Transcript Endocrine System PPT - Effingham County Schools

Ch. 13
Endocrine System
Endocrine System
 System consisting of cells, tissues, and
organs “glands” that release
substances called hormones into the
internal environment of the body.
Gland Types


Endocrine - secretions
go into the blood
stream.
Exocrine - secretions
go into ducts.
 The endocrine
system utilizes
endocrine glands, not
exocrine.
Homeostatic Functions
 Regulate metabolic processes
 Control rates of certain chemical
reactions
 Transport across cell membrane
 Regulate water and electrolyte
balance
 Roles in reproduction,
development, and growth
Hormone Action
 Biochemical released by one cell
to affect second cell(s)
 Travels into extracellular fluid or
by blood stream
 Works only on specific target
cell.
Prostaglandin Action
 Act locally
 Affect the organ from which
they are produced
 Potent and rapidly activated,
not stored
Control of Hormonal
Secretions
 Negative feedback system





Gland secretes a substance
Substance reaches a certain
concentration
Endocrine gland becomes inhibited
(turns off), which is a negative effect.
Due to inhibition, concentration of
substance decreases.
Endocrine gland becomes uninhibited
(turns on)
Control Sources
 Hypothalamus controls pituitary
 Pituitary stimulates other endocrine
glands
 receives constant information from
cerebrospinal fluid.
 info from neural connections in brain
Control Sources Continued
 Brain controls some glands directly
(adrenal medulla - sympathetic
response)
 Responds to internal environment
(insulin production - blood glucose
levels)
Diseases of the
Endocrine System
 Dwarfism insufficient
secretion of growth
hormone during
childhood.
 Gigantism oversecretion of
growth hormone
during childhood.
Diseases of the
Endocrine System



Cretinism - underactive
thyroid gland during
infancy and childhood.
Graves diseases
(hyperthyroidism) overstimulation of the
thyroid gland.
Goiter - an iodine
deficiency causes thyroid
to enlarge and function
improperly
Diseases of the
Endocrine System


Addison’s disease - adrenal
cortex does not secrete
hormones sufficiently
causing a variety of
electrolyte imbalances, low
blood pressure, and
increased skin pigmentation
to name a few.
Cushing’s disease - caused
by hypersecretion of
cortisol (primarily). Causes
high blood pressure, fluid
retention and thin skin to
name a few.