Endocrine System(A&P) Flashcards
Endocrine System Function
- regulatory system
- endocrine glands
- growth and maturation
- metabolism
- reproduction
Hormones
- chemicals secreted into the bloodstream which regulate the activities of the body systems and tissues
- target organ=tissue
- target organ is the tissue.organ that responds to hormone regulation
- classification of hormones: 1)protein 2)steroids
Protein(non steroids)
- classification of hormone
- range from simple polypeptides to complex proteins
Steroids
- classification of hormone
- cholesterol based molecules
- every hormone that is not produced by sex gland or adrenal gland it is a protein
Homeostasis
negative feedback
negative feedback
-production of the hormone or the effect of hormone production causes a decrease in its secretion
positive feedback
- production of the hormone or the effect of hormone production causes an increase in its secretion
ex: applies to situation where there is an end point child birth
Pituitary gland-Master Gland-Hypophysis
- hormones regulate the activity of other glands
- activity of the pituitary is regulated by the hypothalamus
- small gland located in the sphenoid bone
- attached to the hypothalamus(link to the nervous system) by a stalk called the infundibulum
- has 2 distinct lobes: the anterior lobe and the posterior lobe
Anterior Pituitary(Adenohypophysis)
1) Growth hormone GH(Somatotropin)
2) Thyroid Stimulating hormone(TSH)
3) Adrenocorticotropic hormone(ACTH)
4) Prolactin-Lactogenic Hormone-PRL
5) Follicle Stimulating Hormone-FSH-Gonaotropic Hormone
6) Luteinizing Hormone-LH-Gonadotropic Hormone
1)Growth Hormone- Somatotropin(STH)
- part of Anterior Pituitary(Adenohypophysis)
- acts on most body tissues
- causes growth in height prior to closure of the epiphyseal disc
- has a major role in metabolism
- stimulates protein synthesis
- it is needed for tissue repair
- overproduction=gigantism or acromegaly
- underproduction=dwarfism
2)Thyroid Stimulating Hormone(TSH)
- part of Anterior Pituitary(Adenohypophysis)-target tissue:Thyroid gland
- effect secretion of thyroid hormones
3)Adrenocorticotropic Hormone(ACTH)
- part of Anterior Pituitary(Adenohypophysis)-target tissue: adrenal cortex
- effect: secretion of hormones from the adrenal cortex
4)Prolactin-Lactogenic Hormone-(PRL)
- part of Anterior Pituitary(Adenohypophysis)target organ: mammary glands
effect: milk production post partum
5)Follicle Stimulating Hormone-FSH-Gonadotropic Hormone
- part of Anterior Pituitary(Adenohypophysis)target organ: ovaries/testes
effect: development of ova/sperm cells
6)Luteinizing Hormone-LH-Gonadotropic Hormone
- part of Anterior Pituitary(Adenohypophysis)target organ: ovaries
effect: regulation of ovulation and menstruation, ovulation and development of the corpus lutem
LH(interstitial cell stimulating hormone)
- target organ: testes
- effect:testosterone secretion
Posterior Lobe of the pituitary(Neuro Hypophysis)
1) Antidiuretic Hormone(ADH)(Vasopressin)
2) Oxytocin
Antidiuretic Hormone(ADH)(Vasopressin)
- part ofPosterior Lobe of the pituitary(Neuro Hypophysis)
- target organ: kidneys
- effect: reabsorption of water by the kidney tubules from the forming urine
- high concentration cause vasoconstriction
- hyposecretion: diabestes insipidus
- hypersecretion:SIADH
Oxytocin
- part ofPosterior Lobe of the pituitary(Neuro Hypophysis)
- target organ: uterus and breast
- effect: uterine contraction and milk ejection
-oxytocin production is controlled by a positive feedback loop
Thyroid Gland
- located in the neck just under the larynx
- it has two lobes(butterfly)
- hormones produced
1) Thyroxine T4
2) Triodothyronine T3
3) Calcitonin
Thyroxine(T4) an Triiodothyronine(T3)
- increase rate of protein/fat/glucose metabolism
- regulate BMR
- iodine is necessary for making T3 and T4
- increase body temp
- essential for physical growth and development
- essential for reproductive maturity
- essential for mental development(normal growth in function of CNS)
Calcitonin
- increase activity of osteoblasts
- decrease the reabsorption of calcium and phosphorus from the bone
- decrease blood calcium concentration
Disorder of the thyroid gland
Cretinism- hypothyroidism- infants and children, severe physical /mental retardation
- Hypothyroid/goiter/myxedema in adults
- Hyperthyroidism=Graves Disease(increase metabolic rate/tachycardia)
Cretinism(Hypothyroidism)
- in infants in children
- severe physical and mental retardation
Myxedema(Hypothyroidism)
- in adults
- hypothyroid lead to goiter
Graves Disease(Hyperthyroidism)
-increased metabolic rate, tachycardia
Parathyroid Gland
-four peasized glands located on the back of thyroid
Parathyroid Hormone(PTH)
- antagonist of calcitonin
- increases blood calcium concentration
- promoting the activity of osteoclast(bone resorption)
- increasing absorption of calcium from food
- decreased calcium excretion by the kidneys
Adrenal Glands-Suprarenal Glands
- pyramid shaped glands located one on top of each kidney(suprarenal)
- they have 2 parts each the medulla(inside), the cortex(outside)
Medulla
-hormonal secretion (Catecholamines) are produced in response to sympathetic impulse from the nervous system(hypothalamus)
Nor-Epinephrine/Epinephrine
-increases rate and force of cardiac contractions
-dilates the bronchi
-decrease in peristalsis
-promotes conversion of glycogen to glucose
in the liver
-high and dry
-increase cellular respiration
-increase use of fat for energy
-vasodilation in skeletal mucles
-vasoconstriction in skin and visceral organs
Adrenal Cortex
secretes three types of steroid hormones
1) Glucorticoids(Cortisol)
2) Mineralcorticoids(Aldosterone)
3) Sex Hormones(Androgen&Estrogen)
Glucorticoids(Cortisol)
STERIOD HORMONE SECRETED BY THE ADRENAL CORTEX
- secreted by the body under stress whether physiological/psychological stress
- decreases bone reformation\
- increase the use of fat and amino acids for energy
- raise blood glucose level
- increase the blood levels of fatty acid and amino acid
- anti-inflammatory-2nd line of defense-effects would healing/immunity
- increase stomach acid production
MIneralcorticoids(Aldosterone)
STERIOD HORMONE SECRETED BY THE ADRENAL CORTEX
- target organ kidney
- increase reabsorbion of Na in the kidney tubules(water follows sodium)
- promotes excretion of K
- important for fluid and electrolyte ph balance
- renin-angiotension-aldosterone
Sex Hormone
STERIOD HORMONE SECRETED BY THE ADRENAL CORTEX
- androgen for males
- estrogen for females
Addisons Disease
Disorder of the Adrenal Cortex
- hyposecretion of hormones of the adrenal cortex
- Aldosterone-hypersecretion of Na.K retention,severe dehydration,low blood volume,low bp
Cushing Syndrome
- Disorder of the adrenal cortex
- hypersecretion of hormones of the adrenal cortex
- cortisol-hyperglycemia fat deposition in the trunk,moon face,buffalo hump,fragile skin,fragile bone,muscle weakness
Pancreas-Islets of Langerhan
–pancreas is both an exocrine gland and an endocrine gland
-endocrine function of the pancreas take place in islets of langerhan
-2 types of cells:
Alpha cells: make glucagon
Beta cells: make insulin
Alpha cells
make glucagon
Beta cells
make insulin
Insulin
- facilitate the diffusion of glucose across the cell membrane
- lowers blood glucose level
- helps to ensure the cells have glucose to metabolize for energy
- increases glucose uptake by the liver and conversion of glucose to glycogen
- important for fat synthesis
- anabolic(build up)
Glucagon
- causes liver to convert glucogen to glucose
- increases blood glucose levels
- increases the rate of conversion of amino acids to glucose
Diabetes type 1(\disease of secretion)
-no insulin secretion or insufficient insulin secretion, can cause hyperglycemia
Diabetes type 2(disease of response)
- response of the cells to insulin diminshes
- marked by hyperglycemia
effects of chronic hypergycemia
- macrovascular damage: large blood vessel damage do not transport oxygen and nutrients to feet leading to diabeteic foot ulcer
- microvascular damage: small blood vessels damage leading to nephropathy,retinapathy,neuropathy
diabetes
polyphagia(eat) excessive
polydispia(thirst)
polyurea(urine)
Testes
sex gland(gonad)
- located in the scrotal sac
- intestitial cells produce testosterone
- fsh stimulates the testes to produce mature sperm
testosterone
- promote maturation of sperm cells
- development of secondary sex characteristics
ovaries
- located in pelvic cavity
- produce estrogen and progesterone
fsh
development of ovum
LH
ovulation hormone
Estrogen
- helps with maturation of the ovum
- growth of the endometrium in preparation of possible implantaion
- development of seconday characteristics
- lowers level of cholesterol and triglceride levels
- reduce risk of artherscolrosis(corondary heart disease) in pre menopausable women,
Progesterone
- promotes growth of the endometrium
- promotes storage of glycogen in the liver
- enlargement of mammary glands
Pineal Gland
- located in the diencephalon
- very sensitive to light conditions
- secretes melatonin which stimulates the onset of sleep an increases its duration(melatonin secretion follows a daily cycle more is produced in darkness
- serotonin which helps with regulation of mood more is produced in light
Thymus gland
- located in the neck inferior to the thyroid gland
- large in the fetus and children(shrinks with age)
- secretes thymosin which promotes proliferation and maturation of T lymphocytes
kidneys
- located in the abdominal cavitity
- renin-produced in response to low Bp
- part of the renin angiotention-aldosterone mechanism
- erythropoietin: produced in response to tissue hypoxia, promotes erythropoesis
placenta
- temporary secretory organ
- secretes hormone(estrogen and progesterone which maintain the pregnancy
prostaglandins
- local tissue hormones
- produced by most tissue and exert local effects
- they are many different types of prostaglandins
- invovled in: inflammation,vasocontriction,reproduction,blood clotting,pain,vasodilation,uterine contractions
