Endocrine System 1: Pituitary, Pineal, Thyroid, & Parathyroid Flashcards
(122 cards)
1
Q
How does the endocrine system communicate?
A
- chemical messengers (hormone)
- carried by bloodstream
2
Q
Endocrine organs are composed of
A
secretory cells of epithelial origin
3
Q
Endocrine lack
A
DUCTS
4
Q
Endocrine vs nervous control
A
endocrine is slower onset & longer duration
5
Q
Hypothalamus
A
coordinates endocrine functions of body
acts as intermediary between autonomic nervous system & endocrine system
6
Q
Most endocrine glands form
A
discreet organs
Anterior pituitary, pineal, thyroid and suprarenal (adrenal)
7
Q
In the pancreaus
A
endocrine & exocrine tissue intermixe
8
Q
Pituitary (hypophysis) is suspended by
A
a stalk from hypothalamus
9
Q
The pituitary rest in the
A
sella turcica of the sphenoid bone
posterior to he optic chiasm (CN II)
10
Q
WHat are the two major divisons of the Pituitary?
A
- Adenohypophysis (Anterior pituitary)
- Neurohypophysis (Posterior pituitary)
11
Q
Secretion of pituitary hormones is conrolled by
A
hypothlamus
12
Q
hypophyseal portal system allows
A
communication with hypothalamus
pititary
13
Q
How does the Hypothalamus controls secretion of
anterior pituitary
A
hypothalamic regulating factors (hormone
14
Q
Releasing factors stimulate
A
secretion
15
Q
inhibitory factors inhibit
A
secretion
16
Q
Direct acting hormones have
A
non-endocrine target organ
17
Q
What are examples of direct acting hormones?
A
GH, ADH, MSH, oxytocin, prolactin
18
Q
Trophic hormones
A
target organ is another endocrine gland
19
Q
What are examples of trophic hormones?
A
TSH, ACTH, FSH, and LH
20
Q
What are pituitary-dependent endocrine glands?
A
Thyroid gland, adrenal cortex, & gonads
21
Q
Anterior portion of the pituitary contains
A
glandular epithelial tissue
22
Q
posterior of the pituitary contains
A
neural secretory tissue
23
Q
Anterior pituitary =
A
- “Master gland”
- adenohypophysis
- pars anterior
- pars distalis
24
Q
Rathke’s pouch is
A
Specialized glandular tissue, arises from evagination of tissue from oral cavity in region of pharynx
25
What are the 3 regions of Rathke's Pouch
* pars distalis
* pars intermedia
* pars tuberalis
26
pars distallis
bulk of anterior pituitary
27
What part of the pituitary is the Rathke's Pouch?
anterior pituitary
28
pars intermedia
* thin layer between anterior & posterior pituitary
* Secretes MSH & ACTH
* Frequently contains cystic remnants of Rathke’s pouch
29
What secretes MSH and ACTH?
pars intermedia
30
pars tuberalis
* extension of anterior pituitary
* forms collar ~pituitary stalk (=infundibulum)
31
Pars distalis secretes
bulk of pituitary hormones, including both direct acting & trophic
hormones
32
What direct acting hormones does the pars distalis secrete
GH and prolactin
33
What trophic acting hormones does the pars distalis secrete
TSH, ACTH, FSH, LH
34
Secretory cells of anterior that stian
chromophils
35
Secretory cells of anterior that do not stain
chromophobes
36
what are the two types of chromophils
* Acidophils
* Basophils
37
chromophils -Acidophils
* stain with acidic dye
* pink on H&E
38
chromophils- Basophils
* stain with basic dye
* pale blue to light purple on H&E
39
Chromophobes are
* small cells
* don’t take up either dye
* clear on H&E
* represent inactive cells
40
What are the types of Acidophils?
*Somatotrophs
* Mammotrophs
41
Somatotrophs
secrete Growth Hormone (somatotropin)
42
What secrete growth hormones
Somatotrophs
| is an Acidophils which is a subtype of chromophils
43
Somatotrophs make up
50% of cells
44
Mammotrophs secrete
prolactin
45
What secretes prolactin?
Mammotrophs
| is an Acidophils which is a subtype of chromophils
46
Mammotrophs make up
20% of cells
47
Somatostatin inhibits
somatotropin
| growth hormone hormone
48
ghrelin
* stomach enteroendocrine cells
* coordinates food intake with GH secretion
49
What inhibits the release of prolactin?
| inhibits Mammotroph
dopamine
50
Prolactin stimulates
initiation & maintenance of milk
production postpartum
51
What are the 3 types of Basophils?
| chromophils subype
* Thyrotrophs
* Gonadotrophs
* Corticotrophs
52
Thyrotrophs make up
5 % of cells
53
Thyrotrophs secrete
Thyroid Stimulating Hormone
| thyrotropin
54
What secretes Thyroid Stimulating Hormone?
Thyrotrophs
| is an Basophils which is a subtype of chromophils
55
Gonadotrophs make up
5% of cells
56
Gonadotrophs secrete
Follicle Stimulating Hormone (FSH)
& Lutenizing Hormone (LH)
57
what secretes Follicle Stimulating Hormone (FSH)
& Lutenizing Hormone (LH)?
Gonadotrophs
| is an Basophils which is a subtype of chromophils
58
Corticotrophs make up
20% of cells
59
Corticotrophs secretes
Adrenocorticotropic hormone (ACTH), Melanocyte-stimulating hormone (MSH), endorphins
60
What secretes Adrenocorticotropic hormone (ACTH), Melanocyte-stimulating hormone (MSH), and endorphins?
Corticotrophs
| is an Basophils which is a subtype of chromophils
61
What is the order from most to least abunded the cell subtypes of chromophils?
* Somatotrophs
* Corticotrophs
* Mammotrophs
* Gonadotrophs &Thyrotrophs
| Sally Can My Girl Twerk
62
Pituitary gigantism
excessive production of growth hormone
**beginning in childhood**
63
What is usually the cause of death of those with Pituitary gigantism?
heart disease or diabetes
64
Pituitary gigantism is due to
loss of feedback control of growth hormone secretion or
to GH-secreting tumor in pituitary
65
Acromegaly
excessive **adult** production of growth
hormone
66
Acromegaly features
* Growth of face (prognathism), hands &
feet
67
What are treatments for Acromegaly?
* surgery, radiation
* growth hormone receptor antagonis
68
Acromegaly is due to
loss of feedback control of growth
hormone secretion or to GH-secreting tumor in pituitary
69
Pituitary Dwarfism
Growth retardation resulting in
abnormally short adult stature
70
Pituitary Dwarfism is caused by
insufficient growth hormone
71
What are tx for Pituitary Dwarfism?
injections of growth hormone
72
Secretion of Prolactin is mediated primarily by
inhibition control mediated by dopamine
73
Scretion of Prolactin is stimulated by
PRH but suckling during lactation
is the primary stimulus.
74
WHat can act as a birth control?
prolactin
75
How does prolactin act as a birth control?
* inhibits the pulsatile secretion of GnRH
* which suppresses secretion of FSH & LH
76
Pituitary macroadenoma
* >10 mm
* tumor in pituitary
77
Pituitary macroadenoma can impinge
optic chiasm
* producing visual field defects
* (classically: bitemporal hemianopsia
78
ACTH stimulates
| adrenocorticotropic hormone
hormone release by the
adrenal (suprarenal) cortex
79
LPH stimulates
* lipid mobilization in some mammals
* precise role in humans in unknown
80
FSH stimulates
| follicle-stimulating hormone
ovarian follicle development/estrogen secretion or
production of androgen binding protein by Sertoli cells.
81
LH helps control
| luteinizing hormone
* menstrual cycle
* also triggers the release of an egg
82
thyroid stimulating hormone Stimulates
thyroid gland to synthesize, store &
release thyroid hormones
83
TSH is regulated by
| inhibiting
negative feedback loop
| CNS
84
What are Chromophobes
* undifferentiated (stem) cells
* folliculostellate cells
85
86
Pars Intermedia Synthesize
proopiomelanocortin
| stimulate melanin production
87
melanin spread through the
branches of specialized melanocytes calle
melanophores
88
Posterior pituitary is a Downgrowth of
neural ectoderm of hypothalamus
89
Infundibulum
* talk/stem carries axons from hypothalamus
* ontains portal veins & primary capillary plexus
90
Pars nervosa
axon terminals
91
ADH (Vasopressin)—controls
blood pressure by altering
permeability of renal collecting tubules/ducts
92
↓ production of ADH
↑ urine production (as in diabetes insipidus)
93
ADH is synthesized by neuron cell bodies in
supraoptic nucleus of
hypothalamus
94
Oxytocin promotes
smooth Mm contraction in uterus &
breast
| especially during labor & lactation)
95
oxytocin is Synthesized by neuron cell bodies in
paraventricular nucleus of hypothalamus
96
What hormones does the posterior pituitarty release?
* ADH
* Oxytocin
97
Herring bodies
* Endings form large, fusiform swellings
*filled with secretory product
98
Pars nervosa is Surrounded by
specialized glial-like cells called
pituicytes
99
pituicytes
* specialized glial-like cells
* surround pars nervosa
100
Pineal Gland is also know as
* epiphysis cerebri
* pineal body
101
Where is the Pineal Gland found?
* posterior extremity of the third ventricle
* attached by the pineal stalk to the diencephalon
102
The pineal Gland communicates with the
hypothalamus
103
in lower vertebrates the pineal gland acts as
a photoreceptor
104
the pineal gland secretes
melatonin
105
what gland secretes melatonin
pineal gland
106
Melatonin stimulates
melanophores and chromatophores
107
when stimulated melanophores and chromatophores
change in color intensity
with reproductive cycle & serotonin
108
In mammals, melatonin
has anti-gonadal effect, ↓ sex activity
109
Melatonin
| decreases
↓ GNRH from hypothalamus =>
↓ sex hormone secretion from gonads
110
What is the most commom cell type in the pineal gland?
Pinealocytes (95%)
111
Pinealocytes are arranged in
clumps and cords
within the lobules
112
Neuroglial cells
support cells such as
astrocytes, microglial cells
113
Corpora Arenacea
| Brain Sand
Calcified accretions of Ca & Mg
phosphate
114
Corpora Arenacea are found in
aging individuals
115
corpora arenacea are calcified accretions of
Ca and Mg phosphate
116
Melatonin synthesis and secretion is affected by
light exposure to the eyes
117
Melatonin helps establish
body’s circadian rhythm
118
Seasonal Affective Disorder sufferers
| SAD
experience depressive
symptoms in the winte
119
Where is SAD rare
in the tropics
120
What are the typical symptoms of SAD?
* increased need for sleep
* a craving for sweets
* weight gain
121
SAD is a subtype of
major depressive episod
122
