m7 + 8 lecture - endocrine system Flashcards

1
Q

what organs are involved in the endocrine system?

A
  • hypothalamus
  • pineal gland
  • pituitary gland
  • thyroid gland
  • parathyroid gland
  • thymus
  • adrenal glands
  • pancreas
  • ovary (female)
  • testis (male)
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2
Q

what are hormones?

A
  • chemical messengers
  • amino acid or cholesterol based
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3
Q

what are target tissues?

A
  • tissues containing receptors that are activated by specific hormones
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4
Q

what is a steroid hormone?

A
  • made from cholesterol
  • lipid-soluble

ex.) testosterone, estrogen, progesterone, aldosterone, cortisol

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5
Q

how do steroid hormones move?

A

direct gene activation

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6
Q

what is direct gene activation?

A
  • can move thru membrane + into the nucleus
  • attaches to receptor in nucleus
  • activates an enzyme which will target a specific gene on a chromosome
  • results = protein synthesis
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7
Q

what are amino acid based hormones?

A
  • water soluble
  • need surface membrane receptor
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8
Q

how do amino acid based hormones move?

A

second messenger systems

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9
Q

what are second-messenger systems?

A
  • hormone attaches to a surface receptor
  • surface receptor stimulates G-proteins along membrane
  • activating cyclic AMP (triggers a change)
    – cAMP activates any number of different enzymes called Protein Kinase = these creates changes inside the cell
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10
Q

what happens during the positive feedback loop?

A
  • happens with oxytocin release during labor and delivery ONLY
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11
Q

what is the negative feedback loop cycle?

A

repeated cycle
1) stimulus
2) control center
3) hormone
4) action
5) negative impact

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12
Q

what is a humoral stimulus?

A
  • stimulus is determined by blood levels of certain chemicals
  • glucose => insulin/glucagon
  • Ca+ –> parathyroid hormone = 9-11 mg/100ml
  • O2 –> erythropoietin
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13
Q

what is the negative feedback loop?

A
  • one way that the endocrine system tries to keep homeostasis (stability) in the body
  • if an endocrine gland senses that there is too much of one hormone in the body, it will initiate changes to decrease production of that hormone.
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14
Q

what is erythropoietin?

A
  • produced by kidneys
  • a hormone that tells the bone marrow to produce more red blood cells in response to low oxygen levels
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15
Q

what is a neural stimulus?

A
  • where the ANS system initiates a hormone be released
    — epinephrine - SNS
    — stomach hormones - m/c
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16
Q

what is a hormonal stimulus? m/c

A
  • begins at hypothalamus
  • pituitary gland stimulates release of other hormones
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17
Q

what is hypophysis? (pituitary gland)

A
  • hangs below the hypothalamus from the infundibulum
  • controls many other endocrine glands = called master gland
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18
Q

what are the two parts of the hypophysis? (pituitary gland)

A
  • anterior (adenohypophysis)
  • posterior (neurohypophysis)
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19
Q

what does the adenohypophysis do? (anterior pituitary gland)

A
  • produces 6 types of hormones
    –> release regulated by hypophyseal portal system
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20
Q

what happens in the neurohypophysis? (posterior pituitary gland)

A
  • stores hormones secreted by hypothalamic neurosecretory cells that extend down through the infundibulum
21
Q

anterior pituitary gland hormones: name and action

A

GHRH –> growth hormone (GH) - achondroplasia, gigantism, acromegaly
TRH –> thyroid-stimulating hormone (TSH) - thyroid
ACTRH –> adrenocorticotrophic (ACTH) - adrenal cortex
GnRH –> LH + FSH - gonads
PRH - Prolactin - milk production

22
Q

posterior pituitary hormones: name + action

A

oxytocin - 1) uterine contractions 2) milk letdown 3) emotional bonding

anti-diuretic hormone (ADH) - increases permeability of the collecting duct to water = decreased urine loss (less water loss)

23
Q

what causes diabetes insipidus?

A
  • when the body doesn’t make enough anti-diuretic hormone (ADH) - hyposecretion
24
Q

thyroid gland: location + action

A
  • two main portions on either ride of the larynx - connected by isthmus
  • action of hormone: establishes core body temp.
    ex.) “furnace” of the body, runs more in winter than summer bc of the cold - to maintain body temp
25
Q

what is the hormone produced in thyroid gland?

A

thyroxine (T3 or T4)
– is produced with iodine combined with tyrosine (amino acid)
- increases metabolic activity in all tissue cells
- important for normal growth in childhood

26
Q

what are the sx for hypothroidism? (cretinism, myxedema, hashimoto’s dz)

A
  • low thyroxine
  • low vital signs
  • low temp.
  • low appetite
  • lethargic
  • increased weight
  • increased TSH
27
Q

what are the sx for hyperthyroidism? (grave’s dz, exophthalates)

A
  • increased thyroxine
  • increased temp.
  • increased appetite
  • decreased TSH (can’t sleep)
  • decreased weight
28
Q

what do the adrenal glands do?

A
  • sit on top of each kidney
    contain two secretory areas:
    – cortex
    – medullary area
29
Q

what happen in the cortex of the adrenal gland?

A
  • responds to hormonal stimuli
  • produces hormones called corticosteroids
    ex.) cortisol, aldosterone
30
Q

what happens in the medullary area of the adrenal gland?

A
  • responds to neural stimuli through the SNS
  • produces catecholamines
    ex.) epinephrine
31
Q

what is aldosterone (anti-diuretic)?

A
  • mineralocorticoid - regulates salt and water balance in the body
  • secretion stimulated by dehydration and drop in BP –> leads to kidney’s production of renin
  • regulator of extracellular minerals = Na + K
  • renin-angiotensin-aldosterone system (RAAS) –> aldosterone –> increased Na/H2O reabsorption
  • Na retention lead to decrease in K

ex.) extended process = cramping

32
Q

what is the renin-angiotensin-aldosterone system (RAAS)?

A
  • a hormone system that regulates blood pressure, blood volume, and electrolyte balance
  • by increasing sodium and water reabsorption, and vascular tone
  • three main substances: renin, angiotensin II, and aldosterone
33
Q

what are the glucocorticoids?

A
  • cortisol = produced in long-term stress situations (physical or emotional)
34
Q

what happens with glucocorticoids?

A
  • these influence the cells metabolism of glucose
  • stimulated by release of ACTH
  • stimulates process of gluconeogenesis
  • is anti-inflammatory + used medicinally
    ex.) cortisone, prednisone
35
Q

what is gluconeogenesis?

A
  • production of glucose from non-carbohydrate sources to provide more energy for activity
36
Q

what side effects happen during extended cortisol secretion?

A
  • decreased protein formation - affects hair, muscles, nails
  • decreased healing rates
  • suppressed immune reaction
  • high BP
  • decreased mental functions
37
Q

what is cushing’s syndrome?

A
  • hypersecretion of cortisol, due to over secretion of ACTH
    cause: usually tumor on pituitary or adrenal gland
    sx: buffalo hump, moon face, red cheeks
38
Q

what are gonadocorticoids?

A
  • cortex of adrenal gland produces both types of sex hormones
    ex.) testosterone and estrogen
  • may help start puberty and maturation of gonads
39
Q

what happens in the medullary area of the adrenal gland?

A
  • produces catecholamines
    ex.) epinephrine, nor-epinephrine

chromaffin cells:
- produce the hormones

  • short term stress hormones - deal with fight or flight situations
40
Q

what is the pancreas?

A
  • location: just below stomach
  • both an exocrine (enzymes) and an endocrine (hormones) gland
41
Q

what is the endocrine function of the pancreas?

A

islets of langerhan’s:
- pockets of glandular tissue in pancreas
hormones produced:
- insulin
- glucagon

42
Q

what does insulin do?

A
  • produced in the beta cells of the islets
  • stimulation: high blood glucose levels
  • stimulates body tissue cells to absorb glucose to lower blood sugar levels, stimulating protein synthesis, lipogenesis, and glycogenesis
43
Q

what does glucagon do?

A
  • secreted by the alpha cells
  • stimulation: low blood glucose levels
  • effects the liver to release stored glucose in glycogen
44
Q

diabetes mellitus type one: cause, age, and treatment?

A

cause - autoimmune
age- childhood
treatment - insulin injections

45
Q

diabetes mellitus type two: cause, age, and treatment?

A

cause - poor diet
age - adult
treatment - meds, diet, exercise

46
Q

what causes diabetes insipidus?

A

low ADH

47
Q

what happens in the testes?

A
  • controlled by FSH and LH
  • release testosterone and produce sperm
  • control growth in stature, muscle, and promotes male sexual characteristics
48
Q

what happens in the ovaries?

A
  • controlled by FSH and LH
  • regulates ovarian cycle and production of estrogen and progesterone
  • promotes female sexual characteristics and uterine cycle
49
Q

other hormone producing organs, their hormones and their actions:

A

– skin - vitamin D3 –> serotonin –> :)
– heart - atrial natriuretic peptide (ANP) - regulates blood pressure and salt-water balance –> diuretic, blocks aldosterone
– placenta –> progesterone, HCG
– kidney –> EPO, renin
– adipose –> leptin