Functions of the Functions of the Nervous SystemNervous System

Sensory inputSensory input — gathering information — gathering information– Sight, Touch, Hearing, Sight, Touch, Hearing,

Tasting & smellingTasting & smelling– To monitor changes occurring To monitor changes occurring

inside and outside the bodyinside and outside the body– Stimuli causes a reaction by the Stimuli causes a reaction by the

bodybody

Integration Integration – how we use – how we use information provided by all the sensations coming from within the body and from the external environment

Functions of the Nervous SystemFunctions of the Nervous System

Motor outputMotor output– A response to A response to

integrated stimuliintegrated stimuli– The response activates The response activates

muscles or glands to muscles or glands to perform a specific perform a specific actionaction

Example: Timing and Example: Timing and muscle coordination muscle coordination needed to slide into needed to slide into second base gracefully.second base gracefully.

Functions of the Nervous SystemFunctions of the Nervous System

Nervous System OrganizationNervous System Organization

Central nervous systemCentral nervous system– BrainBrain– Spinal cordSpinal cord

Peripheral nervous Peripheral nervous systemsystem

– Nerves outside the brainNerves outside the brain

and spinal cordand spinal cord

Functions of Functions of the Peripheral Nervous Systemthe Peripheral Nervous System

Afferent Sensory division– Nerve fibers that carry

information to the central nervous system

– Info sent to brain for processing

Efferent Motor division– Nerve fibers that carry

impulses away from the central nervous system

– Info sent away from brain to muscles and glands

Motor Division of Peripheral Motor Division of Peripheral Nervous SystemNervous System

Efferent Efferent Motor division Motor division – Two subdivisionsTwo subdivisions

Somatic nervous systemSomatic nervous system = voluntary = voluntary

- You actively control these reactions - You actively control these reactions

- Skeletal muscles- Skeletal muscles

Autonomic nervous systemAutonomic nervous system = involuntary = involuntary - You do NOT control these reactions- You do NOT control these reactions

- Example: sneezing to get rid of foreign substance in - Example: sneezing to get rid of foreign substance in

nasal passagenasal passage

Autonomic Involuntary Autonomic Involuntary Nervous SystemNervous System

Sympathetic Branch – controls “fight-or-flight”fight-or-flight”

response - brain gives off messages which triggers the release of adrenaline

it uses energy, your blood pressure increases, your heart beats faster, and digestion slows down.

The autonomic nervous system acts to maintain normal internal functions. It controls the involuntary functions of organs like, digestion, breathing, metabolism or blood pressure. Consists of two branches.

Autonomic Involuntary Autonomic Involuntary Nervous SystemNervous System

Parasympathetic Branch– lowers heart rate and blood

pressure, diverts blood back to skin and the digestive tract, contracts pupils, constricts bronchiole tubes in lungs, resumes digestion.

The autonomic nervous system acts to maintain normal internal functions. It controls the involuntary functions of organs like, digestion, breathing, metabolism or blood pressure. Consists of two branches.

The sympathetic system undoes the

parasymphathetic effects on the body.

After a stressful event, the parasymphathetic

system returns the body’s levels back to a homeostatic balance.

Homeostasis is the ability to maintain a

constant internal environment in response

to environmental changes.