Essay about Sense Internal organs


1 ) describe the structures and functions with the nervous system

The anxious system

- This is actually the main approach to control in the body.

It has this functions:

5. Controls thinking, planning and learning(voluntary actions) * Collects and interprets information through the sense organs. * Handles automatic(reflex) activities

* Settings the activities of other systems. Eg heart beat, digestive function

The nervous system is made up of two key parts:

1 . Central nervous system; head and spinal-cord

(C. D. S. )

2 . Peripheral nervous program; cranial and spinal nerves, nerve fibres and impression organs


Part| Description| Function

Cerebrum| Largest part, contains a twisted and bumpy surface| Responsible for conscious thought and emotion centers| Cerebellum| Small , and ridged surface| Center pertaining to muscle dexterity and balance| Medulla oblongata| Stalk designed, run into spinal cord| Handles involuntary processes such as breathing| Pituitary| Pea size, underneath| Links stressed and endocrine systems| The spinal cord is situated within the tooth cavity of the backbone (vertebrae). These types of bones protect the spine as the skull helps to protect the brain.

The nervous program links pain to effectors.

Receptors are in the sense organs. These kinds of special cellular material receive stimuli. A incitement is virtually any change that develops that can be recognized by the body. Eg drop in heat or a touch. SENSE ORGAN| RECEPTOR(sense cell)| STIMULUS DIAGNOSED

Eye| Fishing rod cells upon retina| Lumination

| Cone cells on retina| Coloring

Ear| Cochlea cells| Sound

| Semicircular canals| Position of body

Tongue| Taste bud cells| Chemicals in solution

Nose| Coating of nasal cavity| Chemical compounds in gases

Skin| Neurological endings| Pain, touch, sizzling, cold, pressure

Effectors are responsible for carrying out your response to the stimuli. For example muscles or glands

Neural cells (neurons)

There are three main types of neural cells

1 ) Sensory neuron – these types of carry emails from the feeling organs to the C. In. S.

2 . Intermediate neuron-these are found in the brain and spinal cord (C. N. S. ). They will connect physical and electric motor neurons.

3. Electric motor neuron-these hold messages in the C. And. S. to the effector that carries out the response actions.

Neurons hold messages in the form of an electrical impulse from one end to the next. Where two neurons meet they cannot actually contact each other. There exists a small difference called the synapse.

Nerve transmission

When the power impulse actually reaches the end a chemical is released from the 1st neuron this chemical crosses the synapse and goes to the next neuron. In this way a neural impulse is usually transmitted in one neuron to another so the communication is continued.

Voluntary and unconscious actions

A voluntary action is not automatic. The brain needs to think about this action in that case send a note to the required muscles to carry out the actions.

Eg. Picking up a lowered ball

INCITEMENT; ball shedding

RECEPTOR; rods and cone cells


C. N. H.; brain


EFFECTORmuscles of legs

and hands

RESPONSE; grab ball

Voluntary actions are generally not carried out except if a person consciously the decision to complete them. The mind receives information from the perception cells besides making a decision, the response actions is then carried out

Involuntary (Reflex) actions

These actions are not controlled by the person. They are:

2. Automatic

* Quick

2. Serve as a form of protection

Eg's. Pulling your hand away from a hot pot, blinking for the object techniques the eye, leg jerk

The brain does not make a decision on involuntary (reflex) actions they merely happen.

Knee-jerk reflex

STIMULUS; hit beneath knee

RECEPTOR; pressure pain

in pores and skin


C. D. S.; intermediate neuron

in spinal-cord


EFFECTORthigh muscle tissue

RESPONSE; calf springs forward...

Outline the structure with the main cells of the human body. Essay