Ch. 13 Ch. 13 Endocrine SystemEndocrine System

Endocrine SystemEndocrine System

System consisting of cells, tissues, System consisting of cells, tissues, and organs “and organs “glandsglands” that release ” that release substances called hormones into substances called hormones into the internal environment of the the internal environment of the body.body.

Gland TypesGland Types Endocrine - Endocrine -

secretions go into secretions go into the blood stream.the blood stream.

Exocrine - Exocrine - secretions go into secretions go into ducts.ducts.

The endocrine The endocrine system utilizes system utilizes endocrine glands, endocrine glands, not exocrine.not exocrine.

Homeostatic FunctionsHomeostatic Functions

Regulate metabolic processesRegulate metabolic processes Control rates of certain Control rates of certain

chemical reactionschemical reactions Transport across cell membraneTransport across cell membrane Regulate water and electrolyte Regulate water and electrolyte

balancebalance Roles in reproduction, Roles in reproduction,

development, and growthdevelopment, and growth

Hormone ActionHormone Action

Biochemical released by one Biochemical released by one cell to affect second cell(s)cell to affect second cell(s)

Travels into extracellular Travels into extracellular fluid or by blood streamfluid or by blood stream

Works only on specific Works only on specific target target cellcell..

Watch animation from cdWatch animation from cd

Prostaglandin ActionProstaglandin Action

Act locallyAct locally Affect the organ from Affect the organ from

which they are producedwhich they are produced Potent and rapidly Potent and rapidly

activated, not storedactivated, not stored

Control of Hormonal Control of Hormonal SecretionsSecretions

Negative feedback systemNegative feedback system Gland secretes a substanceGland secretes a substance Substance reaches a certain Substance reaches a certain

concentrationconcentration Endocrine gland becomes Endocrine gland becomes

inhibited (turns off), which is a inhibited (turns off), which is a negative effect.negative effect.

Due to inhibition, concentration Due to inhibition, concentration of substance decreases.of substance decreases.

Endocrine gland becomes Endocrine gland becomes uninhibited (turns on)uninhibited (turns on)

Control SourcesControl Sources

Hypothalamus controls Hypothalamus controls pituitarypituitary

Pituitary stimulates other Pituitary stimulates other endocrine glandsendocrine glands receives constant information receives constant information

from cerebrospinal fluid.from cerebrospinal fluid. info from neural connections in info from neural connections in

brainbrain

Control Sources Control Sources ContinuedContinued

Brain controls some glands Brain controls some glands directly (adrenal medulla - directly (adrenal medulla - sympathetic response)sympathetic response)

Responds to internal Responds to internal environment (insulin environment (insulin production - blood glucose production - blood glucose levels)levels)

Diseases of the Diseases of the Endocrine SystemEndocrine System

Dwarfism - Dwarfism - insufficient insufficient secretion of growth secretion of growth hormone during hormone during childhood.childhood.

Gigantism - Gigantism - oversecretion of oversecretion of growth hormone growth hormone during childhood.during childhood.

Diseases of the Diseases of the Endocrine SystemEndocrine System

CretinismCretinism - underactive - underactive thyroid gland during thyroid gland during infancy and childhood.infancy and childhood.

Graves diseases Graves diseases (hyperthyroidism)(hyperthyroidism) - - overstimulation of the overstimulation of the thyroid gland.thyroid gland.

GoiterGoiter - an iodine - an iodine deficiency causes deficiency causes thyroid to enlarge an thyroid to enlarge an function improperlyfunction improperly

Diseases of the Diseases of the Endocrine SystemEndocrine System

Addison’s diseaseAddison’s disease - - adrenal cortex does not adrenal cortex does not secrete hormones secrete hormones sufficiently causing a sufficiently causing a variety of electrolyte variety of electrolyte imbalances, low blood imbalances, low blood pressure, and increased pressure, and increased skin pigmentation to name skin pigmentation to name a few.a few.

Cushing’s diseaseCushing’s disease - - caused by hypersecretion of caused by hypersecretion of cortisol (primarily). Causes cortisol (primarily). Causes high blood pressure, fluid high blood pressure, fluid retention and thin skin to retention and thin skin to name a few.name a few.