sb2 Flashcards
what is the Cerebellum
Controls balance, co-ordination of movement and muscular activity.
What is the Medulla Oblongata
Controls unconscious activities such as heart rate and breathing rate.
What is the Hypothalamus
Regulates temperature and water balance within the body.
What are the 3 main ways used to scan the brain
MRI (magnetic resonance imaging)
CT (computed tomography)
PET (positron emission tomography)
what are MRI scanners
MRI scanners use strong magnetic fields and radio waves to show details of brain structure and function. Patients are asked to perform various tasks and, by looking at the scan, scientists can see which parts of the brain are active when the task is carried out. The patient lies on a bed which moves into the machine. Some people can feel claustrophobic inside an MRI scanner.
What are CT Scans
CT scanners are similar to MRIs. The patient lies on a bed which passes through a ring of equipment (not into the machine like in MRI). The ring takes a series of x-rays from different angles. These are processed by a computer to allow the doctors to see inside brains and other parts of the body.
What are PET scanners
PET scanners detect gamma rays that radiate from a chemical compound called a tracer. PET scans are used to detect high levels of metabolic reactions inside a person. Before going into the scanner the patient consumes the tracer. This travels to any area of the body which has unusually high levels of metabolic reactions. This is often a tumour and so PET scans are used to detect Cancers.
What are the 3 Main Types of Neurone
There are three main types of neurone:
sensory
motor
relay
Wha are Receptors
Receptors are groups of specialised cells. They detect a change in the environment and stimulate electrical impulses in response. Sense organs contain groups of receptors that respond to specific stimuli.
For example The sense organ would be the skin and the stimulus would be touch or temperature
What are effectors
Effectors include muscles and glands. They produce a specific response to a detected stimulus. For example:
a muscle contracting to move an arm
muscle squeezing saliva from the salivary gland
a gland releasing a hormone into the blood.
What are the steps in the Reflex Arc
A receptor in the skin detects a stimulus (the change in temperature).
Sensory neurones send electrical impulses to relay neurones, which are located in the spinal cord. They connect sensory neurones to motor neurones.
Motor neurones send electrical impulses to an effector.
The effector produces a response (muscle contracts to move hand away).
what happens when brain damage occurs
Brain damage is any loss of cells in the brain. This is often because of injuries such as car crashes when a person’s head hits an object with a great force.
How would you test Human reaction times
The ruler drop Test
What is the role of the
What is the cornea
It bends (refracts) light as it enters the eye.
What is the iris
Contains the muscles that contract and relax to control how much light enters the pupil
What is the lens
Further refracts light to focus it onto the retina
What is the optic nerve
Carries impulses between the eye and the Brain
What is Sclera
Though eight outer layer of the eye protects from injury
What is accommodation in the eye
The process of changing the shape of the lens on near or distant objects
How does the eye focus on a near object
The lens becomes thicker which allows the light rays to bend (refract) more strongly
How to focus on a distant object
The lens is pulled thin witch allows light rays to refract slightly
How is short sightedness caused
The eyeball being elongated so that the distance between the lens and the retina is to great
The lens is too thick and curves so that the light is focused in the front of the retina
How can short sightedness be corrected
By placing a concave lens in-front of the eye
What is the cause of long sightedness
The eyeball is to short so the distance between the lens and the retina is too small
There is a loss of elasticity in the lens and it Connor become thick enough to focus
How can long sightedness be fixed
By putting a convex lens in front of the eye
What is laser surgery
Reshaped the cornea surgically commonly used for myopia
