Endocrinology Flashcards
What part of the brain has no real BBB
Hypothalamus
What are two parts of the hypothalamus
anterior and posterior pituitary
Which is neuro and which is adeno: Anterior or posterior pitutitary
Neuro: Posterior pituitary
Adeno: Anterior Pituitary
Where does the pituitary gland sit
Inside the sella tursica in the center of the skull/sphenoid bone
What does the secretory neuron/axons do
Take oxytocin and ADH to the post pituitory to store it
Where does the neurohypophysis come from?
from neuro ectoderm of the forebrain to make the posterior pituitary
Where does the adenohypophysis come from?
the rafkies pouch and grows backward to make the anterior pituitary
which pituitary makes its own hormonal output
Anterior pit
The portal venous system is where?
between hypothalamus and anterior pituitary
What does the anterior pituitary make
TSH, ACTH, Growth Hormone, Prolactin, FSH, LH
What makes oxytocin and ADH?
The hypothalamus, its secreted to the posterior pituitary by secretory neurons/axons
Stored in the posterior pituitary
What does oxytocin do?
smooth muscle contraction
How do second messinger systems work?
They bind peripherally and that causes a receptor on the cell membrane to activate and cause second messingers inside the cell to do something specific for the cell
Steroid vitamin D get in the cell how?
They are lipophillic they go through the cell bind to receptor inside cell and activate
Is thyroid lipophilic
no
ACTH Acts where and does what
adrenal cortex for cortisol production
LH Acts where and does what
Testies, ovary, oestrogen, androgen, ovulation and progesterone
TSH Acts where and does what
thyroid for T4 and T3
Prolactin Acts where and does what
breast for lactation
GH Acts where and does what
growth hormone for growth
FSH Acts where and does what
spermatogenesis follicle growth
what is the classic disease of hypopituitary when there is loss of anterior pituitary out
sheehan’s syndrome/empty sella syndrome
what is the classic disease of hypopituitary when there is loss of posterior pituitary out
diabetes insipididus
What happens in diabetes inspidius
NO ADH from posterior pituitary leads to inability to concentrate the urine and unquenchable thirst that wakes the up at night.
electrolyte disturbances
Hyperpituitarism is from what
the anterior pituitary usually an adenoma
What is the most common adenoma
Prolactinoma
What is somatotropic adenoma secreting and what does it lead to
Excess GH leads to acromegaly(adults) and giantism(kids)
What do corticotrophic tumors secret
ACTH leads to cushings syndrome
What two cells manufacture thyroid hormone
follicular and colloid cells
____+____=thyroid horomone
Tyrosine + Iodine
what thyroid is imported
T3Leio
T4Levo
What enzyme imports Iodine from I- to I2
Oxidation peroxidase
What happens to T3 and T4
- the free form is taken to target tissues when stimulated by TSH
- it is conjugated in bile and gets excreted
What T3 or T4 is active and has a membrane receptor
T3
What enzyme converts T4 to T3
5’deiodinase
What enzyme reduces testosterone
5alpha reductase
What are the cellular actions of T3
Increased metabolism(mitochondrial activity) Increased cell turnover (DNA-mRNa-Protein)
What is body temperature
what hormone effects it
The sum of all mitochrondrial activity
Thyroid can affect it
MC cause of low thyroid
hashimotos thyroiditis
What is graves disease
sx:
Hormones:
thyroid toxicosis/hyperthyroidism
sx: lid retraction, lid lag, proptosis, goiter
Hormones: Increased T3 and T4 low TSH
What is dequervain’s thyroiditis
subacute granulomatous
, begins with hyperthyroid, then goes hypo then euthyroid
Reidels thyroiditis
Rock hard woody thyroid that mimics carcinoma, fibrotic proliferation may cause hpothyroidism
Goiter types
Simple: definciency of iodine or too many goitrogens (calcium and fluorine in water, brassicae, polluted water) commonly graves
Multinodular goiter: large, often mistaken for cancer
Are adenomas of the thyroid benign of malignant
who are they most commonly seen in
90-99% benign may cause pressure symptoms
post menopausal women
What are most malignant tumors of they thyroid
papillary carcinoma
Calcitonin
- what does it do
- where is it produced
- What does it act on to do what
It lowers blood calcium
Made by the parafollicular cells
Acts on
bone: inhibits reasorption by osteoclasts
Kidney: increases ca, na, k excretion and decreases mg excretion
What does parathyroid horome do and how?
raises serum calcium when low by acting on vitamin d to decrease calcium excretion
What is the acronym for order of layers of the adrenal cortex
GFR Salt Sugar Sex the deeper you go the sweeter it gets
2 layers of the adrenal glands are?
cortex::(corticosteroids)
medulla(sympathetic stimulation)
What is the medulla made of and what is it stimulated by to do what?
Made of chromafin cells
stimulated by sympathetic nervous system
makes epi and ne
What three things does the adrenal cortex make, what zones make it and whats the correct order from outer to inner
Zona Glomerulosa-aldosterone
Zona Fasciculata: cortisol
Zona reticularis: sex steroids
What is the mineralcorticoid in the body
aldosterone
What happens to calcium in hyperparathyroidism
Elevates
___serum calcium and ___serum phosphate is seen in what disorder
hypoparathyroidism
Chovesteks/trousseaus sign is seen in what
hypoparathyroidism
pheochromocytoma
Tumor limited to adrenal medulla only
secretes catecholamines=epi+ne
neuroblastoma: is it confined to the adrenal medulla?
childhood tumor of adenal that you are born with
NO
what is a neurological germ cell tumor that is not limited to the adrenal medulla
neuroblastoma
Hypoadrenalism, low cortisol, high ACTH
what else will you see?
Addisons
Low NA, Cl, cortisol and increased K
Hyperadrenalism, ectopic ACTH, high cortisol
cushings
moon like faces, buffalo hump, osteopersosis
What is a solitary aldosterone secreting adenoma in the adrenal cortex?
Conns syndrome
will also see low renin and potassium high na and aldosterone
What does aldosterone do and where?
tells you to excrete potassium and save sodium in the distal tubule
What are the steps to making epi
Tyroisin-L-dopa-Dopa-Ne-Epi
Where do we see N-methyl transferase and what does it do?
adrenal medulla
NE–>Epi requies SAMe, B12 folate
What does epi do in adipose tissue
activates hormone lipase to break down fat
What does epi do the liver or muscle
controls phosphorylase a to break down glycogen into glucose
What is the parent steroid that all other steroids are made from and what is it made from
pregnenolone
from cholesterol
What stimulates aldosterone
ACTH, HyPERKALEMMIA, angiotensin 2
Where does ACE come from and what does it do
comes from the lung to convert angiotensin I to angiotensin II
where is angiotensinogen from and what activates it
the liver activated by renin from the JGA cells in response to low blood volume and GFR
What type of pancreas is ductless
endocrine pancreas
exocrine pancreas has ducts
If the endocrine pancreas is ductless what does this
mean?
ducts?
it means it secretes directly into the blood stream
Ducts: has tubular ducts that make digestive enzymes, lined with cuboidal epithelium
what are the ducts of the pancreas lined with
cuboidal epithelium
Alpha cells of the pancrease secrete what
glucagon
What do the beta cells of the pancreas do
secrete insulin
What do the delta cells of the pancreas do?
secrete somatostatin
Whats happening in type one diabetes
you have anabolism happening and you are breaking yourself down leading to ketosis due to fat breaking down, you pee sugar and water
What is happening in diabetic ketoacidosis
DM 1 is lack of insulin
cells cant get sugar to burn so cells burn fat which leads to ketones and thats poisonous to our body
what substrate in fat degredation goes into ketone formation
acetoacetyl Coa
what is the difference between DMI and DMII
DM I: childhood onset, insulin lack due to beta cell underproduction but has good insulin receptors
DMII: adult onset, to much insulin with not enough receptor activity
both have high blood sugar
Tumor that secretes gastrin
Zollinger-ellison syndrome
leads to HCL secretion
What is a true beta cell tumor that produces hypoglycemia
Insulinoma
Thymic hyperplasia
Lymphoid follicles in the thymus often myasthenia gravis
Digeorge syndrome
aplasia/hypoplasia of the thymus accompanied by parathyroid development and failure