1. The Nervous System

2. Functions of the Nervous System
Control center for all body activities
Responds and adapts to changes that occur both inside and outside the body
(Ex: pain, temperature, pregnancy)

3. Central Nervous System
Neurons : microscopic nerve cells that make up the brain, spinal cord, and nerves
- 30,000 neurons can fit on a pinhead

4. Anatomy of a Neuron Each neuron contains: - Cell body with nucleus
- Dendrites : fibers that receive messages from other neurons
- Axons : fibers that send messages to other neurons

5. Neurons do NOT touch; there is a gap between them called a synapse
Messages are sent across the synapses by special chemicals called neurotransmitters

6. Communication Between Neurons
The use of neurotransmitters causes an electrical current
There is enough electrical current in the brain to power a flashlight

7. Two Major Divisions of the Nervous System

8. Central Nervous System
Brain : a mass of 100 billion neurons located inside the skull
-Learning occurs as more and stronger connections are made between neurons

9. Anatomy of the Brain Cerebrum : largest part of human brain
- Responsible for:
- Thought
- Language
- Senses
- Memory
- Voluntary movement

10. Lobes of the Brain (4) Frontal Lobe Parietal Lobe Occipital Lobe
Temporal Lobe
* Note: Occasionally, the Insula is considered the fifth lobe. It is located deep to the Temporal Lobe.

11. Lobes of the Brain - Frontal
The Frontal Lobe of the brain is located deep to the Frontal Bone of the skull.
It plays an integral role in the following functions/actions:
- Memory Formation
- Emotions
- Decision Making/Reasoning
- Personality
Modified from:

12. Lobes of the Brain - Parietal Lobe
The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull.
It plays a major role in the following functions/actions:
- Senses and integrates sensation(s)
Spatial awareness and perception
(Proprioception - Awareness of body/ body parts in space and in relation to each other)
Modified from:

13. Lobes of the Brain – Occipital Lobe
The Occipital Lobe of the Brain is located deep to the Occipital Bone of the Skull.
Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli.
Modified from:

14. Lobes of the Brain – Temporal Lobe
The Temporal Lobes are located on the sides of the brain, deep to the Temporal Bones of the skull.
They play an integral role in the following functions:
Hearing
Organization/Comprehension of language
Information Retrieval (Memory and Memory Formation)
Modified from:

15. Retrieval of a Memory
A memory is not a snapshot stored in the brain – it must be put together from information stored in various parts of the brain

16. Anatomy of the Brain Cerebellum : at base of brain -Responsible for:
- Muscle coordination
- Balance
- Posture

17. Anatomy of the Brain Brain Stem : connects brain to spinal cord
-Responsible for:
- Breathing
- Swallowing
- Heartbeat
- Blood pressure

18. Central Nervous System
Spinal Cord : Column of nerves from brain to tailbone – protected by vertebrae of spine
Responsible for:
- Conducting impulses between the brain and the rest of the body
*Impulses may travel as fast at 268 miles/hr

19. Peripheral Nervous System
Nerves : visible bundles of axons and dendrites that entend from the brain and spinal cord to all other parts of the body

20. -Responsibilities:
- Sensory nerves - carry messages from body to brain (pain, pressure, temperature)
- Motor nerves – carry messages from brain to body to respond

21. Problems of the Nervous System
Concussion
A temporary disturbance of the brain’s ability to function due to a hard blow to the head

22. Paralysis
A loss of sensation and movement of part of the body due to an injury of the spinal cord or brain

23. Parkinson’s Disease
The brain does not produce enough of the neurotransmitter that transmits messages from the brain to the muscles
Symptoms: tremors, rigid muscles, shuffling walk, and loss of facial expression
Red areas show where chemical is stored

24. Alzheimer’s Disease
A gradual shrinking of the neurons in the cerebrum
Symptoms: memory loss, emotional disturbances, inability to function on own, death

25. Epilepsy
Abnormal transmission of messages between the neurons in the brain
Symptoms: seizures

26. Further Investigation
Phineas Gage: Phineas Gage was a railroad worker in the 19th century living in Cavendish, Vermont. One of his jobs was to set off explosive charges in large rock in order to break them into smaller pieces. On one of these instances, the detonation occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod to be blown right up through his skull and out the top. The rod entered his skull below his left cheek bone and exited after passing through the anterior frontal lobe of his brain.
Frontal

27. Remarkably, Gage never lost consciousness, or quickly regained it (there is still some debate), suffered little to no pain, and was awake and alert when he reached a doctor approximately 45 minutes later. He had a normal pulse and normal vision, and following a short period of rest, returned to work several days later. However, he was not unaffected by this accident.
Learn more about Phineas Gage:
Frontal