The Nervous System PDF

Nervous System Tr. Anna Marie 01 The Brain The brain is protected by the skull and three layers of tissues called meninges. The brain is made up of billions of nerve cells. It weighs about 1.25 kilograms and has a whitish-pink appearance with wrinkled surface. The majoy parts of the brain are c...

Nervous System Tr. Anna Marie 01 The Brain The brain is protected by the skull and three layers of tissues called meninges. The brain is made up of billions of nerve cells. It weighs about 1.25 kilograms and has a whitish-pink appearance with wrinkled surface. The majoy parts of the brain are cerebrum, the cerebellum, and medula obongata or brain stem.  Touch and Movement taste. and speech. sight Cerebrum Hearing and smell Largest structure in the brain. It is the part responsible for controlling speech, memory, emotions, intelligence, reasoning, thinking, and sensations. The right hemisphere controls the left side of the body while the left left hemisphere controls the right side of the body. Cerebellum Second largest part of the brain. It is knwn as the “little brain”. It is reponsible for balance, posture, and motor coordination. If cerebellum is damaged , a person may be paralyzed. Medulla Oblongata or Brain Stem It connects the brain and the spinal cord. The medulla oblongata controls the basic life functions such as heartbeat, breathing and digestion. It takes care of reflex actions such as blinking, coughing, and knee jerk reaction. Other important parts of the brain are the thalamus and hypothalamus. These are brain structures found between the brain stem and the cerebrum. Pre- processing station for the many nerve impulses that pass through it. Motor Centimeters Control movements. There are also areas in the brain called sensory centers, where the signals from different senses are collected. These are receive signals from the different sense organs. Receive signals of touch, heat , cold, pain and pressure from the skin: sight from the eyes; smell from the nose; sound from the ears; and taste from the tongue. 02 The Spinal Cord It is the extension of the brain. It is the main link between brain and the body. It is made up of gray matter, which contains the bodies nerve cells, and white matter, which contains the nerve fibers. The spinal cord’s first main function is to serve as the pathway of nerve impulses to and from the brain. Second function is to serve reflex center. Very delicate organ. When a part is damaged, a person can be paralyzed. 03 The Nerve Cells or Neurons Basic units of nervous system. Main function is to collect and carry nerve impulses. These impulses are relayed to the brain and sent back for proper action or reaction. Three types of nerves: 1. He brain and spinal cord receive messages from different parts of the body through sensory nerves. 2. Through motor nerves, the brain and spinal cord may send messages to body tissues and organs. 3. Connector nerves connect the sensory nerve with the motor nerves and carry impulses. The Nerve Cells or Neurons Each nerve cell has a cell body. On one side of the cell body are short and slender fibers called dendrites. Dendrites receive messages and carry them to cell body. From cell body, the messages travel down to the axon. The axon transmits the messages away from the cell body to the next neuron. The neurons do not touch one another at their ends. There is a small space or gap between one neuron and the next one. This gap isa called synapse. Ailments of Nervous System Polio Meningitis Rabies Sleeping Sickness Brain Tumor Parkinson’s Disease Caring for the Nervous System Caring for the Nervous System