Transcript Endocrine System

Aim: What are the main parts and functions of
the endocrine system?
I. Endocrine System
A. Endocrine (ductless) gland - is a group of
cells that produces and secretes chemicals. A
gland selects and removes materials from the
blood, processes them, and secretes the
finished chemical product for use somewhere in
the body.
** Exocrine gland – a gland that has a duct
and releases it secretions directly to where
they have to go. Ex: pancreatic duct and bile
duct.
DUCTS
B. Hormone - is a chemical messenger from one
cell to another.
C. Target Cell – specific cell that a specific
hormone stimulates.
1. A target cell may do one of the
following when stimulated by a
hormone:
a. Secrete more of its product
b. Stop secreting its product
II. Main endocrine glands
A. Hypothalamus – links the nervous system to
the endocrine system. Releases hormones that
go to the pituitary gland and tells the pituitary
what hormones to secrete.
B. Pituitary Gland “Master Gland” – produces
hormones that affect many other endocrine
glands.
1. Has two lobes (anterior and posterior) that
release their own hormones.
2. Hormones of the pituitary
a. Growth hormone (GH) – controls growth
by promoting growth of bone and muscle.
Robert
Wadlow
b. Thyroid stimulating hormone (TSH) –
stimulates thyroid gland to release thyroxin.
c. Follicle stimulating hormone (FSH) –
stimulates the follicles in females to develop
egg.
C. Thyroid Gland – releases thyroxin which
controls rate of metabolism.
Results from having
insufficient iodine in
diet.
D. Islets of Langerhans – found in the pancreas.
Release hormones insulin and glucagon.
1. Insulin – lowers blood sugar level
2. Glucagon – raises blood sugar level.
E. Adrenal Glands – located on top of kidneys.
Secrete hormones adrenaline (epinephrine) and
noradrenaline (norepinephrine).
1. Adrenaline is the “fight or flight” hormone.
F. Gonads – testes and ovaries.
1. Testes – secrete hormone testosterone
that is responsible for secondary sex
characteristics.
2. Ovaries – secrete hormones estrogen and
progesterone. These hormones are
responsible for secondary sex
characteristics and the menstrual cycle.