home assignment neuroanatomy

Question 1

Which 5 main brain subdivisions arise from the neural tube vesicles?

Answer 1

Telencephalon, Diencephalon, Mesencephalon, Metencephalon, Myelencephalon

Question 2

In Purves Fig. A2, the central nervous system is divided on basis of structures that can be recognized in all mammals. Which seven major structures are used?

Answer 2

Spinal cord, medulla, pons, cerebellum, midbrain, diencephalon, cerebral hemispheres.

Question 3

Which brain structure shows particularly strong developmental characteristics in the human brain?

Answer 3

Cerebral cortex

Question 4

What component of the ventricular system do we encounter in:

telencephalon -
diencephalon -
mesencephalon -
metencephalon -
myelencephalon -

Answer 4

telencephalon diencephalon- Ventricle I/II Ventricle III
mesencephalon- Cerebral aqueduct
metencephalon- Ventricle IV
myelencephalon- Ventricle IV

Question 5

What kind of neurological deficits would you expect to see if the 7th cranial nerve is damaged?

Answer 5

(among others) Paralysis of the facial muscles

Question 6

You are having a cavity filled and your dentist says that he caters to cowards. Since you’re not in a heroic mood you accept the anesthesia. (Branches of) Which cranial nerve will the dentist try to target?

Answer 6

Trigeminal nerve (Nervus trigeminus), branches V-2 (n. maxillaris) or V-3 (n. mandibularis).

Question 7

What are gyri and sulci?

Answer 7

Gyri are bulges or bumps in cortex lying between sulci; the sulci are grooves that separate the gyri

Question 8

What are hemispheres?

Answer 8

The two sphere-like structures with foldings and grooves, that constitute the telencephalon and/or the cerebellum.

Question 9

What sensory dysfunctions will result from a damage to the Spinothalamic tract?

Answer 9

Pain, temperature on contralateral side of the body are affected.

Question 10

What sensory dysfunctions will result from a damage to the cranial nerve 5?

Answer 10

Trigeminal nerve > Pain, temperature, ipsilateral in the face.

Question 11

What is the capsula interna?

Answer 11

A large structure consisting of only white matter in which axons run from cortex to brainstem, spinalcord (NB corticospinal tract) and thalamus and from thalamus and brain stem to cortex (NB sensory fiber tracts).

Question 12

Is the thalamus located lateral or medial to the capsula interna?

Answer 12

Thalamus lies medial to the internal capsule.

Question 13

Via which fiber connections and which brain nucleus does visual information reach the cerebral cortex?

Answer 13

Optic nerve (Nervus opticus), optic chiasma (chiasma opticum), optic tract (tractus opticus), Lateral geniculate nucleus (corpus geniculatum laterale), optic radiation (radiatio optica).

Question 14

In (and around) which sulcus do you find the primary visual cortex? Which Brodmann area constitutes the primary visual cortex?

Answer 14

Calcarine fissure (Sulcus calcarinus). Area 17.

Question 15

The anatomical organization of the visual pathways and somatosensory system are very similar in a general aspect? What aspect is alluded to?

Answer 15

Organizational principle: sensory organ, afferent fiber connection to brain, relay in thalamus, (sensory)
axons from thalamus to cortex.

Question 16

The colliculus superior is involved in what aspect of vision?

Answer 16

Localizing an object in visual space and generating object related reflexory eye movements and movements of head and upper body.

Question 17

The left LGN receives information from which part of the visual field?

Answer 17

Right visual field

Question 18

The primary auditory cortex lies in which lobe and in which gyrus?

Answer 18

Temporal lobe, Superior temporal gyrus (gyrus temporalis superior).

Question 19

The vestibular information arrives in which brain nuclei?

Answer 19

Vestibular nuclei

Question 20

Which cortical areas receive vestibular information and in which functions do these areas partake?

Answer 20

Parietal cortical regions, within and posterior to the primary somatosensory cortex. Areas process proprioceptive, visual and vestibular stimuli.

Question 21

Which two features make the olfactory system unique in comparison to the other sensory systems?

Answer 21

The olfactory output from the sensory organ does NOT reach the thalamus before it arrives in cortex. Topographical organization is apparently absent, i.e. a topographical map of scent has not been found yet.

Question 22

The pathway from solitary nucleus to the amygdala and hypothalamus in Purves Fig. 15.20 B is implicated in which function?

Answer 22

Carrying taste information to areas involved in: e.g. appetite, satiety (motivation).

Question 23

Where is the corticospinal tract between the cortex and the mesencephalon?

Answer 23

In the Capsula interna.

Question 24

Which nuclei belong to the Basal Ganglia?

Answer 24

Caudate nucleus (nucleus caudatus), putamen, globus pallidus, subthalamic nucleus (nucleus
subthalamicus) and substantia nigra.

Question 25

Which components of the Basal Ganglia are localized lateral to the internal capsule?

Answer 25

Putamen, Globus pallidus.

Question 26

The thalamus is engaged in central motor control via which connections?

Answer 26

Thalamus receives input from Basal Ganglia via Globus pallidus and projects to Frontal cortex

Question 27

Describe the connections via which the cerebellum exerts motor control

Answer 27

Input to Cerebellum from: Cerebral cortex (via Pons) [Motor plan], Spinal cord roprioception], Vestibular nuclei [Balance] and Oliva inferior [modulatory influence on Cerebellum] Output to Thalamus (VL complex) [influences motor cortex], red nucleus (nucleus ruber) [motor control of the rubrospinal tract], vestibular nuclei [motor control of
estibulospinal tract], colliculus superior [ motor control of colliculospinal tract].

Question 28

The afferent connections of the cerebellum run in which anatomical structures?

Answer 28

The cerebellar peduncles

Question 29

Which cortical regions, descending pathways, brain stem nuclei and cranial nerves enable you to
- willfully swallow?
– stick out your tongue?

Answer 29

• willfully swallow? Motor cortex (lateral), connections between cortex (via capsula interna) to cranial
  nerve nuclei IX, X and XII. – stick out your tongue? Motor cortex, Nervus XII.

Question 30

How can you distinguish cervical from thoracic sections through the spinal cord?

Answer 30

Cervical sections feature a large volume of grey matter because the motor and sensory control of the upper extremities originates at this level. At the thoracic level the motor and sensory control of the trunk originates. At the lumbar and sacral level we see the same pattern as in cervical levels. The major difference between on the one hand lumbar/sacral and on the other cervical is that at the caudal levels only 1 of the 2 dorsal columns is present: the fasciculus gracilis, which carries mechanosensory information coming from the legs.

Question 31

Broca’s area is situated in what gyrus?

Answer 31

Gyrus frontalis inferior.

Question 32

The fornix is a brain structure involved in memory processing (Purves Fig. 30.9). What exactly is its function?

Answer 32

Hippocampus projects via the Fornix to the Hypothalamus. Hence, the Fornix is purely a fiber bundle that carries memory-related information to the hypothalamus, viz. The mammillary bodies. The fact that the latter
structure degenerates in Korsakoff’s syndrome suggests that it is involved in memory formation.

Question 33

Lesions of specific nuclei in the thalamus of humans and monkeys result in memory disturbances. Explain these memory disturbances on basis of the anatomical connections of this brain region (thalamus)

Answer 33

The lesion sits in the nucleus anterior of the thalamus. This nucleus receives input from the mammillary bodies and is part of the limbic circuitry involved in memory formation via its output to the cingulate gyrus.

Question 34

Via which connections can the Amygdala control autonomous processes like perspiration, cardiac rhythm, breathing frequency that change dramatically in fearful and stressful situations.

Answer 34

Output to Hypothalamus and Autonomous centers in the reticular formation.