1. OPENER
What does it mean to be nervous? What does this have to do with nerves?

2. Nervous System

3. Standards
SAP3. Students will assess the integration and coordination of body functions and their dependence on the endocrine and nervous systems to regulate physiological activities.
b. Investigate the physiology of electrochemical impulses and neural integration and trace the pathway of an impulse, relating biochemical changes involved in the conduction of the impulse.
c. Describe how the body perceives internal and external stimuli and responds to maintain a stable internal environment, as it relates to biofeedback.

4. Unit Essential Question
How does the nervous system work to regulate physiological activities of the body?
LESSON ESSENTIAL QUESTION
How is the brain like a control center of the body?

5. Functions of NS
Uses sensory receptors to monitor changes in/outside the body=sensory input
Changes sensed=stimuli
Processes and interprets the sensory input and makes decisions about what should be done=integration
Effects a response by activating muscles or glands=motor output

6. Example of Functions of Nervous System
Driving a car and you see a red light
Sensory Input
The brain registers that red means stop
Integration
You put your foot on the brake to stop car
Motor output

7. Divisions of Nervous System
Central Nervous System—CNS
Made of brain and spinal cord
Acts as command center, interprets sensory info. and provides instructions
Peripheral Nervous System—PNS
Includes all nerves
Spinal nerves carry impulses to and from the spinal cord
Cranial nerves carry impulses to and from the brain
Serves as communication lines

8. Peripheral Nervous System Classification
Two main parts:
Sensory (afferent) division
Carry nerve impulse from the body to the brain or spinal cord
Motor (efferent) division
Carry nerve impulses from the brain or spinal cord to the muscles and glands
2 subdivisions:
Somatic Nervous System—SNS—consciously, or voluntarily control skeletal muscles
Autonomic Nervous System—ANS—regulates involuntary or autonomic events

9. Autonomic Nervous System
Functions in regulating heart rate, blood pressure, breathing rate, body temperature, and other activities that aid in the maintenance of homeostasis
Sympathetic
Fight or flight
Stress
Emergency situation
Parasympathetic
Normal everyday activities
Counterbalances the effect of the sympathetic
Restores body to a resting state following stress

10. Supporting Cells of CNS: Neuroglial
Found in the brain and spinal cord-more numerous than neurons
Functions to fill spaces, support neurons, act as phagocytes, and hold brain and spinal cord together
They can reproduce and are sometimes responsible for tumors in the brain or spinal cord

11. Types of Neuroglial Cells
Astrocytes: found between capillaries and neurons and play a role in making exchanges between them; control the chemical environment within the brain by “mopping up” potassium ions
Oligodendrocytes: function in the formation of myelin within the brain and spinal cord
Microglia: phagocytes that dispose of debris
Ependymal: help circulate the cerebrospinal fluid and forms a protective cushion around the CNS

13. Supporting Cells of PNS
Schwann Cells
Forms myelin sheaths around nerve fibers that are found in the PNS
Satellite Cells
Act as protective, cushioning cells

14. Concept Check
With your collaborative partner, come up with an example for each of the 3 functions of the nervous system.
If you have damage to your right bicep, which specific nervous system is damaged? Which overall nervous system is damaged?
Identify which function of the ANS is being used:
1—Running away from Freddie Kruger
2—Drinking water
3—Trying to save your grandma from a heart attack
Specific Nervous System (Somatic)
Overall Nervous System (Peripheral)
Running (S), Drinking (P), Grandma (S)

15. Neuron Anatomy Neurons (nerve cells)
Highly specialized to transmit messages from one part of the body to another
Cell Body
Consists of cytoplasm, cell membrane and a nucleus
Processes
Dendrites: receive the impulse and move it toward the cell body
Axons: conduct nerve impulses away from the cell body
Axon terminal contains neurotransmitters
Synaptic cleft separates axons from each other
Space is called the synapse

16. Neurons

17. Neuron Anatomy Cont. Myelin
Protects and insulates the fibers and increases the transmission of an impulse
Myelinated appears white in color (white matter) and unmyelinated appears gray (gray matter)
Neurilemma
Sheath formed by many individual Schwann cells, has gaps which are called Nodes of Ranvier

19. Neuron Classification
Classified according to function or structure:
Function:
Sensory neurons: carry messages to the brain and spinal cord from receptors
Cutaneous sense organs: skin
Proprioceptors: muscles and tendons
“Propria” means “one’s own”
Motor neurons: carry messages from CNS to muscles and/or glands
Interneurons (association neurons): connect the motor and sensory neurons
Structure:
Multipolar neuron
Several processes extending from the cell body
Bipolar neuron
Two processes (axon and dendrite) extending from cell body
Unipolar neuron
Single process extending from cell body

20. Meissner’s corpuscle (touch)
Naked nerve endings (pain and temperature)-most numerous
Proprioceptor (tendon)
Pacinian corpuscle (pressure)
Proprioceptor (muscle)

23. OPENER
Does every reaction come from an instruction from the brain? When might your body want to react to a stimulus so quickly that it doesn’t even bother to consult the brain?

24. Nerve Impulse: Electrical Conditions
Cell Membrane
Polarized: result of an unequal distribution of ions
Nerve cells at rest (resting potential)
High conc. of Na+ on the OUTSIDE of the membrane and a high conc. of K+ ions on the INSIDE
Large numbers of negatively charged ions on the inside which makes the outside have a more positive charge with respect to the inside

25. Nerve Impulse: Action Potential
Membrane disturbed = nerve impulse triggered
Stimulus can include: temperature, pressure, chemical concentrations, electrical, sound, light
Neuron stimulation allows the movement of Na+ and K+ through the membrane
Influx of Na+ causes the membrane to depolarize (threshold potential)
Causes the activation of a neuron, and an action potential to occur
All-or-none response
Repolarization occurs when K+ diffuse out of the neuron restoring the membrane to its resting state (polarized)
Another impulse cannot occur until repolarization has occurred

27. Nerve Impulse: Synapse
Transmission: neurons communicate with other neurons
Presynaptic neurons send the signal
Post synaptic neurons receive the message
Synaptic knob: found at the end of an axon; secretes neurotransmitters
Cleft separates axons
Neurotransmitters: chemicals released from an axon that start or stop a nerve impulse
Excitatory: neurotransmitters that trigger a nerve (Glutamate)
Inhibitory: neurotransmitters that inhibit a nerve impulse (GABA)

28. Reflex Arc
Reflexes are rapid, predictable, and involuntary responses to stimuli
A reflex arc is a pathway to nerve impulses, they do not go to the brain
Somatic reflexes
Stimulate skeletal muscles
Autonomic reflexes
Regulates smooth muscles, heart, glands, saliva secretion, and changes in pupil size
Also regulates digestion, elimination, blood pressure, and sweating
Knee-Jerk Reflex
2 neuron reflex arc
Sensory neuron  spinal cord  motor neuron  knee
Withdrawal Reflex
3 neuron reflex arc
Touch something hot or sharp
Sensory neuron  spinal cord  finger to withdraw  second impulse  brain --> person becomes aware

30. Concept Check How are nerve cells important?
Reason why axons are long and slender projections of a neuron.
Imagine that your body did not have interneurons, can you predict what would happen?

31. OPENER
Why do drugs kill?

32. Brain and Drugs
Chemicals in recreational drugs alter neurological activity by disrupting the activity of one or more of these neurotransmitters

33. Addiction
When the brain gets a lot of stimulation by a neurotransmitter it “ups” the production of these receptors
Leads to tolerance
Withdrawal

34. Brain Weights about 3 lbs. Divided into 4 regions Brain stem
Medulla oblongata
Pons
Midbrain
Cerebellum
Diencephalon
Cerebrum

35. Cerebrum Largest part of the brain Consist of a cerebral cortex
Outer rim of gray matter
Terminology
Convolutions or gyrus: elevated ridges
Sulcus: shallow grooves separate gyrus
Fissures: deep grooves separate brain into lobes

36. Cerebrum
Landmarks
Cerebral hemispheres: divides cerebrum into left and right halves
Longitudinal fissures: separates the right and left cerebral hemispheres
Transverse fissure: separates the cerebrum and cerebellum
Corpus callosum: deep bridge of nerve fibers that connect the two hemispheres

38. Cerebrum Lobes Frontal lobe Parietal lobe Temporal lobe Occipital lobe
Functions in voluntary movements, personality, intelligence, memory and speech
Parietal lobe
Functions in sensations (heat, cold, pain, touch, pressure, body position)
Temporal lobe
Functions in hearing and smell
Occipital lobe
Functions in vision

39. Cerebrum Layers Cerebral cortex White matter
thin layer of gray matter that makes up the outermost portion of the cerebrum
Unmyelinated cell bodies
White matter
Makes up the bulk of the cerebrum
Contains bundles of myelinated nerve fibers

40. Opener
What would happen if a person damages their frontal lobe compared to if they damaged their occipital lobe?

41. Cerebrum Functions Motor areas Sensory areas Association areas
Allows conscious movement of skeletal muscles
Anterior to central sulcus
Broca’s area (needed for speech), damage results in the inability to form words.
Sensory areas
Gives rise to feelings or sensations
Located in the parietal lobe posterior to the central sulcus
Association areas
Related to memory, reasoning, verbalizing, judgment and emotional feelings
Located in the anterior portions of the frontal lobes
Wernicke’s area (interprets speech), damages results in the inability to form correct sentences.

44. Diencephalon (Interbrain)
Thalamus
Serves as a relay station for all sensory impulses except for smell
Produces emotions of pleasantness and unpleasantness
Epithalamus
Pineal body may function in normal sexual maturity
Secretes melatonin (sleepiness)
Choroid plexus form the cerebrospinal fluid
Hypothalamus
Regulates temperature, water balance, and metabolism
Plays a role in the limbic system
Drives and emotions (thirst, appetite, pain)
Regulates the pituitary gland and produces its own hormones
Mammilary bodies are involved in odor recognition

46. OPENER
What are the functions of the cerebrum? What does it NOT control?

47. Brain Stem Midbrain Pons Medulla Oblongata Reticular Formation
Regulates vital visceral activities
Contains control centers for heart rate, blood pressure, breathing, swallowing, and vomiting
Reticular Formation
Plays a role in consciousness and awake/sleep cycles
Midbrain
Cerebral aqueduct
Connects the 3rd and 4th ventricles
Cerebral peduncles
Composed of nerve tracts that travel to and from the cerebral hemispheres
Corpora quadrigemina
Functions in vision and hearing
Pons
Controls breathing

49. Cerebellum Located beneath the occipital lobes
Shaped like a cauliflower
Coordinates all voluntary muscular movements
Controls skeletal muscles to maintain equilibrium
Causes body movements to be smooth
If damaged could lead to a tumor or stroke

51. Meninges (covers the brain and spinal cord)
Outermost—dura mater
Double layer that protects entire brain
Composed of tough, white fibrous connective tissue
Middle layer—arachnoid mater
Looks like a cobweb
Cerebrospinal fluid found in subarachnoid space
Inside layer—pia mater
Clings to the brain and spinal cord in every fold and crease
Contains blood vessels that aid in nourishing the brain and spinal cord
If infected by virus or disease, you get meningitis

54. Blood-Brain Barrier
Protects the brain from harmful substances and pathogens by preventing passage of many substances from the blood into the brain tissue.
Helps maintain a stable environment for the brain.
Trauma, toxins, and inflammation cause a breakdown of the blood-brain barrier

55. Quick Review Which numbers refer to the: Cerebrum? Hypothalamus?
Cerebellum?
Pons?
Thalamus?
Medulla?

56. Spinal Cord Functions: Consists of 31 spinal nerves
Conducts nerve impulses to and from the brain
Serves as a reflex center
Consists of 31 spinal nerves
Cervical enlargement
Bulge in spinal cord in the neck region
Gives off nerves to the arms
Lumbar enlargement
Bulge in spinal cord in the back
Gives off nerves to the legs
Composed of gray matter surrounded by white matter
Tracts
Ascending tracts: conduct impulses from body parts and carry sensory information to the brain
Descending tracts: conduct motor impulses from the brain to muscles and glands

57. Cranial Nerves Consist of 12 pairs Primarily serve the neck and head
Vagus nerve only pair to extend to the thoracic and abdominal cavities
Numbered using Roman numerals from superior to inferior in which they leave the brain
Mneumonic Device
“Oh, oh, oh, to touch and feel very good velvet, ah”

59. Cranial Nerves Olfactory (Smell) Optic (Vision)
Oculomotor (“Eye Mover”)
Trochlear (“Pulley”-eye)
Trigeminal (Chewing)
Abducens (Abducts eyeball)
Facial (Face)
Vestibulocochlear (Hearing and Balance)
Glossopharyngeal (Tongue and Pharynx)
Vagus (somatic sensations)
Accessory (swallowing and movement of head and shoulders)
Hypoglossal (Under tongue)

60. “Oh, oh, oh, to touch and feel very good velvet, ah”

62. Review What are the four major parts of the brain?
Which major part is responsible for necessary functions like respiration and heart beat?
This cauliflower shaped part of the brain helps your movements to be smooth. What is it?

63. Dysfunctions of Brain Concussion Contusion Alzheimer’s Disease
Mild injury, dizziness, may lose consciousness for a short time
Contusion
Results from tissue destruction
Alzheimer’s Disease
A progressive degenerative disease of the brain that ultimately results in mental deterioration

64. CNS Disorders Meningitis- inflammation of the meninges
Encephalitis- swelling of the brain
Epilepsy- seizures
Cerebral palsy- impairs movement, learning, hearing, seeing, and thinking
Poliomyelitis- affect nerves and can lead to partial or full paralysis
Hydrocephalus- buildup of fluid in the brain
Parkinson’s Disease- leads to shaking (tremors) and difficulty with walking, movement, and coordination
Multiple sclerosis- inflammation of the myelin results in muscle weakness and spasm, fatigue, memory loss, depression
Alzheimer’s Disease- progressive brain disease that slowly destroys memory and thinking skills
Brain tumor- growth on brain or spinal cord
Hematoma- collection of blood outside of blood vessels

65. PNS Disorders Neuritis- inflammation of a nerve
Sciatica- pain, weakness, numbness, or tingling in the leg
Neuralgia- pain in one or more nerves that occurs without stimulation of pain receptors
Trigeminal neuralgia- stabbing or electric-shock-like pain in parts of the face
Bell’s palsy- paralysis or weakness of muscles on one side of face
Carpal tunnel syndrome- pressure on median nerve