Endocrine Glands Lecture 21 Flashcards
1
Q
How does the endocrine system communicate?
A
- via chemical messengers (hormones) secretory products of endocrine cells, carried by bloodstream to target tissue containing receptors
2
Q
Endocrine Organs are composed of secretor cells of _____ origin characterized by prominent nuclei and numerous organelles?
A
- epithelial
3
Q
Do endocrine glands have ducts?
A
- no the lack ducts and secrete hormones into surrounding interstitial space
4
Q
What characterizes endocrine organs?
A
- prominent nuclei and numerous organelles
5
Q
______ posses rich blood supply with fenestrated capillary networks to absorb and transport hormones
A
- endocrine organs
6
Q
_____ coordinates endocrine functions of body and acts as intermediary between autonomic nervous system and endocrine system
A
- hypothalamus
7
Q
Endocrine organs integrate function of _____ systems
A
- physiologic
8
Q
Most endocrine glands form discreet organs; but in the pancreas endocrine and exocrine tissue is
A
- intermixed
9
Q
What is another name for the pituitary gland?
A
- hypophysis
10
Q
___ - 1cm diameter, specialized appendage of brain
- lies beneath third ventricle in sella turcica (“Turkish saddle”) of sphenoid bone
A
- pituitary gland
11
Q
Where is pituitary gland?
A
- lies beneath third ventricle in sella turcica (“ Turkish saddle”) of sphenoid bone
12
Q
What controls secretion of pituitary hormones?
A
- hypothalamus with complex blood supply
13
Q
What allows communication with hypothalamus?
A
- hypophyseal portal system
14
Q
How does hypothalamus control secretion of anterior pituitary?
A
- hypothalamic regulating factors (hormones)
releasing factors stimulate secretion; inhibitory factors inhibit secretion
15
Q
What are the two groups of pituitary hormones?
A
- direct acting hormones
- trophic hormones
16
Q
_____ have non endocrine target organ
A
- direct acting hormones
17
Q
Examples of direct acting hormones?
A
- GH
- ADH
- MSH
- Oxytocin
- Prolactin
18
Q
_____ target organ is another endocrine
A
- TSH
- ACTH
- FSH
- LH
19
Q
Thyroid gland, adrenal cortex, and gonads are all _________ dependent endocrine glands
A
- pituitary dependent
20
Q
Functionally anatomically and embryologically the pituitary gland is divided into ______ and _____ portions
A
- Posterior
- Anterior
21
Q
What does the anterior portion of the pituitary gland contain?
A
- epithelial tissue
22
Q
What does the posterior portion of the pituitary contain?
A
- neural secretory tissue
23
Q
What is the “Master gland” (adenohypophysis = pars anterior = pars distalis)
A
- anterior pituitary gland
24
Q
_____ is a specialized glandular tissue, arises from evagination of ectoderm from oral cavity in region of pharynx called Rathke’s pouch?
A
- anterior pituitary
25
Where does anterior pituitary arise from?
- evagination of ectoderm from oral cavity in region of pharynx called rathke's pouch
26
What are the 3 regions of the anterior pituitary?
- pars distalis
| - pars intermedia
27
What is rathkes pouch?
- oral ectoderm that migrates to the brain
28
______ bulk of anterior pituitary
- pars distalis
29
_____ thin layer between anterior pituitary and posterior pituitary
- pars intermedia
30
What part of the anterior pituitary containes cystic remnants of Rathke's pouch?
- pars intermedia
31
What part of anterior pituitary secretes MSH and ACTH?
- pars intermedia
32
______ is an extension of anterior pituitary; forms collar
- pars tuberalis
33
What is another name for collar of anterior pituitary?
- pituitary stalk
| - infundibulum
34
_____ secretes bulk of pituitary hormones including both direct acting and trophic hormones
- Pars distalis
35
What direct acting hormones does the pars distalis secrete?
- GH and prolactin
36
What tropic hormones does pars distalis secrete?
- TSH, ACTH, FSH, LH
37
What are secretory cells of the anterior pituitary that stain?
- chromophils
38
What are the secretory cells of the anterior pituitary which dont stain?
- chromophobes
39
what are the two types of chromophils?
- acidophils
| - basophils
40
_____ stain with acidic dye; pink on H and E
- acidophils
41
______ stain with basic dye; pale blue to light purple on H&E
- basophils
42
______ small cells, dont take up either dye, clear on H and E, represent inactive cells
- chromophobes
43
What are the subtypes ofo acidophils?
- somatotrophs
| - mammotrophs
44
What are the subtypes of basophils?
- thryotrophs
- gonadotrophs
- corticotrophs
45
____ 50% of cells; sec GH
- somatrophs
46
______ (=lactotrophs) ~20% of cells; secrete prolaction
- mammotrophs
47
What acidophile secrete prolactin and control lactation?
- mammotrophs
48
_____ 5% of cells; secrete TSH (thyrotropin)
- thyrotrophs
49
_______ 5% of cells; secrete FSH and LH
- gonadotrophs
50
_______ 20% of cells; secrete ACTH, MSH, endorphins
- corticotrophs
51
What pituitary is a downgrowth of nervous tissue from floord of third ventricle?
- posterior pituitary
52
What is another name for posterior pituitary?
- neurohypophysis=pars nervosa
| - located ventral to hypothalamus
53
What pituitary has the short stalk or infundibulum which contains axons of neurosecretory origin?
- posterior pituitary
54
______ is composed of support cels called pituicytes and neurosecretory nerve axons
- posterior pituitary
55
Where do the axons of the posterior pituitary store and release products from?
- nerve cell bodies in hypothalamus
56
Secretion of posterior pituitary hormones by axons from nerve cells in hypothalams is know as _____
- neurosecretion
57
What regulates neurosecretion?
- regulated by hypothalamic hypophyseal feedback loop
58
What two hormones does the hypothalmus secrete via posterior pituitary?
- ADH (vasopressin)
| - oxytocin
59
Where are ADH and Oxytocin stored?
- stored in neurosecretory granules in dilations of axons of posterior pituitary know as herring bodies
60
____ controls blood pressure by altering permeability of renal collecting tubules
- ADH
61
Decreased production of ADH leads to
- Increased urine production (as in diabetes insipidus)
62
_______ is synthesized by neuron cell bodies in supraoptic nucleus of hypothalamus
- ADH
63
_____ promotes smooth muscle contraction in uterus and breast (especially during labor and lactation?
- oxytocin
64
_____ is synthesized by neuron cell bodies in paraventricular nucleus of hypothalamus
- oxytocin
65
What nucleus secretes oxytocin?
- paraventricular nucleus
66
What nucleus secretes ADH?
- supraoptic nucleus
67
____ is a bilateral lobulated endocrine gland on anterior/ventral neck
- thyroid gland
68
L and R sides of thyroid gland connect by narrow _____
- isthmus
69
What surrounds the thyroid gland?
- loose connective tissue capsule with fine connective tissue septa
70
_____ is embryologically derived from epithelial downgrowth of fetal tongue?
- thyroid gland
71
Thyroid gland is unique among endocrine glands in storage of large amounts of inactive hormone, an eosinophilic glycoprotein colloid called _____
- thyroglobulin
72
Where is throglobulin stored in thyroid gland?
- stored in extracellular follicles (structural units of thyroid gland, lined by simple,cuboidal epithelium)
73
_____ are structural units of thyroid gland, lined by simple, cuboidal epithelium
- extracellular follicles
74
______ concentrate iodine 30-40X blood levels, and secrete it as thryroglobulin via apical microvillli
- follicular epithelial cells
75
Iodination is very important and leads to
- active hormone
76
What are the active hormones of the thyroid gland?
t3 and T4
77
Triiodothyronine is
- T3
78
Thyroxine is ?
- T4
79
_ is deiodinated in the _____ to form T3, the more potent biologically active form
- T4, liver
80
_____ regulates BMR (also growth and development of nervous system)
- T3 and 4
81
Thyroid hormone deficiency during fetal development impairs neural development and myelination and results in_____
- physical stunting and mental retardation (cretinism)
82
What are the secondary secretory cells in the thyroid gland?
- parafollicular cells (=C cells, clear cells)
| dont stain well
83
Where are C cells located?
- at periphery of follicles or scattered within connective tissue
84
what type of cells in lower vertebrats make up a seperate organ?
- c cells/parafollicular cells
85
C cells secrete ______ which regulate blood Ca levels along with parathyroid hormone
- calcitonin
86
When is calcitonin secreted?
- when you need to decrease serum Ca levels
| - it inhibits osteoclasts
87
What is calcitonin effect on osteoclasts?
- inhibits them and activates osteoblasts
88
Synthesis storage and release of thyroid hormones is under control of ______ from anterior pituitary (adenohypophysis)
- TSH
89
What is enlargement of thyroid?
- goiter
| can be indicative of either hypo or hyper thyroidism
90
_______ is increase in number and size of follicle cells
- hyperthyroidism
91
_____ is an autoimmune rxn which results in decrease in size of thyroid gland
- hypothroidism (can cause enlargment)
92
Insufficient dietary iodine can lead to?
- decreased TH production (cant produce hormone)
- possible hypertrophy with non-functional thyroglobulin
- keep making more and more non function thyroglobulin which keeps accumulating
- hypothroidism
93
What foods can cause hypothroidism?
- cruciforus vegtables
| inhibit iodination of thyroglobulin
94
_____ are small oval endocrine glands associated with thyroid
- parathyroid gland
95
T/F parathyroid gland is usually in two pairs in mammalls (superior and inferior) and present on posterior surface of thyroid gland
- T
96
____ is embryologicaly derived form 3rd and 4th branchial (pharyngeal pouches)
- parathyroid gland
97
_____ secretes parathyroid hormone
- Parathyroid gland
98
What are the effects of PTH?
- increases serum Ca levels
| - it slowly increases serum Ca levels while calcitonin rapidly decreases serum Ca
99
What are 3 ways that PTH increases serum Ca level?
- increases osteoclast activity (inhibits osteoblast)
- increases renal tubular absorption of Ca in kidneys (inhibits resorption of phosphate)
- increase Ca absorption from gut via Vit D
100
______ secretion stimulated by decrease in blood Ca
- PTH
101
It is important to maintain parathyroid integrity during thyroid surgery?
- Yes
102
What are complications with Parathryiod gland during thyroid surgery?
- accidental removal (look like nodules)
- fibrosis due to thyroid healing
- possible to damage them
103
_____ is excess PTH production
- huperparathyroidism
| - leads to bony erosion and lysis
104
What are the two types of secretory cells iin the parathyroid gland?
- chief cells
| - oxyphil cells
105
______ most abundant, secrete PTH
- chief cells
106
______ cells are larger less numerous and stain pink with more cytoplasm
- oxyphil cells
107
How do chief cells stain?
- clear to light pink with dark nuclei and moderate amount of cytoplasm
108
What is the function of oxyphil cells?
- occur in clusters and contain large # of mitochondria, but no secretory vesicles so function unknown
109
T/F fatty infiltration of parathyroid gland is common in older individuals
- T
110
where is the adrenal gland located?
- superior to the kidneys
111
What covers the adrenal gland?
- think connective tissue capsule
112
In mammals andrenal gland is a single endocrine gland with ___ different embryological origins?
- two
113
_____ has mesodermal embryological origin, similar to gonads
- adrenal cortex
114
What regulates the adrenal cortex?
- ACTH secreted by anterior pituitary
115
What type of hormones does the adrenal cortex secrete?
- steroid hormones structurally related to cholesterol precursor
116
What are the 3 functional classes of adrenal hormones?
- mineralocorticoids
- glucocorticoids
- sex hormones
117
______ (e.g aldosterone) control electrolyte and fluid balance, and regulate Na and K levels via Na pumps, especially in renal tubules
- mineralocorticoids
| also regulate blood pressure via JGA
118
____ (e.g., cortisol) stimulate gluconeogenesis and glycogenolysis
- glucocorticoids
| both increase blood glucose
119
What hormone increases metabolism, breakdown of proteins, carbs, and lipids?
- glucocorticoids
120
______ (e.g. androgens) very small ammount, supplement gonadal production
- sex hormones
121
What are the 3 layers of the adrenal cortex?
- Zona glomerulosa
- zona fasciculata
- zona reticularis
122
_____ 15% of cortex, thin, dark staining band
| Secretes mineralocorticoids
- zona glomerulosa
123
what band of the adrenal cortex secretes mineralocorticoids?
- zona glomerulosa
124
_______ 80% of cortex, broad, light-staining band
- zona fasciculata
125
What type of cells does the zona fasciculata contain?
- spongiocytes
126
What layer of the cortex secretes glucocorticoids?
- zona fasciculata
| also secretes small amounts of androgens
127
Stress promotes secretion of cortisol which ______ the immune response.
- decreases
128
_______ 5% of cortex; thin dark staining band
- zona reticularis
129
What part of the andrenal cortex secretes small quantities of androgens and glucocorticoids
- zona reticularis
130
Hypoadrenocorticism
- addisons disease
- failure of adrenal cortex to produce hormone (mineralo and glucocorticoids)
- usually due to atrophy of gland (often caused by autoimmune disease)
131
Decrease in aldosterone leads to
- decrease in ECF volume, hypoatremia, hyperkalemia, mild acidosis => shock, death
132
Decrease in cortisol leads to?
- decrease blood glucose
133
How do you treat hypoadrenoocorticism?
- exogenous administration of mineralocorticoids and glucocorticoids (fluorinef and cortisol)
134
What is cushings disease?
- hyperadrenocorticism
| can be primary or secondary
135
______ is due to general hyperplasia or functional tumor of adrenal cortex => excess cortisol secretion
- primary cushings disease (adrenal hyperadrenocorticism)
136
What is the classical form of cushings disease?
- secondary
| pituitary hyperadrenocorticism
137
what causes 2' hypoeradrenocorticism?
- increase ACTH from anterior pituitary
| from pituitary tumor e.g, adenoma or carcinoma
138
Increased ACTH secretion leads to?
- adrenal hyperplasia and excess cortisol secretion
139
Where does the adrenal medulla embryologically derive from?
- neuroectoderm
140
Adrenal medulla contains ______ which are modified post ganglionic neuronal cells with secretory function (epithelioid in appearance)
- chromaffin cells
141
What controls chromaffin cells?
- controlled directly by preganglionic sympathetic nerve fibers
142
What do chromaffin cells secrete?
- catecholamines
143
What are the catecholamines that chromaffin cells secrete?
- adrenaline (epinephrine)
| - noradrenaline (norepinephrine)
144
Adrenaline and noradrenaline are stored in _____
- cytoplasmic granules called dense core granules
145
What does catecholamine release do?
- has systemic effect on adrenergic receptors throughout body (especially skeletal, cardiac, and smooth muscle)
146
What do catecholamines do in concert with glucocorticoids?
- prepare the body for fight or flight response
147
Adrenaline promotes glycogenolysis in liver as energy source and is responsible for production of ______
- enkephalins
148
______ are endogenous opiates responsible for pain relief
- enkephalins
| body knows pain is eminent in fight or flight so is gearing up
149
_____ is a generally benign functional tumor of chromaffin cells of adrenal medulla
- pheochromocytoma
150
what are the symptoms of pheochromocytoma?
- hypertension, headache, cardiac arrhythmias, chest pain, anxiety, panic attacks, nausea
151
What causes the symptoms associated with pheochromocytoma?
- due to increase epi and norepi secretion
152
Bulk of pancreas contains_____ acini which secrete digestive products into gut
- exocrine acini
153
During development of pancreas ______ cells migrate from duct system and agregate around capillaries of pancrease and form ________
- endocrine cells
| - islets of langerhans
154
______ are distributed throughout exocrine pancreatic tissue?
- islets of langerhans
155
Islet cells of pancrease have what three types?
- alpha
- beta
- gamma
156
______ cells (15-20%) secrete glucagon; increase blood glucose, stimulates glucogenesis, and glycogenolysis
- alpha cells
157
______ cells (70%) secrete insulin, which decrease blood glucose and stimulates intracellular glycogen synthesis
- beta cells
158
What cells of the pancreas secrete glucagon?
- alpha cells
159
What cells of the pancreas secrete insulin?
- beta cells
160
_____ cells (5-10%) secrete somatostatin, which inhibits both insulin and glucagon production
- gamma cells
161
What cells secrete somatostatin which inhibits both insulin and glucagon production?
- gamma cells
162
What do the other miscellaneous cell types of the pancreas secrete?
- vasoactive intestinal peptide (VIP)
| - pancreatic polypeptide (PP)
163
What is insulin deficiency/abnormality?
- diabetes mellitus
164
What characterizes diabetes mellitus?
- hyperglycemia (increased blood glucose)
| - glucosuria (glucose in urin)
165
Decrease in insulin would be what type of diabetes?
- type I
166
Adult onset diabetes, which is the decrease in insulin receptors or decrease responsiveness is what type?
- type II
167
what is the only product that decreases blood glucose?
- insulin
168
what gland is 6-8 mm long, located anerodorsal to cerebellum and develops from neuroectoderm as evagination of posterior portion of third ventricle, from roof of diencephalon?
- pineal gland
169
What is the function of pineal gland?
- communicates with hypothalamus and acts as photoreceptor in lower vertebrates (third eye)
170
_____ translates light intensity and duration (photoperiod) into endocrine activity which is important in circadian rhthyms and seasonal reproductive cycles
- pineal gland
171
What does the pineal gland secrete?
- melatonin and seratonin
172
_____ stimulates melanophores, chromatophores [pigment containing cells]) which leads to change in color intensity with reproductive cycle
- melatonin
173
____ is a vasoconstrictor; and neurotransmitter that deals with pleasure
- serotonin
| ectasy
174
What is the effect of melatoniin in mammals?
- anti-gonadal effect which decreases sex activity
175
Melatonin leads to?
- decrease in GNRH from hypothalamus which decreases sex hormone secretion from gonads
176
Mammals
- warm blooded furry and suckle their young
177
Melatonin is stimulated by?
- darkness
178
What is the most common cell in the pineal gland?
- pinealocytes
| modified neurons, secrete melatonin and serotonin
179
_____ are interstitial cells, support cells such as astrocytes and microglial cells
- neuroglial cells
180
Might also see _____ in pineal gland (=brain sand, pineal sand)
- corpora arenacea
181
corpora arenacea are?
- calcified accretions of Ca and Mg phosphate in aging individuals
