Week 4: Neuroanatomy Flashcards
What are the three principlal tissue layers that protect the CNS? Describe each of them.
The meninges include:
Dura mater: outermost and toughest
Arachnoid mater: middle, spiderweb-like layer
Pia mater: innermost and most delicate (direct contact with brain tissue)
What is between the pia and arachnoid mater and what does it contain?
The subarachnoid space is the space between these layers, anc contains CSF
What are the four main lobes of the brain and what is their function?
Frontal lobe: execution, function, cognitive control, movement
Temporal lobe: memory
Parietal lobe: sensory information processing
Occipital lobe: vision
What are the sections of the brainstem and what are the main functions of the brainstem as a whole?
The thalamus, midbrain, pons and medulla oblongata are the sections of brainstem from top to bottom.
The general function of the brainstem is:
1) Pathway for sensory and motor information to and from the cortex/body
2) Provides main motor and sensory nerve supply to the face and neck via cranial nerves
3) Pathway for information entering and exiting the cerebellum (via cerebellar peduncles)
What are the nerve segments of the spinal cord?
Cervical nerves
Thoracic nerves
Lumbar nerves
Sacral nerves
Why do we conduct spinal taps at the L3-L5 segments of the spinal cord? What is the name for the region of nervous tissue in this area?
The end of the spinal cord cuts off at the T12 vertebra, with the nerves below that area belonging to the cauda equina (horse’s tail). These are free nerves attached to the spinal cord, and a lumbar puncture will not “nick” the cord if done at this level.
What are the main shapes found in the brain? When do they occur?
Gyri (ridges)formduring fetal and neonatal development, and thesulci (depressions/grooves) form simultaneously.
What are the four main folding structures on the temporal and parietal lobes that are connected, and what do they do?
The Sylvian fissure, superior temporal gyrus and angular gyrus are all found temporally on the cerebellum. The supramarginal gyrus (the other curve in the photo) is also key.
Angular gyrus = language, reading and writing interpretation
Supramarginal gyrus = somatosensory cortex, limb location and interpretation of tactile sensory data
How do you find the central sulcus from a sagittal section of brain?
Find the cingulate gyrus (pink), and trace the cingulate sulcus (above the gyrus) to the marginal branch of the cingulate sulcus. Then, move one sulcus anteriorly to find the central sulcus.
What are the functions of the gyri near the central sulcus?
Precentral (red) and postcentral (blue) gyri are the primary motor and primary sensory cortices in the brain
What is the paracentral lobule? Where is it located?
The paracentral lobule is where sensory and motor information are integrated, and it bridges the central sulcus deep to the sulcus itself (red curve)
What is the cortical homunculus?
It is the concept that sensory and motor information is “mapped” to certain areas of the brain, for example the feet and toes are within the central region, whereas the eyes, nose, face, lips and tongue are located laterally
What is the importance of the insular cortex?
It is an ancient structure, deep to the lateral sulcus, responsible for everything from compassion and empathy to consciousness, emotion and homeostasis
What is the primary auritory cortex, what is another name for it, and where is it located?
The primary auditory complex, or Heschl’s gyrus, is located posteriorly to the insula (insular cortex), and is responsible for integration of auditory information from the environment. It sits deep to the temporal lobe.
Which aspect of the cortex is “deepest,” and what special cells lie within this aspect? What layer do we find them in?
The fifth layer (V) of the primary cortex contains Betz cells, specialized pyramidal cortical neurons that send motor signals down the spinal cord
Which components of the primary sensory cortex receive sensory information from the skin?
3b and 1
Which components of the primary sensory cortex receive sensory input from the joints and muscles?
3a and 2
What aspects of Brodmann’s areas take in sensory information, and what occurs after that information is processed?
Sensory information is taken in at the primary somatic sensory cortex (BAs) 3, 1 and 2, and is then sent to the posterior parietal cortex (areas 5/7).
Then, that information travels all the way to the premotor cortex (area 8), and the supplemental motor cortex (area 6), then into the primary motor cortex (area 4), and down to the spinal cord to initiate the motor response.
What are the main parts of the limbic system, and how do we remember them?
Limb-ic (like a bird on a limb) “HATCH”
Hippocampus
Amygdala
Thalamus
Cingulate gyrus
Hypothalamus
+ Mammillary body and Fornix
What is the Circuit of Papez and what is the path followed?
The Circuit of Papez is the path information takes through the limbic system. Information comes in through the amygdala, moves through the hippocampus, then through the fornix, through the mamillary bodies, then to the thalamus (it goes further than this, but that’s all we need to know)
What is the cerebellum and where is it located?
The cerebellum regulates motor movement, controlling posture, balance, coordination and speech. This results in smooth and fluid motor movement.
It is located posteriorly in the brain, in the inferior aspect of the hindbrian.
What is the basis pedunculi and where is it located?
The basis pedunculi (cerebral peduncle) attach the cerebrum to the brainstem, and are located medially, inferiorly, and centrally in the brain (near the midbrain).