SPINAL CORD AND BRAIN Flashcards
What are the functions of the spinal meninges
To protect the spinal cord from the bony vertebral column and vascularise the spinal cord
What is the cauda equina and why does it exist?
A bundle of long spinal nerves. The spinal cord ends at L1-2 because the vertebral column grows faster then the spinal cord. The cauda equina allows for the spinal nerves to extend down to the lower limbs.
Where is the epidural space
Between the dura mater and the periosteum. In this space is nerve roots supplying the pelvis and lower limbs
Why are there larger diameters at the cervical and lumbar areas of the spinal cords
To accomodate for the nerve inputs of the brachial and lumbosacral plexus.
Explain the neural pathway of movement without conscious thought
Sensory neurons relay to a motor neuron in the spinal cord via an interneuron. Therefore movement can be performed without conscious thought as the nerve information does not travel to the brain.
This is the case for the patellar and pain reflexes
What is the filum terminale
Not a nerve. It is a modified band of pia mater, 20 cm long
In between conus medullaris (end of spinal cord) and1st coccygeal bone.
Provides stability to spinal cord within vertebral canal
What are the differences between cranial and spinal nerves
Cranial: exit cranial cavity through foramina, relate to special senses
Spinal: (exception of C1) arise from spinal cord and exit via intervertebral foramina. 31 bilateral pairs that have both sensory and motor neurons
Why are there 8 cervical spinal nerves if there are only 7 cervical vertebrae
1st cervical nerve is superior to atlas (C1). The rest exit between vertebrae. Making 8 in total
What is the role of the intercostal nerves
Somatic nerves that control:
intercostal muscles
thoracic pleura
abdominal peritoneum
anterior abdominal wall muscles
Explain the characteristics of the median nerve
C6-T1: Lateral and medial cords
Motor:
Superficial and deep flexors of anterior forearm compartment
Some intrinsic hand muscles
Sensory skin:
Anterolateral surface of hand
Explain the characteristics of the ulnar nerve
C8 + T1 + C7: Medial cord
Motor: Some anterior forearm muscles Ulnar 1/2 flexor digitorum profundus Flexor carpi ulnaris Deep head of flexor pollicis brevis Intrinsic hand muscles
Sensory skin:
Medial edge of hand
Explain the characteristics of the radial nerve
C5-T1: Posterior cord
Motor:
Extensor muscles of posterior compartment of arm and forearm
Sensory skin:
Posterior arm and forearm
Dorsum of hand
Explain the characteristics of the femoral nerve
L2-L4
Motor:
Anterior thigh compartment
Hip flexors
Knee extensors (except Psoas major)
Sensory skin:
Over anteromedial surface of thigh
Medial surface of leg and foot
Explain the characteristics of the sciatic nerve
L4-S3
Motor:
Posterior thigh compartment by tibial division of sciatic nerve
Explain the characteristics of the common fibular nerve
Motor:
Deep part = anterior leg compartment (dorsiflexors)
Superficial part: Lateral leg compartment (eversion)
Short head of biceps femoris (Posterior thigh)
Sensory skin:
lateral leg
dorsum of foot and digits
Explain the characteristics of the tibial nerve
Motor:
Superficial and deep posterior leg compartments
Plantarflexion, inversion, leg flexion at knee
Sensory skin:
Posterolateral leg
Plantar surface of foot + digits
Describe what components make up the parts of the brain
Forebrain: Diencephalon and cerebrum
Midbrain: Mesencephalon
Hindbrain: Cerebellum, pons, medulla oblongata
Brainstem: Mesencephalon, pons, medulla oblongata
Spinal cord: Spinal cord, inferior to medulla oblongata
What is the grey and white matter
grey: cell bodies
White myelinated axons
In brain: white on inside for more direct neuronal pathway
In spinal cord: white on outside
CN 1: Olfactory nerve
SENSORY
Detects smell from olfactory area in nasal cavity
CN 2: Optic nerve
SENSORY
Carries visual info from retina to
CN 3: Oculomotor nerve
MOTOR
Controls intra and extra ocular muscles for eye movement
CN 4: Trochlear nerve
MOTOR
Controls 1 superior extra ocular muscle for eye movement
CN 5: Trigeminal nerve
SENSORY AND MOTOR
Sensory:
Faces, sinuses, teeth, gums, lips, palate
Motor:
Muscles of mastication
CN 6: Abducens nerve
MOTOR
Controls 1 lateral extra ocular muscle for eye movement
CN 7: Facial nerve
SENSORY AND MOTOR
Sensory:
Detects taste from anterior 2/3 of tongue
Motor: Muscles of facial expression
CN 8: Vestibulocochlear nerve
SENSORY
Responsible for hearing, cochlear branch, responsible for orientation and balance
CN 9: Glossopharyngeal nerve
SENSORY AND MOTOR
Sensory:
Detects taste from posterior 1/3 of tongue, sensation of pharynx, sinus, middle ear cavity
Motor:
Stylopharangeus muscle, paratoid gland
CN 10: Vagus nerve
SENSORY AND MOTOR
Sensory:
Pharynx, larynx, bronchial tree, lungs, heart, upper GI tract
Motor:
Palate, pharynx, larynx, trachea and bronchial tree, heart, upper GI tract
CN 11: Spinal accessory nerve
MOTOR
Sternocleidomastoid and trapezius muscles
CN 12: Hypoglossal nerve
MOTOR
Intrinsic and extrinsic muscles of the tongue
What are the first 3 bulges of the neural tube and what do they become
Prosencephalon
telencephalon
diencephalon
Mesencephalon
mesencephalon
Rhombencephalon
metencephalon
myelencephalon
What are the 4 lobes of the cerebrum/telencephalon and what are they responsible for
Frontal: personality, behaviour, speech, movement
Parietal: Touch, pain, temperature
Occipital: Vision
Temporal: hearing
What are nuclei when talking about the nervous system
Nuclei is an aggregation of cell bodies in the white matter (grey spots in white matter)
What is the diencephalon made up of
Thalamus
hypothalamus
epithalamus
subthalamus
inner part of brain associated with limbic system (emotional system)
What 3 parts is the mesencephalon (midbrain) made up of
colliculi
tegmentum (inside)
cerebral peduncles (outside)
What are the metencephalon and the myelencephalon of the rhombencephalon made up of and function for
Metencephalon:
pons (regulates breathing)
cerebellum (coordinates movement)
Myelencephalon (medulla oblongata): Controls respiration from receptors, vomiting, coughing, sneezing
Outline the blood of the circle of willis
Receives blood from:
2 vertebral arteries (right and left)
two internal carotid arteries (right and left)
Supplies cerebrum by:
anterior/ middle/ posterior cerebral artery
supplies cerebellum by:
superior/ anterior inferior/ posterior inferior cerebellar artery