Endocrine Flashcards
1
Q
MAIN GLANDS FORMED IN THE ENDOCRINE SYSTEM
A
o Hypothalamus
o Pituitary gland
o Pineal Gland
o Thyroid Gland
o Parathyroid Gland
o Adrenal Gland
2
Q
Hypothalamus controls the______ gland because hypothalamus is the one that releases hormones
A
pituitary
3
Q
connects the hypothalamus and pituitary gland together
A
Infundibulum
4
Q
Stimulates production of sex hormones by gonads
A
LH (Luteinizing Hormone)
5
Q
Stimulates production of sperm and eggs
A
FSH (Folliclestimulating Hormone)
6
Q
Stimulates the release of thyroid hormone (TH). TH regulates metabolism
A
TSH (Thyroid stimulating Hormone)
7
Q
Promotes milk production
A
PRL (Prolactin)
8
Q
Induces targets to produce insulin-like growth factors (IGF).
IGFS stimulates body growth and a higher metabolic rate
A
GH (Growth Hormone)
9
Q
Induces targets to produce glucocorticoids , which regulate metabolism and the stress response
A
ACTH (Adrenocorti cotropic hormone)
10
Q
▪ A disease to which the thyroid levels are constantly low
A
Hypothyroidism
11
Q
▪ A disease to which the thyroid hormones are constantly high
A
Hyperthyroidism
12
Q
Water balance
A
ADH
13
Q
Triggers uterine contractions during childbirth
A
OT (Oxytocin)
14
Q
ANTERIOR PITUITARY GLAND
• Derived from an outgrowth of oral mucosa (______)
A
Rathke’s pouch
15
Q
Anterior pituitary
SUB-PARTS
A
o Pars distalis (anterior lobe)
o Pars tuberalis (pars infundibularis)
o Pars intermedia (intermediate lobe)
16
Q
o Connects our hypothalamus to our pituitary gland
A
Pituitary Stalk
17
Q
o Located in between the posterior and anterior pituitary gland
A
Pars Intermedia
18
Q
Stimulates growth in epiphyseal plates of long bones via insulin-like growth factors (IGFs) produced in liver
A
Somatotrophs
Somatotropin (growth hormone, GH)
19
Q
Promotes milk secretion
A
Lactotrophs (or mammotrophs)
Prolactin (PRL)
20
Q
promotes ovarian follicle development and
estrogen secretion in women and
spermatogenesis in men;
A
Follicle-stimulating hormone (FSH)
21
Q
promotes ovarian follicle maturation and progesterone secretion in women and interstitial cell androgen secretion in men
A
luteinizing hormone (LH;
22
Q
Stimulates thyroid hormone synthesis, storage, and liberation
A
Thyrotrophs
Thyrotropin (TSH)
23
Q
Stimulates secretion of adrenal cortex hormones
A
Corticotrophs
Adrenal corticotropin (ACTH)
24
Q
Helps regulate lipid metabolism
A
Corticotrophs
Lipotropin (LPH)
25
• Biggest (sub)part of gland o Comprises about 75% of anterior pituitary gland
• Produces nearly all the hormones secreted by pituitary gland
• Hormones collectively referred to as anterior pituitary hormones
PARS DISTALIS
26
- secretory cells. Hormone is stored in cytoplasmic granules, having various colors under microscope, hence the name.
CHROMPOPHILS
27
Acidophils and Basophils
ACIDOPHILS (Alpha Cells)
28
Acidophils
Somatotrophs
Lactotrphs/ Mammotrophs
29
Basophils
Gonadotrophs
Thyrotrophs
Corticotrophs
30
Forms sleeve around pituitary stalk of neurohypophysis (Pars Nervosa)
• More vascular than anterior lobe
o Because it forms sleeves around the pituitary
stalk that's why it has blood vessels
• Cells, mostly gonadotrophs
released by the basophils (beta cells)
PARS TUBERALIS
31
• Separates anterior from posterior lobe
• Boundary with anterior demarcated (borderline) by groove that represents original lumen of rathke's pouch
.
Better developed in fetus; rudimentary in adults
.
Has follicles (rathke's cysts) that contain eosinophilic colloid material
.
Produces melanocyte stimulating hormone (MSH)
PARS INTERMEDIA
32
Herring bodies - Neuro-secretory Bodies
POSTERIOR PITUITARY GLAND
33
Increases water permeability of renal collecting ducts
Vasopressin/antidiuretic hormone (ADH)
34
Stimulates contraction of mammary gland myoepithelial cells and uterine smooth muscle
Oxytocin
35
PINEAL GLAND
• Aka
epiphysis cerebri
36
• Regulates daily rhythm of the body
• Develops from neuroectoderm
• Small; cone-shaped gland
• Arises as evagination of roof of diencephalon
• Base attached to roof of 3rd ventricle by two stalks
Pineal gland
37
• Well-developed in children
• at puberty, starts to involute (curl up)
Pineal gland
38
• Hormone elaborated by pinealocytes
MELATONIN
39
MELATONIN
Secretion is stimulated by_____ and inhibited by____
darkness
light
40
blood level has diurnal pattern; higher
at night than during day blood level much higher in children than adults
Melatonin
41
" it may affect circadian rhythms and
sleep patterns
Melatonin
42
• 95% of cell population
• Produces melatonin
Pinealocytes
43
Interstitial cells
" Comprise 5 % of cell population
•___________ are present to promote homeostasis or balance within the cell
Modified astrocvtes
44
BRAIN SAND
• Also known as:
psammoma bodies,
corpora arenacea
45
Concretions of calcium and magnesium salts
Distinctive feature of pineal gland
Increase in number with age (but no effect in the gland's function)
Brain sand
46
• Largest endocrine gland
THYROID GLAND
47
slightly bigger in women than in men
THYROID GLAND
48
Parts of thyroid gland
Two lateral lobes (right and left)
Isthmus
49
THYROID HORMONES
TRH -Thyroid Releasing Hormone
TSH- Thyroid Stimulating Hormone
T3- Triodothyronine hormone
T4-Thyroxine hormone
50
o Regulate the metabolism of proteins, carbohydrates, fat and some vitamins
THYROID HORMONES
51
THYROID GLAND HORMONES
T3
T4
Calcitonin
52
Regulate the metabolism of proteins, carbohydrates, fat and some vitamins
Controlled by TSH from the anterior pituitary in response to thyrotropin-releasing hormone (TRH)
Thyroxine (T4) & Triiodothyronine (T3)
THYROID HORMONES
53
CALCITONIN (thyrocalcitonin)
Synthesized and secreted by_______ cells
parafollicular
54
T3 and T4 are synthesized by
Follicular cells
55
Function:
• lowers blood calcium levels
• inhibits bone resorption by directly suppressing osteoclasts
Calcitonin
56
divides thyroid gland into poorly-defined lobules
SEPTAE
57
2 capsules of thyroid
Outer capsule
True capsule
58
- releases Calcitonin
• Also known as:
• Mitochondria-rich cells
• C cells -
• C for calcitonin
• Clear cells
Parafollicular cells
59
0.1% of cell population
Parafollicular
60
PARATHYROID GLAND
• Usually 2 pairs (_____ and _____)
superior and inferior
61
• Yellowish-brown, tiny, ovoid bodies attached to posterior surface of thyroid gland
• Lie within capsule of thyroid gland
Parathyroid gland
62
arise from third pharyngeal pouch together with thymus
______
arise from fourth pharyngeal pouch and attach themselves to thyroid glands
• Inferior parathyroid glands
___
• Superior parathyroid glands
63
- functional unit of thyroid tissue
PARENCHYMA
64
EPITHELIAL CELLS of parathyroid
Oxyphil
Chief/ principal cells
65
Elaborate and secrete parathyroid hormone (PTH)
Chief cells (principal cells)
66
• Appear shortly before puberty
Increase in number with age
Occur singly or in clusters
Bigger than chief cells but nuclei slightly smaller
Cytoplasm with many acidophilic granules and hence, intensely eosinophilic
Nonsecretory and function is unknown
Oxyphil cells (acidophil cells)
67
Only hormone produced by parathyroid gland
PARATHYROID HORMONE
68
Most important regulator of blood calcium level
Parathyroid hormones
69
Osteoblasts respond to_____, increasing number and activity of osteoclasts (opposite to Calcitonin)
stimulates Ca2+ reabsorption in distal convoluted tubules of renal cortex and inhibits phosphate reabsorption in proximal tubules
increases Ca2+ absorption in small intestine by stimulating Vitamin D activation
PTH
70
Two pathways of Parathyroid Hormones
Bone
Kindey
71
• Paired (left and right), flat, pyramidal organs
• Left suprarenal gland: semilunar shaped
• Right suprarenal gland: pyramidal shaped
• On upper pole of kidneys
• Each weighs about 5 g and 50 mm long or high, 30 mm wide and 10 mm thick
ADRENAL GLAND
• Other name: Suprarenal Gland
72
indentation at middle of anteromedial aspect
where adrenal vein leaves gland
Hilus
73
3 layers of adrenal cortex
Zona glomerulosa
Zona fasciculata
Zona reticularis
74
Made up of 3 zones: Zona Glomerulosa, fasciculata, reticularis
Outer area
• Completely surrounds medulla
ADRENAL CORTEX
75
Essential for life
80-90% of adrenal gland
produce steroid hormones (adrenocortical hormones)
ADRENAL CORTEX
76
ADRENAL______
• Ectodermal origin
• Not essential for life
Adrenal medulla
77
Hormones released
Zona Glomerulosa
Zona Fasciculata
Zona Reticularis
Mineralocorticoids
Glucocorticoids
Androgens/ Testosterone
78
HORMONES
• Mineralocorticoids
• mainly aldosterone
Zona glomerulosa
79
Increases Na+ reabsorption by collecting tubules of kidney
that's why simple cuboidal epithelial cells ang present
Control of aldosterone secretion
mainly by RAAS
• secondarily by corticotropin (ACTH) from anterior pituitary
Zona glomerulosa
80
• Thickest layer (78%) of adrenal cortex
ZONA FASCICULATA
81
• Thickest layer (78%) of adrenal cortex
• Cells form long, thin (usually one-cell thick), straight cords arranged perpendicular to capsule
• Cords separated by sinusoids that are supported by fine connective tissue septae
Zona fasciculata
82
Zona fasciculata
CELLS: also called _______
spongiocytes
83
HORMONES
Glucocorticoids
Mainly cortisol and corticosterone
Regulate carbohydrate, lipid and protein metabolism (Glucose)
Zona fasciculata
84
Primary regulator of the activity of cells of zona fasciculata is_________
from anterior pituitary
corticotropin (ACTH)
85
• Innermost and thinnest layer (7% of volume of cortex)
• Cells small and arranged in short anastomosing cords
• Between cords are sinusoids
ZONA RETICULARIS
86
• Comprises only 10-20% of adrenal gland
• Thin region completely surrounded by cortex
• Central part with large medullary veins that drain entire gland
ADRENAL MEDULLA
87
Cells of ADRENAL MEDULLA
Chromaffin cells
Ganglion cells
88
ADRENAL MEDULLA SECRETIONS
• Three kinds of catecholamines
Epinephrine
Norepinephrine
Dopamine
89
• secreted by 90% of chromaffin cells
• secreted by 10% of chromaffin cells
• Stronger chromaffin reaction
• Granules more electron dense
• cells that secrete this have not been identified yet
Epinephrine (adrenaline)
Norepinephrine (noradrenaline)
Dopamine
90
• both an exocrine and an endocrine gland
• both endocrine and exocrine components are in the lobules
Pancreas
91
PANCREAS: DUCTS
Intralobular
Interlobular
Pancreatic ducts
92
• Intercalated duct: drains an acinus, squamous or low cuboidal epithelium
Intralobular ducts
93
Union of intercalated ducts
• anastomosing
Interlobular ducts
94
Union of interlobular duct
Lined by simple columnar epithelium
Pancreatic ducts
95
only 2% of pancreas
• Islets of Langerhans
ENDOCRINE PORTION
96
• Aggregations of pale-staining cells (in H & E preparations) scattered throughout darker staining cells of exocrine pancreas
• Combined volume = only 2% of pancreas
• More numerous in tail than in body or head of gland
ISLETS OF LANGERHANS
97
ISLETS OF LANGERHANS
Cell types
ALPHA CELL (A CELL)
BETA CELL (B CELL)
DELTA CELL (D CELL)
F CELL (PP CELL)
98
• About 20% of islet cells
• Large cell and most occupy peripheral areas of islet
• Electron-dense secretory granules of uniform size
ALPHA CELL (A CELL)
99
Secretes glucagon
ALPHA CELL (A CELL)
100
• Acts on several tissues to make energy stored in glycogen and fat available through glycogenolysis and lipolysis
• Increase blood glucose content
glucagon
101
• Most numerous
• 60-75% of islet cells
. Most are in central area of islets
• Smallest of the cells of islet
Secretory granules smaller and less electron dense than a cell
BETA CELL (B CELL)
102
BETA CELL (B CELL)
Secretes ______ and ______
insulin as well as amylin
103
Cause entry of glucose into cells
Promotes decrease of blood glucose content
insulin as well as amylin
104
Only about 5% of islet cell population
Scattered singly all over islets
• Largest of islet cells
DELTA CELL (D CELL)
105
Secretes somatostatin
DELTA CELL (D CELL)
106
• Also produced by some cells of digestive tract and hypothalamus
• But, physiologic effect of hypothalamic
somatostatin
different
• Inhibits release of other islet cell hormones
• Inhibit release of growth hormone and TSH in anterior pituitary
.
Inhibit HCI secretion by gastric parietal cells
somatostatin
107
• Rare
" Widely scattered and sometimes occurs among the pancreatic acini
Secretory granules irregular in shape and variable electron density
F CELL (PP CELL)
108
Secretes pancreatic polypeptide
F CELL (PP CELL)
109
• Stimulate activity of gastric chief cells
• nhibits bile secretion
• Inhibit pancreatic enzyme and bicarbonate secretion
• Inhibit intestinal motility
pancreatic polypeptide
110
a cells
ß cells
- D cells
- F cells
Glucagon
Insulin, Amylin
Somatostatin
Pancreatic Polypeptide
