Nervous System Prac Test

Identify the 8 cranial bones of the skull.

Cranial Stutures & Junctions

• The frontal and parietal bones? Coronal

• The parietal and occipital bones? Lambdoid

• Between parietal bones? Sagittal

• Nasion (joins the nasal part of the frontal bone and the nasal bone) 

• Pterion (joins frontal, parietal, temporal and sphenoid bones) 

• Bregma (joins frontal and parietal bones) 

• Lambda (joins occipital and parietal bones) 

Cranial fossa

Anterior, middle, and posterior.

Identify cranial foramina associated with cranial nerves and blood supply

• Corpus collosum

• Thalamus

• Hypothalamus

Corona radiata

Cerebral peduncles

Brain stem

• Olive

• Pyramids

• Mid brain

• Pons

• Medulla oblongata

• Superior (visual) and inferior (auditory) colliculi

What is ‘closed’ vs ‘open’ medulla referring to?

The "open" medulla is where the fourth ventricle opens, forming the dorsal surface, while the "closed" medulla is where the fourth ventricle is surrounded by the medulla, and the central canal is still enclosed. 

Circle of Willis

• 3x cerebral arteries – which regions of the cortex do they supply?

• 3x cerebellar arteries.

• 3x communicating arteries.

• 3x ‘other’ arteries (basilar, vertebral, ICA)

  

Sinuses

• Superior sagittal sinus

• Inferior sagittal sinus

• Straight sinus

• Transverse sinus

• Sigmoid sinus

Sinuses & CSF

• Cerebrospinal fluid (CSF) circulates within the subarachnoid space, the area between the arachnoid and pia mater layers of the meninges

• It is reabsorbed into the venous system via dural venous sinuses through the arachnoid granulations.

Spinal cross section (1)

Spinal cross section (2)

What information is transmitted via each peduncle?

• Middle Cerebellar Peduncle:

  Transmits cortico-ponto-cerebellar afferent fibers from the cerebral cortex to the cerebellum via the pons. 

• Superior Cerebellar Peduncle:

  Transmits efferent fibers from the cerebellum to the red nucleus and thalamus, particularly the ventrolateral nucleus, which then influences the rubrospinal and corticospinal systems. 

• Inferior Cerebellar Peduncle:

  Carries both afferent and efferent fibers. Afferents include spinocerebellar, medullocerebellar, and vestibular fibers, while efferents connect the cerebellum to the vestibular and reticular nuclei. 

Would a lesion of the left cerebellar hemisphere have ipsilateral or contralateral effects in the spinocerebellar pathway?

Ipsilateral effects in the spinocerebellar pathway, meaning that the symptoms (such as limb ataxia) would be on the left side of the body. The cerebellum processes information about the body's movement on the same side of the body,

Anterior thalamic nuclei

How does the limbic system work together to form the Papez circuit?

Identify the amygdala in coronal slices.

Which structure is posterior to the amygdala?

How might this relationship impact the creation of memories?

The hippocampus is posterior and caudal to the amygdala.

The amygdala adds emotional significance to memories, making them more vivid and enduring. It's essential for recognizing and remembering emotionally salient events. 

globus pallidus

component of the basal ganglia that connects to the thalamus which relays information to the motor areas and the prefrontal cortex

Putamen

regulate movements and influence various types of learning

internal capsule brain

subthalamic nucleus

a small nucleus, located ventral to the thalamus, that is part of the basal ganglia (anterior to red nucleus)

corpus callosum

caudate nucleus - part of basal ganglia

lateral ventricles

3rd ventricle

tentorium cerebelli

separates cerebrum from cerebellum

anterior lobe of cerebellum upper half

Lobe of cerebellum that is separated from anterior via primary fissure (bottom half)

posterior lobe of cerebellum

vermis of cerebellum

The tissue between the two cerebellar hemispheres: concerned with regulation of muscle tone for posture and locomotion.

Nodule of cerebellum

has important connections to the vestibular nuclei and uses information about head movement to influence eye movement

flocculonodular lobe of cerebellum

part of the vestibulo-ocular reflex system and is used to help stabilize gaze during head rotation about any axis of space.

tonsil of cerebellum - planning of motor activity

cerebellar peduncles

4th ventricle

Thalamus

Hypothalamus

hypothalamic sulcus

separates thalamus from hypothalamus

mammillary body

16

thalamic adhesion

pineal gland - regulates melatonin

interpeduncular fossa - space between cerebral peduncles.

red nucleus

(red circle) - motor coordination

substantia nigra

uncus - on medial surface of temporal lobe (olfactory area)

optic chiasm

optic tract

Hippocampus

fornix- a fiber tract that extends from the hippocampus to the mammillary body

Amygdala- fear and aggression

cingulate cortex - emotional and motor processing (cognition)

longitudinal fissure

lateral fissure (sylvian fissure)

central sulcus

Pre-occipital notch

parieto-occipital sulcus

M1

primary motor cortex (precentral gyrus)

S1

primary somatosensory cortex

olfactory bulb

brocas area - controls language expression - an area, usually in the left frontal lobe, that directs the muscle movements involved in speech.

Wernicke's area - language comprehension

olfactory nerve

optic nerve

Oculomotor Nerve (III) - narrows pupil and focuses lens

Trochlear Nerve (IV) - eye movement

Trigemminal Nerve

Abducens Nerve (VI) - lateral eye movement

Facial Nerve (VII) - Movement of facial expression muscles, taste (from anterior 2/3 of tongue)

Vestibulocochlear (VIII) - Equilibrium and Hearing (Special Somatic Sensory)

glossopharyngeal nerve (IX)

vagus nerve

Hypoglossal Nerve (XII) - Controls muscles of tongue

Accessory nerve (XI) - controls trapezius & sternocleidomastoid

controls swallowing movements

dorsal horn of spinal cord

cell bodies synapsed by afferent neurons (sensory)

ventral horn of spinal cord

The upper motor neurons that control the skeletal muscles are found in

lateral horn of spinal cord

Contains the cell bodies of the preganglionic ANS neurons

dorsal column

a white matter tract on the dorsal side of the spinal cord, carrying fine touch and proprioceptive axons to the brain stem

spinothalamic tract

pain and temperature

corticospinal tract

What tract is responsible for voluntary refined movements of distal extremities?

dorsal rootlets

ventral rootlets

spinal nerves

central canal of spinal cord

ventral white comissure

Dorsal Root Ganglion (DRG)

associated with the dorsal horns; cell bodies of sensory neurons are located here

filum terminale. - extension of piamater

conus medullaris

denticulate ligaments

extensions of pia mater that secure cord to dura mater

cauda equina

collection of spinal nerves below the end of the spinal cord (L2 onwards)

rubrospinal tract

locomotion and postural control.

lower motor neurons

ventral horn motor neurons, innervate skeletal muscles

decussation of corticospinal tract

medulla - in the pyramids

Decussation of dorsal column

also medulla - but medial lemniscus.

decussation of spinothalamic tract

spinal cord - white commissure

Diencephalon

thalamus, hypothalamus, epithalamus, subthalamus

basal ganglia - intentional movements

Midbrain

Pons

Medulla Oblongata