Download Nervous System

Nervous System
I.
The Nervous System is a control system in the body
A. Parts of the Nervous System
i. The Brain
ii. The Spinal Cord
iii. The Nerves
B. How it works
i. Carries messages to and from all parts of the body
ii. Messages travel along nerve cells (Called
Neurons)
1. Nerve Cells (Neurons) are cells that send
and receive messages
iii. Nerve Cells (Neurons) are found in bundles called
Nerves
iv. Works similar to an electrical wiring system
C. The Brain
i. The main organ of the Nervous System
ii. Control Center of the body
iii. Most messages enter and leave the brain
iv. Made of three parts
v. Cerebrum
1. Largest part of the brain
2. Folded like a piece of paper to allow more
nerve cells to fit inside the skull
3. Divided into right and left halves
4. Halves control opposite sides of the body
5. Controls thinking processes
6. Controls movement of many muscles
7. Different regions control different activities
vi. Cerebellum
1. Found just under the back part of the
cerebrum
2. Also has many deep folds
3. Helps the muscles work together
II.
4. Helps the body keep balance
vii. Brainstem
1. Found at the base of the brain
2. Controls the functions that keep you alive
3. Controls all of these actions automatically
D. The Spinal Cord
i. The Spinal Cord is a thick cord of nerves found in
the middle of the back
ii. Carries messages to and from the brain
iii. Runs through a hole in the backbone
iv. All nerves in body branch off of the spinal cord
Actions of the Nervous System
A. Three types of control
i. Voluntary – You choose the action
ii. Involuntary – Actions controlled without having
to think about them
iii. Reflex – Automatic responses without thought
controlling the action
B. Three types of nerve cells
i. Sensory Nerve Cells
1. Carry messages to the spinal cord and the
brain
2. Some pick up messages from within the
body
3. Others pick up message from outside your
body
4. Cells that pick up outside messages are
linked to the five senses
ii. Motor Nerve Cells
1. Carry messages away from the brain
2. Carry messages to make the muscles move
iii. Connecting Nerve Cells
1. Connect sensory nerve cells to motor nerve
cells
2. Found within the brain and spinal cord
C. Typical Nervous System Response (with example)
i. Sensory Nerve Cells pick up an outside message
(Telephone rings and is heard by the ear’s sensory
nerve cells)
ii. Sensory Nerve Cells carry the message to
connecting nerve cells in the brain (Brain realizes
that the phone is ringing and decides to send the
boy to answer the phone)
iii. Connecting Nerve Cells in the brain send
messages to the Motor Nerve Cells to go answer
the phone
iv. Motor Nerve Cells tell muscles to get out of chair,
walk to phone, pick it up, and talk
D. Other Nervous System Response
i. Sometimes the Connecting Nerve Cells in the
brain are skipped
ii. If someone hits your knee, your may get a knee
jerk response
iii. The Sensory Nerve Cells send a message to the
connecting nerve cells in the spinal cord and the
spinals cord sends a message to the Motor Nerve
Cells to kick
iv. This is called a reflex action
Endocrine System
III.
Endocrine System
IV.
A. Is a group of specialized organs and body tissues that produce,
store, and secrete chemical substances known as hormones.
B. Hormones are the body’s chemical messengers
C. Regulates body’s growth and development
D. Controls functions of various tissues
E. Supports pregnancy and other reproductive functions
F. Regulates metabolism
G. Hormones are released directly into the bloodstream
Components of the Endocrine system
A. Hypothalamus
B. Pituitary Gland
C. Thyroid
D. Parathyroid
E. Adrenal Gland
F. Pineal Body
G. Ovary
H. Testis
I. Pancreas
V.
Hypothalamus
A. Located deep in the brain
B. Controls the pituitary gland
C. Coordinates the endocrine system
D. Bridges the gap between the nervous system and the endocrine
system
VI. Pituitary Gland
A. Located in a bony cavity just below the base of the brain
B. Body’s master gland
C. Secretes several hormones that regulate the function of other
endocrine glands
D. Regulates the body’s growth
E. Stimulates milk production in women who are breast feeding
F. Also secretes endorphins which are chemicals that act on the
nervous system to reduce pain
VII. Thyroid Gland
A. Located in the neck
B. Regulates growth and metabolism
C. Plays a crucial role in brain development in children
VIII. Parathyroid glands
A. Four small glands located at the four corners of the thyroid
gland
B. Regulates the level of calcium in the blood
IX. Adrenal Glands
A. Located on top of the kidneys
B. Regulate salt and water balance in the body
C. Prepares the body for stress
D. Regulate metabolism
E. Interacts with the immune system
F. Produces adrenaline
i. Increases blood pressure during stress
ii. Increases heart rate during stress
iii. Produces the fight or flight response
X.
Gonads
A. Secrete sex hormones
B. Reproductive component of the endocrine system
C. Female gonads are called the ovaries
i. Located in the pelvis
ii. Produce female sex hormones
iii. Estrogen
iv. Progesterone
v. Controls development of sexual organs
vi. Stimulate the appearance of secondary sex characteristics
vii. Regulate menstruation and pregnancy
A. Male gonads are called the testes
i. Located in the scrotum
ii. Produce male sex hormones and sperm
iii. Testosterone
iv. Controls development of sexual organs
v. Stimulate male secondary sex characteristics
vi. Stimulate muscle growth
XI. Pancreas
A. Located in the upper abdomen just under the stomach
B. Secretes digestive enzymes into the digestive system
C. Produces insulin
D. Regulates energy and metabolism
XII. Pineal Body
A. Located in the middle of the brain
B. Regulates the wake/sleep cycle
XIII. How the endocrine system works
A. Hormones are secreted directly into the blood stream
B. Receptors in the target area bind with the hormones and
produce chemical changes in response to the body’s needs