Flashcards in Week 1 - finished Deck (71):
What is the CNS made up of?
The brain, brainstem and Spinal cord
What are the 6 main regions of the CNS?
Pons and cerebellum
2 cerebral hemispheres
What is the PNS made up of?
And the ganglia of these 2
What can the PNS be divided into? What are the components of these divisions?
Somatic - motor and sensory components
Autonomic - sympathetic, parasympathetic and enteric components
What parts make up the diencephalon?
What parts make up the brainstem?
What is another name for the midbrain?
What are the 4 main region of the brain and what is a brief overview of each of their functions?
Cerebrum: 2 cerebral hemisphere.
- Conscious perception and integration of sensory information
Diencephalon: Contains the:
- Thalamus = The thalamus conveys information to the cerebral hemispheres via thalamic nuclei specific to cortical areas.
- Hypothalamus = The hypothalamus works to maintain homeostasis through the integration of the functions of the autonomic nervous system and the pituitary gland which releases endocrine hormones.
- Also contains:
●neurohypophysis & pituitary stalk
●optic n. & tract
Cerebellum: The primary function of the cerebellum is coordination of movement and balance, it compares the intended or planned event with the event which is actually taking place.
Brainstem: midbrain, pons, medulla oblongata
Controls basic life giving functions such as heart beat and respiration.
Controls head & neck movement to maintain balance & collect sensory info.
Transmits neural info between the spinal cord & supraspinal structures.
What is the core of the brainstem known as?
The reticular formation
What is the function of the reticular formation?
The RF it is important in integrating the actions of the entire brainstem and cerebrum to maintain arousal.
Where do each of the cranial nerves arise from the CNS?
CN I comes directly from the cerebrum
CN II arises from the diencephalon
CN’s III & IV from midbrain
CN’s V, VI, VII & VIII from pons
CN’s IX, X, XI & XII from medulla
The axons in the dorsal root of a spinal nerve only transmit what kind of information?
The axons in the ventral root of a spinal nerve only transmit what kind of information?
What do the dorsal root and the central root join to form? What does this later split to form?
They form the spinal nerve. As the dorsal root is sensory and the ventral root is motor the spinal nerve now has both motor and sensory axons, as well as SNS and PSNS.
Once the spinal nerve has formed it splits to form the ventral and dorsal rami of the spinal nerve. These rami go off to supply various muscles, organs and sections of skin, providing them with sensory and motor innervation.
What is white matter? Why is it white?
Myelinated axons. It's white because myelin sheathes are white.
What is grey matter?
Nerve cell bodies, dendrites, axon terminals, unmyelinated axons and neuroglia
What colour is the cortex of the cerebral hemispheres?
What are deep clusters of grey matter in the brainstem and cerebrum called?
What are clusters of grey matter found in the PNS called?
What is the area called where the dorsal horn and the ventral horn come together in the spinal cord?
What does the intermediate zone in the spinal cord allow for?
It is located between the dorsal and ventral roots and allows to communication of sensory and motor information via interneurons
In the spinal cord, what is the arrangement of grey and white matter?
The grey matter forms an H shape in the middle, surrounded by columns of white matter around the outside.
The H is made of ventral and dorsal horns which exit the spinal cord to before ventral and dorsal roots, ventral roots transmitting motor information and dorsal roots transmitting sensory information.
These grey ventral and dorsal horns meet in the middle to form the intermediate zone, which is the area where sensory and motor information is intergrated. This forms the basis for our reflexes.
What are the names of the columns of white matter in the spinal cord?
Ventral dorsal and lateral
What separates the right and left ventral columns?
The ventral median fissure
What separates the left and right dorsal columns?
The dorsal median sulcus
Where do the lateral columns of the spinal cord lie?
Between the ventral and dorsal rami laterally
What are the 4 divisions of the cerebral hemispheres? What are they named from?
Named by the skull bones that they lie beneath
What separates the frontal and parietal lobes?
The central sulcus
What separates the parietal and temporal lobes?
The lateral sulcus
What separates the parietal and occipital lobes?
The parieto-occipital sulcus
What are the elevated convolutions in the brain called?
What is the name for the functionally distinct area within each lobe?
What are the functions of the frontal lobe?
The frontal lobe plans the sequence of movements required to achieve a goal and regulates the strength of the actions.
This is primarily done by the primary motor cortex located on the precentral gyrus and the premotor areas just anterior.
The primary motor cortex is organised somatotopically as demonstrated by the motor homunculus.
The cortical area assigned to a region of the body does not reflect the size or strength of the muscles represented but rather to the complexity of movement achievable
Where is Broca's area located and what does it do?
It is found on the inferior frontal gyrus on the dominant hemisphere only.
It is the motor area for speech.
Where is the frontal eye field located?
Anterolateral to the premotor area within the frontal lobe.
What is the function of the prefrontal cortex?
It is responsible for higher order cognitive function and emotions
What lies on the anterior and inferior surface of the frontal lobe?
The olfactory bulbs as well as the orbital gyri and the basal forebrain required for processing olfactory information
What is the predominant function of the parietal lobe?
The interpretation and integration of somatosensory information
It functions to perceive pain, touch, temperature and propriception
Where does the parietal lobe receive most of its information from?
The dorsal column medial lemniscus system, the trigeminal system and the anterolateral system
Where is the primary somatosensory cortex located?
The post central gyrus
Where is the primary motor cortex located?
The pre-central gyrus
What does homunculus mean?
The somatotopical arrangement of both the somatosensory and motor cortex
What is the posterior aspect of the parietal lobe (posterior to the post central gyrus) divided into and what divides it?
The inferior and superior parietal lobules. It is divided by the intraparietal sulcus
What is the function of the superior parietal lobule?
Associated with the recognition and perception of self image
What function is the inferior parietal lobule associated with?
It is known as the "common integrative area". It is the confluence of the associated cortices of the occipital, parietal and temporal lobes.
It is involved in the integration of diverse sensory information for speech and perception.
Damage to this area results in learning difficulties
What is the function of the occipital lobe?
It is responsible for visual perception
It also has an area responsible for the perception and recognition of faces
Where is the primary visual cortex found? (Be specific)
Within the walls of the calcarine fissure on the medial surface of the hemispheres in the occipital region of the brain.
What is the function of the primary visual cortex? Is all visual information processed and integrated here?
The primary visual cortex I s responsible for the initial processing of visual information. The secondary and association visual area are responsible for the elaboration of the information, giving form and colour to the images.
What is the function of the temporal lobe?
It mediates our highest order sensory functions, not just somatosensory, as well as memory and emotions.
Where is the primary auditory cortex found?
In the superior temporal gyrus
What is the organisation of the primary auditory cortex?
What is anterior to the auditory association cortex?
An area in the temporal lobe associated with the recognition of faces.
On the dominant side of the body what does the auditory association cortex contain?
Wernickes area, which associated with the interpretation of speech.
What are the 2 areas of the brain required for the articulation of speech?
Broca's area in the frontal lobe, and wernickes area in the temporal lobe.
What is the function of the inferior temporal gyrus?
Detailed perception of visual form and colour
Where is the hippocampus found?
In the floor of the anterior horn of the lateral ventricles.
What is just anterior to the hippocampus?
What is the amygdala responsible for?
What is the function of the hippocampus, amygdala and associated areas of the frontal lobe?
They mediate emotions and memory
Where are the lateral ventricles found?
Curving through the 2 cerebral hemisphere and have an anterior and posterior horn
Where is the third ventricle found?
Between the 2 halves of the diencephalon in the midline
Where is the fourth ventricle located?
Between the brainstem and the cerebellum
What separates the cerebrum and the cerebellum?
The transverse cerebellar fissure
How do the 2 lateral ventricles communicate with the 3rd ventricle?
Via narrow interventricular foramina: foramina of monro
How does the third ventricle communicate with the fourth ventricle?
Via a tunnel through the midbrain called the cerebral aqueduct
What is the 4 ventricle continuous with?
The subarachnoid space and the central canal of the spinal cord
What secretes CSF?
The choroid plexus
What is the purpose of CSF?
Protection/ cushioning as well as nourishment
What are the layers of meninges and spaces from superficial to deep?
-potential subdural space
-subarachnoid space (contains CSF)
What is the function of the dura mater?
It suspends the brain away from the cerebral vault in order to protect it. To do this it folds on itself giving it the appearance of 2 separate layers; the outer one lining and adhering to the cranial periosteum and the inner one traversing and adhering tightly to the deep sulci and fissures of the brain.
These folds create potential spaces as well as the dural sinuses for venous drainage: