Nervous System (Chapter 6)

Nervous System

The system that controls virtually all activities of the body, both voluntary and involuntary.

Parts of Nervous System

• Brain

• Spinal Chord

• Nerves

Parts of Nervous system

• Central Nervous System

• Peripheral Nervous System

Central Nervous System (CNS)

Brain & Spinal chord

Peripheral Nervous System

The part of the nervous system that consists of 31 pairs of spinal nerves and 12 pairs of cranial nerves; these may be sensory nerves, motor nerves, or connecting nerves

Parts of PNS

• Somatic Nervous System

• Autonomic Nervous System

Somatic Nervous System

Regulates actives with voluntary control

Autonomic Nervous System

Regulated involuntary body functions

Brain

The controlling organ of the body and center of consciousness; functions include perception, control of reactions to the environment, emotional responses, and judgment.

Parts of Brain

• Cerebrum

• Cerebellum

• Brain Stem

Cerebrum

• Largest part of brain

• made up of several lobes that control movement, hearing, balance, speech, visual perception, emotions, and personality.

Brain Lobes

• Frontal

• Temporal

• occipital

• Parietal

Cerebellum

coordinates the various activities of the brain, particularly fine body movements

Brainstem

The area of the brain between the spinal cord and cerebrum, surrounded by the cerebellum; controls functions that are necessary for life, such as respiration.

Brainstem Parts

• Midbrain

• Pons

• Medulla Oblongata

Midbrain

The part of the brain that is responsible for helping to regulate the level of consciousness

Pons

An organ that lies below the midbrain and above the medulla and contains numerous important nerve fibers, including those forsleep, respiration, and the medullary respiratory center

Medulla Oblongata

Nerve tissue that is continuous inferiorly with the spinal cord; serves as a conduction pathway for ascending and descending nerve tracts; coordinates heart rate, blood vessel diameter, breathing, swallowing, vomiting, coughing, and sneezing

Reticular Activating System (RAS)

Located in the upper brainstem; responsible for maintenance of consciousness, specifically one’s level of arousal

Spinal Chord

An extension of the brain, composed of virtually all the nerves carrying messages between the brain and the rest of the body. It lies inside of and is protected by the spinal canal.

Parts of Autonomic Nervous System

• Sympathetic

• Parasympathetic

Sympathetic Nervous System

The adrenergic part of the autonomic peripheral nervous system responsible for the fight-or-flight response

Parasympathetic Nervous System

A subdivision of the autonomic nervous system, involved in control of involuntary functions, mediated largely by the vagus nerve through the chemical acetylcholine

Sensory Nerves

The nerves that carry sensations such as touch, taste, smell, heat, cold, and pain from the body to the central nervous system

• Each has specialized nerve endings to only perceive 1 type of sensation

• Can bypass spinal chord

Motor Nerves

Nerves that carry information from the central nervous system to the muscles of the body