Neuropathology Flashcards
What are the 2 divisions of the nervous system?
Central and Peripheral nervous system
What does the central nervous system consist of ?
The brain and spinal cord
How many Paris of cranial nerves do humans have?
12
How many pairs of spinal nerves do humans have?
31
What does the white matter of the brain consist of?
Myelinated nerve fibres
What does the grey matter of the brain consist of?
Nerve cell bodies, dendrites, neuroglia and unmyelinated axons.
What type of matter does the spinal cord contain?
White and grey
What are the two divisions of grey matter in the spinal cord?
Dorsal horn
Ventral horn
Describe the components and pathway type of the dorsal horn of the grey matter in the spinal cord.
Sensory roots and ganglia.
Afferent.
Describe the components and pathway type of the ventral horn of the grey matter in the spinal cord.
Motor roots
Efferent Pathway
Describe what is meant by 6th nerve palsy in terms of the eye.
The 6th cranial nerve controls the eye muscles on the outer side of the eye. If this is damaged, the eye will no longer be pulled to the outer side and so may start to move inwards towards the face. This may also reduce peripheral vision.
What is the main function of the brain stem?
Responsible for automatic survival functions.
What are the main purposes of the medulla?
- Control heartbeat and breathing.
- Receives sensory input/transmits motor output to cranial nerves VIII-XII.
What does the medulla consist of ?
Nuclei and tracts
Where are the pons located?
Above the Medulla
What do the pons consist of ?
Nuclei and tracts and converse axons that are connected to the right and left cerebellum.
What is the pons main function and what area of the pons coordinate this ?
The pneumotaxis area and apneustic area help regulate breathing.
What are the purposes of the reticular formations of the brain?
They are responsible for widespread connections and arousal of the brain as a whole.
- Contains reticular activating systems to maintain consciousness and alertness as well as continuing to allow functions in the sleep and arousal from sleep.
- Responds to touch, pain and temperature.
What is the purpose of the thalamus in the brain
It directs messages to the sensory receiving areas in the cortex and transmits relies to the cerebellum and medulla.
Where is the thalamus located?
On top of the brainstem.
What is the purpose of the cerebellum of the brain?
- Helps coordinate voluntary movement and balance.
- Implicated in cognitive, emotional, sensory, motor and speech processing.
What components make up the Limbic system?
The hypothalamus, pituitary, amygdala and hippocampus.
What are the main purposes of the limbic system
Deal with the basic drives, emotion and memory.
What are the main purposes of the hypothalamus in the limbic system?
- Hunger
- Thirst
- Body temperature
- Pleasure
- Regulates the pituitary gland
What are the main functions of hypothalamus?
- Directs several maintenance activities such as eating, drinking, body temperatures.
- Also helps govern the endocrine system via the pituitary gland.
- Linked to emotions
Where is the hypothalamus in the brain?
Below the thalamus
What is the main purpose of the Amygdala in the brain?
Linked to emotion and fear
Describe the appearance of the Amygdala.
Two almond shaped neural clusters
What is the purpose of the cerebral cortex of the brain?
The body’s ultimate control and information processing centre.
What are the different lobes of the cerebral hemisphere?
Frontal Lobes
Parietal Lobes
Occipital Lobes
Temporal Lobes
What is the purpose of the frontal lobe of the cerebral hemisphere?
Involved in speaking and muscle movements and in making plans and judgement.
What is the purpose of the occipital lobe of the cerebral hemisphere?
Includes the visual areas, which receive visual information from the opposite field.
How does the occipital lobe receive visual from the opposite visual field?
For example; the left eye sends signals to the right side of the brain.
What is the main component of the parietal lobe of the cerebral hemisphere?
Includes the sensory cortex
What is the main function of the temporal lobe of the cerebral hemisphere?
Includes auditory areas, each of which receive auditory information primarily from the opposite ear.
Which lobe of the cerebral hemisphere is the motor cortex?
Frontal
Which lobe of the cerebral hemisphere is the sensory cortex?
Parietal
Which lobe of the cerebral hemisphere is the visual cortex?
Occipital
Which lobe of the cerebral hemisphere is the temporal cortex?
Auditory
Why would the fingers have a much larger region assigned in the cerebral cortex?
Much finer control is required by the fingers in comparison to other areas such as the legs.
In terms of the cerebral cortex, what is Aphasia and what causes this?
Impairment of language usually caused by the left hemisphere being damaged which occurs to either Broca’s area (this ill cause impairment of speech) or damage to Wernicke’s area which will resulting impairment of understanding.
What does damage to Broca’s area in the brain cause ?
Impairment of the speech
What does damage to Wernicke’s area of the brain cause?
Impairment of understanding
Where is Broca’s area of the brain?
Left frontal lobe
What is the purpose of Broca’s area of the brain?
Directs the muscle movement involved in speech.
What is the purpose of Wernicke’s area of the brain?
Involved in language comprehension and expression.
Where is Wernicke’s area of the brain?
In the left temporal lobe.
What techniques can be used to examine functions of the brain?
- Remove a part to see what effect it has on behaviour.
- Examine humans who have suffered brain damage.
What is the Corpus Collosum of the brain?
A large bundle of neural fibres (myelinated axons or white matter) that connects the two hemispheres of the brain.
Epileptic treatment sometimes is cutting of the corpus callous of the brain. Describe the issues this can cause and why.
Without the corpus callous, the left and right cerebral hemispheres are unable to directly communication. This means that information does not reach the left hemisphere. This affects the ability of patients to name objects in the left vision of feel and so patients often struggle to verbalise what they see.
Why do epileptic patients often have their corpus callous cut?
To reduce seizures in the brain.
Give an example of how you may test a split-brain patient using smell and the results of this.
An odour may be presented to the right nostril only but cannot be named because this information cannot reach the left hemisphere. However, the person will be able to use their left hand to reach the source of the odour. This is because the control of the left hand is happening via the right hemisphere of the brain.
Define sensation
The process by which the central nervous system receives input from the environment via sensory neurones.
Define perception
The process by which the brain interprets and organises the sensory information.
What is the absolute threshold in terms of the psychophysics of sensation?
The minimum stimulation needed to detect a stimulus with 50% accuracy.
What is the subliminal stimulation in terms of the psychophysical of sensation ?
Below the absolute threshold for conscious awareness but behaviour may be affected without conscious awareness.
In terms of the psychophysics of sensation, what is sensory adaptation/habituation?
Diminished sensitivity to unchanged stimulus.
What are the 5 major senses?
Vision Hearing Touch Taste Smell
What type of sense is vision and where in the brain is this controlled?
Electromagnetic
Occipital lobe
What type of sense is hearing and where in the brain is this controlled?
Mechanical
Temporal lobe
What type of sense is touch and where in the brain is this controlled?
Mechanical
Sensory cortex
What type of sense is taste and where in the brain is this controlled?
Chemical
Gustatory insular cortex
What type of sense is smell and where in the brain is this controlled?
Chemical
Olfactory bulb and orbitofrontal cortex
What is the vestibular sense and where is this controlled?
Balance and motion
Inner ear
What is the proprioceptive sense and where is this controlled?
Relative position of body parts
Parietal lobe
What is the temperature sense and where is this controlled?
Heat
Thermoreceptors throughout the body and the sensory cortex
What is the nociception sense and where is this controlled?
Pain
Nociceptors throughout the body and in the sensory cortex.
What are the purposes of the rods and cones in the retina?
Rods - brightness
Cones - colour
