Endocrine system #10 Flashcards
Basic function of endocrine sys
Regulates diverse bodily function: metabolism, blood glucose, food intake& digestion, heart rate& blood pressure
Differences between endocrine and exocrine
Endocrine: secretes into internal environment, no duct, secretes hormones
exocrine:
secretes into external environment, duct, secretes other products(sweat,saliva)
Describe the Endocrine organs with exocrine functions
other organs with endocrine function
endocrine organs with exocrine functions
Pancrease
secretes digestive enzyme
ovary and testes
produces and secrete ova and spermatozoa
Other organ with exocrine functions
stomach
secretes gastrin which stimulate hcl secretion
Small intestine
secretin pancrease secretes basic bicarbonate ions
cholecytonin gall bladder to secret bile and pancreas secrete digestive enzyme
Major glands
Hypothalamus
pituitary gland
thyroid
parathyroid gland
thymus
pancreas
adrenal gland
ovary/testes
What are the classes of hormones
Amino acid derivative hormone
serotonin, melatonin
peptide hormone
oxytocin, insulin, glucagon, HGH
Steroid hormone
testosterone
estrogen
cortisol
What are endocrine principles?
1.Specificity
hormones bind to specific receptors on target cell’s surface, nucleus ,cytoplasm
2.Speed of communication
NERVOUS VS ENDOCRINE
Rapid transmission slow transmission
Fast response Slow response
travel through specific pathway to reach target cells
travel through undefined pathways to reach target organ/cell
chemical and electrical means chemical and into circulatory system
3.Enzyme amplification
Hormones bind to receptor to trigger a sequential chemical reaction to initiate appropriate responses(chemical cascade)
4. Cell signal termination
hormone degrading enzyme degrade hormone to terminate signals(stop reaction cascade)
5.Negative feedback
Most Hormones controlled by negative feedback, to decrease own productions, conc of molecules/ hormones
Non-steroidal hormone mechanism
water soluble, cannot passively diffuse through cell membrane
use of second messenger system
1. Hormones(first messenger bind to receptors on cell membrane surface
2.forms hormone-receptor complex, which activates enzyme to catalyse the chemical reaction between (ATP–cAMP)
3. second messenger(cAMP) triggers a reaction cascade
4.cAMP acts on cellular protein which cause hormonal effect
Non-steroidal mechanism
Lipid soluble ,able to diffuse through cell membrane
dont need second messenger system
binds to cytosolic or nuclear receptor
regulate gene transcriptional/activity
1.Lipid soluble-diffuse through cell
2.Bind to cytosolic/nuclear receptor protein
3.Forms hormone-receptor complex
4. transcriptional activation/repression
5.mRNA translate and protein synthesis
6.protein carry out effector function
Describe pituitary gland
pituitary gland
controls activities of many endocrine organs
constitutes anterior(produces and secrete hormones/products) and posterior pituitary(connect to the hypothalamus/brain)
hypothalamus hormones regulate the production of hormones in pituitary gland
Describe hypothalamus
forms hypothalamic-pituitary control system
-links nervous sys with endocrine sys
-signals from brain stimulates release of hormones in hypothalamus
-secrets both releasing/inhibiting hormes
-hormones store in posterior pituitary
-produces 2 hormones
oxytocin and anti diuretic hormone
Describe Thyroid gland
secretes hormones when stimulated by TSH
Thyroxin-stimulates metabolism and promotes growth
goiter=enlargement of thyroid gland due to insufficient iodine production
Thyroid gland secrets calcitonin(bone reabsorption) parathyroid gland
-embedded between connective tissue surrounding thyroid gland
-secretes parathyroid hormone
Describe pancreas
cluster of cells that secret insulin and glucagon and other hormones
-Insulin secreted by beta cells
stimulates increase uptake of glucose in blood into cell
-decrease blood glucose conc
glucagon
-secreted by alpha cells
-stimulates glucagon to break down into glucose
-increase blood- glucose level
Diabetes mellitus_ insufficient insulin
TYPE 1
Autoimmune disease destroyed beta cells
TYPE 2
passed down, autoimmune disease cells resistant to insulin, insufficient insulin produced
Describe adrenal gland
-located at the tip of kidney
-consists of 2 layers
adrenal cortex: cortisol(regulates metabolism during stress)
adrenal medulla :Epinephrine
Increases heart, respiratory and metabolic rate
Diseases caused by endocrine gland
A)Grave’s disease: hyperthyroidism
eyes protrude due to overactive thyroid hormone
B) hashimoto disease:
thyroid gland cannot produce hormone, pituitary gland produces more TSH,more TSH lead to goiter
Gigantism;
over stimulation of HGH
dwarfism:
insufficient HGH secreted by pituitary gland
