L8: Basic Topography of the Brain, Spinal Cord and Peripheral Nerves Flashcards
Label the sections of the brain using the following options:
- Cerebellum
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
- Central sulcus
What are the sulci?
- Sulci (sulcus for singular) are the grooves that cover the brain’s external surface and are used as landmarks in anatomy
What are the fissures of the brain?
- Fissures are deeper grooves that separate large regions of the brain e.g. longitudinal fissure, which separates the two hemispheres
What are the gyri?
Gyri (gyrus for singular) are the raised portions of the brain
What parts of the brain does the central sulcus divide?
Frontal lobe from the parietal lobe
What does the longitudinal fissure separate?
The left and right hemispheres of the brain
What does the central sulcus separate?
The frontal from parietal lobes
What does the lateral sulcus separate?
The temporal lobe from the parietal and frontal lobes
What does the transverse fissure separate?
The occipital lobes from the cerebellum
What is the dura?
- Located within the longitudinal and transverse fissures
- A tough membranous fold
The most outer layer of the meninges
What is the function of the dura?
- Carries venous blood from the brain back to the body within gaps (sinuses) within the dura
Label the diagram using the following options:
- Cerebrum
- Midbrain
- Pons
- Medulla Oblongata
- Cerebellum
- Corpus callosum
What is the function of the cerebellum?
Involved in movement coordination and posture
What is the function of the diencephalon?
Involved in regulation of the autonomic and endocrine systems
What is the function of the brainstem?
Involved in sensory-motor relays and vital autonomic function
What is the function of the spinal cord?
Relays information from the body to the brain
What is the function of the cerebral hemispheres?
Responsible for processing and memory
What are the parts of the brainstem and where are they found?
- Midbrain, pons and medulla oblongata
- Inferior part of the brain and connected to the spinal cord
Label the parts of the brainstem from the following options:
- Pons
- Midbrain
- Medulla
- Pituitary gland
Which part of the brainstem is continuous with the spinal cord?
Medulla oblongata is continuous with the spinal cord
Label the sections of the brain using the following options:
- Corpus callosum
- Internal capsule
- Basal ganglia
- Thalamus
- Third ventricle
- Temporal lobe
- Lateral ventricle
- Insula lobe
What is cranial nerve I and the function?
- Olfactory
- Smell
- Sensory
What is cranial nerve II and the function?
- Optic
- Sight
- Sensory
What is cranial nerve III and the function?
- Oculomotor
- Eye movement
- Motor
What is cranial nerve IV and the function?
- Trochlear
- Eye movement
- Motor
What is cranial nerve V and the function?
- Trigeminal
- Sensory of the face and motor mastication (chewing)
- Sensory and motor
What is cranial nerve VI and the function?
- Abducens
- Lateral eye movement (lateral rectus m.)
- Motor
What is cranial nerve VII and the function?
- Facial
- Facial movement and expression
- Sensory and motor
What is cranial nerve VIII and the function?
- Vestibulocochlear
- Hearing and balance
- Sensory
What is cranial nerve IX and the function?
- Glossopharyngeal
- Tongue and pharynx sensory supply (taste and swallowing)
- Sensory and motor
What is cranial nerve X and the function?
- Vagus
- Pharynx and larynx (parasympathetic innervation to the majority of the abdominal organs)
- Sensory and motor
What is cranial nerve XI and the function?
- Accessory
- Neck and shoulders
- Motor
What is cranial nerve XII and the function?
- Hypoglossal
- Motor of tongue
- Motor
Label the diagram of the cranial nerves from the following options:
- Optic
- Accessory
- Trochlear
- Medulla
- Pituitary stalk
- Olfactory
- Pons
- Abducens
All but two pairs of cranial nerves are attached to the brainstem. Which are the exceptions?
Cranial nerves I and II
Label the areas of the spinal cord from the following options:
- Central canal
- Dorsal horn
- Ventral horn
- Dorsal column
What is found in the dorsal and ventral horns?
Cell bodies of sensory (afferent) and motor (efferent) neurons, there is also a lateral horn in some sections of the spinal cord
Label the diagram of the spinal cord and associated nerves from the following options:
- Dorsal root
- Dorsal root ganglion
- Motor neuron
- Sensory neuron
- Spinal nerve
- Ventral root
Considering what you know about the contents of the dorsal and ventral horns, explain why the dorsal and ventral horns change in size at different levels?
Extra neurons and larger to supply the limbs e.g. lumbar and sacral (lots of grey matter)
Small amount on white matter in sacral - number of nervous fibres reduces as more distal to the CNS containing fewer ascending and descending nervous fibres.
Need to supply the limbs in lumbar and cervical, hence more white matter
Identify on the bones and name where the spinal cord lies protected by the bony column
The spinal cord is enclosed by the vertebral canal
The spinal nerves come out from the spinal cord through intervertebral foramina
A single section of the vertebrae is called an isolated vertebra
How do spinal nerves leave the protection of the vertebral column?
Through the intervertebral foramina
What are dorsal and ventral rami? What kind of nerve fibres do they carry?
- Rami (singular ramus) is a branch
- They are mixed (afferent, efferent and sometimes autonomic fibres)
- Each spinal nerve divides into a number of rami (branches); the first, purely sensory, and very small branch is the meningeal ramus; then the dorsal (posterior) ramus comes off to leave the physically larger ventral (or anterior) ramus
Apart from the spinal cord, what are the contents of the vertebral canal?
- Cerebrospinal fluid
- Connective tissue
- Blood supply (vessels)
Looking at the isolated spinal cord. What is the cauda equina?
Terminal cluster of roots composed of the posterior and anterior roots of lumbar, sacral and coccygeal nerves
At what vertebral level does the cauda equina begin?
L1
How many spinal nerves are there and how are they named?
- 31 pairs of spinal nerves
- Named using Roman numerals between C1-C8, T1-T12, L1-5, S1-5
- Only 30 dermatomes - facial sensations supplied by the cranial nerves
Define the term dermatome
The area of skin supplied by a single spinal cord level, or on one side, by a single spinal nerve pair
What is the muscle group and deficit from the phrenic spinal nerve?
- Diaphragm
- Inability to breathe
What is the muscle group and deficit from the median spinal nerve?
- Forearm flexors, lateral 3 1/2 digits
- Median claw hand
What is the muscle group and deficit from the ulnar spinal nerve?
- Flexor carpi ulnaris and flexor digitorum profundus in the forearm, and hypothenar muscles (forearm).Forearm extensors, median 1 1/2 digits (fingers)
- Ulnar claw hand
What is the muscle group and deficit from the femoral spinal nerve?
- Thigh and hip flexor muscles (the psoas major and iliacus muscles).Anterior compartment of the thigh
- Muscle paralysis - loss of knee extension
What is the muscle group and deficit from the sciatic spinal nerve?
- Posterior compartment of the thigh, lower leg and foot
- Muscle paralysis - Loss of knee flexion, movement of lower leg and foot
