Chpt 15 (12) - Endocrine System Flashcards
Hormone - Target Receptor Relationship
- Hormone; secreted into bloodstream (no ducts)
- Binds to target receptor on target gland/organ
- Specific
- Key in lock theory
- 3D molecular interaction
Endocrine System
Glands which through secretion of hormones control and regulate physiology
- Maintenance of homeostasis
- Hormones (secreted by endocrine glands); bind to target receptors on target organs»_space; response (effect)
- Target organ: contains target receptors for hormones (specific) lock-key
Hypothalamus
Controls output of pituitary gland
Pituitary
Controls output of most all other Endocrine Organs
Thyroid
Metabolism
Parathyroid
Blood calcium and phosphate levels
Adrenal Medulla
Stress reaction (fight/flight)
Adrenal Cortex
Electrolyte levels, immune function, homeostasis, long-term blood glucose control
Pancreas
Short-term blood glucose control
Pineal Gland
Sleep cycle
Ovaries
Female sex steroids (estrogen and progesterone)
Testes
Male Sex Steroids (testosterone)
Thymus
Immune (T&B) cell production
“Hormones” vs Local Tissue Hormones
- Traditional Endocrine System
- Secreted into blood stream
- Long range effects @ target organ
- Systemic effects (body wide)
- “Federal Government”
Hormones vs “Local Tissue Hormones”
- Secreted from local tissue
- Effect surrounding cells (neighbor cells)
- Short range effect on local tissue only
- Minor, local control
- Regional/segmented effects
- “State/Municipal Government”
Prostaglandin
Local tissue hormone example
- Local communication
- Cervix (start labor)
- Lung (inflammatory asthma)
- Inflammatory Response
- Pain Signaling - Sub-types: PG-A, PG-E, PG-F
- Influence depends on type
Hypothalamus / Pituitary (HPO) Axis
Hypothalamus - brain structure involved with monitoring homeostasis
- Secretes "releasing factors"; stimulate pituitary
- Produces ADH and Oxycotin - released from posterior pituitary
Anterior Pituitary
Releasing factors:
- ACTH - Adrenal Corticotropin Hormone
- TSH - Thyroid Stimulating Hormone
- FSH - Follicle Stimulating Hormone
- LH - Leutenizing Hormone
- GH - Growth Hormone
Posterior Pituitary
Releasing Factors:
- ADH - Antidiuretic Hormone
- Oxytocin
Pituitary
- Control of most endocrine organs
Sella Turcica
- Bone structure pituitary sets in
Thyroid
Sets below larynx (Inferior)
- 2 lobes (Isthmus in middle)
- Thyroid Hormones:
- Thyroxin (T4) - most abundant
- Triiodothyroninc (T3) - most potent
- Calcitonin - Calcium into bone; builds bone - Controls metabolic rate
Thyroid Hormones (T3 & T4)
Effect most all cells in body
- Balance energy production and consumption (ATP)
- Metabolism = sum total of all chemical rxns in body
Parathyroid - Parathyroid Hormone (PTH)
- Secretes by 4 glands at back of back of thyroid
- PTH increases the blood calcium level
- Controls the balance of Ca++ between serum and bone
- Big effect on nerve and muscle functions
Thymus
Secretes Thymosin
- Located in Mediastinum, between lungs
- Results in lymphocyte (T-cell) production in lymph nodes
- Increases cell mediated immunity
Adrenal Glands
Supra-renal (sit atop kidneys)
Cortex - Secrete glucocorticoid (corticosteroids) such as cortisone
- Metabolic Control, Blood Sugar, Aldosterone
Medulla - Secrete epinephrine
- fight or flight
Pancreas
Exocrine Function - Digestive Enzymes (Lipase, Trypsin)
Endocrine Function - Islet cells
- Insulin - decreases blood sugar (glucose)
- Glucagon - raises blood glucose
- Insulin released proportionally to document of blood sugar
- Glucagon released as blood sugar lowers to raise blood sugar
- Breaks down large molecules to smaller for sugar
Ovaries
Paired female gonads
- Egg (gamete) production
- Female hormone production/secretion
- Estrogen / Progesterone
- Hormone cycle, Menses, Pregnancy maintenance
Testicles
Sperm production in seminiferous tubules
- Testosterone production
- Androgens (testosterone)
- Musulinizing
- Secondary sexual characteristics
- Muscle and Bone growth
- Libido / aggression
Testosterone is a powerful builder of muscle & bone (men & women)
Aden (o)
Gland
Adren (o)
Adrenal Gland
Gluc (o)
Glucose
Glyc (o)
Sugar (glycose)
Gonad (o)
Sex glands (ovaries or testes)
Pancreat (o)
Pancreas
Thyr (o)
Thyroid gland
ACTH
Adrenocorticotropic Hormone
ADH
Antidiuretic Hormone
CRH
Corticotropin-Releasing Hormone
DM
Diabetes Mellitus
OT
Oxytocin
FSH
Follicle Stimulating Hormone
GH
Growth Hormone
GTT
Glucose Tolerance Test
HCG
Human Chorionic Gomadotropic
Only Endocrine Glands examined by palpation?
Thyroid and Testes
Blood Hormone Levels
Cortisol, T3 or T4, GH …
Oral GTT
Orally ingest sugar; measure insulin after about an hour
Hemoglobin A1C
Blood glucose over 30-40days
Post Prandial Blood Sugar
Blood glucose after eating
Fasting Blood Glucose
Blood glucose after not having eaten
Thyroid Function Test (TFT)
THS, T3, T4 levels
Thyroid Scan
Imaging test for thyroid
Endocrine & Nervous Systems
Nervous - immediate short lived response
Endocrine - Slightly slower onset and longer duration
Hypersecretion
Abnormally high amounts of a hormone secreted with secondary effects
Hypercortisolism - High amounts of cortisol
Hyperthyroidism - High levels of T3 & T4
Hypothyroidism - Low levels of T3 & T4
Hypoparathyroidism - Low PTH
Excessive GH Secretion
Acromegaly - After growth plates close (21yrs)
- Abnormal growth of bones in face, feet, hands
- Metabolic derangements
Gigantism - Before age 21
- Excessive height; overgrowth of all body tissues
- Sexual and mental effects
GH Hyposecretion
Hypopituitarism = dwarfism
Diabetes Insipidus
Hyposecretion of ADH
- Results in frequent urination
- Hypotension and dehydration can occur
Diabetes Mellitus
Under-secretion of insulin; High Blood Glucose
SIADH - Excessive ADH secretion
- Water retention: High Blood Pressure
Goiter - Enlarged thyroid gland due to thyroid dysfunction
- Can be from hyper or hypothyroidism (secretion)
- Hashimotos Thyroiditis: Autoimmune destruction of thyroid
Hyperthyroidism
Excessive T3/T4
- Tachycardia; Anxiety; Restlessness
Thyroid Storm - Severe Hyperthyroidism
Grave’s Disease - Autoimmune; antibodies mimic TSH
- Increased release of T3/T4; Hyperthyroidism
Myxedema
Severe hypothyroidism
- Swelling in legs/hands; slowed response, dry skin, fatigue, weight gain, cognitive slowness
Hypoparathyroidism
Deficient PTH (hypocalcemia)
Cushing’s Disease
Hyper-secretion of cortisol (hyper-adrenalism)
From: ACTH Hyper-secretion from pituitary; Adrenal cortex tumor secreting high amounts of cortisol
Addison’s Disease
Hypo-secretion of cortisol
From: ACTH Hypo-secretion (pituitary); or destruction of adrenal cortex
Diabetes Mellitus IDDM: Type 1
Onset before 30yrs
- Low or no production of insulin
- Hypoinsulinism > Hyperglycemia
- Glucose cannot get into cells (due to low insulin)
- High levels of glucose in blood (>120)
- Body burns fat and protein instead
- Glucosuria (glucose in urine)
Rx: Insulin injection
Diabetes Mellitus NIDDM: Type II
Adult onset (30-65yrs)
- Insulin levels maybe normal
- Cells become resistant to insulin
- Glucose cannot get into cells; hyperglycemia results
- Obesity is risk factor
GDM: Gestational DM
- Occurs 2nd or 3rd trimester of pregnancy
- Disappears after delivery; 20% may develop type 2 later in life
DM Complications
- Long standing DM results in several secondary complications, due to vascular damage in small blood vessels
- Diabetes Nephropathy: Renal disease and progressive kidney failure from “glomerulosclerosis”
- Diabetes Neuropathy: Loss of nerve function in extremities
- Retinopathy: Damage to retina of eye scarring and exudates in retina; blindness results
Adenectomy
Removal of a gland
Adrenalectomy
Removal of adrenal gland
Hypophysectomy
Removal of pituitary gland (usually due to cancer)
Pancreatectomy
Excision of removal of pancreas
Thymectomy
Excision of thymus gland
Corticosteroids
Treat inflammatory diseases/symptoms
Anti-hyperglycemic
Lowers blood sugar or increases sensitivity to insulin
Hormone Replacement Therapy
- Treatment with Estrogen and Progesterone
- To treat climacteric symptoms of menopause, Osteopenia
