Organisation of the Nervous System
Structural Organisation
- CNS/Central Nervous System - consists of brain and spinal cord.
- PNS/Peripheral Nervous System - consists of all neurons which connect the CNS to the rest of the body.
- Somatic Nervous System - under conscious control, and the effector organs are skeletal muscle.
- Autonomic Nervous System - under subconscious control, and works constantly. For example it causes the heart to beat, or for the stomach to contract to churn food. Autonomic nerve impulses control cardiac muscle, smooth muscle and glands.
- Autonomic is divided into...
- Sympathetic Motor System - fight or flight responses transmitted using the neurotransmitter noradrenaline. These generally increase activity, such as a higher heart rate.
- Parasympathetic Motor System - relaxing responses transmitted using the neurotransmitter acetylcholine. These generally decrease activity such as slower breathing rate.
Structure |
Sympathetic Response |
Parasympathetic Response |
Salivary Glands |
Saliva Production Decreased |
Saliva production increased |
Lung |
Bronchial muscle relaxed |
Bronchial muscle contracted |
Kidney |
Decreased urine secretion |
Increased urine secretion |
Stomach |
Peristalsis reduced |
Peristalsis increased |
Small Intestine |
Peristalsis reduced |
Peristalsis increased |