anatomy of human body system

1. Human Physiology:
The Nervous System PPT #2
chapter 29 in text

2. Objectives and Questions:
• 1. I can describe the functions of the nervous system
• 2. I can describe the parts of a neuron cell and identify
how they transmit electrochemical impulses.
• 3. I can compare and contrast the central and
peripheral nervous systems
• 4. I can identify and explain different areas of the brain
and their functions.
• 5. I can explain how the nervous system passes
information between the external environment and
the many parts of the body.

3. The Nervous system is:
• A physically connected network of cells,
tissues and organs that allow us to
communicate with and react to the
environment and perform life activities.

4. Cool Nervous System Facts:
• As a fetus in the womb, neurons develop at
the rate of 250,000 per minute.
• We have about 100 billion nerve cells in our
brain by adulthood (over 600 miles worth) –
yet we typically use around 4% at any given
time
• Neurons are our largest cells
• Messages transmit at speeds up of to 180
MPH

5. FOUR PRIMARY FUNCTIONS OF
NERVOUS SYSTEM
1. Sensing the world
 Vision, Hearing, Smell, Taste, Touch
2. Transmitting information
3. Processing information
4. Producing a response

6.  The functional unit of the
nervous system is the
nerve cell, the NEURON
 They send
electrochemical
messages around the
body
 Glial cells provide support
and protection for neurons

7. Parts of a neuron
Nerve Cell

8. Parts of nerve cell
 Dendrites : recieve chemical signals from
neighboring cells.
 Cell Body: contains the nucleus &
organelles
 Axon: long extension that carries
electrical messages away from the body to
the terminal axons
 Terminal Axons: passes the signal to the
next cell.
 Myelin sheath: Protective covering for
axon

9.  3 main types of neurons:
Sensory neuron = detect stimuli
Interneurons = relay sensory signals to
brain then return message back to motor
neurons.
Motor neuron = pass message from brain to
rest of body for muscle response
This coordinated pathway is known as the
REFLEX ARC
Types of Neurons

11. Reflex Arc
“ what happens when you step on a nail”?
 Reflexes are automatic
 The Stimulus (nail ) is received
by the sensory neurons in the
foot
 This info travels to the spine,
where the interneuron is triggered
 The interneuron transmits signal
to brain (through the spinal
cord)and carries message back
and stimulates the motor neuron,
to move the foot

12. A progressive wave of electric and
chemical activity along a nerve fiber
that stimulates or inhibits the action of
a muscle, gland, or other nerve cell
*This is how the information moves from sensory
neurons to interneuron to motor neurons

13. Nervous System
 Has two main divisions
1. Central Nervous System
( CNS) brain, spinal cord
2. Peripheral Nervous System
( PNS) all other nerves

14. Central Nervous System (CNS)
Receives, interprets and
sends signals to PNS
Has 2 main parts:
Brain – main control center
Spinal Cord – connects and
relays nerve impulses to the
brain
2 MAIN DIVISIONS:

15. Connects CNS to all organ systems
Made up of:
Sensory Neurons: detect stimuli
Motor Neurons: carry signal to stimulate
response
2 major subsystems:
Somatic – voluntary movement (balance,
movement)
Autonomic – involuntary movement
(digestion, fight or flight)
PERIPHERAL NERVOUS SYSTEM (PNS)

16.  Central Nervous
System
 Brain
 Cerebrum
 Cerebellum
 Brain Stem and
Pons
 Lobes (4)
 Spinal Cord
 “information
superhighway”
 Peripheral
 Autonomic
 Sympathetic
 Fight or Flight
 Parasympathetic
 Relaxation
 Somatic
 Sensory and Motor
Nerves
 Reflex Arc
Parts of the
Nervous System

20. •Smaller part of the brain ,towards the
back
FUNCTIONS:
•Coordinates all movement
•Helps maintain posture, muscle control,
and balance

21.  Large front part of the brain
FUNCTIONS:
 Voluntary activity
 Memory
 Language
 Receives and responds to sensory signals
 Controls motor functions

22. Top layer of the brain
Stores: experiences and/or learning
Frontal-
behavior &
emotion
Temporal- memory & emotion, speech and hearing
Occipital- vision
Parietal-
Sensory info
concerning touch

23. BRAIN STEM
 swallowing, coughing,
sneezing, and
vomiting
 Includes the
Medulla Oblongata
PONS
 Breathing
 Heart rate
 Internal Organs
Medulla
• Damage in this area
will usually kill you.

24. “controls: emotions and memories”
Damage to
these areas
can lead to
amnesia or
emotional
disturbances