Download Endocrine System: Anatomy, Function, Pituitary & Reproductive Hormones and more Quizzes Animal Anatomy and Physiology in PDF only on Docsity!
General Features
Uses chemical messengers: hormones chemical produced by one type of cell Released into body fluids Exerts effects on other cells TERM 2
Major Role
DEFINITION 2 Long-term control of metabolism, growth, reproduction, etc TERM 3
Primary sites of Production
DEFINITION 3 Synthesize/store specific hormonesRelease hormones following specific stimulus TERM 4
Primary control of endocrine function
DEFINITION 4 Pituitary gland "brain of endocrine system" Divided into anterior and posterior parts connected to hypothalamus via pituitary stalk TERM 5
Location of pituitary gland
DEFINITION 5 Ventral surface of brainHypothalamus On skull: sellca turecia
Posterior Pituitary Neurons originate in two
regions of hypothalamus
Supraoptic nucleus (SON) Paraventricular nucleus (PVN) TERM 7
Pathway of posterior pituitary gland
DEFINITION 7 Originate in SON and PVN Axons extend down stalk, end of posterior pituitary Cell bodies synthesize specific hormones, transport hormone to nerve endings in posterior pituitary Stimulation of hypothalamic nucleus causes neurons to fire and release appropriate hormone into systemic circulation TERM 8
Supraoptic nucleus (SON)
DEFINITION 8 Antidiuretic hormone (ADH) increases reabsorption in the nephron; retains water in body a strong vasoconstrictor; "vassopressin" TERM 9
Paraventricular nucleus (PVN)
DEFINITION 9 Oxytocin Women - stimulates uterus to contract during childbirth; stimulates milk release during lactation Men - possible role in ejaculation TERM 10
Anterior Pituitary Gland Location
DEFINITION 10 Starts in various areas in hypothalamus, but travel to only the beginning (top) of the pituitary stalk
Thyroid stimulating hormone
Causes the thyroid to secrete thyroxine and triiodothyronie TERM 17
Follicle stimulating hormone
DEFINITION 17 Affects reprodcutive function in women and men TERM 18
Luteinizing hormone
DEFINITION 18 Affects reproductive function in women and men TERM 19
Prolactin
DEFINITION 19 Promotes breast development and milk secretion in women TERM 20
Control of hypothalamic-anterior pituitary
function (3 key structures)
DEFINITION 20 Hypothalamus --> releasing factor Anterior Pituitary --> Anterior pituitary hormone Endocrine gland --> hormone
Adrenal Cortex Hormones
Aldosterone: increases sodium reabosrpiton in kidneysCortisol: controls carboydrate, protein, and fat metabolism also helps body deal with stress high doses have anti-inflammatory nad immunosuppressive effects TERM 22
Thyroid Gland Hormones
DEFINITION 22 Thyroxine (T4) and triiodothyronine (T3) increase metabolism in almost all cells/tissues throughout the body small amount needed for normal mental and physical development in childhood Calcitonin: promotes movement of calcium out of blood stream and into bones - antiostoporosis TERM 23
Parathyroid Gland Hormone
DEFINITION 23 Parathormone (PTH) - primary hormone that controls calcium levels in the body; affects calcium levels by: increasing calcium release from bones (never want to get to low in calcium Increasing calcium absorption from GI tract decreasing calcium excretion from kidneys TERM 24
Pancreatic hormones
DEFINITION 24 5% endocrine - Islets of langerhans (clumps of cells) 95% exocrine (outside of body: opposite of endocrine) - digestive enzymes; secreted into GI tract TERM 25
Islets of Langerhans
DEFINITION 25 Alpha Cells - produce glucagon Beta Cells - produce insulin Delta Cells - (not as famous) produce somatostatin: not as much known: probably has some function in the GI tract
Testosterone
Several male hormones (androgens) Primary androgen: testosterone (main male cell) Source: Leydig cells in testes note also: role of sertoli cells (make sperm) Leydig cells make testosterone TERM 32
Function/effects of testosterone
DEFINITION 32 Fetus: small amounts from fetal testes; critical for development of male organs (if not enough could have certain developmental issues - adrogenous) During/ after puberty: development/maintenance male sexual characteristics; spermatogenesis Positive feedback - testosterone kicks in makes more testosterone TERM 33
Testosterone production
DEFINITION 33 Hypothalamus --> gonadotropin R.H --> Anterior Pituitary Anterior Pituitary --> LH (luteinizing hormone) --> Leydig cells --> Testosterone --> sertoli cells (increases size produce sperm)Anterior Pituitary --> FSH (follicle stimulating hormone) -->Sertoli cells TERM 34
Feedback/control of testosterone
DEFINITION 34 Negative Feedback: testosterone inhibits hypothalamus Sertoli cells release "inhibin": inhibits FSH release from anterior pituitary TERM 35
Two Primary groups of female hormones
DEFINITION 35 Estrogen (estadiol)Progestins (progesterone)
Source of Estrogen of Progesterone
Ovaries TERM 37
Ovaries
DEFINITION 37 Developing Follicle: estrogen (developing follicle - nutrients around developing egg)Corpus luteum: estrogen and progesterone (yellow body) TERM 38
Function/effects Progesterone
DEFINITION 38 More during getting ready for birth regulation uterine.menstrual cycle Stimulates/prepares breast for lactation TERM 39
Function/effects Estrogen
DEFINITION 39 Regulation uterine/menstrual cycle Growth/maturation female reproductive organs (more important during puberty) Breast development Changes in body composition/fat distribution Bone growth/skeletal maturation Other estrogen effects (cardiovascular health) TERM 40
Estrogen and progesterone: control of
uterine/menstrual cycle
DEFINITION 40 General strategy: Cycle lasts approx. 28 days 2 basic phases: follicular (proliforative phase lureal (secretory) phase Goal: prepare uterine lining (endometrium)for implantation of fertilized egg If no implantation, endometrium detaches, lost via menstruation (menses) Start new cycle, regenerate endometrium - roughly one month
Effects of progesterone
Increases glandular development, secretion of endometrium TERM 47
Regulation of uterine/menstrual cycle
DEFINITION 47 Hypothalamus releases GnRH; anterior pituitary releases FSH FSH: promotes follicle development; follicle begins EST production Mid-cycle: increasing EST production and/or small amount of PRO cause sudden release LH from anterior pituitary LH surge cause ovulation (positive feedback) LH and FSH promote development of corpus luteum which continues to secrete EST and PRO High levels EST and PRO eventually cause negative feedback on hypo and anterior pituitary; inhibit LH and FSH release TERM 48
Regulation of uterine/menstrual cycle
(continued)
DEFINITION 48 Without FSH and LH, corpus luteum dgenerates; stops producing EST and PRO (corpus luteum - gives up and goes away) Without EST and PRO, endometrium cannot be sustained; lost via menstruation Negative feedback on hyp/anterior pituitary is removed; new cycle begins TERM 49
If fertilization/implantation of egg
occurs
DEFINITION 49 Fertilized ovum secretes human chorionic gonadotropin (HCG) Acts like LH, prevents degeneration of corpus luteum ( HCG keeps corpus luteum alive) EST, PRO secretion from corpus luteum prevents menstruation Placenta eventually takes over, produces EST and PRO
