Cross-sectional Anatomy

Question 1

How does CT work differently from MRI?

Answer 1

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

Question 2

How does MRI work differently from CT?

Answer 2

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

Question 3

What is bright on a T1 weighted image?

Answer 3

T1 - Fat
White matter is brighter than grey matter
Bone is white (fat of the bone marrow)
Ventricles are dark

Question 4

What is white on a T2 weighted image?

Answer 4

T2 - water

Ventricles are white
Grey matter is white (outer edge of brain)

Question 5

What are the axes for imaging?

Answer 5

Cranial - caudal
Dorsal - ventral
Superior - inferior
Anterior - posterior
Medial - lateral

Question 6

What are the planes for imaging?

Answer 6

Sagittal
Coronal
Axial

Question 7

How do you find the central sulcus?

Answer 7

Sylvian fissure
Inferior frontal gyrus
Inferior frontal sulcus
Precentral sulcus
Central sulcus

Question 8

Which gyrus is thicker, precentral or post central?

Answer 8

Precentral gyrus (motor) is thicker than the post central gyrus

Question 9

Where is Broca’s area located?

Answer 9

Inferior frontal lobe - pars opercularis

Question 10

Where is the inferior parietal lobule?

Answer 10

Immediately posterior to the post central gyrus

Composed of supramarginal gyrus and angular gyrus

Question 11

How do you find the supramarginal gyrus?

Answer 11

Part of the inferior parietal lobule
Horseshoe directly superior to the back of the Sylvian fissure

Question 12

What is the location and function of the angular gyrus?

Answer 12

Inferior parietal lobule
Directly posterior to supramarginal gyrus

Left: language
Semantic and phonologic
Reading and writing
Word and sentence comprehension
Processing and understanding numbers

Question 13

What syndrome arises from damage to the left angular gyrus?

Answer 13

Gerstmann syndrome

Finger agnosia
Dyscalculia
Dysgraphia
R-L disorientation

Question 14

What are the three components of the temporal lobe?

Answer 14

Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus

Question 15

What are the three components of the occipital lobe?

Answer 15

Superior occipital gyrus
Middle occipital gyrus
Inferior occipital gyrus

Question 16

What is the location and function of Herschl’s gyrus?

Answer 16

Immediately posterior to the insula
Function: Primary auditory cortex

Question 17

How does the precentral gyrus present in a mid-sagittal section?

Answer 17

Hook

Question 18

What is the sulcus immediately superior to the corpus callosum?

Answer 18

Callosal sulcus

Question 19

What is the gyrus immediately superior to the callosal sulcus?

Answer 19

Cingulate gyrus

Question 20

What part of the cingulate sulcus is on the surface of the brain?

Answer 20

Pars marginalis
(Posterior to post central gyrus)
Bracket sign in axial view

Question 21

What is the para central lobule composed of?

Answer 21

Pre and post central gyri

Question 22

What gyrus is directly anterior to the para central lobule?

Answer 22

Superior frontal gyrus

Question 23

What gyri does the parieto-occipital sulcus separate?

Answer 23

Precuneus (parietal)
Cuneus (occipital)

Question 24

What structure is inferior to the cuneus?

Answer 24

Lingual gyrus

Question 25

What is the role of the lingual gyrus?

Answer 25

Identification and recognition of words

Question 26

How can you identify the central sulcus in the axial plane?

Answer 26

Door handle/omega shaped sulcus Precentral gyrus thicker than postcentral gyrus

Question 27

What is the function of the precentral gyrus?

Answer 27

Primary motor area

Question 28

What is the function of the postcentral gyrus?

Answer 28

Primary somatosensory cortex

Question 29

What is the location and function of the supplementary motor area?

Answer 29

Posterior aspect of the superior frontal gyrus Planning, coordination, and initiation of movement

Question 30

What is the location and function of the promotors cortex?

Answer 30

At the posterior junction of the superior and middle frontal gyri Integration of stimuli for movement related tasks, including mirroring

Question 31

What is the operculum?

Answer 31

The part of the brain that covers the insula

Question 32

Where is the fusiform gyrus found on a coronal section?

Answer 32

Medial and inferior to the inferior temporal gyrus

Question 33

What part of the brain is associated with navigation?

Answer 33

Hippocampus (spatial memory)

Question 34

What structure connects the hippocampus to the mammillary bodies

Answer 34

Fornix

Question 35

What kind of matter are the basal ganglia?

Answer 35

Grey matter (nuclei)

Question 36

Which structure is more anterior, the caudate or the putamen ?

Answer 36

Caudate

Question 37

What is the collective name of the putamem and the globus pallidus?

Answer 37

Lentiform nucleus

Question 38

What are the white matter structures around the basal ganglia?

Answer 38

Internal and external capsules

Question 39

What is the location and function of the thalamus?

Answer 39

Medial to the posterior limb of the putamen Relay of information Consciousness Sleep Memory Sensory and motor functions?

Question 40

Where do the cranial nerves arise from?

Answer 40

Midbrain pons and medulla

Question 41

What is the function of the cerebellum?

Answer 41

Posture Balance Coordination Sleep

Question 42

What are the 1st and 2nd ventricles?

Answer 42

Lateral ventricles

Question 43

Where is the cerebral aqueduct?

Answer 43

Between the 3rd and 4th ventricles