Nervous System Flashcards
What are the three components of the brainstem in order?
Midbrain, Pons, Medulla
What does the cerebellum take part in?
Coordination of movement
What are the three components that make up the hind brain?
Cerebellum, medulla, pons
What are the folds of the brain called?
Gyrus/gyri
What are the gaps between folds of the brain called?
Sulci
What are the folds made up of?
Grey matter 6-7 mm thick with a layer of white matter underneath.
What are the 3 key sulci?
Central sulcus, parieto-occipital sulcus, lateral sulcus (fissure)
What is the name of the important notch in the brain?
Preoccipital notch
What does the central sulcus separate?
Frontal and parietal lobe
What are the four gyri of the frontal lobe?
Superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, precentral gyrus
What lies beneath the lateral fissure?
Temporal lobe
What are the three longitudinal gyri of the temporal lobe?
Superior, middle and inferior temporal gyrus
What is behind the temporal lobe?
Occipital lobe
What lobe lies between the frontal, occipital and temporal lobe?
Parietal lobe
What is the name of the sulcus which separates the parietal lobe into an upper and lower part?
Intraparietal sulcus
What is the parietal lobe split into?
Superior and inferior parietal lobule
What are the names of the two gyri found on the inferior parietal lobule? What is special about them?
Supramarginal gyrus and angular gyrus. They are connected to form an m shape.
What is the other singular gyrus of the parietal lobe?
Postcentral gyrus
What does the precentral gyrus correspond with? What does it control?
Primary motor cortex. Controls muscles on the other side of the body.
What is the primary motor cortex dominated by?
The face and hands
What is meant by somatotopical?
Organised by body region. Increasing complexity requires more brain cells and a larger region of the cortex.
What is meant by primary and motor of primary motor cortex?
Primary: critical role
Motor: movement
What does the postcentral gyrus correspond with? What is it involved with?
Primary somatosensory cortex. Where you consciously appreciate every touch on your skin.
Large areas of the primary somatosensory cortex are devoted to ________ ____________ regions of the body.
Highly discriminatory
What is the purpose of the primary visual cortex?
Allows you to see the world.
What surrounds the primary visual cortex?
The calcarine sulcus
How is the primary visual cortex organised?
Visuotopically organised (retinotopically)
Why don’t we see a line down the middle of the world?
Visual cortex on one side communicates with the visual cortex on the other.
What do the areas around the primary visual cortex do? What are they called?
Add value (shape and colour) to the original picture. Supplementary/secondary visual cortices
From where does the primary auditory area get input from?
Gets input from the ear on the opposite side.
In which gyrus is the primary auditory area located?
The transverse gyrus of Heschl, deep within the brain.
How is the sound received by the primary auditory area organised
High tones and frequencies at one end whilst low tones and frequencies at the other. Tonotopically organised.
What does Wernicke’s speech area allow us to do?
Understand what is being said.
What happens when a person gets a stroke/tumour at Wernicke’s speech area?
Disorder of speech: a fluent/sensory aphasia. Can hear but not understand spoken word.
What is meant by an aphasia?
Disorder of speech associated with the brain.
What does Wernicke’s speech area communicate with? By what?
Broca’s speech area through a large bundle of fibres called the arcuate fasciculus.
What is the Wernicke’s and Broca’s speech areas associated with
W: sensory aspect of speech recognition.
B: motor aspect of speech recognition.
What does Broca’s speech area do?
Allows us to pronounce words by communicating with muscles that control speech.
What happens when we get a lesion on the Broca’s speech area?
Can’t pronounce words: non-fluent aphasia
What happens when the arculate fasciculus is broken?
Give an example.
A conduction aphasia. E.g. What did you have for lunch today? It’s going to rain outside.
What are the supramarginal and angular gyri responsible for?
Reading and writing
Which area controls which muscles are to be activated during writing?
Exner’s area
What is the non dominant right hemisphere responsible for in comparison with verbal language on the left side?
Non-verbal language: Body language Emotional expression Spatial skills Conceptual understanding Artistic/musical skills
What are the effects of injury on the non-dominant hemisphere?
Spatial disorientation Inability to recognise familiar objects Loss of musical appreciation Speech lacks emotion Loss of non-verbal language
What are the functions of the frontal association cortex?
Intelligence Personality Behaviour Mood Cognitive function
What are the functions of the parietal association cortex?
Spatial skills
3D recognition: shapes, faces, written words, concepts, abstract perception.
Wernicke’s area is larger on the _______ side.
Left
What information does Broca’s speech area contain?
How to pronounce words
What are the functions of the temporal association cortex?
Memory, mood, aggression, intelligence
What does Exner’s area do?
Drives muscles for writing.
Verbal language areas are concentrated mainly in the _________ hemisphere.
Left
In the right hemisphere, the general areas of verbal language of the left hemisphere are instead replaced by _________.
Non verbal language areas
What regions add value to the original visual cortex?
Supplementary visual cortices
Which regions are most highly developed in humans?
Complex association areas
What types of nerves are in the first upper region of the spinal cord? How many pairs are there?
Cervical (neck) nerves
8 pairs
What does the spinal cord extend down?
The middle of the vertebral column
Coming away from the spinal cord are ________
Nerves on each side called spinal nerves
How many pairs of spinal nerves are there?
31
What nerves are underneath the cervical nerves?
Thoracic spinal nerves
12 pairs
What spinal nerves are underneath the thoracic spinal nerves? How many?
Lumbar nerves
5 pairs
Each spinal nerve goes out towards ______
An area of the skin
What spinal nerves are under the lumbar nerves? How many?
Sacral nerves
5 pairs
Which pair of spinal nerves does not go towards the skin?
C1
What spinal nerves are at the very bottom of the spinal cord? How many?
Coccygeal nerves
1 pair
What would happen if one of the spinal nerves was cut?
The area that is goes towards would be numb.
What is meant by a dermatome?
A region of skin innervated by a spinal nerve.
How many dermatomes are there?
30
What are the two roots going into and out of the spinal cord?
Dorsal root
Ventral root
What are the functions of the dorsal and ventral root?
Dorsal: Receives sensory information
Ventral: Sends motor information to muscles
What do the dorsal and ventral roots join up to form?
Spinal nerve
What are the two major sets of information from the skin?
Touch and pressure
Pain and temperature
What two special types of receptor sit right under the skin?
Touch: Meissner corpuscles
Pressure: Pacinian corpuscles
What type of receptor is used for discriminative sensation?
Encapsulated receptors (more dense on lips and hands)
How are nerves of encapsulated receptors activated?
The receptor is depressed and nerve at centre is activated.
Where are the cell bodies of the nerves entering the dorsal root located?
In a swelling called the ganglion.
What area of the spinal cord do sensory nerves go to?
Dorsal area
What is considered discriminative sensation?
Touch and pressure
There are more nerves going to the _____ than the _____ (chest/hand)
hand
chest
How fast do nerves travel along myelinated fibres?
50 m/s
How fast do signals travel along non-myelinated fibres?
1 m/s
What is considered non-discriminative sensation?
Pain and temperature
What type of sensation occurs through free nerve endings?
Non-discriminative