The human nervous system Flashcards
Name the three main parts of the brain and state the role of each
cerebral cortex – is the outer ‘wrinkled’ layer of the brain it is responsible for intelligence, language, memory and consciousness
cerebellum – is located at the lower part of the back of the brain and is responsible for voluntary coordination of the muscles
medulla – is located in the lower part of the brain stem it is responsible for involuntary coordination such as breathing, swallowing and heart rate
How do neuroscientists study the brain?
Studying patients with brain damage, electrically stimulating the brain and using magnetic resonance imaging (MRI) scanning.
What is an EEG?
Electroencephalogram (EEG) is a test used to find problems related to electrical activity of the brain.
What is an MRI?
A device that uses strong magnetic fields and radio waves to produce detailed images of the brain and spinal cord.
What does an MRI do?
MRI can distinguish between different types of tissues, including detecting cancerous cells.
Description and function of cornea.
Transparent layer at the front of the eye, it refracts light into the eye.
Description and function of iris.
The coloured part of the eye, contains muscles that control the amount of light entering the eye.
Description and function of pupil.
The hole in the middle of the iris that lets light in. Its diameter is controlled by the iris.
Description and function of lens.
A transparent, biconvex structure in the eye that refracts light onto the retina.
Description and function of retina.
Thin layer of tissue at the back of the eye that contains receptor cells for light and colour.
Description and function of sclera.
Tough white supporting wall of the eye.
Description and function of ciliary muscles.
Muscles that are connected to the lens by the suspensory ligaments; they change the shape of the lens.
Description and function of suspensory ligaments.
These connect the lens to the ciliary muscles.
Description and function of optic nerve.
Carries impulses fro the retina to the brain.
What is accommodation?
The process of changing the shape of the lens focus on near or distant objects
How does the eye focus on distant objects?
The ciliary muscles relax, the suspensory ligaments are pulled tight, the lens is then pulled thin and only slightly refracts light rays
How does the eye focus on near objects?
The ciliary muscles contract, the suspensory ligaments loosen, the lens is then thicker and refracts light rays strongly.
What is myopia? How can it be corrected?
Short-sightedness, it can be corrected with concave lenses
What is hyperopia? How can it be corrected?
Long-sightedness, it can be corrected with convex lenses
Name three ways that vision can be corrected?
Contact lenses, laser surgery and lens replacement
State the optimum human body temperature.
37*c
What part of the brain monitors and controls temperature?
Thermoregulatory centre
Describe what happens in vasoconstriction and vasodilation.
- If the body temperature is too low, blood vessels constrict (vasoconstriction), sweating stops and skeletal muscles contract (shiver).
- If the body temperature is too high, blood vessels dilate (vasodilation) and sweat is produced from the sweat glands. Both these mechanisms cause a transfer of energy from the skin to the environment.
