Cross-sectional Anatomy Flashcards
How does CT work differently from MRI?
X-Ray radiation
Attenuation of the X-Ray is measured for coefficient
Denser elements appear whiter, less dense darker
Generates images in trans-axial slices
3D image data allows for reconstruction in any plane
How does MRI work differently from CT?
Uses radio waves and magnetic fields
Measures the hydrogen content of each voxel (3D section) and represents it as shades of grey (or colour) in pixels
Images can be obtained in different planes and angles simultaneously
What is bright on a T1 weighted image?
T1 - Fat
White matter is brighter than grey matter
Bone is white (fat of the bone marrow)
Ventricles are dark
What is white on a T2 weighted image?
T2 - water
Ventricles are white
Grey matter is white (outer edge of brain)
What are the axes for imaging?
Cranial - caudal
Dorsal - ventral
Superior - inferior
Anterior - posterior
Medial - lateral
What are the planes for imaging?
Sagittal
Coronal
Axial
How do you find the central sulcus?
Sylvian fissure
Inferior frontal gyrus
Inferior frontal sulcus
Precentral sulcus
Central sulcus
Which gyrus is thicker, precentral or post central?
Precentral gyrus (motor) is thicker than the post central gyrus
Where is Broca’s area located?
Inferior frontal lobe - pars opercularis
Where is the inferior parietal lobule?
Immediately posterior to the post central gyrus
Composed of supramarginal gyrus and angular gyrus
How do you find the supramarginal gyrus?
Part of the inferior parietal lobule
Horseshoe directly superior to the back of the Sylvian fissure
What is the location and function of the angular gyrus?
Inferior parietal lobule
Directly posterior to supramarginal gyrus
Left: language
Semantic and phonologic
Reading and writing
Word and sentence comprehension
Processing and understanding numbers
What syndrome arises from damage to the left angular gyrus?
Gerstmann syndrome
Finger agnosia
Dyscalculia
Dysgraphia
R-L disorientation
What are the three components of the temporal lobe?
Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
What are the three components of the occipital lobe?
Superior occipital gyrus
Middle occipital gyrus
Inferior occipital gyrus
What is the location and function of Herschl’s gyrus?
Immediately posterior to the insula
Function: Primary auditory cortex
How does the precentral gyrus present in a mid-sagittal section?
Hook
What is the sulcus immediately superior to the corpus callosum?
Callosal sulcus
What is the gyrus immediately superior to the callosal sulcus?
Cingulate gyrus
What part of the cingulate sulcus is on the surface of the brain?
Pars marginalis
(Posterior to post central gyrus)
Bracket sign in axial view
What is the para central lobule composed of?
Pre and post central gyri
What gyrus is directly anterior to the para central lobule?
Superior frontal gyrus
What gyri does the parieto-occipital sulcus separate?
Precuneus (parietal)
Cuneus (occipital)
What structure is inferior to the cuneus?
Lingual gyrus
What is the role of the lingual gyrus?
Identification and recognition of words
How can you identify the central sulcus in the axial plane?
Door handle/omega shaped sulcus
Precentral gyrus thicker than postcentral gyrus
What is the function of the precentral gyrus?
Primary motor area
What is the function of the postcentral gyrus?
Primary somatosensory cortex
What is the location and function of the supplementary motor area?
Posterior aspect of the superior frontal gyrus
Planning, coordination, and initiation of movement
What is the location and function of the promotors cortex?
At the posterior junction of the superior and middle frontal gyri
Integration of stimuli for movement related tasks, including mirroring
What is the operculum?
The part of the brain that covers the insula
Where is the fusiform gyrus found on a coronal section?
Medial and inferior to the inferior temporal gyrus
What part of the brain is associated with navigation?
Hippocampus (spatial memory)
What structure connects the hippocampus to the mammillary bodies
Fornix
What kind of matter are the basal ganglia?
Grey matter (nuclei)
Which structure is more anterior, the caudate or the putamen ?
Caudate
What is the collective name of the putamem and the globus pallidus?
Lentiform nucleus
What are the white matter structures around the basal ganglia?
Internal and external capsules
What is the location and function of the thalamus?
Medial to the posterior limb of the putamen
Relay of information
Consciousness
Sleep
Memory
Sensory and motor functions?
Where do the cranial nerves arise from?
Midbrain pons and medulla
What is the function of the cerebellum?
Posture
Balance
Coordination
Sleep
What are the 1st and 2nd ventricles?
Lateral ventricles
Where is the cerebral aqueduct?
Between the 3rd and 4th ventricles
