1. Anatomy and Physiology
Biology
Anatomy and Physiology

2. The Nervous System Basics

3. Function of the Nervous System
Mediates (coordinates) communication between different parts of the body and the body’s interactions with the environment

4. The Neuron specialized cells within the nervous system
Axon terminals
Myelin sheath
Nodes
Cell body
Axon
Nucleus
Dendrites

5. Neurons transmit messages
Nerve impulse = Message
Dendrites- pick up message from environment or other neurons. Sends message to cell body
Cell body-performs normal cell tasks for cell, relays message to next neuron through the axon
Axon- Carries message from the cell body to the next neuron.
myelin sheeth-coating that insulates and speeds up message.
axon terminal- releases chemicals, “neurotransmitters” to stimulate the next neuron to “fire” or continue the nerve impulse.
threshold- the minimal amount of stimulus required to cause the next neuron to “fire” or continue the impulse

6. Nerve Impulses Are Electrical As They Travel Through The Neuron
Outside of cell
Resting Potential-When a neuron is ready
“fire” if it is hit with a “threshold” stimulus
High Potassium Ion (K+)Concentration Inside
Low Potassium Ion (K+)Concentration Outside
Cell membrane
High Sodium Ion (Na+) Concentration Outside
Low Sodium Ion (Na+)Concentration Inside
1)Sodium is pumped out by a protein pump
*ATP needed
2)Potassium ions leak through cell membrane
creating a negative charge inside cell and
positive charge outside cell
RESTING POTENTIAL NOW REACH WHEN
INSIDE HAS BECOME NEGATIVE
Inside of cell

7. Movement of the “Action” Potential Action Potential = A electrical charge moving through a neuron CAUSED BY SODIUM GATES OPENING ALLOWING Na+ IN
Action Potential
At rest.
As the action potential passes, potassium gates open, allowing K+ ions to flow out.
Action Potential
Action Potential
At the leading edge of the impulse, the sodium gates open. The membrane becomes more permeable to Na+ ions and an action potential occurs.
The action potential continues to move along the axon in the direction of the nerve impulse.
Once Action Potential Passes Na + Gates Close and Na+ Pumped Back Out and Resting Potential Restored

8. Types of Neurons
Sensory Neurons-detect stimulus send a nerve impulse to brain (sensation)
Interneurons-located in the brain, process information received and formulate responses (thought)
Motor Neurons- carry an “action” or response impulse from the brain back to the body (response)

9. REFLEX ARC
What is the pathway of nerve impulse as your hand touches a hot stove?
SENSORY NEURONINTERNEURONMOTOR NEURON
This is called the a reflex or reflex arc?
This process can also occur with conscious control. Can you think of an example of this?

10. The Central Nervous System
Consists of the brain and spinal cord
Both the brain and spinal cord is wrapped in 3 layers of connective tissues called the meninges.
dura mater, arachnoid, pia matter
Between the meninges and the brain/spinal cord is cerebrospinal fluid
Bathes brain and spinal cord
Shock absorber
Exchange of nutrients and waste between blood and nervous tissue

11. The Brain

12.
Cerebrum
Cerebellum
Pons
Medulla Oblongata
Thalamus
Hypothalamus
Pituitary Gland
KNOW WHAT EACH DOES!!!

13. The Spinal Cord Like a “major telephone line”
31 pairs of spinal nerves branch out from the spinal cord to the rest of the body.
Reflexes may be processed directly by the spinal cord

14. The Peripheral Nervous System
The peripheral nervous system lies outside the central nervous system.
The peripheral nervous system consists of the peripheral nerves throughout the body (outside of spinal cord) and the sensory organs

15. The Peripheral Nervous System Sensory vs Motor Divisons
Sensory Division – transmits sensory impulses from the sense organs to the central nervous system
Motor Division – transmits response impulses from the central nervous system to the muscles and glands
The motor division is further divided into the somatic and autonomic division

16. The Sensory Division Sense Organs
Nose=Smell
Mouth=Taste
Ears=Sound
Eyes=Sight
Skin=Touch
All have specialized sensory neurons to pick up or detect stimulus that transmit impulses to the brain for processing

17. Types of Sensory Receptors
Pain receptors- respond to chemicals released by damaged cells
Located everywhere except brain, essential to bodies ability to detect injury or illness
Thermoreceptors- detect changes in temperature
Located in skin, body core, and hypothalamus
Mechanoreceptors- sensitive to touch, pressure
Found within skin, skeletal muscles, and ears
Chemoreceptors- sensitive to chemical in external environment entering the body
Located in nose and taste buds
Photoreceptors- sensitive to light
Located on the retina within the eye

18. Motor Division Somatic Nervous System
Regulates activities that are under conscious control such as movement of the skeletal muscles.

19. Motor Division Autonomic Nervous System
The autonomic nervous system regulates activities that are automatic or involuntary control
Heart beat, blood pressure, sweating ect…
sympathetic vs parasympathetic
Sympathetic-speed up systems (like a gas pedal)
Parasympathetic- slow down systems (like a brake)