1. The Nervous System

2. Functions of the Nervous System
1. Communication between body parts
2. integration[combination/coordination] of body parts
3. controls all your body’s functions
4. recognizes sensory stimuli

3. There are 2 types of cells in the nervous system:
1. nerve cells called neurons
2. glia cells they support the neurons

4. The neuron
Messages travel along pathways made up of specialized cells called neurons[nerve cells]
The message being sent is called a nerve impulse
Nerve impulses travel through neurons very rapidly at speeds of up to 100 m/sec

5. Every neuron does 3 things:
1. Receives impulses
2. Conducts impulses
3. Sends impulses

7. Parts of the neuron: Dendrites: The receiving end of a neuron
Made up of a series of branching extensions
They gather all the messages coming into the neuron

8. Cell body:
The main part
Also called a cyton of the neuron
Contains the nerve cell’s nucleus

9. Axon:
Extends out of the cell body
Carries impulses away from the cell body

10. The axon ends in a small series of terminal brushes[end brushes], which send the impulse on its way

11. On the axon you have the myelin sheath and the Schwann cells
Schwann cells produce myelin
Myelin is fatty white material found on the axon for protection

12. Synapse: a space between the dendrite of 1 neuron and the axon of another

13. The neurotransmitters
Neurotransmitters are chemicals produced by the nerve cells
Neurotransmitters regulate how the body responds to the environment
The chemical at the end of the first nerve cell moves toward the receptors which are at the beginning of the next nerve cell

14. The chemical attaches itself to the receptor {lock and key}
Each receptor is specific and can only respond to a specific chemical {nerve signal}, which fits into the receptor

15. Now the receptor with the chemical sends a message through its nerve cell to either a muscle, gland or another nerve cell telling it what to do

17. Examples of neurotransmitters:
Dopamine: It’s a neurotransmitter found in the brain that’s involved with:
The control of body movements and other functions
Feelings of pleasure or reward

18. Acetylcholine
acetylcholine receptors are found widely throughout the body and brain.
In the brain, acetylcholine is involved in learning and memory
It also stimulates muscle tissue

20. 3 kinds of neurons
1. sensory neurons: sends impulses from the body to the spinal cord then to the brain
2. motor neurons: carry impulse away from the brain and spinal cord and toward the glands or muscles which results in a response

21. 3.interneurons:
They’re in between the sensory neurons and the motor neurons
carry the impulse to the motor neurons

22. The path of a reflex arc is:
Reflex arc: a nerve pathway that consists of a sensory neuron, interneuron and a motor neuron
The path of a reflex arc is:
Receptersensory neuroninterneuronmotor neuroneffector

23. Any event, change, or condition in the environment that causes an organism to react is called a stimulus[the cause]
The reaction of the organism is called a response[ your reaction]

24. Organization of the nervous system
The nervous system includes a central and a peripheral nervous system

25. Central nervous system
Consist of the Brain and spinal cord

26. Brain Has 3 sections: 1.brain stem[medulla oblongata] 2. cerebellum
3. cerebrum

27. Functions of the brain stem[medulla oblongata]
Regulates heart rate and pulse rate
Regulates the rate of breathing
Controls your blood pressure

28. Functions of the cerebellum:
1. balance and coordination
2. maintains equilibrium
3. aids in posture

29. cerebrum
Cerebrum-largest part of brain.

30. Functions of the cerebrum
Sensory perception
Emotional control
Memory
Voluntary moves
Writing, reading, and speaking

31. Creativity
Site of reasoning
Site of intelligence
Thinking
consciousness

32. Spinal cord- begins at the brain stem and ends at the tail bone
Carries messages to and from the brain

33. Both the brain and spinal cord are covered by a membrane system called the meninges

34. The meninges has 3 layers
There’s cerebral spinal fluid {CSF} in between the middle and bottom layer

35. The CSF brings nutrients to the meninges
The CSF is also a shock absorber; it protects the brain and spinal cord

36. Peripheral nervous system

37. somatic system
Consists of the sensory neurons and motor neurons that carry information to and from the central nervous system

38. The somatic system has 12 pairs of cranial nerves and 31 pairs of spinal nerves

39. autonomic system
controls the involuntary activities of the body[closely associated with regulating heart rate]

40. sympathetic nervous system parasympathetic nervous system
The autonomic system is made up of 2 parts:
sympathetic nervous system
parasympathetic nervous system
instructions from these 2 systems are generally opposite each other in order to maintain homeostasis

41. impulses from the sympathetic nervous system does the following:
speeds up the heart
increases the level of oxygen in the blood
prepares the body to deal with difficult, dangerous, or stressful situations

42. It counterbalances the effects of the sympathetic system
Then parasympathetic nervous system is most active when the body is relaxed
It counterbalances the effects of the sympathetic system
It restores the body to a resting state after a stressful experience

43. Disorders of the nervous system

44. Cerebral palsy
failure of brain development or deterioration of one or several of its parts, which causes conditions that affect motor skills that cause physical disability in humans, early on in infancy and into early childhood.
It occurs before birth due to lack of oxygen

45. Multiple sclerosis (MS)
is a nervous system disease that affects your brain and spinal cord.
It damages the myelin sheath which slows down or blocks messages between your brain and your body

46. Alzheimer's disease
a brain disorder that seriously affects a person's ability to carry out daily activities
It first involves the parts of the brain that control thought, memory and language

47. Parkinson's disease is a type of movement disorder Symptoms include:
Trembling of hands, arms, legs, jaw and face
Stiffness of the arms, legs and trunk
Slowness of movement
Poor balance and coordination

48. Meningitis
is inflammation of the thin tissue that surrounds the brain and spinal cord, called the meninges

49. Encephalitis
is an inflammation of the brain

50. OR STROKE when a blood clot blocks a blood vessel in the brain
when a blood vessel breaks and bleeds into the brain

51. Epilepsy
a medical condition that produces seizures affecting a variety of mental and physical functions.

52. Narcolepsy
is a sleep disorder that causes excessive sleepiness and frequent daytime sleep attacks.