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76 Cards in this Set
- Front
- Back
Exocrine glands
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release enzymes into external environment through ducts
include: 1. sweat 2. mucous 3. digestive |
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Endocrine glands
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release hormones directly into body fluids
effects are (when compared to nervous system): 1. slower 2. less direct 3. longer lasting alter metabolic activities, regulate growth and development, and guide reproduction works in conjunction with nervous system |
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Receptors
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all hormones act by binding to protein receptors
highly specific for its hormone reduction or increase of receptors can regulate hormones can be on the membrane or inside the cell |
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3 types of hormones
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1. peptide
2. steroid 3. tyrosine derivatives |
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Peptide hormones
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derived from peptide
large or small and often include carbohydrate portions manufactured in rough ER as a perprohormone water soluble, move freely through blood difficulty diffusing through cell membrane |
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effector
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target cell of hormone
cell that hormone is meant to affect |
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hormone-receptor binding
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instead of diffusing through membrane, peptide hormones bind to membrane-bound receptor
1. receptor may act as ion channel 2. activate or deactivate intrinsic membrane proteins that also act as ion channels 3. activate intracellular second messenger (cAMP, cGMP or calmodulin) which activates or deactivates enzymes and or ion channels and often creates "cascades" that amplify effect of hormone |
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Peptide hormones to know:
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1. anterior pituitary hormones: FSH, LH, ACTH, hGH, TSH and Prolactin
2. posterior pituitary hormones: ADH and oxytocin 3. parathyroid hormone: PTH 4. pancreatic hormones: glucagon and insulin |
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Steroid hormones
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derived from and often chemically similar to cholesterol
formed in smooth ER and mitochondria lipids, require protein transport molecule in order to dissolve in blood stream lipid soluble, diffuse through cell membrane of effector once inside cell, combine with receptor in cytosol, which transports it into nucleus and acts a transcription level typical effect is to increase certain membrane or cellular proteins within effector |
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steroid hormones to know:
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1. glucocorticoids and mineral corticoids of adrenal cortex: cortisol and aldosterone
2. gonadal hormones: estrogen, progesterone, testosterone |
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Tyrosine derivative hormones
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thyroid hormones
lipid soluble and must be carried in blood by plasma protein carriers bind to receptors inside nucleus of effector increase transcription of large numbers of genes in all cells of body |
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Tyrosine derivative hormones to know:
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1. T3 (triiodothyronine contains 3 iodine atoms)
2. T4 (thyroxine contains 4 iodine atoms) 3. catecholamines formed in adrenal medulla: epinephrine and norepinephrine (water soluble and dissolve in blood, bind to receptors on effector and act through second messenger system) |
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negative feedback
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body responds in attempt to correct back to normal
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Anterior Pituitary
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located in brain, beneath hypothalamus (controls release of anterior pituitary hormones by releasing inhibitory hormones)
6 peptide hormones: 1. human growth hormone (hGH) 2. adrenocorticotropin (ACTH) 3. thyroid-stimulating hormone (TSH) 4. follicle-stimulating hormone (FSH) 5. leutinizing hormone (LH) 6. prolactin |
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Human growth hormone (hGH)
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peptide
stimulates growth in almost all ells increases: episodes of mitosis, cell size, rate of protein synthesis, mobilization fat stores, use of fatty acids for energy decreases: use of glucose |
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Adrenocorticotropic hormone (ACTH)
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peptide
stimulates adrenal cortex to release glucocorticoids via second messenger system (cAMP) stimulated by stress, glucocorticoids are stress hormones |
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Thyroid-stimulating hormone (TSH)
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peptide
stimulates thyroid release of T3 and T4 via second messenger system (cAMP) increase thyroid cell size, number and rate of secretion of T3 and T4 T3 and T4 concentrations have a negative feedback effect on TSH release, both at anterior pituitary and hypothalamus |
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Prolactin
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peptide
promotes lactation by breasts (inhibited by progesterone and estrogen) hypothalamus inhibits release of prolactin |
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Posterior Pituitary
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composed of support tissue for nerve endings extending from hypothalamus
1. oxytoxin 2. ADH hormones synthesized in neural cell bodies of hypothalamus and transported down axons to posterior pituitary, where they are released into blood small polypeptides |
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Oxytocin
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small peptide
increase uterine contractions during pregnancy causes milk to be ejected from breats |
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Antidiuretic hormone (ADH or vasopressin)
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small peptide
causes collecting ducts of kidney to become permeable to water, reducing amount of urine and concentrating urine since fluids are reabsorbed, blood pressure also increases coffee and beer are ADH blockers that increase urine volume |
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Adrenal glands
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located on top of kidneys
separated into adrenal cortex and adrenal medulla |
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Adrenal cortex
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outside portion of gland
secretes only steroid hormones 1. mineral corticoids - affect electrolyte balance in blood stream (aldosterone) 2. glucocorticoids - increase blood glucose concentration and increase fat and protein metabolism (cortisol) |
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Aldosterone
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steroid, mineral corticoid
acts in distal convoluted tubule and collecting duct increase Na+ and Cl- reabsorption increase K+ and H+ secretion creates net gain in particles in plasma, which results in increase in blood pressure same effect on sweat, salivary and intestine glands |
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cortisol
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steroid, glucocorticoid
increases blood glucose levels by stimulating gluconeogenesis in liver (creation of glucose and glycogen, in liver, from amino acids, glycerol and or lactic acid) degrades adipose tissue to fatty acids to be used for cellular energy causes decreases in use of glucose by cells causes degradation of nonhepatic proteins, decrease of nonhepatic amino acids and as a result increase in liver and plasma proteins and amino acids stress hormone |
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Catecholamines
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tyrsoine derivatives
synthesize in adrenal medulla 1. epinephrine (adrenaline) 2. norepinephrine (noradrenaline) vasoconstrictors of most internal organs and skin vasodilators of skeletal muscles fight or flight response, stress hormones |
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Thyroid
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1. T3
2. T4 (thyroxine) 3. calcitonin located along the trachea just in front of larynx |
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T3 & T4
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similar in effect
T3 (3 iodine atoms) T4 (4 iodine atoms) lipid soluble tyrosine derivatives diffuse through lipid bilayer act in nucleus of cells increase basal metabolic rate (resting metabolic rate) secretion is regulated by TSH |
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Calcitonin
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large peptide
released by thyroid gland decreases blood calcium by decreasing osteoclast activity and number not necessary for calcium level control |
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Pancreas (islets of langerhans)
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acts as endocrine and exocrine gland
peptides, released in blood 1. insulin 2. glucagon |
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Insulin
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peptide, released by beta-cells of pancreas
released when blood levels of carbohydrates and proteins are high affects carbohydrate, protein and dat metabolism causes storage of carbohydrates as glycogen in liver and muscles, fat in adipose tissue and amino acids taken up by cells and made into proteins net effect is to lower blood glucose levels binds to membrane receptor and causes cascade reaction, which causes cells (except neurons in brain) to become permeable to glucose, amino acids and intracellular metabolic enzymes are activated and translation and transcription rates are effected receptor is not glucose carrier |
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Glucagon
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peptide, released by alpha-cells of pancreas
effects are opposite of insulin stimulates glycogenolysis (breakdown of glycogen) and gluconeogenesis in liver acts via second messenger system (cAMP) high concentrations cause glucagon breakdown of adipose tissue, increasing fatty acid level in blood net effect is to raise blood glucose levels |
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parathyroid
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4 small parathyroid glands attached to back of thyroid
release parathyroid hormone (PTH) |
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parathyroid hormone (PTH)
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peptide, increases blood calcium
increases osteocyte absorption of calcium and phosphate from bone stimulates proliferation of osteoclasts increases renal calcium reabsorption and renal phosphate excretion increase calcium and phosphate uptake from gut by increasing renal production of steroid DOHCC (derived from vitamin D) regulated by calcium ion plasma concentration parathyroid glands shrink and grow accordingly |
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Non-steroid reproductive hormones
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peptides
1. FSH 2. LH 3. HCG |
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Male gonads
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testes
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Seminiferous tubules
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production of sperm
in testes |
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Spermatogonia
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located in seminiferous tubules
arise from epithelial tissue to become spermatocytes, spermatids and then spermatozoa |
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FSH
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stimulate sertoli cells, which surround and nurture spermatocyte and spematids
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Testosterone
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released by leydig cells, located in interstitium between tubules, when stimulated by LH
primary androgen (male sex hormone) stimulates germ cells to become sperm responsible for development of secondary sex characteristics (pubic hair, enlargement of larynx, growth of penis and seminal vesicles) |
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Spermatozoon
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no cytoplasm
1. head (nuclear material and enzymes) 2. midpiece (mitochondria) 3. tail (locomotion) |
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Epididymus
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location where spermatozoon matures
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Vas deferens
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upon ejaculation, path through which spematozoa are propelled
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Urethra
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site of urine spermatozoa excretion
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Semen
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complete mixture of spermatozoa and fluid that leaves penis upon ejaculation
composed of fluid from seminal vesicles, prostate and bulbourethral glands (Cowper's glands) |
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Zona pellucida
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viscous substance secreted by granulosa cells around the egg
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Estradiol
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type of estrogen
upon stimulation by LH, theca cells secrete androgen which is converted estradiol by granulosa cells in presence of FSH and secreted into blood steroid hormone, prepares uterine wall for pregnancy inhibits LH secretion by anterior pituitary |
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Ovulation
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bursting of follicle, releasing egg
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luteal surge
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prior to, estradiol level rise rapidly, causing a dramatic increase in LH secretion
results from positive feedback loop of rising estrogen levels which increase LH levels, which increase estrogen levels causes the follicle to burst (ovulation), releasing the egg (secondary oocyte) into body cavity |
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Fallopian (uterine) tube or oviduct
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where egg is swept into after ovulation, by fimbriae
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Corpus luteum
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remaining portion of follicle left behind after ovulation
secretes estradiol and progesterone throughout pregnancy, or in case of no pregnancy, for 2 weeks until corpus luteum degrades |
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Corpus albicans
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degraded corpus luteum and 2 weeks
no pregnancy |
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6 steps of ovulation
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1. primary oocyte within follicle
2. growing follicle consists of theca cells surrounding granulosa cells which surround the zona pellucida and oocyte 3. secondary (graffian) follicle 4. ovulation: follicle ruptures, releasing secondary oocyte 5. corpus luteum develops from remnants of follicle 6. corpus luteum degenerates to corpus albicans if not fertilization of egg |
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Menstrual cycle
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repeats itself every 28 days after puberty, unless pregnancy occurs
several oocytes may begin ovulation process, but only one completes the development to ovulation 3 phases: 1. follicular phase 2. luteal phase 3. flow |
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follicular phase
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begins with development of follicle and ends at ovulation
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luteal phase
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begins with ovulation and ends with degeneration of corpus luteum into corpus albicans
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flow
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shedding of uterine lining lasting ~5 days
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ovum
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once sperm nucleus enters cytoplasm of oocyte and cortical reaction occurs, occyte goes through second meiotic division to form an ovum and releases a second polar body
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Fertilization
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occurs when nuclei of ovum and sperm fuse to form zygote
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cleavage
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begins while zygote is still in fallopian tube
goes through various cycles of mitosis |
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Morula
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when zygote comprises of 8 or more cells
embryo, at this stage, doesn't grow during cleavage 1st 8 cells are equivalent in size, shape and are totipotent |
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blastocyst
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hollow fluid filled ball after 4 days of diving post morula phase
lodges in uterus made up of embryonic stem cells |
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implantation
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5th - 7th day after ovulation
blastocyst lodges in uterus female is said to be pregnant |
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human chorionic gonadotropin (HCG)
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peptide hormone
secreted by egg upon implantation prevents degeneration of corpus luteum maintains secretion of estrogen adn progesterone in blood and urine of mother, sign of pregnancy |
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Placenta
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formed from tissue of egg and mother
takes over job of hormone secretion reaches full development by end of 1st trimester begins secreting its own estrogen and progesterone while lowering its secretion of HCG |
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Determination
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process where cell becomes committed to a specialized developmental path
determined to give rise to specific tissue early one, no longer stem cells |
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Differentiation
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specialization that occurs at end of development forming a specialized tissue cell
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gastrula
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formation occurs in 2nd week after fertilization
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gastrulation
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process of gastrula formation
3 primary germ layers are formed: 1. ectoderm 2. mesoderm 3. endoderm |
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ectoderm
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develope into outer coverings of body
outer layers of skin, nails, tooth enamel and into cells of nervous system and sense organs |
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mesoderm
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everything between ectoderm and endoderm
between inner and outer covering of body muscle, bone, etc |
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endoderm
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develop into lining of digestive tract, liver and pancreas
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neurula
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3rd week gastrula forms neurula
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neurulation
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process of neurula formation
notochord (mesoderm) induces overlying ectoderm to thicken and form neural plate |
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notochord induction
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made from mesoderm
induces ectoderm to thicken and form neural plate eventually degenerates, while neural tube forms from neural plate to become spinal cord, brain and nervous system induction occurs when one cell type affects the direction of differentiation of another cell type |
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Apoptosis
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programmed cell death
part of normal development essential for development of nervous system, operation of immune system and destruction of tissue between fingers and toes damaged cells may undergo this process as well, failure to do may result in cancer regulated by protein activity and not transcription or translation |