The Nervous System Flashcards
What is neurology?
Neurology is the study or knowledge of the branch of medicine that deals with the nervous system and its disease.
What are the functions of the nervous system?
The nervous system is the chief co-ordinator in the body, necessary so the stable body conditions (homeostasis) can be maintained.
How does the body adapt itself to new conditions?
Conditions within and outside the body are constantly changing. The nervous system responds to these changes, which are known as stimuli, and causes the body to adapt itself to new conditions.
What is a functioning nervous system necessary for?
A functioning nervous system is necessary for survival.
What organs make up the nervous system?
The brain, spinal cord and nerves make up the nervous system.
How is the nervous system divided up?
The nervous system is divided into the central nervous system and the peripheral nervous system.
What does the central nervous system include?
The central nervous system includes the brain and the spinal cord.
How is the peripheral nervous system divided?
The peripheral nervous system is divided into cranial nerves (12 pairs) and the spinal nerves (31 pairs).
What does the peripheral nervous system include?
The peripheral nervous system includes all the nerves (cranial and spinal) outside the central nervous system.
What do cranial nerves carry?
Cranial nerves carry impulses to and from the brain.
What do spinal nerves carry and how are spinal nerves distributed?
Spinal nerves carry impulses to and from the spinal cord. They are distributed evenly in segments down the spinal cord.
How much does the brain weigh approximately?
Weighs about 3 pounds, and it is a jelly like consistency.
When do neutrons of the brain undergo mitosis?
Neurons of the brain undergo mitosis only before birth and a few months after birth. Although they grow in size they do not increase in number.
When does the brain reach its full size?
The brain attains its full size by 18 years of age, but grows rapidly only in the first 9 years.
What are neurons?
Neurons are nerve cells or conducting cells of the nervous system.
What are the three main parts of the brain?
1) Cerebrum 2) Cerebellum 3) Brain Stem
What is the cerebrum?
The cerebrum is the major portion of the brain occupying almost the entire portion of the skull above the eyes. It contains many neurons which are concentrated in the small space.
What divides the cerebrum?
A fissure divides the cerebrum into two hemispheres, which are linked by nerve fibres.
How is the brain organized?
The brain is organized so that the left side controls the right side of the body and vice versa.
What are the two hemispheres of the cerebrum?
The left cerebrum hemisphere (logical side) and the right cerebrum hemisphere (artistic side).
What are some things that the left cerebrum hemisphere is responsible for?
The left cerebrum hemisphere is responsible for speech, handwriting, reading, mathematics, and recognition of body parts. (Usually dominate in right handed people).
What are some things that the right cerebrum hemisphere is responsible for?
The right cerebrum hemisphere is responsible for music, geographic sense, and recognition of face.
What are the four visible lobes that the hemispheres are divided into and what are they responsible for?
1) Occipital (back) - vision
2) Parietal (upper) - distance, sizes, shapes, touch
3) Frontal (front) - movement, speech
4) Temporal (side) - smell, hearing
What is the function of the cerebellum?
The cerebellum maintains balance, posture, and muscular co-ordination.
What is the brain stem?
The brain stem connects the brain with the spinal cord - deals with important basic and involuntary functions.
What are the four parts of the brain stem?
1) Hypothalamus
2) Mid brain
3) Pons
4) Medulla Oblongata
What is the hypothalamus responsible for?
Hormones, temperature, water balance, cravings and appetite - thus linking the nervous and endocrine systems together.
What does the midbrain control?
The midbrain controls visual and auditory reflex centres.
What is the pons responsible for?
The pons controls eye and facial movements and regulates breathing.
What is the medulla oblongata responsible for?
The medulla oblongata is responsible for breathing, swallowing, intestinal activity. It controls the involuntary actions of the respiratory and circulatory systems and some reflux actions (i.e. sneezing, coughing and vomiting)
What encloses the spinal cord?
The spinal cord is enclosed in the bony vertebral column of the back.
How many pairs of nerves are in the spinal cord?
31 pairs of nerves.
How do nerves enter or leave the spinal cord?
Except for the 12 pairs of cranial nerves that connect directly with the brain, all nerves enter or leave the spinal cord through the openings in the vertebrae.
What do sensory impulses do?
Sensory impulses of many kinds enter the outside white matter of the spinal cord and travel upward far enough to trigger spinal reflexes at various levels or travel to the brain.
What do motor impulses do?
Motor impulses travel downwards from the nerve cells in the brain to reach spinal cells which relay messages to various muscles, organs, glands and blood vessels.
What is the structure of the spinal cord?
The spinal cord is an H shaped area, of grey matter surrounded by white matter.
What are the functions of the spinal cord?
- Reflex activities, which involve the transfer and integration of messages that enter the cord, so that sensory (afferent) impulses may enter and motor (efferent) messages may leave the cord without involving the brain.
- Conduction of sensory impulses - from afferent (sensory) nerves upward through ascending tracts to the brain.
- Conduction of motor (efferent) impulses from the brain down through decending tracts to the nerves that supply muscles or glands.
What does the peripheral nervous system include?
The peripheral nervous system (P.N.S) includes all the nerves outside the central nervous system (C.N.S)
How are the 12 pairs of cranial nerves numbered and where are they located?
The 12 pairs of cranial nerves are numbered according to their connection with the brain, beginning at the front and proceeding back.
What do the first 9 pairs and the 12th pair of cranial nerves supply?
The first 9 pairs and the 12th pair supply structures in the head.
What are the functions of cranial nerves?
- Special sensory impulses
- General sensory impulses
- Voluntary motor impulses
- Involuntary motor impulses
What are special sensory impulses?
Special sensory impulses, (coming into the brain) such as those for smell, taste, vision, and hearing.