The endocrine system Flashcards
does endocrine system act slowly or quickly
slowly
what does endocrine system use
chemical messages called hormones
hormones (where produced and carried where)
produced in organs callled glands and carried in the blood
neurotransmitter (distributed by what and example)
distributed by blood and act as neuro-hormone
ie norepinephrine
endocrine glands
secretes hormones in blood
exocrine glands
secretes their products (milk or saliva) into a duct for transport to outside
chemical hormones subtype based on chemical structure
proteins, amino acid derivatives, steroids
chemical hormones subtypes based on polarity
lipophilic (fat-soluble): bind to intracellular receptors, hydrophilic (water-soluble): bind to extracellular receptors
lipophilic hormones
1-circulate in the blood attached to a transport protein
2-dissociate from carrier when reaches target cell
3-pass through cell membrane and bind to an intracellular receptor in cytoplasm or nucleus
4-hormone-receptor complex forms to regulate gene expression
hydrophilic hormones
1-circulate in blood without transport carrier
2- too large or polar so cant cross cell membrane of target cells
3-bind to extracellular receptor
4-receptors activate kinase enzymes that alter cellular activity
5-these hormones work by producing second messenger (cAMP)
Pituitary gland and consists of what
hangs by a stalk from hypothalamus
consists of anterior pituitary (appears glandular) and posterior pituitary (appears fibrous)
posterior pituitary and hormones
directly connected to hypothalamus by tract of axons
stores and releases 2 hormones: ADH+oxytocin
oxytocin
milk ejection reflex in mammals + uterine contraction during labor + regulates reproductive behavior
ADH
stimulates water reabsorbtion by kidney inhibiting urine production
negative feedback in hypothalamus and anterior pituitary
hypothalamus-trh-pituitary gland-tsh-thyroid gland-thyroxine-negative feedback-hypothalamus
anterior pituitary and hormones (and where acts)
produces 6 essential hormones called tropic hormones: ACTH (adrenal cortex), GH (long bones), PRL (mammary gland), TSH (thyroid), LH (gonads), FSH (gonadsP
GH fct and what happens when excess-dificiency child vs adult
stimulates growth of muscles and connective tissue cell division so bone elongation
- gigantism: excessive secretion of growth hormone during childhood (in adults: acromegaly bc cartilage plates are bones)
- dwarfism
thyroid gland and location and hormones
shaped like a bow tie below adams apple
-secretes thyroxine (t4), triiodothyronine (t3), calcitonin
t4 fct
regulates carbohydrate and lipid metabolism
hypothyroidism
low thyroxine prod
reduced metablism and overweight
hyperthyroidism
high prod of thyroxine high metabolism and weight loss -protruding eyes -enlargemnt thyroid gland -intolerance to heat
cause of goiters (growth thyroid gland)
iodine dificiency in food or related to hyper-hypothyroidism
thyroid gland stimulates uptake of calcium into bones by secreting what?
see schma but calcitonin
parathyroid glands and hormones
4 small glands attached to thyroid parathyroid hormone (PTH)
parathyroid stimulates what
Parathyroid stimulates: osteoclasts to dissolve calcium in the bone matrix and release Ca2+ into blood
Stimulates the kidneys to reabsorb Ca2+ from the urine
adrenal glands and location and parts
above kidneys
- medulla (inner portion)
- Cortex (outer portion)
Medulla in adrenal glands
stimulated by sympathetic division of autonomic nervous system and releases epinephrine and norepinephrine
epinephrine and norepinephrine
triggers alarm response helping body prepare for extreme efforts + leads to increase in:
heart rate, blood pressure, blood glucose level, blood flow to heart+muscle
Cortex in adrenal glands
stimulated by anterior pituitary through hormone ACTH and secretes corticosteroids
corticosteroids (2 types) and fct
- glucococorticoids (such as cortisol): maintain glucose homeostasis and immune system
- mineralocorticoids (such as aldosterone): regulate mineral balance by stimulating kidneys to reabsorb Na+ and secrete K+
pancreas location and hormones
adjacent to stomach and connected to small intetsine by pancreatic duct
Hormones that regulate blood glucose level: insulin and glucagon
Insulin in pancreas: secreted by what and stimulates what
secreted by beta cells of islets and stimulates cellular uptake of blood glucose and its storage as glycogen in liver and muscle cells or as fait in fat cells
glucagon in pancreas: secreted by what and promotes what
secreted by alpha cells of islets and promotes hydrolysis of glycogen in liver and fat in adipose
2 types of diabetes
Type 1: insulin dependant diabetes (lack insulin b cells so daily injections of insulin)
Type 2: non insulin dependant (most and trated by diet and exercise)
Gonads fct and hormones
produce sex steroids that regulate reproductive development
- Female hormones: estrogen and progesterone
- Male hormones: testosterone and its derivatives
Pineal gland location and hormone
roof of 3rd ventricle of brain and secretes hormone melatonin (regulate biological clock)
2 insect hormones
-molting by molting hormone (shelding of old exoskeleton) and metamorphosis by low levels of juvenile hormone (radical transformation from the larval to the adult form)
