Topography of the Brain Flashcards
What does topography relate to?
- the organisation/layout of something
What 2 components make up the CNS?
1 - brain
2 - spinal cord
The 3 main parts of the brain are composed from the primary vesicles that form from neurulation. The 3 primary vesicles are seen in the image below. What are the 3 main parts of the brain that these primary vesicles go on to form (3 major regions of the brain)?
1 - forebrain
2 - midbrain
3 - hindbrain
What are the ventricles of the brain?
- interconnected cavities known as cerebral ventricles in the brain
What fluid is found within and created by the 4 ventricles of the brain?
- cerebrospinal fluid
What produces the majority of cerebrospinal fluid located in the ventricles of the brain?
- choroid plexus composed of ependymal cells
- venous epiphyseal cells
- dural venous sinus
- thymus
- choroid plexus composed of ependymal cells
How many pairs of spinal nerves are there?
- 31 pairs
What are the 2 functions/parts of the peripheral nervous system?
1 - somatic (voluntary system)
2 - autonomic nervous system
What are the surfaces (labelled A and B) and the views (labelled C and D)?
- medial view (side on view but sagittal cut)
- lateral view (side on)
- superior view (above)
- inferior view (underneath)
- A = superior view (above)
- B = inferior view (underneath)
- C = lateral view (side on)
- D = medial view (side on view but sagital cut)
What are the 3 tracts, essentially organisation of white matter, present in the brain?
- projection, association and commissural tracts
- accessory, association and commissural tracts
- projection, accessory and commissural tracts
- projection, association and accessory tracts
- projection, association and commissural tracts
- commissural (left to right cerebral cortex)
- association (spinal cord to cerebral cortex)
- projection (cerebral cortex to same side of cerebral cortex)
What is grey and white matter in the brain?
- white = myelineated axons (tracts of the brain)
- grey = neuronal cell body (cerebral cortex, brain nuclei)
The forebrain, midbrain and hindbrain are formed from what 3 primary vesicles?
1 - forebrain = Prosencephalon (latin for front)
2 - midbrain = Mesencephalon (middle)
3 - hindbrain = Rhombencephalon (back of)
The prosencephalon (latin for front), also referred to as the forebrain is the most rostrol part of the brain. From this 2 secondary ventricles are formed called the Telencephalon and the Diencephalon. What is the main part of the Telencephalon and the 2 main structures of the Diencephalon?
1 - Telencephalon = cerebral cortex
2 - Diencephalon = thalamus
3 - Diencephalon = hypothalamus
The rhombencephalon, also referred to as the hindbrain is the most caudal part of the brain. From this 2 secondary ventricles are formed called the Metencephalon and the Mesencephalon. What are the 3 part that forms from these?
1 - cerebellum
2 - pons
3 - medulla
What connects the hindbrian and midbrain?
- tectum
- tegmentum
When we are looking at the forebrain, specifically the cerebral hemisphere, what are the fore lobes?
1 - frontal
2 - parietal
3 - temporal
4 - occipital
What are 3 poles of the brain?
1 - frontal (most rostral)
2 - occipital (most caudal)
3 - temporal
What are the 3 surfaces of the brain?
1 - medial
2 - inferior
3 - superolateral
Label the 2 major parts of the Prosencephalon, also called the forebrain?
- 1 = cerebral cortex
- 2 = thalamus
What is the term given to the cerebral cortex when we refer to the secondary vesicles that are formed?
- Telencephalon
Labels the different sulcus (sinking folds of the brain) and the gyrus (raised parts of the brain) using the labels below:
- lateral sulcus (separates temporal and parietal lobes)
- central sulcus (separates frontal and parietal lobes)
- pre-central gyrus (motor)
- postcentral gyrus (sensory)
- 1 = pre-central gyrus (motor)
- 2 = central sulcus (separates frontal and parietal lobes)
- 3 = postcentral gyrus (sensory)
- 4 = lateral sulcus (separates temporal and parietal lobes)
The cerebral cortex (grey matter) is separated by folds called gyrus and sulcus into functional areas, what are these functional areas called?
- broadmans areas
Subcortical (meaning below the cerebral cortex), also referred to as the subcortex, are collections of grey matter called nuclei. The 3 key parts of the diencephalon that make up the subcortical structures?
1 - thalamus
2 - hypothalamus
3 - basal nuclei
What is the main function of each of the 4 lobes?
1 - frontal = motor
2 - parietal = sensory
3 - temporal = auditory
4 - occipital = vision
Which lobe is the auditory cortex and olfactory cortex located in?
- temporal lobe
Which lobe is the somatosensory cortex located in?
- parietal lobe
Which lobe is the visual cortex located in?
- occipital
Which lobe is the Broca’s area in?
- frontal lobe
Which lobe is the primary motor cortex, responsible for control of motor activity, located in?
- frontal lobe
Which lobe is the gustatory cortex, responsible for taste located in?
- frontal lobe
The pre central gyrus and the post central gyrus, which are separated by the central sulcus. What are the the primary functions of the pre central and post central gyrus?
- pre central gyrus = primary motor area (blue in image)
- post central gyrus = primary sensory area (red in image)
How many broadman areas are there?
- 52
What is a lesion?
- any damage or abnormal change to tissue
Why is it helpful to be aware of all the different brodmann areas?
- if you locate a lesion or damage you can identify what it may affect on the opposite side of the body
What is frontal lobe syndrome?
- damage of higher functioning processes of the brain
- occurs in prefrontal cortex, which is part of frontal lobe (orange in pic)
Does the left and right side of the brain control the left and right side of the body?
- left side of brain = right side of body
- right side of brain = left side of body
When we look at the homunculus some areas of the brain appear to be associated with larger regions of the brain. Why do some parts of the body appear to have a greater representation in the brain than others?
- the skill level of the body part
- hands have a higher presentation than the knee in the brain
Label the 4 parts of the diencephalon, which is part of the forebrain?
corpus callosum
thalamus
fornix
hypothalamus
1 - thalamus
2 - hypothalamus
3 - corpus callouss
4 - fornix
The fornix, which is latin for arch, is a C-shaped bundle of white matter located superior to the thalamus and below the corpus callosum is part of the limbic system. What is the primary function?
- cognition, episodic memory recall, emotions and sexual responses.
The thalamus is a paired structure, where there is a thalamus on each hemisphere. What is the function of the thalamus?
- sensory relay function
- organises nearly all sensory info that comes into the brain
Label the structures highlighted in the image numbered 1-3?
1 - thalamus
2 - hypothalamus
3 - thalamus
What are the main functions of the hypothalamus?
- co-ordinates the ANS
- endocrine control (linked to pituatory gland)
- links nervous and endocrine systems
- thirst/hunger
- circadian
- linked to limbic system (emotions)
Label the structures identified in the image using the labels?
hypothalamus
thalamus
pineal gland (regulate melatonin)
pituitary gland
1 - thalamus
2 - hypothalamus
3 - pituitary gland
4 - pineal gland
What is the corpus callosum, latin for tough body?
- largest bundle of fibres in brain (tough fibres)
- commissural tract connecting left and right hemispheres
What are the 4 parts of the corpus callosum?
body
genu
isthmus
splenium
1 - genu
2 - body
3- isthmus
4 - splenium
There is a large white matter tract that forms the main highway for the input and output of the cerebral cortex. What is this called and where does it run?
- internal capsule which is where projection fibres run
- connects brain stem to cerebral cortex
Where is the most common site in the brain for an infarction or haemorrhage?
- internal capsule
- blood vessels that supply this area are end arteries
- can have significant clinical implications due to importance of the white matter tract (connect spinal cord and cerebral cortex)
What is the basal nuclei/ganglia?
- a collection of grey matter (cell bodies)
- composed of:
1 - substantia nigra (pars compacta = dopamine to striatum)
2 - thalamus
3 - internal/external globus pallidus
4 - striatum (caudate nucleus and putamen)
5 - sub thalamic nucleus
There are 4 groups of basal ganglia that are located within the Diencephalon. They are paired, so one on each side of the hemisphere and sit centrally in the brain next to the thalamus. Once we remove the thalamus, hypothalamus and corpus callosum, we can see them. Using the labels below, what are the numbers in the image labelled 1-4?
- head of caudate nucleus
- lentiform nucleus
- body of caudate nucleus
- tail of caudate nucleus
1 - body of caudate nucleus
2 - head of caudate nucleus
3 - lentiform nucleus (putamen and globus pallidus)
4 - tail of caudate nucleus
The image below shows a coronal and horizontal section of the brain, with 3 basal nuclei (collections of cell bodies) labelled, what are they?
1 - head of caudate nuclei
2 - lentiform (as it is shaped like a lentil) nucleus (putamen and globus pallidus)
3 - tail of caudate nuclei
The lentiform nucleus, is one of the basal ganglia located in the diencephalon. What 2 nuclei make up the lentiform nucleus?
- putamen and the globus pallidus
The caudate nucleus is the largest of the basal nuclei (collections of cell bodies) that is c shaped and extends all around the diencephalon. What are the 3 main parts of the the caudate nucleus labelled here 1-3?
1 - head (caput in latin)
2 - body (corpus in latin)
3 - tail (cauda in latin)
The caudate nuclei (collections of cell bodies), the largest of the basal nuclei with a head, body and tail located in the Diencephalon. Which ventricle is located directly below the caudate nucleus on each side of the hemisphere?
- lateral ventricles
What 2 key basal nuclei make up the corpus striatum?
1 - lentiform nucleus (putamen and globus pallidus)
2 - caudate nucleus
The lentiform nucleus is one of the 2 parts of the corpus striatum, along with the caudate nucleus. The lentiform nucleus is located within the Diencephalon and has 3 parts what are they?
1 - putamen (most lateral and largest)
2 - globus pallidus external (middle size)
3 - globus pallidus internal (most medial and smallest)
Label the parts of the basal ganglia using the labels below:
external globus pallidus
caudate nucleus
internal globus pallidus
subthalamic nucleus
substantia nigra
putamen
1 = caudate nucleus
2 = subthalamic nucleus
3 = substantia nigra
4 = internal globus pallidus
5 = external globus pallidus
6 = putamen
The substantia nigra (SN), is latin for black substance as it appears darker on imaging. What is the SN?
- a collection of cell bodies
- located inferiorly on brain stem close to the VTA
- important for reward and movement
The hippocampus is an important complex located in the temporal lobe that contributes to learning and memory, what sea creature does this resemble?
- seahorse
The limbic system can often be called the limbic lobe and creates a ring. What are the 2 secondary vesicles that are part of the forebrain that the limbic system covers?
- Telencephalon
- Diencephalon
The limbic system contributes to emotions in the brain. Label the main components of the limbic system using the labels below?
- hippocaampus
- fornix
- cingulate cortex
- thalamus
- amygdala
- mammillary bodies
- hypothalamus
1 - cingulate cortex
2 - fornix
3 - thalamus
4 - hypothalamus
5 - mammillary bodies
6 - amygdala
7 - hippocaampus
The fornix, latin for arch, makes up one component of the limbic system. It is a bundle of white matter fibres that arches around the thalamus. What is one of the key functions of the fornix?
- acts as a highway connecting parts of the limbic system
The fornix, latin for arch, makes up one component of the limbic system. It is a bundle of white matter fibres that arches around the thalamus. The fornix connects different parts of the limbic system. Using the labels below, what are the parts of the limbic system that the fornix connects?
- mammillary body
- body of fornix
- hippocampus
- amygdala
1 - body of fornix
2 - mammillary body
3 - amygdala
4 - hippocampus
What are the 3 key structures of the brainstem?
1 - midbrain
2 - pons
3 - medulla
The cerebral peduncles, often described as the feet of the brain. What is the purpose of the cerebral peduncles?
- anchors the cerebral hemisphere to the rest of the brain
- connects the pons to the forebrain/diencephalon
In the midbrain there are 2 colliculi, what are they called and what is their function? Numbered 1 and 2 in the image below
1 - superior colliculus – Visual reflexes
2 - inferior colliculus – Auditory reflexes
What is the main purpose of the pons?
- relays information to the cerebellum
What are some of the key features of the medulla oblongata?
- respiration
- cardiovascular control
What are the 2 key structures on the anterior surface of the medulla oblongata? Numbered 1 (an important tract) and 2 in image below.
1 - pyramid
2 - olive
The pryramid is part of the anterior surface of the medulla oblongata. What is the purpose of the pyramid?
- main voluntary motor pathway
- pyramids = corticospinal (voluntary movement)
- non-pyramidal = involuntary movement
The pryramids are part of the anterior surface of the medulla oblongata. This is the main voluntary pathway for voluntary movement. What is this called?
- corticospinal tract
Laterally to the pyramids on the anterior aspect of the medulla oblongata is what?
- olive
The olives are laterally to the pyramids on the anterior aspect of the medulla oblongata. What is their function?
- provide motor relay to the cerebellum
- formed by the olivary nuclei
What are the 2 key structures on the posterolateral surface of the medulla oblongata? Numbered 1 and 2 in image below.
1 - cuneate tubercle (half of the dorsal column nuclei)
2 - gracile tubercle (half of the dorsal column nuclei)
- caudate and gracile fascicles, white matter tracts in the spine that form the dorsal column
The 2 key structures on the posterolateral surface of the medulla oblongata are the cuneate and gracile tubercle. What does this go on to form?
- dorsal column nuclei
- location for the synapse in brain stem for the ascending tract dorsal column
What is the second largest part of the brain?
- cerebellum
Lebel the different parts of the cerebellum numbered 1-6?
- left hemisphere
- vermis
- flocculonodular lobe
- anterior lobe
- posterior lobe
- right hemisphere
1 - anterior lobe
2 - flocculonodular lobe
3 - posterior lobe
4 - vermis
5 - right hemisphere
6 - left hemisphere
The cerebellum is composed of 2 different type of matter (white and grey), what are their names and which is white and which is grey?
- white = arbor vitae (latin for tree of life)
- grey = cerebellar cortex
The cingulate cortex is a section of the cerebral cortex and is considered part of the limbic system. Where is this located in the brain?
- medial portion of the cerebral hemispheres
Label the ventricles in the brain numbered 1-4?
1 = lateral ventricle
2 = 3rd ventricle
3 = 4th ventricle
Does the cerebella or cerebellum have more neurons?
- cerebral = billions of neurons
- cerebellum = trillions of neurons
What are the 4 ventricles in the brain that secrete and contain CSF?
- lateral ventricles (x2)
- 3rd ventricle
- 4th ventricle
The lateral ventricles have 3 parts, using the labels below label the image 1-3?
- posterior horn
- anterior horn
- body
1 - anterior horn
2 - body
3 - posterior horn
The choroid plexus is located in the 4 ventricles in the brain, lateral (x2), 3rd and 4th ventricles. What is the choriod plexus?
- secretory tissue that secretes CSF
What does the mnemonic On Occasion Our Trusty Truck Acts Funny Very Good Vehicle Any How relate to cranial nerves (CN)?
- On = CN I (1) Olfactory
- Occasion = CN II (2) Optic
- Our = CN III (3) Oculomotor
- Trusty = CN IV (4) Trochlear
- Truck = CN V (5) Trigeminal
- Acts = CN IV (6) Abducens
- Funny = CN VII (7) Facial
- Very = CN (8) Vestibulocochlear
- Good = CN IX (9) Glossopharyngeal
- Vehicle = CN X (10) Vagus
- Any = CN XI (11) Accessory
- How = CN XII (12) Hypoglossal
The mnemonic On Occasion Our Trusty Truck Acts Funny. Very Good Vehicle Anyhow relate to cranial nerves (CN) below.
- On = CN I (1) Olfactory
- Occasion = CN II (2) Optic
- Our = CN III (3) Oculomotor
- Trusty = CN IV (4) Trochlear
- Truck = CN V (5) Trigeminal
- Acts = CN IV (6) Abducens
- Funny = CN VII (7) Facial
- Very = CN VIII (8) Vestibulocochlear
- Good = CN IX (9) Glossopharyngeal
- Vehicle = CN X (10) Vagus
- Any = CN XI (11) Accessory
- How = CN XII (12) Hypoglossal
What is the mnemonic to remember if the CN are sensory, motor or both?
- Some = S = sensory CN I (1)
- Say= S = sensory CN II (2)
- Marry = M = motor CN III (3)
- Money = M = motor CN IV (4)
- But = B = both CN V (5)
- My = M = motor CN VI (6)
- Mum = M = motor CN VII (7)
- Says = S = sensory CN VIII (8)
- Big = B = both CN IX (9)
- Brains = B = both CN X (10)
- Matter = M = motor CN XI (11)
- More = M = motor CN XII (12)
The substantia nigra (SN), is latin for black substance as it appears darker on imaging. It is a collection of cell bodies located superiorly on brain stem close to the VTA and is important for reward and movement. There are 2 parts to the SN, what are they?
In the cerebellum possesses 3 pairs of peduncles, which are white matter that act as connections. What are the 3 pairs of peduncles called and what is the function of each?
- anterior peduncle = connects cerebellum with midbrain
- middle peduncle = connects cerebellum with the pons
- inferior peduncle = connects cerebellum with medulla
