CT3 Flashcards
Neurones
Nerve cells
Cerebral Cortex
The main part of the brain, it makes up 80% of the brain.
Has a wrinkled surface.
It is divided up into two hemispheres.
Cerebral Hemispheres
The Cerebral Cortex is divided into two hemispheres.
Cerebellum
The part of the brain that controls balance, posture, and gross motor skills.
Medulla Oblongata
Part of the brain that controls heart rate, breathing, and vital reflexes.
Reflexes
Reactions that you cannot control.
CT Scan
Uses X-rays to build a 3D picture of structures.(S)
PET Scan
A scan that uses radioactive materials such as glucose. Taken in more active areas. (F)
MRI scans
Uses magnetic resinence for structural and functional investigations.
RX (X-rays)
Go through tissues/show bones, tumors.(S)
What is the nervous system made up of?
Interconnected neurones
What parts of the body does each cerebral hemisphere control?
They control the opposite sides of the body.
Spinal cord problems
- Injuries caused by force
- Tumors
- Genetic defect
- Compression or cutting of nerves
What happens if the lower part of the spinal cord is damaged?
Loss of feeling and movement in legs
What happens if the upper part of the spinal cord is damaged?
Loss of use of arms and legs
= Quadriplegia
What are the treatments for (brain) cancer
- Surgical removal of tumor.
- Chemotherapy
- Radiotherapy
Tumor
Growth of abnormal cells
Radiotherapy
Use of ionizing radiation to treat diseases such as Cancer.
Chemotherapy
Use of drugs to treat diseases such as cancer. (injecting the drugs)
What are the cons of chemotherapy?
- Many side effects.
- May not work due to the blood brain barrier.
Blood Brain Barrier
Natural filter that prevents the entry of some things into the brain.
What is another way to investigate brain and spinal cord problems?
Using electrodes to stimulate certain areas.
Stimulus
A change in the surrounding environment.
Sense organs
An organ that contains receptors.
Receptor cells
Specialized cells that detect a change in the environment.
Central Nervous System (CNS)
The part of the nervous system made up of the brain an spinal cord.
Sensory neurone
A neurone that carries an electrical impulse from a receptor to the central nervous system.
Myelin sheath
A fatty layer that surrounds neurones and speeds up impulses and stops the electrical impulse from being lost.
Examples of a stimulus
- Light
- Sound
- Pressure
- Temperature
Examples of receptors
- Eye
- Ear
- Skin
What are some important jobs that the nervous system does?
- Brain growth/development
- Senses
- Perceptions
- Emotions & thoughts
- Memory
- Balance & posture
- Sleep
What do dendrites do?
They receive impulses from receptor cells.
What do axon terminals do?
They pass impulses to other neurones.
Retina
Where the light sensitive cells are found. (layers or cones and rods)
Cornea
Clear, colourless covering at the front of the eye that bends/focuses the lights.
Optic nerve
A sensory neurone that takes messages from the retina to the brain.
Rods
Detect low levels of light (small light intensity).
Cones
Detect high light intensities (colour).
Pupil
A hole at the front of the eye.
Iris
The coloured part of the eye containing muscles that contract and relax to open and close the pupil.
Lens
A transparent jelly-like structure that fine tunes the focusing of the light.
Cataract
Protein that builds up in the lens causing cloudy eyes and vision.
Effectors
The part of the body that carries out the action.
Motor Neurones
A type of neurone that carries electrical impulses to effectors.
Replay Neurones
A type of neurone that links neurones together (found in the spinal cord).
Synapse
The gap between two neurones.
Neurotransmitter
The chemical that is released at the synapse (tiny gap).
Reflex
An automatic response to a stimulus.
Reflex Arc
The pathway taken by impulses in a reflex reaction - Sensory, relay, motor neurone.
What is the point of every reflex action in the body?
To protect the body from harm.
Sexual reproduction
Reproduction that involves fertilization of a female sex cell (egg cell)
Asexual reproduction
Reproduction without fertilization - the offspring are clones (genetically identical)
Variation
Differences within organisms
What organisms can reproduce sexually and asexually?
- Plants (strawberries)
- Insects (Aphids)
- Invertebrates
Which form of reproduction is quicker?
Asexual reproduction
Advantages to sexual reproduction
- More variation
Disadvantages to sexual reproduction
- Slow
- Need a mate
- Needs fertile adults
- Needs energy
Advantages to asexual reproduction
- Quick
- No mates required
Disadvantages to asexual reproduction
- Less variation
- Less likely to adapt
Genome
All of the DNA in an organism.
Diploid
Two sets of chromosomes (23 pairs).
Haploid
One set of chromosomes (23 single chromosomes).
Daughter cells
Cells that are produced as a result of meiosis
Zygote
A fertilized egg cell
