Nervous System

The ANS and Simple Behaviour Patterns

Nervous System

Nervous System

Nervous System:

Conscios activity

controlled by the voluntary (somatic) nervous system

Unconscious activity

controlled by the autonomic nervous system

Autonomic Nervous System

Autonomic Nervous System

Sympathetic System

The motor neurones secrete noradrenaline at the synapse

Parasympathetic

The motor neurounes secrete acetylcholine at the synapse

Sympathetic

Causes the “fight or flight” Divert blood from the gut to the lungs, heart

and voluntary muscle Increase supply to the muscles The lungs absorb more oxygen More blood available for the heart and lungs

Parasympatheic

Prepare the body for rest Decrease heart beat rate Decrease ventilation rate Increase peristalsis in the gut, food can be

digested

Comparison of the sympathetic and parasympathetic nerovs systems

Feature Sysmpathetic Parasympathetic

Transmitter substance at synapses

Noradrenaline Acetylcholine

Heart rate Speeds up Slows down

Iris Dilates Constricts

movements of digestive tract

Slows down Speeds up

Sweating Stimulated Not stimulated

Heart Beat

Affect on heart rate

Sympathetic nerves increase the rate of cardiac muscle contraction

Parasympathetic nerves relax muscles

ANS

1. Blood stretches the baroreceptors

2. Action potential sent 3. Impulse send along the

motor vagus nerve4. SAN slow the rate5. Blood put pressure6. Bainbridge reflex7. Baroreceptors control the

pressure of blood flowing to the head