Lecture Exam 1- Endocrine and Lymphatic Flashcards
Lecture topics and Desicriptions
General comparisons and differences of nervous and endocrine system
both specialize in coordination and communication. Nervous communicates using neurotransmitters, endocrine uses hormones
four principal mechanisms of communication
gap junctions, neurotransmitters, hormones, and paracrines
gap junctions
pores in cell membrane, joining smooth & cardiac muscle, and epithelial. Enable cells to pass nutrients, electrolytes, and signaling molecules from cytoplasm to cytoplasm
neurotransmitter
released by neuron through synaptic cleft
paracrine
secreted by one cell, diffuse to nearby cells in same tissue throughout organs
hormones
chemical messengers transported by bloodstream and stimulate some type of response in cells and organ tissues pretty far away by traveling through blood with more widespread effects to multiple organs.
Speed and persistence of response in nervous vs. endocrine
Nervous: reacts quickly (ms timescale), stops immediately
Endocrine: reacts slowly (seconds or days), effect may continue for days or longer
Adaptation to long-term stimuli in nervous vs. endocrine
Nervous: response declines (adapts quickly)
Endocrine: response persists (adapts slowly)
Area of effect in nervous vs. endocrine
Nervous: targeted and specific (one organ)
Endocrine: general, widespread effects (many organs)
Comparing Communication by the Nervous and endocrine System
sometimes use the same hormones/neurotransmitter (norepinephrine, dopamine, and antidiuretic hormone), or have the same effect (hormone secretion stimulate or inhibit neurons). Has specialized receptors that only receive signal in that area of the body or that organ (target neuron/target organ)
Neuroendocrine glands
act like neurons in many respects, but release secretions (ex. oxytocin) into bloodstream
Physiology of Hypothalamus-
Regulates primitive functions from water balance and thermoregulation to sex drive and childbirth functions carried out by pituitary gland. Produce 8 hormones, six regulate the anterior pituitary and two are released into capillaries in the posterior pituitary stored until released into the blood
6 hormones Secreted by Hypothalamus and travel to Anterior Pituitary:
Hint: all of the releasing and inhibiting hormones that pituitary ends up secreting!
Gonadotropin-releasing hormone (↑FSH & LH), thyrotropin-releasing hormone (↑TSH and prolactin), corticotropin-releasing hormone (↑ACTH), prolactin-releasing hormone, prolactin-inhibiting hormone (ḻ prolactin), growth hormone- releasing hormone (↑GH), and somatostatin (growth hormone inhibiting hormone ḻ GH & TSH)
Secreted by Anterior Pituitary that is under control of hypothalamus
follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone (thyrotropin), Adrenocorticotropic hormone, prolactin, and growth hormone
Hormones released by posterior pituitary
two Hormones made in hypothalamus but stored and released by posterior pituitary anti-diuretic hormone & oxytocin
FSH
follicle stimulating hormone secreted by anterior pituitary. women-stimulates secretion of ovarian sex hormones (estrogen) and egg follicles, men- stimulates sperm production
LH
luteinizing hormone secreted by anterior pituitary. women-stimulates ovulation (release of egg) and secretion of progesterone by corpus luteum, men- stimulates testes to secrete testosterone
TSH
thyroid stimulating hormone/thyrotopin. Secreted by anterior pituitary stimulates growth of thyroid gland and secretion of thyroid hormone (impacts metabolic rate, body temperature etc.)
ACTH
adrenocorticotropic hormones/corticotropin. Secreted by anterior pituitary stimulates adrenocortex to secrete glucocorticoids (cortisol impacting glucose, protein, and fat metabolism stress response)
PRL
prolactin secreted by anterior pituitary after birth stimulates mammary glands to synthesizing milk
GH
growth hormone/somatotropin secreted by anterior pituitary most numerous stimulating mitosis and cellular differentiation. GH has widespread effects on the body tissues including bones, muscle, fats, ligaments but also induces liver to produce growth stimulants
ADH
antidiuretic hormone secreted by posterior pituitary affects kidneys increasing water retention by decrease urine volume preventing dehydration. Also a neurotransmitter aka vasopressin causing vasoconstriction
OT
oxytocin secreted by posterior pituitary affecting uterus and mammary glands leading to uterine/labor contractions, milk release, sexual arousal and orgasm, and bonding mother to child and sexual satisfaction
Control of Anterior Pituitary Secretions w/ examples:
Hypothalamic control allows brain to monitor conditions w/in and outside body based on feedback and stimulate or inhibit release of anterior lobe caused Negative feedback—increased target organ hormone levels inhibit release of hypothalamic and/or pituitary hormones. Ex. stress cause ACTH secretion for tissue repair, pregnancy prolactin for after birth.
Control of Posterior Pituitary Secretions w/ examples
Posterior pituitary controlled by neuroendocrine reflexes, based on the release of hormones in response to nerve signals. Ex. Dehydration raises osmolarity of blood detected by osmoreceptors triggering ADH causing water conservation decreasing blood osmolarity; high BP cause stretch receptors in heart to secrete natriuretic causes reflex that inhibits ADH release increasing urine output. Ex. infant succling or crying sends signal to hypothalamus to respond and release oxytocin. Stress disrupt ovulation, menstrual cycle, and fertility
negative feedback of hypothalamus and examples
increased target organ hormone levels inhibit release of hypothalamic and/or pituitary hormones. Example: thyroid hormone final hormone inhibits release of TRH by hypothalamus and of TSH by anterior pituitary
positive feedback of hypothalamus and examples
Positive feedback can also occur
Stretching of uterus increases OT release, causes contractions, causing more stretching of uterus, etc. until delivery
Insulin-like growth factors
prolong the action of GH. GH affect is only 6-20 minutes. IGF-I: has a 20 hour half life, which leads to protein synthesis, lipid metabolism (protein sparing), carbohydrate metabolism (glucose-sparing effect for brain) using fatty acids reducing cells need for glucose, increasing glucose synthesis, and electrolyte balance retention of sodium, potassium and chlorine by kidneys, and Calcium retention by small intestine, potassium absorption in kidneys & tissues
GH affects in children, and adults
Bone growth, thickening, and remodeling influenced, especially during childhood and adolescence
Secretion high during first 2 hours of sleep.
Can peak in response to vigorous exercise, trauma, physical or emotional stress, hypoglycemia. Causes hunger by ghrelin hormone in stomach negative beeback for GHRH.
GH levels decline gradually with age wrinkling of skin, loss of muscle mass and strength
Pineal Gland Structure and Function
pine cone shape attached to roof of third ventricle beneath the posterior end of corpus callosum.
Function: synchronizes w/ 24 hour circadian rhythms, releasing melatonin from serotonin at night. Also fluctuates seasonally w/ day length
Pineal gland in children
After age 7, it undergoes involution(shrinkage)
Down 75% by end of puberty
Tiny mass of shrunken tissue in adults
Pineal gland may influence timing of puberty in humans
seasonal affective disorder
influenced by the pineal gland and typically found in winter or northern climates includes depression, sleepiness, irritability, and carb cravings relieved w/ 2-3 hours of bright light decreasing the symptoms of the disorder.
Thymus systems it affects, structure, function, and affect w/ age
plays a role in three systems: endocrine, lymphatic, immune
made of two lobes that split. Involution as we age turns to fat more as you get older just fat. Located behind the sternal manubrium superior to the heart. Secretes hormones (thymopoietin, thymosin, and thymulin) that stimulate development of other lymphatic organs and regulate development & activity of T lymphocytes, site where they mature
Thyroid gland functions
Release thyroid hormone (thyroxine/T4/tetraiodothyronine) or 10% is T3 (triiodothyronine). TH increase metabolic rate (breakdown of carbs, fat, and protein for fuel), raising oxygen consumption (therefore increasing heat production), raise respiratory rate, heart rate, and strength of heartbeat, stimulating appetite, promote alertness & quicker reflexes. Stimulates growth hormone for bones, hair, skin, nails and teeth.
thyroid effects in children
Contains special parafollicular cells (C cells) periphery of follicles respond to rising blood Ca releasing calcitonin antagonizing PTH stimulating osteoblast promoting calcium deposision and formation mostly affecting children.
Parathyroid Gland function:
Secrete parathyroid hormone, which regulates blood calcium (when low: reabsorption of calcium from bones, decreasing loss in urine; when high increase urinary excretion, bone formation). Not directly regulated by pituitary monitor blood calcium
Medulla is classified as ? and what is its function in times of stress
endocrine gland and ganglion of SNS, will atrophy w/out stimulation w/out stimulation of cortisol. In times of fear, pain, or stress release signal originates in medulla leading to cortex to secrete corticosteroids as well as catecholamine (raise heart rate, blood pressure, circulation to muscles, pulmonary airflow, and metabolic rate, inhibit urine production) release epinephrine (glucose-sparing effect inhbitting secretion of insulin so organs consume less glucose change to alternative fuels allowing brain for glucose) , norepinephrine, and dopamine increasing alertness, prepare for physical activity, high energy fuels (lactate, fatty, acids, and glucose) boosts glycogenesis (hydrolysis of glycogen to glucose) and glucogenesis (conversion of fats, amino acids and noncarbs to glucose).
Cortex location, function, kinds and general functions of hormones
- surrounding medulla, produces corticosteroids are all made from cholesterol three kinds: mineralocorticoid (regulate body’s electrolyte balance), glucocorticoid (regulate metabolism of glucose and other fuels), and sex steroids (controlling developmental and reproductive functions)
Aldosterone kind and function
mineralocorticoid, uses renin-angiotensin-aldosterone system (baroreceptors cause angiotensin II then aldosterone) stimulates sodium retention in kidneys w/ water maintaining blood volume and pressure.
Cortisol kind and function
-glucocorticoid responding to ACTH stimulate fat and protein catabolism, gluconeogenesis, release of fatty acids and glucose into blood allowing body to adapt to stress and repair tissue. Additional Anti-inflammatory effect
Androgen kind and function
primary adrenal sex steroids regulated by ACTH, induce growth of pubic and axillary hair and apocrine scent glands, stimulate libido throughout life and prenatal male development
Estradiol kind and function
sex steroids and a kind of adrenal estrogen important after menopause, fat converts androgen to estrogen which promote adolescent skeletal growth maintaining adult bone mass
glucagon function
secreted by alpha cells between meals affecting liver when blood glucose concentrations are falling causing 1) glycogenolysis or the breakdown of glycogen into glucose and 2) Gluconeogenesis synthesis of glucose from fats and proteins. These two stimulates release of glucose into circulation, raising levels. In adipose- stimulates fatty catabolism release of free fatty acids. Secreted in response to rising amino acids promoting absorption creating raw material for gluconeogenesis.
Insulin function
secreted by beta cells during and immediately after a mean affecting liver, muscles, and adipose causing to absorb flucose, fatty acids, and amino acids for storage and metabolism lowering the levels in blood. Promoting synthesis of glycogen (in liver), fat, and protein enhancing cellular growth and differentiation. ad alaready stored fuels brain liver kidneys w/out sinuslin but others reuqite it without its diabetes.
Somatostatin function
secreted by D cells, which works suppresses secretion of insulin and glucagon, prolonging absorption of nutrients by inhibiting it.
Gonads classification, timing, and function
endocrine and exocrine (whole cells-eggs and sperm). Only active puberty and on.
secretes egg, sperm, estradiol, progesterone, and inihibin, and testosterone
Ovaries main hormones’ location and function
found in woman secrete estradiol (made by outer cells of egg follicle), progesterone (secrete by the remains of follicle after rupture aka corpus luteum), and inhibin (secreted by follicle and corpus luteum suppresses FSH by negative feedback). Estradiol and progesterone- development of reproductive system and feminine physique, adolescent bone growth, regulate menstrual cycle, sustain pregnancy, prepare mammary for lactation.
Testes main hormones’ location and function
found in men secrete testosterone (between tubules stimulates development of male reproductive system in fetus and adolescent, masculine physique, sex drive, sustains sperm production and sexual instinct throughout adult), inhibins (seminiferous tubules limiting FSH secretion regulating sperm production), and weaker androgens and estrogens.
skin endocrine function
Keratinocytes convert a cholesterol-like steroid into cholecalciferol using UV from sun to calcitriol regulating calcium.
Liver endocrine function
involved in the production of at least five hormones. 1) cholecalciferol into calcidiol for calcitriol. 2) angiotensinogen converts to angiotensin regulating BP. 3) erythropoietin stimulates red bone marrow to produce red blood cells increasing carrying capacity of oxygen. 4) IGF-I- mediates growth hormone. 5) hepcidin- controls iron homeostasis inhibitting
Kidneys main hormones’ function
play role in production of three hormones 1) convert calcidiol into calcitriol (vitamin d), raising blood concentration of calcium by promoting intestinal absorption inhibiting its loss in urine. 2) renin-converts angiotensinogen to angiotensin converted further constricting blood vessels and raising BP. 3) 85% of erythropoietin- bone marrow to produce RBCs renal failure causing anemia
Heart endocrine function
- rising blood pressure stimulates muscle to secrete natriuretic peptides increasing sodium excretion and urine output, decreasing blood volume opposing angiotensin II, lowering blood pressure
Stomach and small intestines general endocrine function
secrete at least 10 enteric hormones secreted by enteroendocrine cells coordinate different regions and gland of system w/ each other stimulating hypothalamus influence hunger and satiety. Ex. Gastrin-upon arrival of food to stomach to release HCl and Ghrelin- secreted when stomach is empty stimulating appetite and GHRH
Adipose tissue endocrine function and hormone
fat cells secrete leptin- appetite regulation w/ low level indicating deficiency of body fat, increases appetite and food intake, high leptin blunts appetite, signals onset of puberty, which can be delayed by low body fat.
Osseous tissue endocrine function
osteoblasts secrete osteocalcin, inhibit weight gain, onset of type 2 diabetes, iincrease B cells, increase insulin secretion, insulin sensitivity to tissues, reduce fat deposition
Placenta endocrine function
Secretes estrogen, progesterone, and others regulate pregnancy development of fetus and mammary glands.
Hormone Chemistry: three chemical classes,
steroids, monoamines, and peptides
examples of each class
steroids- derived from cholesterol ex. Sex steroids, corticosteroids only produced in adrenal and gonads
peptides- synthesized in same way as any protein ex. Oxytocin, ADH, insulin hypothalamus hormones besides doapmine.
Monoamines ex. catecholamines: Dopamine, epinephrine, norepinephrine;, melatonin (synthesized from the amino acid tryptophan), and thyroid (two tyrosine and an iodine)
Other monoamines come from the amino acid tyrosine
How are hormones transported, how are they conserved?
Most monoamines and peptides are hydrophilic
Steroids and thyroid hormone are hydrophobic bind to transport proteins (albumin and globulin made in liver) to get from one place to another. Longer half life protected from liver enzymes and kidney filtration lasting for hours and weeks, unbound hormones leave capillary to go to target cells broken down in minutes.
Thyroid hormone binds to three transport proteins in the plasma
Steroid hormones bind to globulins
Transcortin: the transport protein for cortisol
Aldosterone0 short half life unbound and would bind to albumin
hormone receptors and modes of action
hormones stimulate only cells that have receptors for them including proteins or glycoproteins in plasma membrane, cytoplasm, or nucleus specifically binding only that receptor w/ a saturation limit that no more hormones can affect.
Peptide & catecholamine hormones receptors and mode of action
hydrophilic so Cannot penetrate target cell
Bind to surface receptors (protein or glycoprotein molecules act like switches tunrning on metabolic pathways when hormones bind to them) and activate intracellular processes through second messengers. ex. cAMP or DAG. Specificity for each hormone and saturation where all occupied. relatively quickly because no synthesis necessary
Steroid hormones receptor’s and mode of action
Estrogen binds to cells in nucleus gene for progesterone and binds to same receptors for synthesizing enzymes one hormone released causing another then to own receptor causing something to happen w/ multi-step.
Penetrate plasma membrane and bind to internal receptors (usually in nucleus)
Influence expression of genes of target cell
Take several hours to days to show effect due to lag for protein synthesis
Steroids and Thyroid Hormone receptor means of action
estrogen binds to nuclear receptors in cells of uterus impacting the activation or inhibition of transcription of gene w/ easy diffusion through plasma membrane. Thyroid hormone enters target cell by means of an ATP- dependent transport protein converting to T3 binding to chromatin NA-K ATPase, activating norepinephrine receptor, and myosin production accounting for the responsiveness of cardiac muscle, sympathetic stimulation and increasing strength of heartbeat.
Signal Amplification and modulation of target-cell sensitivity in response
hormones are potent chemicals w/ one hormone triggering many enzyme molecules aka small stimulus w/ large effect. Tend to be low in hormone concentrations can have big effect if amplifying overtime. Receptors for hormones therefore can change on the cell surface depending upon the regulation of the hormone (w/ increased receptors allowing for it to be more sensitive to hormones, down regulation fewer receptors and cell sensitivity decreases or high hormone levels. Or tolerance.
Hormone Interactions why do they occur? synergistic? permissive?antagonistic?
more than one hormone for one receptor but multiple receptors for different hormones per cell. synergistic effects-work together to produce an effect that is greater than the sum of their separate effects. FSH and testosterone together increasing sperm production, permissive- one hormone enhances target organ’s response to later hormone ex. estrogen preparing uterus for progesterone in event of pregnancy, antagonistic- one hormone opposes action of other blood lowering glucose w/ insulin and glycogen raising it.
Hormone Clearance how does it work how can it be measured
Hormone signals, must be turned off when they have served their purpose. Most hormones are taken up and degraded by liver and kidney excreted in bile and urine, or degraded by target cells. Metabolic clearance rate (MCR) faster MCF shorter the half life.
What is stress? when does it occur?
Stress—any kind of situation that upsets homeostasis and threatens one’s physical or emotional well-being
Injury, surgery, infection, intense exercise, pain, grief, depression, anger, etc.
General adaptation syndrome (GAS) and its three stages
Consistent way the body reacts to stress; typically involves elevated levels of epinephrine and glucocorticoids (especially cortisol)
Occurs in three stages: alarm reaction, stage of resistance, and exhaustion
Alarm reaction
initial response to stress mediated by norepinephrine of SNS (fight flight or freeze) and epinephrine from adrenal medulla. Stored glycogen consumed, stimulate aldosterone and angiotensin raising BP, sodium and water conservation offsetting possible sweating and bleeding.
Stage of resistance
- few hours, glycogen reserves gone, need glucose, w/ stress dominated by cortisol. hypothalamus secrete CRH > pituitary ACTH to release cortisol and glucocorticoids, which convert fat and protein to fatty and amino acids lactate to feed glucose providing liver w/ gluconeogenesis materials. Adverse effects suppresses sex hormones disturbing fertility and sexual function, depressing immune system, susceptible to ulcer infections & cancer, wounds heal poorly.
Stage of exhaustion
stress levels and fat reserves (can carry for months) gone homeostasis is overwhelmed rapid decline of individual ending in death. Protein breakdown contributing to wasting of muscle. Adrenocortex stops producing glucocorticoids not managing glucose well, hypertension from retaining to much water, conserved sodium increased elimination of potassium and hydrogen creating hypokalemia and alkalosis, w/ nervous and muscular dysfunction to heart failure from overwork, kidney failure, or infection leading to death
Paracrine signaling and its three major examples
—chemical messengers that diffuse short distances and stimulate nearby cells.
ex. Histamine- released by mast cells along blood vessels diffusing to smooth muscle relaxing it),
Nitric oxide-endotheltium of blood vessels
Catecholamines- epinephrine from adrenal medulla to cortex stimulating corticosterone secretion. act as neurotransmitters and similar to effect on system
Anti-inflammatory Drugs:
cortisol and corticosterone, aspirin, ibuprofen, and celecoxib (celebrex)
nonsteroidal anti-inflammatory drugs
(NSAIDs). Cortisol and corticosteroids and nsaids anti inflammatory- inhibit inflammation by blocking arachidonic acids from plasma membrane inhibiting certain chemical messengers. No steroid
COX Inhibitory
since block cyclooxygenase, do not affect lipoxygenase or leukotriene. Treat fever and thrombosis because of inhibiting prostaglandin synthesis and antithrombotic effect by inhibiting thromboxane.
Hyposecretion and examples
—inadequate hormone release resulting from Tumors or lesions destroying glands or anything that interferes w/ communication to that area. Ex. fractured sphenoid severs the hypothalamo-hypophyseal tract preventing transport to posterior pituitary can cause diabetes insipidus. Diabetes mellitus as a result from antibodies attacking own endocrine cells
Hypersecretion and examples
—hormone release. Tumors can cause overgrowth of tissue ex. Tumor on adrenal medulla secretes excessive amounts of epinephrine and norepinephrine causing random bouts of sympatheitc nervous system, severe headaches, uncontrollable sweating. Toxic goiter autoantibodies mimic TSH causing TH hypersecretion
Congenital hypothyroidism description and symptoms
present from birth hallmark of decreased TH, causes swelling, treatable. Stunted physical development, thickened facial features, low body temp., lethargy, brain damage
Myxedema
description and symptoms
due to severe or prolonged adult hypothyroidism or graves decreased TH. characterized by low metabolic rate, sluggishness and sleepiness, weight gain, constipation, dry skin and hair, abnormal sensitivity to cold, hypertension, and tissue swelling
Hypoparathyroidism description and symptoms
result of surgery removing glands causing rapid decline of blood calcium causing suffocating spasm of muscle of laryx.
Hyperparathyroidism description and symptoms
excess PTH secretion caused by tumor bones become soft, deformed, and fragile raising calcium and phosphate levels, renal calculi (kidney stone formation)
Goiter description and symptoms
- results from deficiency of dietary iodine not allowing gland to synthesize TH producing more and more thyroglobulin swelling the neck depending on geographic and population all tend to have that random release of hormones.
Cushing syndrome description and symptoms
excessive cortisol because of ACTH hypersecretion, ACTH-secreting tumors, hyperactivity of adrenal cortex. Disrupts cab and protein metabolism, causing hyperglycemia, hypertension, muscular weakness, and edema. Muscle and bone loss as protein catabolized w/ abnormal fat deposition between shoulders creating bufallo humped or in face moon face. Treatable w/ hydrocortisone therapy
Adrenogenital syndrome (AGS) description and symptoms
hypersecretion of adrenal androgens, accompanies cushing often. Cause enlargement of sexual gonads and earlier puberty, masculinization of women w/ increased body hair, deepening of voice and ear growth
Diabetes Mellitus description and symptoms
disruption of carb, fat, and protein metabolism from hyposecretion or inaction of insulin. First presentation: three polys- polyuria (excessive urine output), polydipsia (thirst), and polyphage (hunger) confirming hyperglycemia (high glucose), glycosuria & kenonuria (glucose and ketone in the urine)
Type 1 diabetes causes and treatmen
- heredity genetically susceptible individual infected by viruses destroy pancreatic beta cells require insulin daily w/ meal planning, exercise, and self-monitoring
Type 2 diabetes causes and treatments
- insulin resistance unresponsiveness to the hormone. w/ age, obesity, and sedentary lifestyle along w/ certain populations, and hereditary genes w/ muscle mass important and helpful to regulating glucose. More body fat less efficient glucose uptake w/ weight loss.
Diabetes Pathogenesis
cells cannot absorb glucose, must rely on fat and proteins for energy needs, thus weight loss and weakness. Leading cause of adult blindness, renal failure, gangrene, limb amputations.
