1. BIOLOGY 30 – Unit 1 Nervous and Endocrine Systems

2. Vertebrate Nervous Systems
The nervous system can be divided into two main categories, both of which can be further subdivided

3. The Central Nervous System (CNS)
Contains the nerves of the brain and the spinal cord
Acts as a coordination center for incoming and outgoing information

4. The Peripheral Nervous System (PNS)
Relay of info btwn body organs and CNS – both motor and sensory neurons
Autonomic: INVOLUNTARY
Internal Organs
Sympathetic: Prepares body for stress
“Fight or Flight”
Parasympathetic: Restores body to normal after stress
“Rest and Digest”
Somatic: VOLUNTARY
Skeletal muscle, bones, skin
Work in opposition

5. Cells in the Nervous System
Two different types of cells exist within the nervous system:
Glial Cells (neuroglial cells): Non-conducting cells that are responsible for supporting the neural cells structurally and metabolism within nerve cells
Neurons: Cells responsible for conducting electrochemical messages throughout the body

6. Neuron – functional unit of nervous system
Sensory Neurons: (Afferent)
From external environment to CNS
Interneurons: (Association)
Link neurons
Only found in brain and spinal cord
Motor Neurons: (Efferent)
From CNS to effector (muscle, organ)

7. The Structure of the Neuron
All neurons are made up of 4 different parts:
The Dendrites
The Cell Body
The Axon
Axon Terminal

8. The Dendrites
The dendrite is responsible for receiving information either from the environment or from other neurons
Dendrite

9. The Cell Body
Contains the nucleus, which acts as a cell control centre, directing cell activity
Cell Body

10. The Axon
Where the impulse travels down and conducts the impulse throughout the neuron
Some neurons contain a myelin sheath:
Insulated covering of axon
Speeds transmission
Produced by Schwann Cell
**White Matter + myelin
***Grey Matter – myelin
Nodes of Ranvier
gaps between myelin sheath
Myelin Sheath
Axon

11. The Axon Terminal
The end of the neuron which contains and releases neurotransmitters, allowing neurons to communicate with one another
The neuron sending the message is called the pre-synaptic neuron
The neuron receiving the message is called the post-synaptic neuron

13. Repair of Damaged Nerves
Sensory and motor neurons contain two addition cellular structures, absent in interneuron cells
Neurilemma
Membrane that surrounds some nerve cells
Produced by Schwann Cells
Promotes regeneration
Found in PNS
Not found in CNS

14. Nerves Nerves are the visible parts of the nervous system
Made up of bundles of neurons

15. Kim Peek – The Real Rain Man