Unit 2 sensitivity and coordination
Maria boizas
Stimuli
A stimulus is anything you see,hear,touch,smell or taste.
There are two types of stimuli: Internal stimuliExternal stimuli
The smell of a flower is an external stimuli.
receptors
There are two types of receptors:Internal receptorsExternal receptors
Responses
A response is the body’s answer to a stimulus
There are two different types of responses:Muscular responses Glandular responses
Chewing is a muscular response
The senses
sight
The eye is the organ of sight.
it is made up of the eyeball and protected by the eyebrows,eyelids and eye lashes.
Process of sight
First light goes through the cornea.Then light passes through the pupil,the
opening of the iris.After that light passes through the lens
with focuses the image on the retina.The information in the retina travels to
the brain through the optic nerve
smell The nose is the organ of smell.The
receptorsof smell are in the pituitary gland,inside the nostrils.
hearing The ear is the organ os hearing. It has three parts:
The outer ear The middle ear The inner ear
The process of hearing
First the outer ear receives soundsThen the middle ear changes sounds
into vibrations.Finally the inner ear changes vibrations
into nerve impulses that go to the brain
touch The skin is the organ of touch. It is made up of three layers:
Epidermis Dermis Hypodermis
tasteThe tongue is the organ of taste.The receptors of taste are in the taste
buds.There are taste buds all around the
tongue.
The nervous system
The nervous system is made up of nerve centres and nerves.
The peripheral nervous system is made up of:Sensory nerves Motor nerves
The central nervous system has two parts:The brainThe spinal cord
neurons
They are made up of a cell body,dendrites and axons.
Neurons receive information from other neurons.
Voluntary and involuntary movements
Our bodies react to stimuli making voluntary or involuntary movements.
Voluntary movements
When we see the clouds our sensory nerves inform the brain about this.
Our brain processes the information and produces a response.
Our motor nerves transmit a response to the muscles.
Involuntary movements
The spinal cord produces a response in the case of involuntary movements.Sensory nerves transmit information about
involuntary movements to the spinal cord.The spinal cord produces a very fast
response.
The skeletal system
The skeletal and muscular system is in charge of carrying muscular responses created by the nervous system.it is made up of the skeleton and the musculature.
The skeleton
The skeleton is made up of all the bones in the body.Head bones:skull bones and facial bones.Trunk bones:spine and rib cage.Limb bones:there are two groups the upper
limb bones and the lower limb bones.
joints
The joints are located where two or more bones meet.Bones are connected by ligaments.
There are three types of joints:Moveable jointsSemi-moveable joints Fixed joints
The musculature
The musculature is the set of muscles in the body.locomotor muscles are conected to the bones.when they contract or relax,they move the bones.
Head muscles:masseter,buccinator and orbicular. Trunk muscles:sternocleidomastoid,abdominal, pectoral,intercostal and trapezius. Limb muscles:biceps,triceps,deltoid,quadriceps, gluteus and calf muscles..
The end
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