Lec 6 Flashcards
Endocanabinoids
Potent stimulators of food intake
Part of the orexic hypothalamic
Orexic Non Hypothalamic
Ghrelin is secreted mostly by the cells in the stomach epithilium and stimulate feeding.
- galanin
AgRP( agouti related protein)
Hyperphagia
Orexic hypothalamic
POMC
Neurons in the brain associated with anorexia and have receptor for leptin
CART
Co-express cocaine-anphetamine. Appetite auppresion
Neurotension neurons
Stimulate neurons that release CRH
Leptin
Produced in the brain and adipose tissue. Increase metabolic rate
Adiponectin
A protein hormone that works im addition to leptin.
Gastrin
Stimulate gastric acid secretion and proliferation of gastric epithelium.
- presence of peptide and amino acid in gastric lumen.
Hypergastrinema
Excessive release of gastric
Enterochromaffin like cells
Produce histamine
- histamine + gastrin = regulators of acid secretion from PARIETAL CELL
CCK
Stimulates secretion of pancreatic enzymes and contraction and emptying of the gal bladder
- presence of fatty acids and amino acids in the small intestine
- found in duodenum
- PZ is a very similar hormone
Secretin
Stimulates the pancreas and bile ducts to release bicarbonate base
- the duodenum needs to be acidified first
GIP ( Gastric inhibitory peptide)
Similar to secretin and inhibits gastric function
- produces from the K cells of the duodenal mucosa.
Ghrelin
Appears to be a strong stimulant for appetite and feeding
- also a potent stimulator of growth hormone secretion.
- found in the epithelial cells of the stomach
- placenta, kidney
- g cells of stomach
Motilin
Apparently involved in stimulating housekeeping patterns of motility in the stomach and small intestine and duodenum.
- 2 hour cycle
- after meal
- cleaning tubes
- stimulated by alkalinity in duodenum
Exocrine pancrease
Produce: salt & enzymes—> duodenum
1) bicarbonate : neutralize gastric acid
2) amylase: starch—> small carbs
3) lipase
Endocrine pancrease
Release hormones that go into the bloodstream.
Many islets cells (Islets of langethans)
1) a-islets: release a hormone called glucagon.(Main function):glycogen --> glucose 2) b-islets: releases and house insulin( diabetes) too much glucose. Type 1 And type 2 diabetes
3) D-islets : produces somatostatin
3) F- islets: produces pancreatic polypeptide
Insulin
Insulin mRNA –> preproinsulin–> transported into the endoplasmic reticulum –> proinsulin—> transported to the Golgi apparatus —> insulin—> B cells in the pancreas
Epinephrin in adrenal inhibit insulin secretion
- cell growth
- beta cell survival and develpment
- stored in hexamer
- facilitates entry on glucose to the cell
- promotes synthesis of fatty acid in the liver
- synthesis on glycogen
- inhibit breakdown of far from adipose tissue
- receptors are embedded in the plasma membrane
Hypoglycemia
Insulin excess, brain death
Glucose
Transported inside the b cells by facilitated diffusion
Intracellular calcium
Increase in this triggers for exocytosis of insulin
Increase levels of glucose
Activate calcium independent pathway for insulin secretion.
Cellular glucose event
1) Glucose is transported into the cell by glucose transporter GLUT4
2) phosphorylated by glucokinase
3) glucose generates signals that inhibit ATP sensitive K channels –> membrane depolarization.
4) activates ca+ channels and increase intracellular ca+ levels
5) triggers the fusion of insulin vesicles
6) glucose goes in the cell.
Incretins
GIP and GLP-1 are two major hormones secreted from the intestine upon ingestion of glucose or nutrients to stimulate insulin secretion from pancreatic b cells
Type 2 diabetes
Insulin resistance and diminished insulin secretion
Ketone bodies
Problems during starvation
- low glucose body uses muscle tissue to provide the amino acid precursors ( gluconeogenesis)
- the it uses ketone bodies
Renin - angiotensin - aldosterone system ( RAS)
Liver–>(releases angiotensinogen) —> this gets converted into angiotension 1 ( by the action of renin - enzyme released by the kidney due to low fluid volume. –> gets converted to angiotension 2 ( this happens by an enzyme called ACE ( lives in the lung) —> angiotension 2 acts on the adrenal gland—> causes it to release aldosterone—> act on the collecting duct of the kidney which causes the nephrone to retain water —> increase blood pressure.
Aldosterone
Conserve sodium and this water and to excrete potassium.
Adrenal cortex
Glucocoticoids
Anti inflammatory effect
- from cholesterol
- stored in adrenals
Cortisol—> binds to glucocorticoids receptor in the cytoplasma–>
Galanin
Level rise before meals and have roles in weight gain in teen
Function of GI hormones
Release enzyme to break down good
Histamine and gastrin
They cause secretion from parietal cells
Calcitonin function
- Calcium release in bones
- calcium reabsorption from kidney
- inhibit food intake
- vitamin D metabolism
PTH
Raises calcium and reduces phosphate
- target kidney , gut, bone
- chief cells
Orexic hypothalic Hormone
Stimulate appetite increasing gastric secretion, metabolic rate and behaviors.
Neuropeptide- orexic agent
Target tissue of glucagon
Liver and adipose
Location of glucagon and insuline receptor
Plasma membrane
What controls aldosterone secretion
Renin angiotensin system
- kidney
- liver
- lung
When is aldosterone secreted
Low NaCl
- low BV
- low BP
- high K+
Whenis ADH released
Excess salt or dehydration
Where is renin produced
Juxtaglamerular body
- blood pressure and sodium concentration
Function of angiotensin 1
Release norepinephrine from medulla
ACE2 location
In kidney, heart
Other name for pineal gland
Epiphysis
What hormone does pineal glad produce
Melatonin and serotonin
Function of pineal gland
Aging
- immune system
Flurise accumulation
Early onset of puberty
Melatonin
Immune function
Metabolism
Circadian rythms
Melatonin in frogs
Skin lightening
Prototheria
Mammary glands and lay eggs ( monitremes)
Metatheria
Mammary glands and have pouches ( marsupials)
Eutheria
Mammary gland and placenta ( placentals)
How do mammals produce gonadotropin
In cyles
-mesntral cycle
Estrous cycle
Menstrual cycle
Menses—> shedding of the uterus lining ( endometrial)
LH
Ovulation and formation of corpus luthia h
FSH
Gametogenesis
- follicules in a women
hCG
Hormone produced by embryo soon after cenception and later produced by placenta
- prevents disitegration of corpus l.
- maintains progesteron production
