F215:04:05 The Brain Flashcards
What is the cerebrum?
The largest and most recognisable part of the brain. It is responsible for the elements of the nervous system that is associated with being ‘human’, including though, imagination and reasoning
What is the cerebrum divided into?
two hemispheres
What are the two hemispheres on the cerebrum connected by?
the corpus callosum
What is the approximate surface area of the outer most layer of the cerebrum?
2.5m
What surrounds the outer most layer of the cerebrum?
the cerebral cortex, its a thin layer of nerve cell bodies
Which part of the brain is more developed in humans than in any other organism?
The cerebral cortex
What does the cerebral cortex control?
The higher brain functions such as:
- conscious thought and emotional responses
- the ability to override some reflexes
- features associated with intelligence such as reasoning and judgement
What 3 main parts is the cerebral cortex divided into?
Sensory areas
Association areas
Motor areas
What are Sensory areas of the Cerebral cortex?
they recieve impulses indirectly from the receptors
What are the association areas in the cerebral cortex?
The part of the brain that compares inout with previous experiences in order to interpret what the input means and judge an appropriate response
What are motor areas of the cerebral cortex?
They send impulses to effectors (muscles and glands)
Where part of the body does the left and right cerebral cortex control?
the muscular movements on the opposite side
Where is the conscious decision to move voluntary muscles initiated?
In the central hemisphere
Give some examples of actions that involve a significant amount of nonconscious operation
walking
riding a bike
driving a car
playing a musical instruments
Give an example of a nonconscious muscular activity
responding to the changes in body position to remain balanced and upright
Give an example of a sensory activity that requires non conscious decisions
judging the positions of objects and limbs
What does the cerebellum do?
It controls the coordination of movement and posture
What does the hypothalamus do?
It controls the autonomic nervous system and the endocrine glands
What does the medulla oblongata do?
It controls the action of smooth muscle in the gut wall, and controls breathing movements and heart rate
What is the role of the neurones coming from the cerebellum that carry impulses to the motor areas?
so that the motor output to the effectors can be adjusted appropriately in relation to their requirements
What allows us to go into ‘autopilot’?
As actions carried out regularly are often programmed into the cerebrum
What proportion of all the nerve cells in the brain are found in the cerebellum?
Over half
How does the cerebellum play a key role in co-ordinating balance and fine movement?
It needs to process sensory information from the retina, the balance organs in the inner ears, spindles and joints
What are the four areas that the cerebellum must process sensory information from in order to co-ordinate balance and fine movement?
- the retina
- the balance organs in the inner ear
- specialised fibres in muscles called ‘spindles’
- the joints
How do ‘spindles’ help the cerebellum help co-ordinating balance and fine movement?
as they give the cerebellum information about muscle tension
Outline the functions of the medulla oblongata
- Controls non-skeletal muscles (i.e. cardiac and involuntary muscles)
- Therefore effectively in control of the autonomic nervous system
- Regulatory centres for a number of vital processes are found e.g.:
the cardiac centre, regulates heart rate
the respiratory centre, controls breathing and regulates the rate and depth of breathing
What is the cardiac centre in the medulla oblongata responsible for?
which regulates heart rate
What is the respiratory centre responsible for in the medulla oblongata?
controls breathing and regulates the rate and depth of breathing
What is the role of the hypothalamus?
- Controls most of the homeostatic mechanisms
- Controls much of the endocrine function of the body because it regulates the pituitary glands
What are the names of the two parts of the brain associated with understanding language?
Broca and Wernicke
What leads to an individual being unable to understand language but unable to repeat words?
Damage to the neurones that connect the two areas
Suggest and explain whether the Broca area of the brain is a sensory, motor or association area?
motor area- damage results in the inability to make motor movements associated with speaking
Suggest and explain whether the Wernickes area is a sensory motor or association area?
An association area- damage results not in the loss of sensory function but the ability to make sense of the sensory input received
List the areas of the brain that would be involved in reading aloud
Visual sensory Visual association Wernickes area Broca area hearing sensory area
List the areas of the brain that would be involved in singing along to a song being played on the radio
Hearing sensory area
Hearing association area
Wernickes area
Broca area
Suggest what effect damage to the cerebellum might have on a person
Damage to the cerebellum results in a general lack of musclar coordination.
The ability to walk properly is also affected as impulses rom the balace organs in the inner ear are not effectively co-ordinated with musclar movements associated with balance. People with such damage appear to be intoxicated by alcohol by how they move
Explain why a cerebrovascular accident (stroke) leading to damage to the left side of the brain can result in paralysis of the right arm and leg
This is because the motor centres at one side of the brain are responsible for stimulating movement in the muscles in the opposite side of the body
Figure 2 shows the left cerebral hemisphere- how do you know this
The diagram shows the areas associated with speech: these are present on the left cerebral hemisphere in almost all people
