The Brain Flashcards
What is brain composed of and what do they do?
The brain is composed of over 100 billion neurons, each receiving messages simultaneously from thousands of other neurons.
What is the brain protected by?
The brain is protected by the skull bones, meninges (three membranes) and cerebrospinal fluid
Draw a diagram of the brain
i think
What is the cerebrum?
Our conscious brain, with different parts having different jobs to do.
What is the hypothalmus?
the centre for the regulation of the internal organs
What is the pituitary gland?
the pituitary ‘[master]’ gland secretes hormones that stimulate other glands to release their hormones.
What does the cerebellum do?
The cerebellum co-ordinates processes that we have learned to do automatically, such as speaking.
What does the medulla oblongata do ?
The medulla oblongata co-ordinates involuntary, automatic processes - such as breathing, heartbeat.
What are the parts of the brain?
skull, fluid, meninges, cerebrum, cerebellum, vertebra, spinal cord, medulla oblongata, pituitary, hypothalamus.
Draw the spinal chord
.
What is the spinal cord protected by?
The spinal cord is well protected by the vertibrae, meninges (three membranes) and cerebrospinal fluid.
What does the spinal cord do?
It transmits impulses to and from the brain and controls many reflex actions
What does a cross-section through the spinal cord show and what is it composed of?
A cross-section through the spinal cord shows a small central canal, filled with cerebrospinal fluid, surrounded by an area of grey matter, shaped somewhat like the letter H.
What are the parts of the spinal cord?
Spinal cord, white matter, grey matter, dorsal root, ventral root, synapse, sensory neuron, motor neuron.
What are the two directions along the spinal cord?
To brain and from brain
Grey matter
Grey matter contains cell bodies and dendrites (regions of a neuron that have no white myelin covering)
White matter
Outside the grey matter, the spinal cord consists of white matter (containing axons only).
Dendrites
Regions of a neuron that have no white myelin covering
What does white matter contain?
axons only
How many spinal nerves branch off from the spinal cord in humans?
31 pairs
What does each spinal nerve have?
a dorsal root and a ventral root
What does the dorsal root consist of?
The dorsal root consists of nerve fibres carrying information into the spinal cord from the senses.
What is the dorsal root ganglion?
A swelling that consists of the cell bodies of the sensory neurons.
Draw the side view of a spinal cord
.
Where do nerve fibres in the in the dorsal root carry information to and from?
Into the spinal cord from the senses
What does the dorsal root ganglion consist of?
The cell bodies of the sensory neurons
What does the ventral root consist of?
nerve fibres carrying information out from the spinal cord to the muscles and glands.
Where are the cell bodies of the motor neurons positioned?
Within the grey matter of the cord.
What does the spinal cord do?
Transmits impulses to and from the brain and controls many reflex actions.
Where do nerve fibres in the in the ventral root carry information to and from?
from the spinal cord to the muscles and glands
What is a reflex action?
A reflex action is a quick, automatic response to a particular stimulus.
Draw a diagram of the reflex arc
.
Name a nervous system disorder
Parkinson’s disease
What are the symptoms of Parkinson’s disease?
Muscles become rigid and movement is slow and difficult, with persistent tremors [shaking]
What are the causes of Parkinson’s disease?
It is caused by the brain reducing the normal amount of dopamine that it makes.
What are the treatments/preventions of Parkinson’s disease?
There is at present no means of preventing it, but giving L-dopa (which the body changes into dopamine) can relieve the symptoms in many patients. No treatment.
What is Parkinson’s disease?
A nervous system disorder, normally seen in older people, in which muscles become rigid and movement is slow and difficult, with persistent tremors [shaking].
Who does Parkinson’s usually affect?
It is normally seen in older people
How may senses do we have?
5
What are the 5 sense organs?
eye, ear, skin, tongue, nose
What is the organ and stimulus detected in sight?
Eye - light [by rods and cones in the retina]
What is the organ and stimulus detected in hearing?
Ear - sound [receptors in cochlea]
What is the organ and stimulus detected in touch?
skin - touch, pressure, temperature and pain [receptors spread throughout body]
What is the organ and stimulus detected in taste?
tongue - chemicals [taste buds detect sweet, sour, salt and bitter]
What is the organ and stimulus detected in smell?
nose - chemicals [receptors in the nasal cavity detect vapours]
