Week 1 - A Ton of Neuroanatomy Flashcards
What component of the neuron is found in the cerebral cortex? What part is in the medulla?
All the cell bodies of the neurons of the Cerebrum are found in the cortex {grey matter}. The fibres from these neurons are concentrated in the white matter of the medulla.
What is the transverse fissure and where is it located?
The Transverse Fissure is located on the posterior aspect of the brain between the cerebellum and cerebrum.
Which side of the brain is the language centre located in most people.
In the majority of people the Language Centres are located within the left hemisphere of the brain.
What two things are contained within the Subarachnoid Space?
It contains both the superficial cerebral arteries and the Cerebral Spinal Fluid {CSF}.
What is the major communication structure between the two hemispheres of the brain?
The Corpus Callosum {means Hard Body} consists of commissural fibres and allows for communication between the two hemisphere.
What is the bridge between the cerebrum and the cerebellum?
The Pons.
Where are the Central Respiratory Control Centres located?
The Medulla.
What is the relay station of the brain and what goes through it?
The Thalamus is an incoming relay station which processes all incoming information and sends it to the correct portion of the brain. All afferent nerve fibres will go through the Thalamus.
What is the Hypothalamus responsible for?
Everything to do with the Viscera of the body.
What two structures are included in the Diencephalon?
The Thalamus and the Hypothalamus.
What is the role of the Short Association Fibres?
Short Association Fibres {U-Shaped Fibres} interconnect the gyri of the brain allowing them to communicate with each other.
What is the role of the Long Association Fibres?
The Long Association Fibres interconnect the different lobes of the brain in each hemisphere. They do not cross over.
What is the role of the Commissural Fibres? What is an example of a structure of these fibres?
Commissural Fibres interconnect the hemispheres and allow for communication between the left and right brain. The Corpus Callosum is the largest collection of these fibres.
What is the role of Projection Fibres? What are the Efferent and Afferent Branches of these Projection Fibres?
Projection Fibres go from the cortex to peripheral areas of the CNS {Efferent; Corticospinal; usually motor}, or from the peripheral CNS to the cortex {Afferent; Spinothalamic; usually sensory} and cross over to the opposite side of the body.
What is conveyed by the Spinothalamic Fibres?
These afferent fibres convey both pain and temperature. {+Itch}
What is the Precentral Gyrus responsible for? What is it part of? What does it form the Sensory-Motor Strip with?
The Precentral Gyrus controls movement on the opposite side of the body and is part of the Premotor Cortex. The Primary Central Somatic Gyrus is also called the Postcentral Gyrus. Together these from the Sensory-Motor Strip.
What part of the premotor cortex is involved with the lower limb?
Control of the lower limb is in the medial aspect of the premotor cortex. Remember the way Leann acted it out in lab…
What is Functional Localization?
Functional Localization is the idea that certain areas of the brain are more involved with particular functions, but never exclusively so.
What is Association?
Association is the integration of diverse sensory information for the planning of purposeful action.
What part of the brain is responsible for Proprioception?
The Parietal Lobe.
Describe the jobs of the parts of the brain involved with performing a movement.
The Premotor Cortex {pMC} plans the muscles movements needed for the desired maneuver.
The Primary Motor Cortex {PMC} performs the action passed onto it from the premotor cortex.
The Supplementary Motor Cortex Area {SMA} programs complex sequences of movements.
What is Apraxia? Lesions in which areas will result in Apraxia?
The inability to perform a purposeful motor movement due to brain damage. A lesion of the pMC or SMA will result in apraxia, while lesions of the PMC will result in weakness and paralysis.
What is Broca’s area involved with? What type of aphasia is caused by damage to this area?
Broca’s Motor Speech Area is involved in the formulation of speech and is located in the frontal lobe {Motor; Expressive Aphasia}.
What is Wernicke’s area involved with? What type of aphasia is caused by damage to this area?
Wernicke’s Sensory Speech Area is involved in language comprehension and is located in the parietal lobe {Sensory; Receptive Aphasia}.
What is Conduction {Associative} Aphasia?
A Conduction Aphasia {Associative Aphasia} occurs when there is a disconnect between Broca’s and Wernicke’s resulting in the ability to comprehend, but not to repeat.
How many neurons are involved in the Dorsal Column – Medial Lemniscal Long Tract?
What is this tract for?
At what level do these neurons cross to the contralateral side?
The DORSAL COLUMN — MEDIAL LEMNISCAL {3 Neuron} is the main pathway for Tactile Information, Proprioception, Stereognosis, and Discriminative & Light Touch.
These neurons cross contralaterally at the level of the medulla, after synapsing to the 2nd order neuron.
How many neurons are involved in the Corticospinal Long Tract?
What is this tract for?
At what level do these neurons cross to the contralateral side?
The CORTICOSPINAL {2 Neuron} is the main Motor pathway involving voluntary skilled motor activity.
Neuron goes from the cortex down to the point where it is about to leave the spinal cord.These will cross over at the level of the medulla and synapse with the Lower Motor Nerve at the level that they leave spinal cord.
How many neurons are involved in the Anterolateral – Spinothalamic Long Tract?
What is this tract for? At what level do these neurons cross to the contralateral side?
The ANTEROLATERAL SYSTEM — SPINOTHALAMIC {3 Neuron} is the main pathway for Pain & Temperature {+ Itch}.
These fibres cross over at the same level which they enter the spinal cord after synapsing with the 2nd order neurons.
Which portion of the Dorsal Column receives sensory innervation from the legs? Which one from the arms?
The Gracile portion of the DC receives sensory innervation from the lower limb and trunk. The Cuneate DC portion receives sensory innervation from the upper limb and trunk.
What do Oligodendrocytes do?
Oligodendrocytes myelinate the axons of the CNS & provide a structural framework to support the neurons.
What do Microglia do?
Microglia remove cell debris, wastes, and pathogens by phagocytosis — they are like little janitors.
What do Ependymal Cells do?
Ependymal Cells line the ventricles and spinal cord central canal producing CSF.
What do Astrocytes do?
Astrocytes maintain the Blood Brain Barrier {BBB}; regulate ion, nutrient, & dissolved gas concentration; absorb and recycle neuro-transmitters; and form Glial Scars after injury.
What do Satellite Cells do?
Satellite Cells surround the neuronal cell body and play a supportive role; not much is known about the functions of these cells.
What do Schwann Cells do?
Schwann Cells myelinate peripheral axons {sensory and motor}. Each Schwann Cell only myelinates a single segment.
All _______ neurons are myelinated while not all _______ neurons are.
Motor; Sensory
What are some features of Autonomic Ganglia?
Autonomic Ganglia are the cell bodies of postsynaptic motor neurons. They are Multipolar Neurons with an eccentrically located nucleus. Satellite cells are less apparent.
What are Cephalohematomas?
Cephalohematoma are subperiosteal hematoma between the periosteum and the skull. These hematoma are limited in size by the sutures and will be small, only covering one bone.
What are Subgaleal Hematomas?
Subgaleal Hematoma are no bounded by the sutures and can become huge, the blood loss resulting from these hematoma can be life threatening.
What colour is blood on CT?
White! It is brighter than Grey Matter in the first 10 days; equal to Grey Matter from 10 - 20 days; and darker than Grey Matter > 20 days.
2 - 3 Head CTs will increase the risk of what?
5 - 10 Head CTs will increase the risk of what?
Triple the risk of brain cancer;
Triple the risk of leukemia.
How will a Subdural Hematoma present?
Subdural Hematoma will present as a crescentic collection that crosses the suture. A mixed density will indicate acute and subacute blood.