Central Nervous System PDF

1 The Central Nervous System The CNS is made up of the brain and spinal cord. It acts as the bodyʼs control centre and coordinates the bodyʼs activities. Impulses travel through neurons from sensory receptors to reach your CNS. The CNS integrates and processes this neu...

1 The Central Nervous System The CNS is made up of the brain and spinal cord. It acts as the bodyʼs control centre and coordinates the bodyʼs activities. Impulses travel through neurons from sensory receptors to reach your CNS. The CNS integrates and processes this neural information. It then initiates outgoing responses to the body. 2 CNS Nerve Tissue Grey matter ▹ Found around outsides of the brain ▹ Forms a butterfly-shaped core of the spinal cord ▹ Contains mostly cell bodies, dendrites, and short, unmyelinated axons (nerve fibres) White matter ▹ Forms the inner region of some areas of the brain ▹ Forms the outer area of the spinal cord ▹ Contains myelinated axons 3 Spinal Cord The spinal cord is a column of nerve tissue extending from the skull down through a canal within the backbone. It is a vital communication link between the brain and peripheral nervous system. 4 Spinal Cord The spinal cord allows a means of passage for messages from the body to the brain, and back to the effectors once interpreted. Primary reflex centre. ▹ Coordinates rapid neural information 5 Spinal Cord Delicate spinal cord tissues are protected by: ▹ cerebrospinal fluid ▹ soft tissue layers ▹ the spinal column (vertebrae) Injury to the spinal column has the potential of damaging the spinal cord. 6 The Brain The brain is fragile and has a gelatin-like consistency. ▹ The skull forms a protective bony armour around it ▹ The brain and spinal cord are surrounded by three tough elastic tissue layers, called meninges. ▹ Cerebrospinal fluid surrounds the brain to provide cushion Contains over 100 billion nerve cells. ▹ each with up to 10 000 connections to other nerve cells The brain has the central role for maintaining homeostasis in the human body. 7 Parts of the Brain Cerebrum Brain Stem Cerebellum 8 Parts of the Brain The cerebrum is the wrinkly part of the brain. ▹ It deals with high mental function and problem solving The cerebellum is responsible for balance and coordination. 9 Parts of the Brain The brain stem regulates visceral functions. 10 Parts of the Brain There are two hemispheres of the brain: left and right The corpus callosum connects the two hemispheres. 11 Frontal Lobe executive Parietal Lobe functions perception, sense-making, math Occipital Lobe vision Temporal Lobe memory, language 12 Brain Stem 13 14 Brain Stem Midbrain Visual reflexes, eye movements Pons Relay sensory information Medulla oblongata Heart, respiration, blood pressure 15 Limbic System The limbic system is responsible for behaviour and emotional response. The amygdala stores memories associated with emotion. ▹ It is also associated with fear and aggression 16 Hippocampus The hippocampus is involved in the storage and retrieval of memories.