Structure and function of the CNS 1 Flashcards
2 sub divisions of the nervous system
Central nervous system and peripheral nervous system
2 sub divisions of the CNS
Brain and spinal cord
2 sub divisions of the peripheral nervous system
Autonomic nervous system and peripheral nerves
Where is the mesencephalic flexure?
Mid brain
Where is the cervical flexure?
Junction between myelencephalon and spinal cord
Where is the pontine flexure?
Region of pons
Which is the largest part of the brain?
Cerebral hemisphere
What are the four lobes of the brain?
Frontal, parietal, temporal and occipital
What is grey matter in the brain?
Nerve cell bodies, outer layer of cerebral cortex
What is white matter in the brain?
Nerves located in inner layer
What are nuclei in brain?
Aggregates of nerve cell bodies contained within inner layer of cerebral cortex and brainstem
What is a nerve tract?
Collection of nerve fibre bundles serving a particular function, run within white matter
What is cerebral cortex?
Grey matter forming outer layer
What are gyre?
Convoluted ridges
What are sulci?
Furrows
Function of central sulcus
Divides motor area (front) and sensory (behind)
Function of calcarine sulcus
Separates two zones for visual information
Function of great longitudinal fissure
Incompletely separates left and right hemisphere
Function of cingulate salcus?
Splits parietal lobe from cingulate gyrus
Function of corpus callosum
White matter that holds two hemispheres together, found at depth of great longitudinal fissure
What is the deep layer of the brain?
White matter formed by axons from cells of cerebral cortex
What is the internal capsule?
The vast majority of the axons that pass between the cerebral cortex and subcortical structures form a condensed broad sheet of white matter called the internal capsule
Function of great longitudinal fissure
Incompletely separates two cerebral hemispheres
What are corona radiate?
Radiating fibres between internal capsule and cerebral cortex
What does cerebral cortex do?
Conscious awareness, thought, memory, intellect
High level for representation of motor system
Function of parietal lobe
Somatosensory (sensation)
Function of occipital lobe
Vision
Function of temporal lobe
Hearing
Function of frontal lobe
Organisation of movements - primary motor, pre-motor and supplementary motor areas
Symptoms of frontal lobe syndrome
- Difficulty initiating behaviour
- Inability to stop a behavioral pattern
- Difficulties in planning and problem solving
- Incapable of creative thinking
Symptoms of apraxia
Difficulty with planning and performing motor activities
Symptoms of agnosia
- Also known as motor or non-fluent (expressive) aphasia
Symptoms of aphasia
Difficulty with production and comprehension of language or speech, read and write
Symptoms of amnesia
Also known as motor or non-fluent (expressive) aphasia
What is Broca’s aphasia?
Can’t speak or write - not due to muscle impairment
Know what they want but can’t express
Stroke patients
Which part of the brain does Broca’s aphasia affect?
Frontal lobe
What is Wernicke’s aphasia?
Speech is fluent but loss of language comprehension - can’t produce meaningful speech
Which part of the brain does Wernicke’s aphasia affect?
Left posterior superior temporal lobe
What is hemispheric specialisation?
Majority of people have left hemisphere dominance for language, areas of association cortex in frontal, parietal and temporal lobes of left hemisphere are responsible for comprehension and expression of language
What is the cortical homunculus?
Distorted representation of parts of the human body in the brain based on neurological map of the areas and proportions of the brain dedicated to processing of motor or sensory functions
What is limbic lobe?
Lies on medial side of each hemisphere, consists of parts of frontal, parietal and temporal lobes
What are the 3 major components of the limbic lobe?
Cingulate gyrus, mammillary body, hippocampus, amygdala
Main function of limbic lobe
Instinctive and emotional aspect of behavior including motivation and memory (episodic, semantic and implicit)
What are basal ganglia?
Collection of nuclear masses that lie within the cerebral hemispheres
Prominent parts of basal ganglia
Caudate nucleus, putamen, globus pallidus
Function of basal ganglia
Controlling movement and physical expression of behavior driven by affective and motivational state
What is the diencephalon?
Basal ganglia and thalamus
Where do the nuclei in the thalamus form connections with?
Cerebral cortex
Which ventricular wall does the thalamus contribute to?
Lateral wall of third ventricle
Where is thalamus?
Between brainstem and cerebral hemispheres
Symptoms of thalamic lesions
Loss of sensation in contra-lateral face and limbs and thalamic pain (Dejerine-Roussy syndrome)
Function of hypothalamus
Homeostatic mechanisms
Autonomic, neuroendocrine and limbric functions
Which nervous system does the hypothalamus regulate?
Autonomic
Posterior = sympathetic
Anterior = parasympathetic
What is a ventricle in the brain?
Communicating network of cavities filled with cerebrospinal fluid
What does brainstem contain?
Nerve tracts of CNS
Nuclei
What is decussation and where does it occur?
Nerve tracts crossover to opposite side
Brainstem
3 centres found in medulla oblongata
Respiratory, cardiac and vasomotor
What attaches brainstem to cerebellum?
cerebellar peduncles
What are the dorsal columns?
Faciculus gracilis and nucleus gracilis & faciculus cuneatus and nucleus cuteatus
What does the superior colliculus do?
Visual system
What does the inferior colliculus do?
Auditory system
Which ventricle does the brain stem bulb contribute to?
Floor of fourth
What does the brain stem bulb act as the pyramid for?
Pyramidal tract or corticospinal tract
What is the thalamus a gateway to?
Cerebral cortex
