Term
| ACTIONS OF THYROID HORMONES |
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Definition
- metabolic actions
-permissive actions
- growth and development
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Term
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Definition
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Term
| Adrenal Insufficiency and Cushing’s Syndrome PT 1 |
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Definition
-The general term for any situation in which plasma levels of cortisol are chronically lower than normal is adrenal insufficiency.
-Patients with adrenal insufficiency suffer from a diffuse array of symptoms, depending on the severity and cause of the disease, including: weakness, lethargy, and loss of appetite.
-Examination may reveal low blood pressure (in part because cortisol is needed to permit the full extent of the cardiovascular actions of epinephrine) and low blood sugar, especially after fasting (because of the loss of the normal metabolic actions of cortisol). |
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Term
| Adrenal Insufficiency and Cushing’s Syndrome PT 2 |
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Definition
-Primary adrenal insufficiency is due to a loss of adrenal cortical function, as may occur, for example, when infectious diseases such as tuberculosis infiltrate the adrenal glands and destroy them.
-The adrenals can also (rarely) be destroyed by invasive tumors.
-Most commonly the syndrome is due to autoimmune attack causing the destruction of many of the cells of the adrenal glands.
-Because of this, all of the zones of the adrenal cortex are affected. Thus, not only cortisol but also aldosterone levels are decreased below normal in primary adrenal insufficiency. |
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Term
| Adrenal Insufficiency and Cushing’s Syndrome PT 3 |
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Definition
-This decrease in aldosterone concentration creates the additional problem of an imbalance in Na+, K+, and water in the blood because aldosterone is a key regulator of those variables.
-The loss of salt and water balance may lead to hypotension (low blood pressure).
-Primary adrenal insufficiency from any of these causes is also known as Addison’s disease. |
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Term
| Adrenal Insufficiency and Cushing’s Syndrome PT 4 |
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Definition
-Adrenal insufficiency can also be due to a deficiency of ACTH—secondary adrenal insufficiency—which may arise from pituitary disease.
-Its symptoms are often less dramatic than primary adrenal insufficiency, because aldosterone secretion, which does not rely on ACTH, is maintained by other mechanisms.
-Adrenal insufficiency can be life-threatening if not treated aggressively. |
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Term
| Adrenal Insufficiency and Cushing’s Syndrome PT 5 |
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Definition
-In Cushing’s Syndrome, there is excess cortisol in the blood, even in the nonstressed individual.
-The cause may be a primary defect (e.g., a cortisol-secreting tumor of the adrenal) or may be secondary (usually due to an ACTH-secreting tumor of the pituitary gland).
-In Cushing’s disease (secondary) the increased blood levels of cortisol tend to promote uncontrolled catabolism of bone, muscle, skin, and other organs. |
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Term
| Adrenal Insufficiency and Cushing’s Syndrome PT 6 |
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Definition
-In Cushing’s Syndrome problems include:
Osteoporosis
Muscles weakness
Blood sugar increases to levels observed in diabetes mellitus
Immunosuppression
Redistribution of fat (buffalo hump and moon face)
Hypertension (high blood pressure)
-Treatment of Cushing’s Syndrome depends on the cause.
Surgical removal of the pituitary tumor
Adrenalectomy |
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Term
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Definition
-Hypothyroidism – may be a primary defect (at the thyroid), or secondary (at the anterior pituitary) or tertiary (at the hypothalamus)
-Iodine deficiency in the diet is a worldwide problem (decreased T3 and T4 results in reduced negative feedback on the pituitary and this results in increased TRH and TSH). The final effect is an enlarged thyroid or goiter
-Symptoms include cold intolerance and weight gain |
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Term
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Definition
-Muscle Cramps: electrolyte imbalace fr. overexcercise/persistent dehydration induces APs in neurons & muscle cells
- Hypocalcemic Tetany: Low extracellular (Ca2+) causes depolarization & opening of Na+ channels
- Muscular Dystrophy: genetic loss of protein that maintains structural integrity off muscle fibers
- Myasthenia Gravis: decreased number of ACh receptors causes progressive weakening
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Term
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Definition
-Muscle Cramps: electrolyte imbalace fr. overexcercise/persistent dehydration induces APs in neurons & muscle cells
- Hypocalcemic Tetany: Low extracellular (Ca2+) causes depolarization & opening of Na+ channels
- Muscular Dystrophy: genetic loss of protein that maintains structural integrity off muscle fibers
- Myasthenia Gravis: decreased number of ACh receptors causes progressive weakening
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Term
| CONTROL BY OTHER HORMONES |
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Definition
-a hormones that controls the secretion of another hormone is called a tropic hormone
-ex: human chronic gonadotrophin stiml. progesterone rel.
-adrenocortitroponin (ACTH/cortitrophin) = rel. adrenaline
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Term
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Definition
-Calcitonin, which is secreted by parafollicular cells of the thyroid gland, decreases plasma calcium concentration by inhibiting osteoclasts.
-Its secretion is stimulated by high plasma calcium concentration, and it is only a factor when the concentration is very high. |
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Term
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Definition
Peptides and catecholamines: in plasma = free(unbound), receptors = plasma mem.
steroids and thyroid hormones: in plasma = protein bound, receptors = intracell |
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Term
| EFFECTS INC. PLASMA CORTISOL CONCIN. DURING STRESS |
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Definition
1. effects on organic metabolism
a. stiml. of protein catabolism in bone, lymph, mus., and other
b.stiml. of liver uptake of amino acids and their conversion to glucose (gluconeogenesis)
c. maintain. of plasma glucose levels
d.stiml. of triglyceride catabolismin adipose tiss., w/ realease of glycerol and fatty acidsinto the blood
2. enhanced vascular reactivity (inc. ability to maintain vasoconstriction in response to morepinephrine and other stimuli)
3. unidentified protective effects against the damaging influences of stress
4. inhibit inflamm. and specif. immune response.
5. inhibit of nonessential funct. (repro & growth) |
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Term
| ENDOCRINE CONTROL OF GROWTH |
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Definition
-At least a dozen hormones directly or indirectly play important roles in controlling growth.
-bone growth, |
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Term
| ENVIRONMENTAL FACTORS INFLUENCING GROWTH |
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Definition
| -Insufficient amounts of amino acids, fatty acids, vitamins, or minerals interferes with growth. |
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Term
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Definition
-Hyperthyroidism – can occur as a result of hormone secreting tumors of the thyroid or an autoimmune disease called Grave’s Disease. In this condition, antibodies bind to and activate TSH receptors on thyroid cells
-->Symptoms include heat intolerance and weight loss AND goiter as T3 and T4 reduce TSH secretion but cannot turn off antibody production |
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Term
| EXCERCISE, STRESS, FASTING, LOW PLASMA GLUCOSE, SLEEP |
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Definition
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Term
| Effector Sites for Calcium Homeostasis |
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Definition
-Calcium storage, absorption into the body and excretion from the body occur at 3 main sites:
-Bone
-Kidneys
-Gastrointestinal Tract |
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Term
| Endocrine Control of Ca2+ Homeostasis |
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Definition
-Ca2+ homeostasis is so vital that the absence of the hormones for its control would be catastrophic.
-This is a highly regulated and finely balanced system involving several hormones. |
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Term
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Definition
-To prevent runaway secretion of cortisol during a stressful interval, this adrenal steroid hormone exerts a negative-feedback relationship to the hypothalamic and pituitary hormones that influence cortisol synthesis. |
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Term
| HORMONAL INFLUENCES ON GROWTH |
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Definition
-Growth hormone and Insulin-like growth factors
-Thyroid hormones
-Insulin
-Sex hormones (testosterone, estrogen)
-Cortisol |
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Term
| HORMONE METABOLISM AND EXCRETION |
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Definition
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Term
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Definition
- The ability of a cell to respond to a hormone depends up the precense of receptors for that hormone on or in target cell
- an inc. in the # of receptors for a hormone is called up-regulations (base for premissive action)
- a dec. in the number of receptors for a hormone is called down regulation
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Term
| HORMONE STRUCTUES AND SYNTHESIS |
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Definition
-major chem. classes of hormones:
-Amines =derived from tryosine
-thyroid hormones and catecholamines
-peptides and proteins
-Most hormones
-posttranslational modification
-steroids
-lipid derivities of cholesterol
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Term
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Definition
-blood borne
-peptide and catecholamines = H2O sol. and dissolved in plasma
-steroids & thyroid hormones = are not
-->most are bound to plasma proteins
-->some small % =free
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Term
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Definition
-Hypothalamic “realeasing” hormones are delivered to the anterior pituitary gland via hypothamic pituitatry portal system
-Upon the arrival the releasing hormones bind to the receptors on the pituitary cells to envoke the secretion of pituitary cells |
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Term
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Definition
-Two major hormones regulate plasma calcium concentration:
Parathyroid hormone
1,25-dihydroxyvitamin D
-Calcitonin plays a limited role. |
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Term
| INPUTS THAT CONTROL HORMONE SECRETION |
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Definition
ions or nutrients---> endocrine cells
neurotransmitters --->endocrine cells
hormones ---> endocrine cells
EC: alters rate of hormone secretion
E-glands: hypothalamus, pituitary, thyroids, adrenal, pineal glands, and others..
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Term
| MAJOR EFFECTS OF GROWTH HORMONE |
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Definition
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Term
| MAJOR HORMONES INFLUNCING GROWTH |
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Definition
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Term
| Other Hormones Released During Stress |
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Definition
-Aldosterone, vasopressin, growth hormone, glucagon, beta-endorphin.
-Fight-or-flight response: epinephrine and norepinephrine. |
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Term
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Definition
-Parathyroid hormone (PH) is secreted by the parathyroid glands (4 glands located in the neck on the thyroid gland).
-PH is critically important to regulation of Calcium levels. |
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Term
| PHARMACOLOGICAL EFFECTS OF HORMONES |
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Definition
-administration of lrg. quantities of hormones for med. purposes may have effects in an induv. that are not usually seen in a healthy person
- testosterone derivites (anabolic steriods) can be converted to estrogens
-brests/testicular atrophy in steroid abusing males
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Term
| PHYSIOLOGICAL FUNCT. OF CORTISOL |
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Definition
-Permits action of epinephrine and norepinephrine on muscles and blood vessels.
-Maintains cellular concentrations of metabolic enzymes required to produce glucose between meals.
-Decreases events associated with the inflammatory response such as capillary permeability and production of prostaglandins.
-Important for fetal development. |
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Term
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Definition
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Term
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Definition
-stimulates uterine lining for implantation (thickening and other features necssary for implantation
-->fertilization results in the fert. egg secreting human chrionic gonadotrophin = stimulates pregesterone prod. & maintains corpus luteum
-corpus luteum: is norm. a temp. struct. derived fr. an ovarial follicle
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Term
| REL. B/T HYPOTHALAMIC & PITUITARY HORMONES |
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Definition
-CRH (corticotropin-rel. hormone)-->stimulates scretion of ACTH
-TRH (thyrotropin-rel. horm.)-->" TSH
-GHRH (growth hormone releasing hormone)-->"GH
-SS(Somatosatin)--> inhibits serct. of GH
-GnRH (gonadotropin-releasing hormone) --> " LH & FSH
- DA (dopamine)--> inhibit secretion of prolactin
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Term
| ROLE OF Ca2+ AND TROPONIN |
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Definition
-TROP: in cardiac & skel. mus. cells
--> made of 3 subunits (heterotrimer)
-C: (Ca2+ binding) unit binds Ca2+
-T: (tropomyo binding) unit binds tropomyo
-I: unit (Inhibitory) binds actin
- when Ca2+ binds to C, troponin T undergoes a conformational change = moves tropomyo awayfr. binding binding site on actin
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Term
| ROLE OF Ca2+ AND TROPONIN |
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Definition
-TROP: in cardiac & skel. mus. cells
--> made of 3 subunits (heterotrimer)
-C: (Ca2+ binding) unit binds Ca2+
-T: (tropomyo binding) unit binds tropomyo
-I: unit (Inhibitory) binds actin
- when Ca2+ binds to C, troponin T undergoes a conformational change = moves tropomyo awayfr. binding binding site on actin
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Term
| SIX CHAR. HORMONES SECRETED BY ANTERIOR PITUITARY GLAND & TARGET CELLS |
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Definition
-FSH (follicole stimulating hormone) & LH (Lutenizing hormone) -->GONADS--->
-->Germ cell development: male= sperm, female= Ovum
--> secrete hormones:male= tesosterone, female= estradol, progesterone
-GH (growth hormone):-->liver and other cells= secreats IGF-1
---> many organs and tissues= proteins synth., carbs.,and lipid metabolism
-TSH (thyroid-stimulatin hormone): -->thyroid: secretes thyroxine, triiodothyronine
-Prolactin: Breasts= breast devlopment & milk prod. (in male mayfacilitate reprod. funct.)
-ACTH (adrenocorticotropic hormone): adrenal cortex: secrets cortisol
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Term
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Definition
-[image]
Made in the adrenal cortex |
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Term
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Definition
Hypothal. (inc. in hormone 1 secretion)-->inc. in plasma hormone 1 --> anterior pituitary (inc. in hormone 2 secretion) -->inc. in plasma hormone 2--> ENDOCRINE GLAND (inc. in hormone 3 secretion) --> inc. plasma in hormone 3 --> TARGET CELLs of hormone 3, respond to hormone 3 |
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Term
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Definition
-Cortisol secreted by the adrenal cortex
Increases blood sugar levels
Decreases immune response
-Epinephrine secreted by the adrenal medulla
Increases heart rate
Increases respiratory rate
Shifts blood to skeletal muscles
Vasoconstricts gut vessels
Vasodilates skeletal muscle vessels |
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Term
| SYNTHESIS OF SEX HORMONES |
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Definition
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Term
| TYPES OF ENDOCRINE DISORDERS |
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Definition
-hyposecretion: the secretion of too LITTLE hormones
-hypersecretion: the secretion of to MUCH hormones
-hyporeponsiveness/unreposivenss: occurs when the target cells do not respond properly to a hormone
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Term
| The Endocrine Response to Stress |
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Definition
| The endocrine system responds to stresses on the body such as trauma, infection, pain, sleep deprivation, fright, and other emotional stresses by increasing the release of cortisol from the adrenal cortex and epinephrine from the adrenal medulla. |
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Term
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Definition
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Term
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Definition
-cocin. in blood depends on: rate of secretion & removal
-removal = excretion (kidneys)
-->inactivation by metabolism (liver) |
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Term
| POSTERIOR PITUITARY HORMONES |
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Definition
- doesn't synth. any hormones, only secretes
- oxytocin: involeved in the milk ejection reflex of nunrsing mothers & emo. bonding
- antidiuretic hormone: (vasopressin) = involved in regulation of H2O balance and osmolarity
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Term
| ACTIONS OF THYROID HORMONES |
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Definition
- stimulates carb. absorbtion
- inc. FA release fr. adipocytes
- stimulates activity of Na/K-ATPase
- calorigenic action: inc. ATP comsumpt. req. inc. stores of ATP which req. inc. metabolism of fuels
- permissive effects on catecholamines
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Term
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Definition
-human chrionic gonadotropin stimulates progesterone prod.
-hormones often simulate other hormones |
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