»Ever wonder how you can do everything you do?

1 Allows us to sense our external environment as well as sense changes internally.

2 Movements (actions both involuntary and voluntary)

3. Allows us to have memory and intelligence – Thinking!

4. Helps maintain homeostasis by detecting changes either on the outside or inside and allowing your body to react appropriately.

»Central Nervous System (CNS) Central Nervous System (CNS) = brain and spinal cord

»Peripheral Nervous System (PNS) Peripheral Nervous System (PNS) = cranial and spinal nerves and are information lines (like corded telephones)

» The CNS is like the control center. It houses the brain and spinal cord.

» The PNS is the message center. It connects the CNS to the rest of the body.

1.1. Neurons or nerve cells: Neurons or nerve cells: the basic cell and functional unit of the nervous system. ˃ They transmit information to the body in the

form nerve impulses. ˃ They have a rounded area called the nerve

cell body and two extensions: the dendrites and axons.

2.2. Nervous Tissue: Nervous Tissue: Bundles of neurons or nerve cells put together.

3.3. Neuroglial cells: Neuroglial cells: supporting cells in the nervous tissue.

Conducts impulses to the

neuron

Conducts impulses to the

body

1.1. FunctionFunction: : Fill in spaces, provide structural frameworks, produce myelin, carry on phagocytosis

2. 2. TypesTypes:: ˃ Microglial, Oligodendrocites,

AstrocytesAstrocytes, , EpendymalEpendymal, , Schwann cellsSchwann cells

1.1. White MatterWhite Matter: In the CNS, myelinated axons that appear white

2.2. Gray Matter: Gray Matter: Unmyelinated axons and neuron cell bodies in the PNS appear gray.

Depending on what your body needs to do- there are different types of neurons. 1. Bipolar 2. Unipolar 3. Multipolar

1. Each neuron is either a Sensory Neuron, a Motor Neuron or an Interneuron.

1. SENSORY NEURON: Is considered Afferent or it brings information from the body into the neurons located in the brain or spinal cord (CNS). Stimulated by changes from inside or outside the body- the sense it and act on it.

2. MOTOR NEURON: Is considered Efferent or it brings messages away from the CNS and sends them to the body. It stimulates muscles to contract, or your body to “do” something either voluntarily or involuntarily.

3. INTERNEURON: Lie within the CNS and link other neurons together. They transmit impulses from one part of the brain or spinal cord to another.

1. Autonomic nervous system Autonomic nervous system – controls everything we don’t think about.. Smooth muscles, glands, breathing, etc. = involuntary movement

2. Somatic nervous system Somatic nervous system – controls the skeletal muscle = voluntary movement

1. Use the book and your notes to create a foldable about the different types of neurons.

2. You may fold it anyway you like as long as on the outside you have three flaps (1 for each of the types of neurons)

3. The outside you will need to draw what each neuron looks like and label it.

4. The inside will answer the following info: 1. Where it is located. 2. Something about the number of axons and

dendrites. 3. If it is a sensory neuron, interneuron, or motor

neuron and what that means. 4. Is it afferent or efferent. 5. One piece of other information.

1. The brain is composed of about 100 billion multipolar neurons and even more nerve fibers to communicate.

2. Divided into three major portions: The cerebrum, cerebellum, and the brain stem

1.1. CerebrumCerebrum controls sensory and motor functions, higher mental functions – memory and reasoning (Divided into sections)

2.2. Cerebellum Cerebellum coordinates voluntary muscle activity

3.3. Brain stem Brain stem regulates visceral activities and connects various parts of the nervous system

1. The Frontal Lobe2. The Parietal Lobe3. The Occipital Lobe4. The Temporal Lobe

1. Forms the anterior portion of each hemisphere (Your brain is divided into left and right portions).

Functions:Functions:• How we know what we are doing

within our environment (Consciousness).

• Controls our emotional response. • Controls our expressive language.

Observed Problems:Observed Problems:• Loss of simple movement of various body parts

(Paralysis). • Inability to plan a sequence of complex

movements needed to complete multi-stepped tasks, such as making coffee (Sequencing).

• Inability to express language (Broca's Aphasia).

Location: Location: Posterior to the frontal lobe, on the top part of the cerebrum.

Function: Function: •Location for visual attention. •Location for touch perception.

Observed Problems:Observed Problems:• Inability to locate the words for writing.• Problems with reading. • Difficulty with drawing objects. • Difficulty in distinguishing left from right. • Difficulty with doing mathematics. • Inability to focus visual attention. • Difficulties with eye and hand coordination.

Location: Location: Most posterior, at the back of the head/brain. Function: Function: •Vision control center. Observed Problems: Observed Problems: •Defects in vision•Difficulty with identifying colors •Production of hallucinations •Difficulties with reading and writing.

Location: Location: Laterally (each side of brain close to the ears. FunctionFunction: •Hearing ability •Memory

Observed problemsObserved problems: •Difficulty in recognizing faces. •Short-term memory loss. •Right lobe damage can cause persistent talking. •Increased aggressive behavior.

Deep in Brain, leads to spinal cord.Functions: » Breathing, Heart Rate, Swallowing, Reflexes to seeing and

hearing, controls sweating, blood pressure, digestion, temperature (Autonomic Nervous System). Anything you Can’t Control.

» Sense of balance (Vestibular Function). Observed Problems:» Decreased vital capacity in breathing. » Problems with balance and movement. Dizziness and

nausea.» Sleeping difficulties (Insomnia, sleep apnea).

» Includes midbrain, pons, and medulla oblongata» Midbrain –vision reflex and auditory reflex» Pons – relay sensory impulses from peripheral

nerves to the brain» Medulla oblongata –controls the cardiac center,

blood vessel constriction, and respiratory center.

Located at the base of the skull.Functions:» Coordination of voluntary movement Balance

and equilibrium Observed Problems:» Loss of ability to coordinate fine movements.

Loss of ability to walk. Slurred Speech

» Contains the thalamus and hypothalamus and medial forebrain

» Hypothalamus is important in maintaining homeostasis by regulating:˃ Heart rate˃ Water and electrolyte balance˃ Hunger and body weight˃ Body temp

Cranial NervesPair of nerves What is does

1.Olfactory smell

2. Optic vision

3. Oculomotor Raise eyelids, move the eye, controls involuntary muscles of the eye, adjusts amount of light into the eyes

4. Trochlear Carries motor impulses to the fifth voluntary muscle of the eye

5. Trigeminal Ophthalmic division = sensory fibers from the surface of the eye, tear glands, anterior scalp, forehead, upper eyelidsMaxillary division = upper teeth, upper gum, upper lipMandibular division = scalp behind ears, skin of jaw, lower teeth, lower gum, lower lip

Pair of nerves What is does

6. Abducens Moves the rest of the eye

7. Facial Taste, anterior two-thirds of tongue, facial expression

8. Vestibulocochlear Vestibular branch = maintain equilibriumCochlear branch = hearing

9. Glossopharyngeal Tongue and pharynx, tonsils, posterior third of tongue

10. Vagus Somatic= Larynx, swallowing, speechAutonomic = heart and smooth muscles

11. Accessory Cranial branch = soft palate, pharynx, larynxSpinal branch = neck muscles

12. Hypoglossal Move the tongue for speaking, chewing, swallowing

The Spinal CordThe Spinal Cord

Spinal Cord

» connected to the brain » descends down the middle of the back and is

surrounded and protected by the bony vertebral column

» surrounded by a clear fluid called Cerebral Spinal Cerebral Spinal Fluid (CSF),Fluid (CSF), that acts as a cushion to protect the delicate nerve tissues against damage from banging against the inside of the vertebrae

» transmit electrical informationelectrical information to and from the limbs, trunk and organs of the body, back to and from the brain

The Spinal Cord

» Cerebral Spinal Fluid:

Spinal NervesThere are four main groups of spinal nerves which exit

different levels of the spinal cord.

These are in descending order down the vertebral column:

1.1. Cervical Nerves "C"Cervical Nerves "C" : (nerves in the neck) supply movement and feeling to the arms, neck and upper trunk. (8 total)

2.2. Thoracic Nerves "T"Thoracic Nerves "T" : (nerves in the upper back) supply the trunk and abdomen. (12 total)

3. Lumbar Nerves "L" and Sacral Nerves "S"Lumbar Nerves "L" and Sacral Nerves "S" : (nerves in the lower back) supply the legs, the bladder, bowel and sexual organs. (5L and 5S)

How does your brain How does your brain send out signals?send out signals?

» The surface of a cell membrane is usually electrically charged. »When the charges are not equal it

is said to be polarized and is VERY IMPORTANT in sending Nerve impulses to and from the body CNS to the PNS!

» The difference in electrical charge between the inside and outside of a cell is called the POTENTIAL DIFFERENCE. POTENTIAL DIFFERENCE.

» In a nerve cell that is “RESTING” or not sending impulses this difference in charges is called the RESTING POTENTIALRESTING POTENTIAL

» As long as the nerve cell remains undisturbed or the charges do not change it will remain in a resting potential state.

» Action Potential: Action Potential: 1. Electrical charges change by sodium channels

opening and allowing positive sodium into the cell. This makes it positive. And is called DEPOLARIZATION

2. Soon after potassium channels open and allow potassium in ions in again bringing the charge back to negative. This is called REPOLARIZATION

The action potential is the rapid change from The action potential is the rapid change from Depolarization to Repolarization which Depolarization to Repolarization which causes an impulse to be sent through the causes an impulse to be sent through the neuron neuron

» A wave of action potentials that move down the neuron and axon until they hit either another neuron or body cell to transmit the impulse.

» Nerve Pathways- when nerve impulses travel from neuron to neuron.

» The junction between two communicating neurons is called the synapsesynapse.

» The neurons DO NOT TOUCH- there is a gap that separates them

1. An Impulse (action potential) travels from the dendrite to the cell body and then the axon to the axon terminals (or end of the neuron).

2. At the end of a neuron or synapse, NEUROTRANSMITTERS are released from the axon terminals.

3. Neurotransmitters diffuse to the next neuron or body cell.

» The simplest nerve pathways that are only a few neurons long are called REFLEXE ARCS.

» Reflexes are automatic subconscious responses to changes within or outside the body.

» Example: The Knee-Jerk reflex: Only 2 neurons. A sensory neuron communicating directly with a motor neuron.

Page 221-222 in book

Knee Jerk activity