Parts Of The Brain Flashcards
What is the cerebrum divided into?
2 hemispheres
What are the 2 hemispheres of the cerebrum connected by?
The corpus callosum
What surface area does the outermost layer of the cerebrum have?
2.5m2
What is the outermost layer of the cerebrum like, what does it consist of and what is this called?
- It is folded
* It consists of a layer of nerve cell bodies called the cerebral cortex.
What is the cerebral cortex in control of?
- emotional response and conscious thought
- ability to override certain reflexes
- features associated with intelligence; judgement and reasoning
What is the cerebrum?
The largest and most recognisable part of the brain.
It is responsible for elements of the nervous system associated with being ‘human’ - imagination, reasoning and thought.
What’s the cerebral cortex subdivided into?
Areas responsible for specific activities and body regions
What are these areas and what do they do?
- Sensory areas: receive impulses indirectly from the receptors
- Association areas: compare input with previous experiences to interpret what the input means and judge an appropriate response
- Motor areas: send impulses to effectors (muscles and glands)
What alone cannot operate the human body in a coordinated way?
The conscious decision to move voluntary muscles, initiated by the cerebral cortex
How many nerve cells in the brain does the cerebellum contain?
Over half of all nerve cells in the brain
What are the names of the two areas of the brain associated with understanding language and speaking and where are they located?
Names:
• Wernicke’s area
• Broca’s area
Location:
• Left cerebral hemisphere
What are …
• Broca’s area
• Wernicke’s area
Broca’s area:
•Named after Paul Broca
•In 1860s, he examined the brains of patients with an inability to speak (aphasia) and discovered the region responsible for this problem in the brain
Wernicke’s area:
•Named after Karl Wernicke
•In 1860s, he identified another region, damage to which caused problems with understanding language
What are Wernicke’s area and Broca’s area connected by?
A bundle of neurones
What happens if this bundle of neurones is damaged?
An individual will be able to understand language but UNABLE to repeat words
Suggest whether …
1) Broca’s area
2) Wernicke’s area
… is a sensory/motor/association area
1) Broca’s area = motor area
• damage results in inability to make motor movements associated with speaking
2) Wernicke’s area = association area
• damage results NOT in the loss of sensory function but the ability to make sense of the sensory input received
What’s different about the cerebral cortex in humans than in other organisms?
It is more developed in humans than in any other organism
What is the hypothalamus?
The hypothalamus controls the autonomic nervous system and the endocrine glands
What are some examples of nonconscious operation?
- Muscular activities associated with responding to changes in body position
- Sensory activities e.g. judging position of objects and limbs
- Tensioning of muscles to manipulate tools/instruments effectively
- Feeding back information on muscle position, tension + fine movements
- Operation of antagonistic muscles to coordinate contraction + relaxation
What do neurones from the cerebellum do and what does this explain?
Neurones from the cerebellum carry impulses to the motor areas so that the motor output to the effectors can be adjusted appropriately in relation to these requirements.
- this explains why we often go on “auto-pilot” when carrying out such activities, as they are said to become programmed into the cerebellum.
What is the cerebellum?
The cerebellum controls the coordination of movement and posture
Suggest what effect damage to the cerebellum may have on a person
Damage to the cerebellum results in:
• General lack of muscular coordination
• ability to walk properly is affected, as impulses from the balance organs in the inner ear are not effectively coordinated with muscular movements associated with balance
(People with such damage appeared to be intoxicated by alcohol in terms of how they move)
What is the function of the hypothalamus?
- Controls most of the body’s homeostatic mechanisms
- Controls much of endocrine function of the body because it regulates the pituitary gland
- Receives sensory input from temperature receptors and osmoreceptors:
leads to initiation of automatic responses that regulate..
• body temperature
• blood water potential
Where does the cerebellum process sensory information in order for it to carry out its function?
- the retina
- the balance organs in the inner ear
- the joints
- specialised fibres in muscles (spindle fibres) which give info on muscle tension
What is the medulla oblongata?
The medulla oblongata controls the action of smooth muscle in the gut wall, and controls breathing movements + heart rate
What is the function of the medulla oblongata?
- Controls non-skeletal muscles (cardiac + involuntary muscles)
- Effectively in control of the autonomic nervous system
- It is home to a number of regulatory centres for a number of vital processes:
• cardiac centre; regulates heart rate
• Respiratory centre; controls breathing + regulates rate + depth of breathing
What does the fine control of muscular movements -such as that involved in walking/riding bike/driving - require?
A significant degree of non-conscious operation
List the areas of the brain that would be involved in:
1) reading out loud
2) singing along to a song on the radio
1) visual sensory area visual association area Wernicke's area Broca's area Hearing sensory area
2) Hearing sensory area Hearing association area Wernicke's area Broca's area
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
