Endo Flashcards
Endocrine
-Broad, target many cells, coordinates whole body action
-Can’t control which cells respond
-Slow to begin = Long lasting
NS
-Precise control (Mov. Of pink finger)
-Can’t coordinate large areas of the body.
-Fast acting= short response
Endocrine
(Endo;within) - secret into the circulation/blood and act on target tissues.
Synaptic
Neuron to neuron or muscle
Hormones
Messenger compounds the body uses for normal physiology and homeostasis (Most hormones derived from AA or cholesterol)
What hormones compromise majority?
Amino acid hormones (Include peptide hormones)
Hormones made by cholesterol?
Sex steroid hormones= Testosterone, progesterone, estrogen, cortisol, aldosterone
AA hormones
Thyroid, epinephrine (adrenaline), norepinephrine (Noradrenaline)
Glycoprotein/ Peptide hormones
Insulin, oxytocin, ADH, GH
Eicosanoids
Large class of lipid soluble inflammatory molecules: Leukotrienes, thromboxane, prostacyclins, lipoxins.
Eicosanoids are derived from ?
Dietary omega 6 and omega 3 fatty acids
Hormones will affect one of the 3 actions?
Genes, protein synthesis and membrane permeability to all compounds ((ions))
Lipophilic hormones???
Eicosanoids, steroids, melatonin and thyroid.
Need binding protein to travel in the blood
-stay in the blood much longer due to blood protein
RECEPTOR IS INSIDE
Hydrophilic hormones??
insulin, oxytocin, prolactin, GH, ADH, releasing and stimulating hormones, and all hormones secreted by the heart, thalamus, thymus, digestive tract.
DO NOT LAST IN BLOOD VERY LONG!
RECEPTOR IS OUTSIDE
Secondary messegners include?
Cyclic AMP (cAMP), cyclic GMP (cGMP), and Ca2+
First messenger ??
Hormones; ephinephrine, norepinephrine, calcitonin, parathyroid hormone, ADH, ACTH, FSH, LH, TSH.
Function of G-proteins
1- G-proteins activate Adenylate Cyclase - turns ATP into cAMP (secondary messenger)= Activates enzymes and opens ion channels
2- activates Ca2+ channels
Phosphodiesterase (PDE)
Regulating enzyme that breaks down cAMP back into AMP
Caffeine
Boosts cAMP (inhibits PDE)
Hormone regulation
-Humoral (blood composition)
-hormonal Stimuli (arrival or removal)
-Neural
what type of hormones does the hypothalamus releases?
“Regulatory” hormones- releasing hormones
what is the other name for pituitary gland ?
Hypophysis
Adenohypophysis
(Endocrine based)
Neurohypophysis
Nerve based (posterior)
Anterior adenohypophysis
Activated by “releasing” hormones that transverse a specialized capillary network between the hypothalamus and anterior pituitary only—— Hypophysial portal system
How does Adenohypophysis regulates hormones?
It regulates them via both an axial and non-axial regulation
Axial regulation
Hypothalamus-RH-Pituitary gland- Anterior lobe - Hormone 1- Endocrine organ- Hormone 2- Target cell
Non-axial regulatory hormones of Anterior pituitary
prolactin and GH (somatotropin)
Prolactin releasing hormone
Produced by the hypothalamus.
-Stimulates anterior pituitary release of prolactin “let down response” in women milk, regulatory function in men (behavior/ immune)
Prolactin is controlled by - feedback by ?
-Prolactin inhibits prolactin releasing hormone (PR-RH)
-Prolactin activates prolactin inhibiting hormone (PRL-IH) dopamine preventing prolactin production.
Ex: Prolactin-releasing hormone: PRL-RH -> Prolactin-> mammary glands (milk production) -> a. negative feedback b. Prolactin-inhibiting hormone: PRL-IH
GH
Somatomedins release and have an action on a. chondrocytes (ECM and collagen) b. Skeletal muscles. C. Bone
MSH
-Melanocyte stimulating hormone is secreted from the anterior pituitary gland
-Dopamine inhibits MSH
What hormones does posterior- neurohypophysis releases?
ADH and Oxytocin ( They’re activated by the neuronal activation via the hypothalamus
ADH
vasopressin
Releases mainly as a result from increased solute concentration or low BV/BP
-Acts on kidneys to retain water
-Alcohol inhibits ADH
Oxytocin
-Stimulates smooth contraction of uterus
-Promotes milk-let down response (post-delivery)
-Important in pair bonding in both men and women
Thyroid hormone
Make 2 types of hormones T4 (thyroxine) and T3 (Tri-iodothyronine); both are lipophilic.
What type of cells surround the colloid?
Simple cuboidal cells
What makes calcitonin?
Among cuboidal cells are C-cells (parafollicular cells) different types of endocrine cells- make calcitonin
Calcitonin
C-cells make calcitonin- secreted when blood Ca2+ are too high
-Increases secretion of Ca2+ into urine
-Prevent Ca2+ absorption in gut
-Stimulate bone growth in children
-reduces bone loss in starvation and in late srares of pregnancy (Dependent on vitamin K2)
K1-phylloquinone
Derived from plants
K2: Menaquinone
Derived from animals.
K3- menadione
Synthetic
Parathyroid Glands
(4 on the back of the thyroid) involve with calcium homeostasis and usually increase calcium via breakdown of bone. 1% in blood 99 % in bone
What are the two types of cells ?
Parathyroid (principle) cells and Oxyphil cells
What hormone is secreted to raise blood Ca2+ levels?
Parathyroid hormone (PTH)
What hormone activates osteoclasts to break down bone to liberate Ca2+ ?
PTH
What hormone decreases urinary excretion?
PTH
What hormone increases Ca2+ gut absorption (via calcitriol)
PTH
Adrenal glands
(2x) sit on top the kidneys.
It has 4 layers: outer to innermost: Zone glomurulosa (mineralocorticoids), Zona fasciculata (glucocorticoids), zona reticularis (androgens) and medulla (NE/E)
Pineal gland
Makes melatonin (lipophilic) - involved with circadian rhythms of the body (sleep wake cycle)
Pancreas
Contains 4 cell types- Alpha, beta, delta, pancreatic polypeptide (PP)
Has both endocrine and exocrine functions
Endocrine cells
Alpha-cells- Glucagon
-Stimulated by dropping blood glucose
-Breaks down glycogen, breaks down TAGs, stimulates gluconeogenesis
Endocrine-
Beta-cells: Insulin
-Stimulated by increasing blood glucose
- Shuttle glucose uptake, glycogen formation, amino acid absorption/ protein synthesis, TAG formation
Endocrine-
Delta cells- GH-IH
Endocrine-
Pancreatic polypeptide cells-
Glucagon Inhibits GB contraction and regulates enzymes
Kidney Hormones:
-Calcitriol
Responds to PTH due to low blood Ca2+ or infection.
What hormone is responsible for Ca2+ and PO4-3 absorption in gut ?
Calcitriol
What hormone is responsible for formation of osteogenic cells ?
Calcitriol
What hormone is responsible for stimulating bone resorption ?
Calcitriol
What hormone is responsible for Ca2+ reabsorption in kidneys?
Calcitriol
What hormone is responsible for stimulating bone resorption Suppressing PTH?
Calcitriol
The kidneys make CALCITRIOL for what purpose ?
CA2+ absorption
All cell make Carcitriol for what purpose?
Immune and other functions
Kidney Hormone-
Erythropoietin
Stimulated by low O2 to activate production of RBCs within the bone marrow -> Kidney make EPO
Kidney hormone-
Renin
Stimulated by sympathetic nervous system as a result of declined blood flow, or low blood volume/pressure
Activates angiotensiogen into angiotensin I
Renin
Heart
Atrial natriuretic peptide (Na+ excretion)
Thymus
Thymic hormone (thymosins) promote lymphocyte development
Gonads
Sex hormones
Adipose tissue
Secretes leptin (fat and appetite regulator)
Why is leptin necessary ?
It is necessary to activate GnRG for puberty and maturation
What causes puberty to get delayed in girls?
Excessively low adipose
Infertility issues in women can be caused by ?
Excessively low adipose
Menstruation can be affected by?
Low body weight
Adrenal medulla secretes?
Epinephrine and Norepinephrine
Thyroid gland secretes?
Thyroxine and triiodothyronine
Pancreas secretes?
Insulin and glucagon
Pineal gland secretes?
Melatonin
Parathyroid gland secretes ?
parathyroid hormone
Adrenal cortex secretes?
Steroid hormone
anterior pituitary secretes?
Thyroid-stimulating hormone and growth hormone
The hypothalamus communicates with the ________________________ via the hypothalamic-hypophyseal portal system.
Anterior pituitary gland
