Block 4 general Flashcards
(134 cards)
1
Q
female genital ducts and glands derive from
A
UG sinus, paramesonephric ducts
2
Q
what kind of process is sexual determination of female?
A
active
3
Q
what supports persistence and devel of paramesonephric ducts?
A
estrogens
4
Q
what does the unfused portion of the paramesonephric duct become?
A
uterine tubes
5
Q
what does the fused portions of the paramesonephric duct become?
A
uterus and superior vagina
6
Q
what develops from the UG sinus?
A
inferior vagina bladder, urethra, paraurethral glands, greater vestibular glands
7
Q
bicornate uterus
A
incomplete fusion of the paramesonephric ducts
8
Q
what happens to primitive sex cords in females?
A
primitive sex cords dissociate in females and second generation of cortical cords develop
9
Q
where do the gonadal ridges appear?
A
gonadal (or “genital”) ridges appear on the medial surface of the urogenital ridges
10
Q
what does the genital system consist of
A
gonads genital ducts and glands external genitalia
11
Q
what are the three events initiating puberty
A
1) proper nutrition 2) gene activation 3) development of limbic system
12
Q
A 15 year-old male does not demonstrate any signs of puberty. He is short for his age, his testicles show no evidence of enlargement, his testosterone levels are low, and he has a reduced ability to smell.
A
Kallmann syndrome
- KAL1 gene deficiency
- KAL1 induces migration of nerves from olfactory placode to olfactory bulb
- responsible for differentation and migration of GnRH secreting nerves
- Lack of GnRH results in ↓ LH, FSH, testosterone, sperm count
13
Q
IGF-3
A
- allows descent of testes
- under influence of gene HOXA10
14
Q
precocious puberty
A
premature development of genital organs and secondary sexual characteristics
- can be due to GnRH secreting tumor (optic glioma or hypothalmic astrocytoma)
15
Q
chromophils
A
- acidophils (40%)
- basophils (10%)
- part of pars distalis of the anterior pituitary
- ectoderm origin
- synthesize and secrete a variety of hormones
- each type generally secretes a single hormone
- arranged in cords; envolped by a delicate covering of connective tissue
- large cells, alot of RER, well developed Golgi complex, many secretion granules
- become chromophobes when they dump their hormones
16
Q
chromophobe
A
chlorophils that have released their specific hormones and are “degranulated” and thus stain poorly
17
Q
Identify
A
Chromophils
- large cells, much RER,well developed Golgi complex, many secretion granules (contain hormone)
18
Q
Idenitfy circled structure
A
Chromophobe
- chromophils that have released their specific hormones and are “degranulated”
- therefore, stain poorly
19
Q
Steroidogenic TF
A
promotes gonadotroph lineage
20
Q
T-box TF (“Tpit”)
A
promotes the corticotroph lineage
21
Q
POU1F1
A
- encodes a POU domain
- this domain is essential for differentiation and expansion of somatotrophs, lactotrophs and thyrotrophs
- transcription factor
- mutations - responsbile for GH, PRL and TSH deficiencies
22
Q
supraoptic nuclei
A
ADH
23
Q
Paraventricular nuclei
A
oxytocin
24
Q
hypothalamic nuclei
A
cell bodies of neurosecretory neurons that releasing or release-inhibiting hormones are synthesized
25
how do release/release-inhibiting hormones reach their target cells in the pars distalis?
hypophyseal portal system
26
Hypophyseal Portal System
primary capillary plexus, portal venules and secondary capillary plexus
27
colloid cysts
found in **pars intermedia**
* colloid = viscous material within
* cyst = encapsulated structure
28
Identify
**Pars nervosa** (of the **posterior pituitary**)
* dots are **nuclei of glial cells**
* axons are the stringy lines throughout (where the lines are pointing)
* stores neuroendocrine secretions made by the neurons of the hypothalamus
29
Identify
Herring bodies
* found in the **pars nervosa** of the **posterior pituitary**
* large swellings formed by ends of axons
* stores oxytocin (from paraventricular nuclei) and ADH (from supraoptic nuclei)
30
Identify
**Pars nervosa** of the posterior pituitary
* can visualize axons (arrows pointing to them) and lots of secretory vesicles that are storing hormones
* Oxytocin (from paraventricular nuclei of hypothalamus)
* ADH (from supraoptic nuclei of hypothalamus)
* axon terminals end near fenestrated capillary
31
Diabetes insipidus
excessive thrist and urination due to **inadequate secretion** or **utilization** of vasopressin / ADH
* could be caused by damage to hypothalamus, damage to pituitary stalk, brain tumors
* neurogenic
* mutations in neurophysin II
* nephrogenic
* mutation in V2 receptor, aquaporin channel
32
What do corticotropes express?
express ACTH, contains alpha MSH
therefore, stimulates cortisol synthesis in adrenal gland but IN EXCESS, will stimulate melanin produciton in melanocytes (recall that hyperpigmentation allows differentiation between primary and secondary adrenal insufficiency)
33
A 15-year-old male presents to his pediatrician with complaints of **fatigue, weight loss, and recurrent nausea and vomitting**. On physical exam he appears weak and has skin that appears **abnormally tan**. A basic metabolic panel reveals **hyponatremia** and **hyperkalemia.**
Addison disease / Primary adrenal insufficiency
* elevated plasma ACTH
* low cortisol levels in response to ACTH stim test
* decreased aldosterone, therefore
* hyponatremia
* hyperkalemia
* hypoglycemia
* increased BUN & Cr
* metabolic acidosis
* eosinophilia
34
secondary adrenal insufficency
no hyperpigmentation and overall decreased ACTH
## Footnote
due to: isolated failure of ACTH production
35
JAK tyrosine kinase
* the type of tyrosine kinases that **GH and prolactin** receptors associate with
* **activate STAT**
* which regulates transcription
36
STAT
* activated by JAK tyrosine kinase (which is activated by association with GH and prolactin receptors)
* regulates transcription
37
GH release type
GH is a peptide hormone and therefore release is exocytosis
38
mucosa
epithelium
lmaina propria
muscularis mucosae
39
serosa
epithelium and CT
40
muscularis externa
longitudinal muscle and circular muscle
41
isthmus of gastric mucosa
parietal cells
42
neck of gastric mucosa
neck mucous cells
stem cells
parietal cells
43
base of gastric gland
* peptic cells
* parietal cells
* mucous cells
* neuroendocrine cells
44
What kind of cells in the stomach make histamine
ECL
45
What kind of cells make gastrin?
G cells in the pylorus of the stomach
46
Gastrin
* made by G cells of the pylorus
* peptide
* increases secretion of HCL, pepsionogen
* Increases motility
47
What are the direct ways of promoting HCl release from the parietal cells?
ACh acts on muscarinic reeptor
Gastrin acts on CCK receptor
48
Whats an indirect ways of promoting HCl release from the parietal cells?
Acetylcholine and gastrin can work to stimulate the ECL cell, which causes the ECL cell to release **histamine**
* histamine will then act on H2 receptor to directly stimulate parietal cell to release H
49
enteroendocrine cells
* "neuroendocrine cells"
* must be stained with certain antibodies
* involved in coordination of GI funciton
* anatomically dispersed throughout GI tract
* Receive and send signals
50
three phases of bacteria in stomach
**1. Active phase -**produce ammonia to increase pH through "urase"
**2. Stationary phase** - attach to a receptor on cell; make proteases, get nutrients from cell, attract leukocytes
**3. Colonization phahse** - detach from receptor, replicate and then attach to sialic and acid cotaining proteins in mucus blanket
51
Hormones made in pylorus of the stomach
gastrin
somatostatin
52
histological features of pyloric stomach
deep pits and short, coiled glands
53
histological features of the cardiac stomach
equal lengh pits and glands
54
histological features of the fundic stomach
short pits with long glands
55
Identify
Microvilli
* actin filaments extend down where they attach to termianl web
* core of actin filaments are crosslinked by several actin binding proteins
* number and shape associate with absorptive capacity
* glycocalyx is an amorphous coat of glycoprotein
* have plasmalemma
* found at **apical surface of enterocytes**
* ****have lactase, maltase and sucrase
56
Three places enzymes in duodenum come from
1. liver/gall baldder
2. microvillus brushboarder of enterocytes
3. pancreas
57
cholecystokinin
* from intestine
* slows down emptying of stomach by acting on pyloric sphincter
* stimulates bile release from gallbladder and secretion of pancreatic enzymes
*
58
Secretin
* stimulates pancreatic bicarbonate secretin
* enhances insulin secretion by B cells of the islet of Langerhans
59
Gastrin
* stimulates HCl secretion from **parietal cells**
* stimulates insulin secretion from **B cells on islet of langerhans**
* stimulates gastric motility and growth of mucosal cells
60
Teniae coli
equally spaced bands of outer longitudinal layer of muscularis externa
61
haustra coli
sacculations between teniae coli; parts of colon contract independently
62
funcitons of the colon
* recovery of water, salt and fat soluble vitamins
* Na/K ATPase driven system
* get fat soluble vitamins derived from bacetrial activity
63
What are some histological features that can help you identify the large intestine?
you will not see any villi or plicae
the mucosa has straight, tubular glands that are arranged like testubes
64
Crypts of Liberkuhn
* found in both small and large intestine
* simple columnar epithelium
* glands
65
Four cell types of the large intestine epithelium
1. mucus producing **goblet cells**
2. absorptive cells
3. regenerative cells
4. enteroendocrine cells - release paracrine hormones
66
Hirschprung's disease
* agangionosis - arrest in migration of neural crest cell (precursor cells for ganglion cell)
* permanently contracted distal segment - no entry of contents
* "megacolon" = congenital malformation
* mutuation in four different genes which regulate differntiation and migration of neural crest cells that form enteric nervous system
67
what does a deficiency of AVP cause?
* recall AVP = arginine vasopressin = ADH
* an ADH deficiency prevents sodium and water reuptake
* therefore, deficiency in ADH means the patient cannot concentrate urine, resulting in production of large quantities of dilute urine
note: release of AVP is more sensitive to small changes in plasma osmolarity than to small changes in blood volume
68
what is the most important factor regulating ADH secretion
increased plasma osmolarity
69
prolactin inhibits
GnRH release (thereby decreasing FSH and LH)
70
menopause
permanent cessation of menstruation resulting from loss of **ovarian follicular activity**
71
where is thyroid hormone metabolized
* IN THE PERIPHERY
* aka mainly the liver
* therefore, in graves disease, youre going to have increased cAMP in the THYROID
72
How does estrogen inhibit differentiation and activation of osteoclasts
estrogens suppress activation by inhibiting M-CSF and RANK-ligand from the osteoblast
recall: the osteoblast secretes M-CSF , which causes the monocyte precursor to express a RANK receptor, which then binds the RANK-ligand which is secreted from the osteoblast
THIS HELPS EXPLAIN OSTEOPOROOSIS!!! because in menopause, ovaries not producing estrogen, thus estrogen can't inhibit bone resorption
73
osteoprotegin
* binds to RANK-L and prevents it from causing osteoclast differntiation and activity
* osteoprotegin is stimulated by estrogen
* osteoPROTEC(T)gin - it protects against osteoporsis
* when no more estrogen (menopause), no more osteoprotecgin, therefore, can get osteoporosis
74
hepatic failure effect on TBG
* TBG = thyroxine-binding globulin
* this is what T3 and T4 bind to in circulation
* TBG DECREASES in hepatic failure (unlike pregnancy where it increases)
* this decrease causes
* **decrease** in **total thyroid hormone** levels
* **normal** levels of **free hormone**
75
TBG in pregnancy
* TBG = thyroxine-binding globulin
* this is what T3 and T4 bind to in circulation
* TBG INCREASES in pregnancy (unlike hepatic failure where it decreases
* this increase causes
* increase in total thyroid hormone levels
* normal levels of free hormone
76
what enzyme converts T4 to T3
5'-iodinase
77
Result of dexamethasone suppression test in patient with **Adrenal Cushings Syndrome**
* in **adrenal cushings syndrome** the adrenal gland is just making its own cortisol for no reason
* therefore, the levels of ACTH are low (its not that the pituitary is secreting too much ACTH)
* the cortisol secretion will NOT be suppressed by dexamethasone because its not the pituitary's problem
* the adrenal gland is just over secreting tumor without the message from the pituitary (ACTH)
78
Result of the dexamethasone supppression test in a patient with an **ectopic ACTH secreting tumor (ex: NSCLC)**
* with an **ectopic ACTH secreting tumor** levels of ACTH are high
* as a result, will have excess cortisol secretion
* however, because the tumor is **ectopic** the ACTH is not coming from the anterior pituitary
* therefore, a dexamethasone suppression test will result in NO suppression
79
Result of the dexamethasone suppression test in a patient with pituitary adenoma?
* pituitary tumor causes increased secretion of ACTH therefore ACTH levels are high
* high levels of ACTH cause high levels of cortisol
* using the dexamethasone suppression test WILL result in suppression because the dexamethasone at such a high does will cause the pituitary to get some negative feedback and then should get decr in ACTH and the cortisol prod should decr
80
What conditions can the dexamethasone suppression test be used to differnetiate between?
* cushings syndrome tumor (normal ACTH, adrenal gland secreting excess cortisol)
* ectopic ACTH secreting tumor (NSCLC)
* pituitary adenoma (excess ACTH secretion from anterior pituitary)
81
what makes and secretes PTH
chief cells of the parathyroid glands
82
what makes calcitonin
parafollicular cells of the thyroid gland ("C-cells")
83
spironolactone
potassium sparing diuretic; aldosterone antagonist
used to treat **Conn's syndrome** - which is an aldosterone secreting tumor
84
what factors increase 1 alpha hydroxylase activity
1 alpha hydroxylase makes active form of vitamine D in the kidney!!!
decr serum calcium
incr PTH
decr serum phosphate
85
decreased Ca
increased PO4
response to PTH administration
hypoparathyroidism
(note: increase in PO4 is incr in blood PO4 , while the urinary phospahte is decraesed (becasuse more is reabsorbed into systemic circ))
86
decr Ca
decr PO4
vit D deficiency
87
88
onset of menopause is indicated by
onset of irregular menses
89
what causes contractions in early labor
estrogen induction of PROSTAGLANDIN!!!!
90
placental hPL
increases diabetogenicity in pregnancy; **glucose** is **major energy source** for the fetus; therefore hPL (which is similar to prolacitn) **inhibits maternal glucose uptake** in order to provide more avaliable glucose for baby
91
92
93
94
95
What delays puberty in boys?
* decreased leptin
* obesity
96
What does elevated leptin do to puberty in females?
causes precocious puberty
97
What does definitive zone give rise to?
zona glomerulosa
98
what does the transitional zone give rise to?
zona fasiculata
99
3rd pharyngeal pouch
thymus and the inferior part of the parathyroid gland
100
cleft
outside
101
pouch
inside
102
arch
cleft outside and pouch inside; the arch is the whole thing
103
what does the arch come from
mesenchyme
104
when do pharyngeal arches go to develope face, palate, ears
wk 4
105
how does the external auditory meatus form?
when the cleft meets up with pouch
pharyngeal arch 1
106
what does #2,3,4 form?
cervical sinus
107
what nerves do the pharyngeal pouches correspond to
**M**andibular (V)
**F**acial (VII)
**G**lossopharyngeal (IX)
**V**agus (X)
108
what are the three parts of the **intermaxillary segment**
labial
jaw
palate
109
What nerve comes from the midbrain
V3
110
What nerves of the pharyngeal pouches come from the hindbrain
facial, glossopharyngeal, vagus
111
location of the myoid cells (aka the myoepithelial cells)
between the basement membrane and the plasma membrane of the sertoli cells
112
5 alpha reductase
causes the conversion of testosterone to DHT
113
What information does the carotid sinus sense and how does it take that information to the brain?
the carotid sinus has **baroreceptors** therefore senses pressure; communicates informatino to brain via the glossopharyngeal nerve (IX)
114
lactose
glucose + galactose
115
what kind of cells predominate in the sublingual gland?
mucus secreting cells ; apical region is occupied by mucin-filled secretory vesicles
116
117
epithelium in stomach
simple columnar
118
119
gastrulation
week 3 - converts bilaminar embryo to trilaminar embryo
120
intermediate mesoderm
part of mesoderm that gives rise to
* UG system
* ducts
* seminal vesicle
* upper vagina
121
what gives rise to prostate
Endoderm
122
what gives rise to urinary bladdar??
endoderm
123
\_\_\_\_\_ is a longitudinal elevation of the intermediate mesoderm
urogenital ridge
* recall gonadal/genital ridge appear on the midline of the urogenital ridge
124
Describe the descent of the testes
* **reach inguinal** region around 12 weeks
* acutally migrate **through the inguinal canal** ~28 weeks
* reach **scrotum** 33 weeks
125
cryptorchidism
* testes doesnt descend as they should
* either remains in inguinal region, pelvic cavity or at top of scrotum, rather than descending to their normal location toward bottom of scrotum
126
when is genetic sex determiend?
at fertilization
127
secondary cortical cords
only develop in females; do not develop in males
128
what do testes cords contain?
germ cells and sertoli cells
129
what do leydig cells derive from?
mesenchyme
130
in males, what do mesonephric ducts devleop into
the leydig cells make testosterone, which allow mesonephric ducts to develop into: epididymous, vas deferens , seminal vesicle, ejaculator duct
131
what is the normal path of sperm
seminiferous tubules --\> rete testes --\> efferent tubules --\> epididymus -\> vas deferens
132
cloaca
expanded caudal poriton of hindgut
133
urorectal septum
divides the cloaca into the **rectum** and the **urogenital sinus**
134
UG sinus in male becomes
bladder, bulbourethral glands, prostate, most of male urethra
