Nervous System Flashcards
Why do animals need a nervous system?
What characteristics do animals need in
a nervous system?
- fast
- accurate
- reset quickly
NERVOUS CONTROL OF HOMEOSTASIS
- The human nervous system is divided into TWO parts
- CENTRAL NERVOUS SYSTEM (CNS)
- PERIPHERAL NERVOUS SYSTEM (PNS)
Central nervous system (CNS)
Brain - receives and processes sensory information, initiates responses, stores, memories generates thoughts and emotions.
Spinal cord - Conducts signals from the brain control reflex activities
PERIPHERAL NERVOUS SYSTEM
SOMATIC NERVOUS SYSTEM
Includes MOTOR NEURONS that are under conscious control and ALL of the SENSORY NEURONS in your body.
AUTONOMIC NERVOUS SYSTEM
Includes only the MOTOR NEURONS that function without conscious control.
We don’t consciously think about making our heart beat…
Two types of nerves that make up the Autonomic Nervous System
SYMPATHETIC NERVES
Prepares the body for danger!
- Increase size of pupils
- Speed up heart rate
- Slow digestion
- Relax bladder muscles
PARASYMPATHETIC NERVES
Returns the body to a normal state after a stressful situation!
- Makes pupils of the eye smaller
- Slows down the heart rate
- Increases rate of digestion
- Contract bladder muscles