Nervous System Notes

FUNCTION OF NERVOUS SYSTEM Sensory Function – detects changes (stimuli) within body and outside body Integrative Function – It analyzes sensory information, stores some aspects, and makes decisions regarding appropriate behaviors

Motor Functions – it may respond to stimuli by initiating muscular contractions or glandular secretions These muscles or glands are called effectors

DIVISIONS OF NERVOUS SYSTEM Two primary divisions : Central Nervous System (CNS) – consists of brain and spinal cord

information is integrated thoughts and emotions are generated memories are formed and stored Most nerve impulses that influence effector organs begin in CNS

Peripheral Nervous System (PNS) – consists of cranial and spinal nerves Sensory/afferent neurons – carry information from body toward CNS Motor/efferent neurons – carry instructions away from CNS to target or effector organs of body

PERIPHERAL NERVOUS SYSTEM PNS divided into: Somatic Nervous System (SNS)– brings info from skin, special senses, body wall and limbs to CNS, and motor neurons to skeletal muscles Voluntary portion of PNS

AUTONOMIC NERVOUS SYSTEM (ANS) brings info from receptors in internal organs to CNS and motor neurons to smooth muscle, cardiac muscle and glands. Responses are involuntary

ANS divided into: Sympathetic Nervous System – “fight or flight” Emergency or non-normal situations

Parasympathetic Nervous System – “feed and breed” Normal everyday situations Most organs receive input from both divisions