Stimulus: Hormones from hypothalamus
Response: Anterior pituitary gland secretes hormones that stimulate other endocrine glands to secrete hormones

74
Q

Explain how hormone release in regulated

A

(-) feedback mechanism- some internal and external stimulus triggers hormone secretion. As levels of a hormone rise, it causes target organ effects, which then feedback to inhibit further hormone release. Result: blood levels of many hormones vary w/in narrow range

75
Q

Blood levels of hormones reflect…

A

A balance between secretion and degradation/excretion.

Liver and kidneys- major degrade hormones; breakdown products are excreted in urine and feces

76
Q

Permissiveness

A

Situation in which one hormone must be present in order for another hormone to exert its full effects

77
Q

Synergism

A

Occurs when 2 or more hormones produce the same effects in a target cell and their results together are amplified

78
Q

Antagonism

A

Occurs when a hormone opposes or reverses the effect of another hormone

79
Q

Identify factors that influence activation of a target cell by a hormone

A

Bloody levels of hormone

Relative #s of receptors for the hormone on or in the target cells

Affinity (strength) of the binding between hormone and receptor

80
Q

Up-regulation

A

Persistently low levels of a hormone can cause its target cells to form additional receptor for that hormone

81
Q

Down-regulation

A

Prolonged exposure to high hormone concentrations can decrease the # of receptors for that hormone

Desensitizes the target cells, so they respond less vigorously to hormonal stimulation, preventing them from overreacting to persistently high hormone levels

82
Q

Down-regulation

A

Prolonged exposure to high hormone concentrations can decrease the # of receptors for that hormone

Desensitizes the target cells, so they respond less vigorously to hormonal stimulation, preventing them from overreacting to persistently high hormone levels

83
Q

Lipid-soluble hormones

A

Consist of: all steroid hormones and thyroid hormone

Sources: adrenal cortex, gonads, and thyroid gland

Stored in secretory vesicles: no

Transport in blood: bound to plasma in proteins

1/2 life in blood: long (most need to be metabolized by liver)

Location of receptors: usually inside cell

Mechanism of action at target cell: activate genes, causing synthesis of new proteins

84
Q

Water-soluble hormones

A

Consist of: All amino acid-based hormones except thyroid hormone

Sources: all other endocrine glands

Stored in secretory vesicles: yes

Transport in blood: usually free in plasma

1/2 life in blood: short (most can be removed by kidneys)

Location of receptors: on plasma membrane

Mechanisms of action at target cell: usually act through 2nd messenger systems

85
Q

Which type of hormone generally stays in blood longer following its secretion?

A

Lipid-soluble: long 1/2 life

86
Q

Which type of hormone generally stays in blood longer following its secretion?

A

Lipid-soluble: long 1/2 life

87
Q

Describe structural and functional relationships between the hypothalamus and pituitary gland

A

Pituitary gland is connected to your hypothalamus through a stalk of blood vessels and nerves. Through the stalk your hypothalamus communicates with the anterior pituitary lobe via hormones and posterior lobe through nerve impulses

88
Q

Discuss the structure of the posterior pituitary, and describe the effects of the 2 hormones it releases

A

Located base of brain; made up of unmyelinated secretory neurons and is connected to hypothalamus through nerve tract

Vasopressin/ADH: helps regulate water balance and blood pressure

Oxytocin: causes uterus to contract during childbirth and immediately after delivery to prevent excessive bleeding and stimulates contractions of milk ducts in the breast which move milk to nipple

89
Q

Discuss the structure of the posterior pituitary, and describe the effects of the 2 hormones it releases

A

Located base of brain; made up of unmyelinated secretory neurons and is connected to hypothalamus through nerve tract

Vasopressin/ADH: helps regulate water balance and blood pressure

Oxytocin: causes uterus to contract during childbirth and immediately after delivery to prevent excessive bleeding and stimulates contractions of milk ducts in the breast which move milk to nipple

90
Q

Posterior pituitary release of hormones

A

APs travel down the axons of hypothalamic neurons, causing hormone release from their axon terminals and posterior pituitary

91
Q

Posterior pituitary hormone release steps

A

1) hypothalamic neurons synthesize oxycotcin or ADH
2) oxytocin and ADH are transported down the axons of hypothalamic-hypophyseal tract to posterior pituitary
3) oxytocin and ADH are stored in axon terminals in posterior pituitary
4)when associated, hypothalamic neurons fire, APs arriving at the axon terminals cause oxytocin or ADH to be released into the blood

92
Q

Posterior pituitary hormone release steps

A

1) hypothalamic neurons synthesize oxycotcin or ADH
2) oxytocin and ADH are transported down the axons of hypothalamic-hypophyseal tract to posterior pituitary
3) oxytocin and ADH are stored in axon terminals in posterior pituitary
4)when associated, hypothalamic neurons fire, APs arriving at the axon terminals cause oxytocin or ADH to be released into the blood

93
Q

Anterior pituitary hormone release

A

Hypothalamic hormones released into special blood vessels (the hypophyseal portal system) control the release of anterior pituitary hormones

94
Q

Anterior pituitary hormone release

A

Hypothalamic hormones released into special blood vessels (the hypophyseal portal system) control the release of anterior pituitary hormones

95
Q

Anterior pituitary hormone release steps

A

1)when appropriately stimulated, hypothalamic neuron secrete releasing or inhibiting hormones into the primary capillary plexus
2) hypothalamic hormones travel through portal veins to the anterior pituitary where they stimulate or inhibit release of hormones made in the anterior pituitary
3)in response to releasing hormones, anterior pituitary secretes hormones into secondary capillary plexus this in turn empties into general circulation

96
Q

List the 4 anterior pituitary hormones that are tropic hormones and name their glands

A

LH and FSH are tropic hormones that act on gonads, TSH is a tropic that acts on the thyroid, and ACTH is a tropic that acts on adrenal cortex

97
Q

Topin/tropic hormones

A

Regulate the secretory action of other endocrine glands

-TSH
-ACTH
-FSH
-LH

98
Q

Steroid hormones

A

-derivatives of cholesterol
-hydrophobic
-transported by carrier proteins
-typically lipid-soluble
-cross cell membrane, enter cells, and bind to intracellular receptors (cytoplasm and nucleus)- then alter transcription and translation of certain proteins

99
Q

Peptide hormones

A

-Lipophobic- water affinity but cannot freely cross fatty membrane
-bind to cell surface receptors
-inactivated by gastric acid and peptidases

100
Q

Amine Hormones

A

-derived from amino acid tyrosine and tryptophan
-thyroid hormones behave similarly to steroid hormones (binds to intracellular receptors)

101
Q

Effect of excess thyroid hormone

A

Release more TSH

102
Q

Paracrine

A

Chemical signal acts locally but affect cell types other than the releasing cells

103
Q

Somatostatin

A

GHIH

104
Q

Somatostatin

A

GHIH

105
Q

Oxytocin

A

-paraventricular nucleus
-stimulated by…
-fetus stretching Cervix of uterus> activates stretch receptors in uterus>sends signal to hypothalamus>tells para. Nucleus to secrete oxytocin>binds to myometrium(middle layer of uterus)>PIP2-calcium-signaling-mechanism>increases intracellular concentration of Ca2+>enhances contraction process of muscle cells
-suckling>mechano receptors pick up signal and send to hypothalamus>releqse of oxytocin>acts on myoepithelial cells>PIP2>intracellular ca2+ levels in cell increase>enhances contractile process>ducts squeezed>milk ejected

Hyper: undesirable increase in oxytocin effects
Hypo: difficulty pushing baby out and post partum hemorrhaging

106
Q

PIP2-calcium-signaling-mechanism

A

-hormone binds
-activates Gq protein
-binds to phospholipase C
-breaks PIP2 into DAG and IP3
-DAG:
-activates protein kinase C (phosphorylates proteins)
-ex. Phosphorylates membrane protein to allow for Ca2+ entry
-IP3:
-activates sarcoplasmic reticulum
-pushes Ca2+ out into sarcoplasm

107
Q

Stimulus of ADH

A

Low blood pressure
-angiotensin 2 (hormone produced when blood pressure is low)
-receptor for angiotensin 2>sends signal to supraoptic nucleus to release ADH

High plasma osmolality (high solutes)
-hypertonic blood
-water volume concentration is low
-osmoreceptors pickup high plasma osmolality>tell supraoptic nucleus to release ADH

108
Q

Stimulus of ADH

A

Low blood pressure
-angiotensin 2 (hormone produced when blood pressure is low)
-receptor for angiotensin 2>sends signal to supraoptic nucleus to release ADH

High plasma osmolality (high solutes)
-hypertonic blood
-water volume concentration is low
-osmoreceptors pickup high plasma osmolality>tell supraoptic nucleus to release ADH

109
Q

How is ADH increased?

A

-ADH binds to vasopressin 2 receptors on cell of collecting duct
-activates Gs protein, binds to GTP and turns on Gs protein
-protein binds to adenylate cyclase which actives it
- GTP>GDP
-Gs=turned off
-ATP>CaMP
-CaMP activates protein kinase A
-protein kinase A stimulates genes of nucleus (undergoes transcription and translation>makes proteins>rough ER>golgi>packed into vesicles- has aquaporin 2 on vesicles)
-PKA phosphorylates proteins>vescicles w/ aquaporins fuses w/ cell membrane
-H2o enters from filtrations into cells of collecting duct
-h2o enters blood from aquaporin 3 and 4
H2o⬆️:
Plasma volume⬇️ >Blood pressure⬆️
Plasma osmolality ⬇️(wants isotonic: solutes=solvents)

Also:
ADH receptors on smooth muscle: vasopressin 1
-binds
-vasoconstriction
⬆️peripheral resistance>⬆️blood pressure

110
Q

GH stimulated by

A

-⬆️AA levels in blood
-⬇️glucose levels in blood(hypoglycemia)
-⬇️fatty acids in blood
-excersize
-healthy stressors

111
Q

IGF-1 protein made when…

A

GH binds to the liver

112
Q

IGF effects on muscle

A

-binds to receptor on skeletal muscle cell>activates signaling pathways>activates genes> produces proteins>protein activates channels to allow amino acids to enter the skeletal muscle and converts AA into proteins which increase muscle size

Effects: ⬆️AA uptake
⬆️protein synthesis
⬆️muscle size

113
Q

IGF effects on bone

A

⬆️osteoblast and osteoclast activity (important role in endochondral ossification)

(Protein) collagen type 1 production

⬆️proteoglycans (makes bone thicker)

114
Q

IGF effects on cartilage

A

⬆️interstitial growth (in length):
⬆️proliferation of chondroblasts
⬆️size of chondroblasts
⬆️differentiation of chondroblasts

115
Q

GH effects on liver

A

⬆️glyconeogenesis (making glycogen
W/o glucose)
IGF-1 production

116
Q

GH effects on liver

A

⬆️glyconeogenesis (making glycogen in the liver from non-carb sources like AA and lactase)
IGF-1 production

117
Q

GH effects on adipose

A

GH bonds to adipose tissue>activate hormone sensitive lipase which breaks down triglycerides into glycerol and fatty acids in a process called lipolysis

⬆️lipolysis (triglycerides breaks down into glycerol and free fatty acid)

118
Q

GH effects on muscle

A

⬆️AA uptake

119
Q

Prolactin

A

Peptide

Stimulate alveolar cell to produce milk
-mammary gland- modified apocrine gland
-lobules- consist of alveolar cells which produce milk

Arcuate nucleus produces PIH= dopamine

PIH acts on lactotrope to inhibit cell from releasing prolactin

Paraventricular nucleus secretes TRH>binds to receptors on lactotrope>gives stimulating signals>produces prolactin

Estrogen stimulates prolactin and can inhibit arcuate nucleus from producing PIH (after birth of baby, estrogen levels slowly fall, because extremely high estrogen levels do not allow prolactin to act on alveolar cell)

Breast feeding>stimulates production of oxytocin and prolactin