Endocri 25 Bio Flashcards
Endocrine
Think hormones and biological cascade. The glands have no ducts.
Steroid hormone
Synthesized from cholesterol.
E.g estro, andro, cortisol, progester, cortisone, aldoster, etc….
Lipid soluble
Polypeptide hormone
Insulin, composed of aa ( with C,H,O,N,S)
Dalton (D): unit of mass of aa
Amine Hormones/ Catecholamines
Made from the aa tyrosine, H2O soluble. A catechol is benzene ring with two hydroxy groups.
Soluble hormone
H2O soluble hormone: binds to cell surface receptor protein
Lipid soluble hormone: binds to an intracellular receptor in cytoplasm or nucleus
Hypothalamus
Link between nervous and endocrine system.
Oxytocin: Stims contraction of the uterus and mammary glands. + feedback
ADH (vasopressin): Antidiuretic hormone
ADH and Oxy are stored in posterior pitutiary.
ADH
H2O retention by kidneys. During severe hemorrhage, by retaining more H2O, this increases blood volume and therefore blood pressure. ADH decrease urine volume.
Anterior Pituitary Gland
Tropic hormones - released to stim other endo glands to release their hormones.
FLAT PG
Growth hormones/ Somatotropin
Inc DNA, RNA, and protein synthesis. Stims the liver to release insulin gf for bone and cartilage growth. Inc blood sugar.
FSH
Ovarian follicle in women, spermatogenesis in males
LH
Stims ovulation, progesterone secretion, corpus luteum formation (f), and testosterone (m)
TSH
Stim the thyroid gland to make and release hormones
ACTH/ Adrenocorticotropic hormone
Stims the adrenal cortex to secrete glucocorticods (cortisol)
Prolactin
Non tropic hormone. Stims mammary gland and milk production. Some link with immune system acting like a growth factor.
Melanocyte Stim Hormone (MSH)
Non tropic hormone. Regs function of melanocytes. Can suppress appetite in humans by binding to receptors in the hypothalamus (similar to Leptin)
T3 and T4
Triiodothyronine (3 Is) and Thyroxine (4 Is, more abundant)
Involved in growth, cell diff, O2 consumption, and basal metabolic rate.
Hyperthyroidism
Inc in metabolism, weight loss, profuse sweating, high blood pressure, irritability.
Hypothyroidism
Cold, gain weight, and lethargy.
Body tries to compensate for this by increasing TSH from the ant pituitary. Constant TSH results in enlarged thyroid = goiter.
E.g. of hypothyroidism
Myxedema: swelling of face, lips, eyelids, and tongue. HR and BP are low.
Hashimoto is autoimmune. (F), middle aged - can lead to heart problems, goiter, and depression.
Cretinism: extreme hypothyroid in fetal life leading to retardation and growth failure..
Calcitonin
Lowers blood Ca2+. Calcitonin will inhibit osteoclastic activity and will promote bone formation by osteoblasts.
Parathyroid (PTH)
Increase in blood calcium.
Bone, kidneys, and intestine.
It also induces some kidney cells to activate Vit.D and take Ca2+ from the intestines.
Hypoparathroidism
Ca2+ conc. are low. Tetany can results and sporadic contractions of skeletal muscles muscles and generalized convulsions.
Pancreas
Both endo ( no ducts) and exo. Makes digestive enzymes and secretes bicarbonate ion.
Insulin and glucagon control blood glucose
Controls the concentration need for homeostasis.
Pancreas cells
Alpha cells (20%): secretes glucagon which causes glycogen breakdown, blood sugar rises Beta cells (70%): secretes insulin which lowers blood sugar. Enhances synthesis of fat, proteins, and transport of aa. Somatostatin (10%): Made by delta cells, inhibition of insulin and glucagon. Inhibitory hormone. These cells are also found in the stomach and small intestine.
DM
Insulin deficiency or decrease response to insulin in tissues. Glucose is excreted through urine.
Type I: autoimmune, beta cell destruction. External insulin.
Type II: Target cells fail to respond normally, though insulin levels are close to normal and glucose uptake is compromised.
Adrenal Glands
Has endocrine and neuroendocrine functions.
Adrenal Medulla
Medulla cells are connected with SNS, making 80% of epinephrine and 20% norepinephrine (the cateholamines).
Epinephrine and norepinephrine differ in structure
by a CH3 group.
Epi/Norepi are involved in
Short term stress responses such as inc BP, HR, glycogenolysis, and metabolic rate.
Norepinephrine are continuously released
into circulation at low levels, while epinephrine is released only when we are under stress.
Catecholamines can dilate or constrict blood vessels.
1) Blood is increased to areas of the heart, brain, and skeletal muscles (dilation).
2) Blood is decreases to areas of skin, kidneys, and digestive organs (constriction).
Adrenal cortex
Produces glucocorticoids that raise the glucose level in blood. Glucocorticoids include cortisol (hydrocortisone) and corticosterone.
Also makes aldosterone.
Glucocorticoids
1) Stim glueconeogenesis, particularly in the liver.
2) Fatty acid breakdown
3) Breakdown of skeletal muscle where aa are made into glucose.
Glucocorticoids side functions
Sometimes glucocorticords can be used as anti inflammatory agents, they act by dec the body’s immune cells.
Too much cortisol: Cushing syndrome
Addison’s disease: too little
Aldosterone
Side product: Deoxycorticosterone.
Stim kidney cells to reabsorb Na along with H2O. This inc blood volume, then BP.
Zona glomerulosa
Zona fasciculata
Zona Reticularis
Glom: Mieralocorticoids
Fasci: Glucocorticoids
Reti: Androgens
Gonads hormones
Estrogen, progestin, and androgens.
Estrogens
Development of female sex characteristics, egg maturation, prep for preg, and it’s maintenance. Triggers the luteal surge.
Estradiol controls the way fat is distributed in the female. Males also have estradiol but in much lowers amounts.
Progestins
Including progesterone. Involved with preparing and maintaining the uterus for pregnancy. Directly effects breast development, reg mucus produced by the glands of the uterine cervix.
Androgens
Includes testerone. Male secondary sex characteristics, muscle building, sperm formation, growth, and development.
Hypothalamus also makes
GnRH - Gonadotropin releasing hormone. Stims the release of FSH and LH from the ant pituitary gland.
Thyrotropin releasing hormone
Stim TSH release
Corticotropin releasing hormone
Stims ACTH release
Dopamine (Prolactin inhibiting hormone)
inhibits prolactin release.
Pineal Gland
The third eye, pine cone shaped, produces melatonin. Pinealocytes make you sleep. Biological rhythms. Melatonin production is stimulated in darkness and inhibited when there is light.
Placenta
Exchanges between mother and fetus without mixing their bloodstreams. Makes progesterone and estrogen.
Relaxin work with progesterone to help maintain pregnancy. Also helps to relax the pelvic ligaments at the end of gestation and helps dilate/soften the cervix in prep for birth.
Human Chorionic Gonadotropin (hCG)
What pregnancy tests look for
Endocrine gland Heart
Atrial Natriuretic peptide is a cardiac hormone. Lowers BP by relaxing the arterioles and inhibiting the reabsorption of Na+ by the kidney.
EPO/ eyrthropoietin
Made by the kidneys. EPO binds with bone marrow receptors to stimulate the production of RBC.
Renin
Made in the kidneys. Involved with blood pressure reg. Increase in BP.
Negative feedback examples
Calcitonin and PTH.
Ecdysone
Insect hormone. Involved with molting and metamorphosis in insects. It is a steroid hormone made by glands in the thorax.
Prostaglandins
Mod fatty acids. Derived from arachidonic acid. Made my many cells and involved in promoting fever and inflammation. Inhibit platelet aggregation, and act as vasodilators.
Signs of inflammation
Redness, Heat, swelling, and pain.
What is down regulation?
Decrease in cellular component. Decrease i n cell receptors in response to a hormone.
Type II DM, with high insulin to see a reduction in receptors.
Up regulation examples
RNA or protein. Liver cells increase production of p450 enzymes when exposed to dioxin.
Tongue
Largest structure in the oral cavity, complex muscular organ. Extrinsic muscles: move tongue in and out and side to side.
Intrinsic muscles: alter shape of tongue.
Tongue function
Swallowing, perception (detect taste, texture, pain, press), speech, respiration, jaw development.
External Ear
Pinna: outer ear you can touch
Auditory canal: Collects sound waves that enter the ear. The waves are channeled to the cone shaped eardrum (tympanic membrane). The tympanic membrane vibrates in response to sound waves.
Middle Ear
Vibrations are transmitted to the incus, malleus, and stapes. They form a bridge connecting the tympanic membrane to the inner ear.
The oval window is a membrane that causes vibrations to move to the inner ear.
The eustachian tube
Connects the middle ear to the nasopharynx and equalizes air pressure on either side of the eardrum.
Inner ear
Fluid filled channels in the bones of the skull. Cochlea is a channel that has a snail like structure which contains a sensory receptor called the organ of Corti. Semicircular canals, the utricle, and saccule.
Organ of Corti
holds hair cells, the nerve receptors, and mechanoreceptors.
Balance and the ears
Movement of middle ear bones exert pressure on the cochlea. The fluid in the cochlea stimulate tiny hair cells which through the auditory nerve are sent to the brain.
Causes of potential deafness
a) Cochlea damage
b) Auditory nerve damage
c) Vibration transmittance to inner ear it hindered
d) Loud sounds
Insect and Fish detect sounds
Insects use tympanic membrane which allows sound waves to vibrate and receptor cells convert to nerve impulses.
Fish lack a tympanic membrane and a cochlea. Fish conduct sound waves through bones.
