Nervous system

Central Nervous System (CNS)

Brain for conscious and unconscious nervous activity. Maintains homeostasis. Spinal-cord for communication

Peripheral Nervous System (PNS）

All the nerves outside the CNS. Sensory (afferent) and motor (efferent) nerves. Motor nerves are divided into somatic NS or autonomic NS 

Somatic

Somatic controls voluntary movement of skeletal muscles.

Autonomic

Autonomic controls involuntary e.g.; HR, breathing, digestion. Is divided into sympathetic NS and parasympathetic NS

Sympathetic Nervous system (SNS)

fight or flight e.g.; increases HR, BP, vital capacity, metabolism, sweat.

Parasympathetic Nervous System

decreases HR, BP, ventilation, increases digestion, constriction of pupils, airways

brain stem

Connect brain to spinal column deals with subconscious information .

cerebellum

coordinates skilled movement

Cerebrum

2 hemispheres, contains cerebral cortex for conscious thinking and decision making

thalamus

Sensory relay, motor control, consciousness

hypothalamus

Homeostasis, autonomic control, hormone regulation

Intrinsic excitation

Sinoatrial node in right atrium stimulates contraction of atria. The atrioventricular node picks up the signal and sends to bundle of His which passes the pulse to Purkinje fibres which contract ventricles.