human body Flashcards
human nervous system
The system formed by brain, spinal cord and different types of nerves
central nervous system
the nervous system formed by the brain and spinal cord
Brain
the most developed organ which controls various activities of human body. It is procted by the box of bones called cranium. The weight of the brain of adults is 1200 to 1400 gram.
three layers of brain
Piamater, arachnoid and duramater. dura mater is attached to the inner surface of the skull while the arachnoid is attached to the surface of the brain.
What is the name of the fluid which protects the brain from mechanical shocks.
Cerebrospinal Fluid
cerebrum
the dome-shaped part of the brain consists of four regions; viz. frontal, parietal, occipital and temporal. largest part of th brain which occupies about 80% of the brain.
Functions of cerebrum
- It controls various metabolic activities like monitoring, thinking, learning, reasoning, intelligence, etc.
- it controls the functions of different organs of the body.
- It controls anger, emotions, will, speech etc.
- It controls feeling of love, admiration, hatred, etc.
What is the function of the brain in the human body?
The brain works as the highest coordinating centre in the human body.
What are the three protective membranes surrounding the brain called?
Meninges
The three layers are duramater, piamater, and arachnoid.
Which layer of the meninges remains attached to the inner surface of the skull?
Duramater.
What is the space between the arachnoid and piamater filled with?
Cerebrospinal fluid.
What is the primary function of cerebrospinal fluid?
It protects the brain from mechanical shocks.
Into how many main parts is the brain divided?
Three parts.
List the three main parts of the brain.
- Cerebrum
- Cerebellum
- Medulla oblongata
What percentage of the brain does the cerebrum occupy?
80%.
What are the four regions of the cerebrum?
- Frontal
- Parietal
- Temporal
- Occipital
What structure separates the left and right cerebral hemispheres?
Corpus callosum.
What increases the surface area of the cerebral hemispheres?
Convolutions.
What types of matter make up the outer and inner parts of the cerebral hemispheres?
Outer part: gray matter; Inner part: white matter.
What happens to a person when the cerebrum receives a mechanical shock?
The person enters into a coma.
Name one mental activity controlled by the cerebrum.
Memorizing.
What emotional functions does the cerebrum control?
- Anger
- Emotions
- Will
- Speech
- Feelings of love, hatred, admiration
Where is the cerebellum located in relation to the spinal cord?
At the back of the head, just above and behind where the spinal cord connects to the brain.
What is a consequence of a small injury to the cerebellum?
Dizziness which disturbs body balance.
How does alcohol affect the cerebellum?
It affects body balance.
What shape do the two small hemispheres of the cerebellum resemble?
Lemon.
What types of matter are present in the cerebellum?
Gray matter and white matter.
Functions of cerebellum
- It maintains body balance.
- It controls muscular tone.
- It controls voluntary muscles.
Medulla oblongata
A cylindrical shaped lower part of the Brain which is connected to the spinal cord. Consists of Gray and white matter.
What causes instant death?
Damage to the medulla oblongata
Functions of medulla oblongata
It controls vomitting, swallowing, coughing etc.
It controls heartbeat, blood pressure and breathing.
It controls a contraction and relaxation of blood vessels.
It controls peristalsis and secretion of hormones and enzymes, secretion of saliva, etc.
Spinal cord
An elongated and cylindrical structure which arises form the medulla oblongata and passes down the neural cavity of vertebrae column up to the lumbar vertebrae. Outer surface- white matter, inner surface- Grey matter
Spinal injury?
Any shock or injury to the spinal cord causes paralysis of the body below the portion of injury.
function of the spinal cord
It connects different parts of the body to the brain.
it controls reflex actions.
neuron
the smallest unit of the nervous system which consists of axon and dendrites
axon and dendrites
axon - the long braches of neuron which caries impulses away form the cell body
dendrites- the short branch of neurons which collect messages towards the cell body.
types of nerve cells
sensory or afferent neuron- carries the impulses from the receptor to the spinal cord or brain.
Motor or efferent neuron- carries impulses from the spinal cord or brain to different body parts.
Inter neuron- converts sensory impulses into motor impulses.
peripheral nervous system
The nervous system which consists of nerve tisues that communicates between the brain and different parts of the body
cranial nerve fibres
the nerve fibres that originate from the brain. 12 pairs arise from the brain.
Spinal nerve fibres
The nerve fibers originate from the spinal cord and form a network of nerve fibers that connect different parts of the body. 31 pairs
autonomic nervous system
The nervous system controls the function of muscles and certain glands when we are sleeping or waking up.
parasympathetic and sympathetic
rest and digest/fight or flight
constrict pupils / dilate pupils
slows heartbeat/ increases heartbeat
constrict airways / relax airways
stimulate the activity of the stomach/ inhibit the activity of the stomach
stimulate gallbladder/ inhibit gallbladder
stimulate activity of intestines/ inhibit activity of intestines
contract bladder/ relax bladder
glandular system
the system which is formed by the groups of glands
glands
the group of epithelia cells which secrete hormones or enzymes
exocrine glands
Has a duct or tube to pass their secretion
secretes enzymes.
Salivary glands, gastric glands, intestinal glands, sweat glands, etc.
Present near the site of action.
endocrine gland
does not have a duct or tube to pass its secretion
secretes hormones
pituitary glands, thyroid glands, adrenal glands, etc.
present away form the site of action.
hormones
the chemical substance produced by endocrine glands which control, co-ordinate and regulate metabolic activities, growth and development of body.