Chapter 14 Endocrine System

tetany

1) a deficiency of parathyroid hormone causes this life-threatening hypocalcemic condition 2) characterized by sustained muscle contraction & an inability to ventilate (breathe)

cretinism

1) an infant born with a deficiency of thyroid hormones develop this condition, characterized by a severe delay in both physical & mental development 2) requires replacement doses of T3&T4

addisons disease

1) condition that is caused by a deficiency of adrenocortical steroids 2) if untreated, this deficiency disease will progress to adrenal shock 3) requires replacement doses of steroids, especially mineralocorticoid

biorhythms

1) describes this pattern of horomone secretion: cortisol secretion is highest in the morning, lowest inthe evening 2) an example is circadian rhythm 3) jet lag & night shift work alter this pattern of hormone secretion 4) an example is the menstrual cycle

hormones of the anterior pituitary gland

1) growth hormone stimulates growth and maintains blood glucose levels during periods of fasting 2) prolactin (lactogenic hormone) stimulates milk production by the breast 3) tropic hormones stimulate other glands to secrete hormones. these include thyroid stimulating hormones(TSH), adrenocorticotropic hormone (ACTH) and the gonadotropins(FSH,LH) 4) thyroid stimulating hormone stimulates the thyroid gland 5) adrenocortropic hormone(ACTH) stimulates the adrenal cortex 6) teh gonadotropic hormone (FSH & LH) stimulate the gonads (ovaries & testes) 7) the hypothalamus & this gland are parts of the hypothalamic-hypophyseal portal system 8) called the adenohypophysis

hormone receptors

1) hormones are aimed at receptors of target organs 2) receptors are located on the outer surface of the membrane or inside the cell 3) hormone secretion is controlled by 3 mechanisms: feedback control, biorhythms and control by the CNS

pineal gland

1) houses the "biological clock" & secretes melatonin 2) cone shaped gland located in the brain

glucagon

1) pancreatic hormone that increase blood sugar glucose levels

thymus gland plays an important role in the immune sysem

1) plays an important part in the immune system, and involutes or shrinks after puberty

diabetes mellitus

1) results from a deficiency of insulin; the person becomes hyperglycemic & glucosuric 2) condition that is treated with replacement does of insulin 3) if untreated, this condition progresses to ketoacidosis 4) ketoacidosis is caused by the rapid & incomplete breakdown of fatty acids

adrenal gland adrenal cortex adrenal medulla

1) the adrenal medulla secretes the catecholamines epinephrine & norepinephrine & causes the "fight or flight" response 2)the adrenal cortex secrets the steroids: gluccorticoids, mineralocorticoids, & sex hormones 3) the adrenal cortex = its hormonal secretion is conrolled by ACTH 4)adrenal cortex= secretes the hormones that are concerned with sugar, salt, sex

myxedema

1) the adult form of hypothyroidism that is treated with thyroid hormone 2) requires replacement doses of T3 & T4

other endocrine glands thyroid gland

1) the follicular cells synthesize triiodothronine (T3) & tetraiodothyronine, or thyroxine (T4). T3 & T4 regulate matabolic rate 2) the parafollicular cells secrete calcitonin. Calcitonin lowers blood calcium level 3) thyroid gland secrets iodine-containing hormones 4) uses iodine to synthesize its hormone 5) target gland of TSH 6) this gland is associated with these words: isthmus, follicular cells, colloid and iodine 7) glands that enlarges as a goiter

gonads

1) the ovaries are stimulates by the gonadotropins & secrete estrogens & progesterone 2) the testes are stimulated by the gonadotropins & secrete testosterone

pancreas

1) the pancreas secretes insulin & glucagon 2) insulin lowers blood sugar levels, whereas glucagon increases blood glucose levels 3) contains the beta cells of the islets of Langerhans

Pituitary gland Hypothalamic-hypophyseal portal system

1) the portal system is a system of capillaries that connects the hypothalamus and the anterior pituitary 2) the portal system transports releasin hormones from the hypothalamus to the anterior pituitaty gland

goiter

1) this results from an iodine-deficient diet, which causes a hyperplasia or overgrowth of the thyroid gland

exocrine glands

1) type of glands that secrete into the ducts (sweat glands, sebaceous glands) 2) type of glands that secrete their products into ducts that open onto a surface

growth hormone

1)also called somatotropic hormone 2) this anterior pituitary hormone stimulates the growth of the musculoskeletal syatem

target tissue (organ)

1)describes a specific tissue or organ to which a hormone binds 2) tissue at which a hormone is aimed

hormones

1)endocrine secretions that are classified as proteins, protein like substances, or steriods 2) substance secreted by an endocrine gland into the blood

classification of hormones

1)hormones are secreted by endocrine glands directly in to the blood 2) hormones are classified as proteins (protein related substances) and steriods

receptors

1)hormones bind to these special areas in the cell or on the surface of the cell membrane of the target tissue

ACTH

1)prednisone (cortisol) shuts down the secretion of this adenohypophyseal hormone 2) a tropic hormone that is suppressed by increasing plasma levels of cortisol 3) tropic hormone that stimulates the adenal cortex to secrete cortisol

T3 & T4

1)regulates metabolic rate 2) TSH stimulates the thyroid gland to release these hormones 3) iodine-containing hormones that regulate basal matabolic rate (BMR)

hormones of the posterior pituatary gland

1)secretes antidiuretic hormone(ADH) stimulates the kidney to reabsorb water 2) oxytocin stimulates the uterine muscle to contract for labor and stimulates the breast to release milk during suckling (milk-let-down reflex) 3) called the neurohypophysis; secretes ADH & oxytocin

hypothalamus

1)secretes releasing hormones

prolactin

1)stimulates breast milk` 2)lactogenic hormone

parathyroid hormone

1)stimulates osteoclastic activity to increase blood calcium 2) hormone that acts on 3 target organs (bones, kidneys, intestines) to increase the blood levels of calcium 3) a decrease in plasma calcium is the stimulus for its release

oxytocin

1)stimulates the uterine muscle to contract for labor and stimulates the breast to release milk during suckling 2)posterior pituitary hormone that enhances labor

aldosterone

1)the mineralocorticoid (steriod) secreted by the adrenal cortex: stimulates the kidney to reabsorb sodium & water & to excrete potassium 2) salt-retaining hormone 3) a deficiency in aldosterone causes a decrease in blood volume 4) stimulates the reabsortption of sodium & water by the kidney

ADH

1)the neurohypophyseal hormone that controls water balance 2)posterior pituitary hormone that is secreted in response to a low blood volume & concentrated blood, as occurs in dehydration 3) also called vasopressin

insulin

1)the only hormone that lowers blood glucose 2) the stimulus for its release is an increasing blood sugar glucose level 2) deficiency of insulin causes hyperglycemia, glucosuria & ketoacidosis

parathyroid

1)the parathyroid glands secret parathyroid hormone (PTH) 2) PTH stimulates the bones, kidneys, & intestines to increase blood calcium levels 3) parathyroid gland=its hormone moves calcium from the bone to the blood 4) low plasma levels of calcium stimulate these glands to secrete parathyroid hormone(PTH) 5) glands that are sometimes embedded within the thyroid gland; removal causes hypocalcemic tetany

endocrine glands

1)type of glands that secret hormones: called ductless glands 2) ductless glands that secrete hormones, usually into the blood for transport throughout the body

cushings syndrome

a person who takes high doses of steroids over an extended period of time develop this group of signs & symptoms

positive feedback control

a self amplification cycle (give me more) in which a change is the stimulus for an even greater change in the same direction

graves disease

antithyroid drugs & surgery are used to treat this form of hyperthyroidism

epinephrine

catecholamine that participates in the flight or flight response

giantism

condition that is caused by a hypersection of somatotropic hormone in a child

acromegaly

condition that is caused by hypersecretion of growth hormone in an adult (after the fusion of the epiphyseal disc)

dwarfism

condition that is caused by hyposecretion of somototropic hormone in a child

pheochromocytoma

condition that results from a tumor of the adrenal medulla, which causes a very high and dangerous blood pressure

steroids

cortisol, aldosterone,& testosterone

second chemical messenger

cyclic adenosine monophosphate (cAMP)

exophthalmos

describes the bulging or protruding eyes that characterize hyperthyroidism

negative feedback control

describes, for example, this sequence of events: corticotropin-releasing hormone (CRH) stimulates the release of adrenocorticotropic hormone (ACTH), which in turn stimulates the secretion of cortisol; as the blood level of cortisol increases, it shuts off the further secretion of ACTH & CRH

catecholamines

epinephrine & norepinephrine; sympathomimetic hormones

tropic hormones

hormones that are "aimed at" a target

releasing hormones

hypothalamic hormones that control the hormonal secretion of the anterior pituitary gland

gonadotropins

include follicle-stimulating hormone (FSH) & luteinizing hormone (LH)

calcitonin

parafollicular cels, thyroid gland, stimulates osteoblasic activity

diabetes insipidus

results from deficiency of ADH that causes the person to urinate up to 25L/day of pale urine