Lesson 8 Spinal Cord Flashcards
What nerve roots originate the common fibular (peroneal) nerve?
L4, L5, S1, S2, S3
The common fibular nerve is part of the lumbosacral plexus.
Which muscle does the common fibular nerve supply?
Biceps femoris (short head)
The common fibular nerve is responsible for innervating this specific muscle.
What is the origin of the deep fibular nerve?
Common fibular (peroneal) nerve
This nerve innervates muscles in the anterior compartment of the leg.
List the muscles innervated by the deep fibular nerve.
- Tibialis anterior
- Fibularis tertius
- Extensor digitorum longus
- Extensor hallucis longus
- Extensor digitorum brevis
These muscles are primarily responsible for dorsiflexion and toe extension.
What is the sensory innervation provided by the deep fibular nerve?
Great and second toes
This nerve provides sensation to the skin in this region.
What muscles does the superficial fibular nerve supply?
- Fibularis longus
- Fibularis brevis
These muscles are involved in plantar flexion and eversion of the foot.
What area does the superficial fibular nerve provide cutaneous innervation to?
Dorsal anterior third of leg and dorsum of the foot
This nerve supplies sensation to the skin over these areas.
What is the origin of the tibial nerve?
L4 through S3
The tibial nerve arises from the lumbosacral plexus.
List the muscles innervated by the tibial nerve.
- Adductor Magnus
- Biceps femoris (long head)
- Semimembranosus
- Semitendinosus
- Popliteus
- Gastrocnemius
- Soleus
- Flexor digitorum longus
- Flexor hallucis longus
- Tibialis posterior
These muscles are involved in knee flexion and foot plantar flexion.
What are the cutaneous innervations provided by the sural nerve?
Lateral foot anteriorly and posterior leg and foot
The sural nerve provides sensory innervation to these regions.
What is the function of the spinal cord?
Carries out integrative functions and communicates with the brain
The spinal cord is part of the central nervous system.
What structures are associated with each spinal segment?
A pair of spinal nerves
Each spinal segment has a predictable organization of gray and white matter.
What is the cauda equina?
A tuft of nerves below the lumbosacral enlargement
It consists of the nerve roots that extend below the termination of the spinal cord.
What are the three meningeal membranes surrounding the spinal cord?
- Dura mater
- Arachnoid mater
- Pia mater
These membranes protect the spinal cord and provide structural support.
What is the gray matter of the spinal cord shaped like?
A butterfly
The gray matter consists of nerve cell bodies and is surrounded by white matter.
What is the anterior median fissure?
A deep invagination in the anterior column of the spinal cord
It separates the two halves of the spinal cord.
What is the role of sensory neurons in the reflex arc?
They synapse with interneurons or directly with motor neurons
This allows for rapid response to stimuli.
True or False: The stretch reflex involves a sensory neuron, an interneuron, and a motor neuron.
True
In a monosynaptic reflex, the sensory neuron connects directly to the motor neuron.
What is the function of the femoral nerve?
Innervates muscles that extend the knee
It originates from L2, L3, and L4.
What does the sciatic nerve consist of?
Tibial and common fibular (peroneal) nerves
These two nerves are bound together within the same sheath in the thigh.
What is the origin of the quadriceps femoris muscle?
Pelvis
The quadriceps femoris muscle originates from the pelvis and becomes the patellar tendon and ligament with the patella inside.
What sensory structure is marked as 1 in the context of the quadriceps femoris muscle?
Muscle spindle
The muscle spindle is where the sensory stimulus originates.
What is the role of the alpha motor neuron in the stretch reflex?
Innervates muscle fibers
The alpha motor neuron receives synapses from sensory neurons and is responsible for muscle contraction.
Fill in the blank: The __________ reflex is shown by the extension of the leg.
Stretch
The stretch reflex results in the extension of the leg.
What is the function of the Golgi tendon organ?
Detects tension in tendons
The Golgi tendon organ sends sensory signals to the spinal cord in response to increased tension.
What is the origin of the axillary nerve?
Posterior cord of brachial plexus
The axillary nerve arises from the posterior cord and innervates specific muscles in the shoulder.
Which muscles are innervated by the radial nerve?
- Long head of triceps brachii
- Lateral head of triceps brachii
- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Anconeus
- Supinator
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Extensor indicis
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
The radial nerve controls movement and sensation in the posterior arm and forearm.
True or False: The ulnar nerve innervates the flexor carpi ulnaris.
True
The ulnar nerve supplies the flexor carpi ulnaris and other muscles in the forearm.
What is the primary function of the median nerve?
Controls forearm flexors and hand muscles
The median nerve innervates various muscles including the thenar muscles and flexor digitorum superficialis.
List the nerve roots that form the obturator nerve.
- L2
- L3
- L4
The obturator nerve emerges from the lumbosacral plexus and innervates specific thigh muscles.
What is the origin of the femoral nerve?
L2, L3, L4
The femoral nerve originates from the lumbar plexus and innervates the anterior compartment of the thigh.
What are the major branches of the brachial plexus?
- Axillary nerve
- Radial nerve
- Musculocutaneous nerve
- Median nerve
- Ulnar nerve
These branches innervate various muscles of the shoulder, arm, and hand.
Fill in the blank: The __________ nerve originates from L5 and supplies the gluteal muscles.
Superior gluteal
The superior gluteal nerve innervates the gluteus medius and minimus.
What is the function of the inferior gluteal nerve?
Innervates gluteus maximus
The inferior gluteal nerve is responsible for the motor function of the gluteus maximus muscle.
What does the term ‘lumbosacral trunk’ refer to?
Nerve roots from L5
The lumbosacral trunk connects the lumbar and sacral plexuses.
True or False: The sciatic nerve is the largest nerve in the body.
True
The sciatic nerve is formed from L4 to S3 and innervates the posterior thigh and all of the leg and foot.
What is the sensory innervation of the ulnar nerve?
Medial third of hand
The ulnar nerve provides sensory innervation to the little finger and the medial half of the ring finger.
What is the cutaneous distribution of the median nerve?
Lateral two-thirds of the palm
The median nerve provides sensory innervation to the thumb, index, middle fingers, and part of the ring finger.
What gives out branches that combine with other nerve roots to form the nerves?
Nerve root
Nerve roots emerge from the spinal cord and are responsible for forming the peripheral nerves.
Which nerves branch from C1 and C2?
Lesser occipital nerve
The lesser occipital nerve is involved in sensory innervation of the scalp.
What nerve branches from C2 and C3?
Greater auricular nerve
This nerve provides sensory innervation to parts of the ear and skin over the parotid gland.
Which nerve supplies the sternocleidomastoid muscle?
Nerve to sternocleidomastoid muscle
This nerve branches from C2 and the accessory nerve.
What is the function of the transverse cervical nerve?
It extends as a branch to infrahyoid muscles
The transverse cervical nerve branches from C3.
What are the roots of ansa cervicalis?
Superior root and inferior root
The superior root has C1 branches, while the inferior root has C3 branches.
Which nerve branches are responsible for innervating the trapezius muscle?
Branches from C4 and C5
The trapezius muscle is involved in shoulder movement and stabilization.
From which cervical nerves does the phrenic nerve originate?
C3, C4, C5
The phrenic nerve is crucial for diaphragm movement and respiratory function.
What is the hypoglossal nerve associated with?
C1 nerve root
The hypoglossal nerve is responsible for tongue movement.
What emerges from the spinal cord to form the dorsal root?
Rootlets
Rootlets are small projections that join to form the dorsal root.
What do the dorsal and ventral roots combine to form?
Spinal nerve
The spinal nerve further branches into dorsal and ventral rami.
What is the function of the dorsal ramus of the spinal nerve?
It innervates the muscles and skin of the back
The dorsal ramus supplies sensory and motor functions to the posterior body.
What is the main role of the ventral ramus of the spinal nerve?
It innervates the anterior and lateral body wall and limbs
The ventral ramus contributes to the formation of plexuses.
What does the communicating ramus connect?
Two ventral rami
The communicating ramus is associated with the sympathetic nervous system.
What is the role of the splanchnic nerve?
It carries autonomic fibers to the abdominal and pelvic organs
Splanchnic nerves arise from the sympathetic chain.
What happens to the sensory neuron when a pin pierces the foot?
It travels to the spinal cord via the dorsal root
This initiates the withdrawal reflex.
In the withdrawal reflex, what does the sensory neuron form a synapse with?
An excitatory interneuron
This interneuron then activates the alpha motor neuron for muscle contraction.
What is reciprocal innervation?
The process where an interneuron inhibits the extensor muscle while activating the flexor muscle
This allows for coordinated movement during reflex actions.
What characterizes the crossed extensor reflex?
It involves the contralateral activation of extensor muscles
This reflex helps maintain balance when one limb is withdrawn.
What is the function of the ascending axon in spinal cord reflexes?
It crosses the midline and travels up through the ascending tract
This allows sensory information to reach the brain.
What covers the spinal nerve?
Epineurium
The epineurium is the outermost layer that protects the nerve.
What is the structure of a fascicle in a spinal nerve?
It contains endoneurium and is surrounded by perineurium
Fascicles are bundles of axons within a nerve.
How are spinal nerves categorized?
Cervical, thoracic, lumbar, sacral, coccygeal
Each category has a specific number of nerve pairs.
What is the function of C1 through C4 spinal nerves?
Head movement and diaphragm movement
These nerves play a crucial role in respiratory function.
What is spinal stenosis?
Narrowing of the spinal canal leading to nerve compression
Symptoms may include pain and weakness.
What is encephalitis?
Inflammation of the brain, often caused by a virus
Symptoms can include fever and convulsions.
What is meningitis?
Inflammation of the meninges, usually due to infection
Symptoms include neck stiffness and headache.
What causes tetanus?
Bacterial neurotoxin affecting lower motor neurons
It leads to muscle rigidity and spasms.
What is multiple sclerosis?
An autoimmune condition characterized by demyelination
Symptoms include exaggerated reflexes and tremors.
What is neuralgia?
Severe nerve pain along the pathway of a nerve
It can result from inflammation or nerve damage.
What is diabetic neuropathy?
Nerve damage due to high blood sugar levels
It often results in pain or numbness in extremities.
What is myasthenia gravis?
An autoimmune disorder affecting acetylcholine receptors
It leads to muscle weakness and fatigue.
How many pairs of spinal nerves are there?
Thirty-one pairs of spinal nerves
Where does the first pair of spinal nerves exit the vertebral column?
Between the skull and atlas
How many pairs of cervical spinal nerves are there?
Eight pairs
What is a dermatomal map?
A skin area supplied with sensory innervation by spinal nerves
What does the dorsal ramus innervate?
Deep muscles of the trunk and skin near the midline of the back
What is the function of the ventral ramus?
Innervation depends upon which part of the spinal cord is considered
What are intercostal nerves?
Nerves that innervate the intercostal muscles and the skin over the thorax
Which plexus is formed by the ventral rami of C1 to C4?
Cervical plexus
Which plexus is formed by the ventral rami of C5 to T1?
Brachial plexus
What is the epineurium?
The connective tissue that surrounds the entire nerve
What does the phrenic nerve innervate?
Diaphragm
What muscles does the ansa cervicalis serve?
Infrahyoid muscles
Fill in the blank: The __________ is a group of related disorders involving compression of nerves and vessels in the thoracic outlet region.
Thoracic outlet syndrome
Which nerve is commonly affected in Carpal Tunnel Syndrome?
Median nerve
Name the branches of the brachial plexus.
- Axillary
- Radial
- Musculocutaneous
- Ulnar
- Median
What can cause thoracic outlet syndrome?
Compression of the brachial plexus or subclavian artery/vein
What is the cutaneous innervation of the femoral nerve?
Anterior and medial thigh and leg
What is the origin of the musculocutaneous nerve?
Lateral cord of brachial plexus, C5–C7
True or False: Cervical ribs occur in about 0.5% of the population.
True
What is the primary role of the epineurium?
Surrounds the entire nerve
What are common risk factors for developing Carpal Tunnel Syndrome?
- Repetitive overhead arm motions
- Droopy shoulders
- Heavy backpacks
- Obesity
- Pregnancy-related joint changes
- Trauma
What symptoms did Sarah experience that led to the diagnosis of thoracic outlet syndrome?
Pain, tingling, and numbness in the ring and little fingers of her right hand
Fill in the blank: The __________ ramus communicates with the sympathetic chain of ganglia.
Communicating
What anatomical structure is involved in Carpal Tunnel Syndrome?
Median nerve
What is the function of the lumbar plexus?
Innervates lower limb muscles and skin
Where does the spinal cord begin and end?
From the foramen magnum to the second lumbar vertebra.
How many pairs of spinal nerves are associated with the spinal cord?
31 pairs of spinal nerves.
What are the segments of the spinal cord?
- Cervical
- Thoracic
- Lumbar
- Sacral
What is the cervical enlargement responsible for?
Supplying upper limbs.
What is the lumbar enlargement responsible for?
Supplying lower limbs.
What is the conus medullaris?
Tapered inferior end of the spinal cord.
What is the cauda equina?
Origins of spinal nerves extending inferiorly from lumbosacral enlargement and conus medullaris.
What are the three layers of meninges surrounding the spinal cord?
- Dura mater
- Arachnoid mater
- Pia mater
What is found in the epidural space?
- Blood vessels
- Areolar connective tissue
- Fat
What is meningitis?
Inflammation of meninges caused by viral or bacterial infection.
What are the main components of the reflex arc?
- Sensory receptor
- Sensory neuron
- Interneuron
- Motor neuron
- Effector organ
What are monosynaptic reflexes?
Reflexes with no interneurons.
What are polysynaptic reflexes?
Reflexes with multiple synapses and interneurons.
What is the function of the stretch reflex?
Muscles contract in response to a stretching force.
What is a muscle spindle?
Specialized muscle cells that respond to stretch.
What is the role of gamma motor neurons?
Control sensitivity of muscle spindle.
What happens in the Golgi tendon reflex?
Prevents contracting muscles from applying excessive tension to tendons.
What is reciprocal innervation?
Relaxation of extensor muscle when flexor muscle contracts.
What does the crossed extensor reflex do?
Causes extension of opposite lower limb during withdrawal reflex.
What is the role of descending tracts from the brain in reflexes?
Carry information to modify the reflex.
What is the clinical significance of the stretch reflex?
Assesses spinal cord integrity, peripheral nerve function, and muscle tone.
What does the dorsal root ganglion contain?
Collections of cell bodies of pseudo-unipolar sensory neurons.
What is spinal stenosis?
Narrowing of spinal canal or area around nerve roots, leading to nerve compression.
What is the thecal sac?
Protective membrane surrounding the spinal cord and nerve roots.
What is a lumbar puncture used for?
To remove cerebrospinal fluid for examination.
What are the two types of reflexes based on development?
- Innate reflexes
- Learned reflexes
What is the role of alpha motor neurons?
Cause muscle contraction.
What is the significance of the Achilles tendon reflex?
Checks S1 spinal segment integrity.
What is a withdrawal reflex?
Removes a body limb from a painful stimulus.
What is reduced sensation to light touch and vibration in the feet and lower legs indicative of?
Sensory Examination
This may suggest a neuropathy affecting sensory nerves.
What reflex is absent in the described condition?
Achilles tendon reflexes
The absence may indicate lower motor neuron dysfunction.
What type of gait is characterized by foot drop?
High-stepping gait
This gait pattern occurs due to weakness in dorsiflexion.
What condition is characterized by a high-arched foot?
Pes cavus
This often accompanies neurological disorders.
What diagnostic study shows marked reduction in nerve conduction velocities?
Nerve Conduction Study (NCS)
This indicates a demyelinating neuropathy.
Which gene mutation is associated with the described condition?
PMP22 gene
Mutations in this gene are linked to Charcot-Marie-Tooth disease.
What is spinal stenosis?
Narrowing of spinal canal or area around nerve roots
This can lead to nerve compression and symptoms like pain and numbness.
What is encephalitis?
Inflammation of the brain caused by a virus
Symptoms may include fever, coma, and convulsions.
What are the symptoms of meningitis?
Stiffness in the neck, headache, and fever
Severe cases can cause paralysis, coma, or death.
What is rabies?
Viral disease transmitted by an infected animal
It leads to brain infection resulting in aggression, paralysis, and death.
What causes tetanus?
Bacterial neurotoxin affecting lower motor neurons
It leads to muscle rigidity and spasms.
What condition is characterized by autoimmune demyelination?
Multiple sclerosis
Symptoms include exaggerated reflexes and tremors.
What does anesthesia refer to?
Loss of sensation
It can be a pathological condition or induced temporarily.
What is neuritis?
Inflammation of a nerve
Can result in loss of motor function or anesthesia.
What is neuralgia?
Nerve pain characterized by severe spasms of pain
Often results from inflammation or nerve damage.
What is sciatica?
Neuralgia of the sciatic nerve
Pain radiates down the back of the leg, commonly due to a herniated disk.
What is leprosy?
Bacterial disease affecting skin and PNS cells
Characterized by disfiguring nodules and tissue necrosis.
What does poliomyelitis primarily damage?
Somatic motor neurons
Leads to paralysis and muscle atrophy.
What is diabetic neuropathy?
Damage to nerves due to high blood sugar levels
Symptoms may include pain or numbness in extremities.
What is Charcot-Marie-Tooth disease?
Common hereditary neurological disorder
Characterized by muscle weakness and loss of sensation.
What is neurofibromatosis?
Genetic disorder with benign tumors along peripheral nerves
Results in skin growths from early childhood.
What is myasthenia gravis?
Autoimmune disorder affecting acetylcholine receptors
Leads to muscle weakness and increased fatigue.
What is the function of spinal nerves?
Transmit action potentials to and from the spinal cord
They are part of the peripheral nervous system.
What does the spinal cord carry out?
Integrative functions and communication with the brain
Each spinal segment has a predictable organization of gray and white matter.
What are the three layers of meninges surrounding the spinal cord?
- Dura mater
- Arachnoid mater
- Pia mater
These layers provide protection to the spinal cord.
What is the primary role of the dorsal horn in the spinal cord?
Sensory processing
Contains sensory neurons that receive input from the body.
What is a reflex arc?
Pathway that mediates a reflex action
Involves sensory neurons, interneurons, and motor neurons.
What is the knee jerk reflex an example of?
Stretch reflex
It involves the quadriceps muscle and is tested using a reflex hammer.
What does the Golgi tendon reflex involve?
Inhibition of alpha motor neurons
It protects muscles from excessive tension.
What is the withdrawal reflex?
A protective reflex that withdraws a limb from a harmful stimulus
Involves sensory neurons and interneurons to activate flexor muscles.
What is reciprocal innervation?
Simultaneous contraction of one muscle and relaxation of its antagonist
It occurs during withdrawal reflexes to allow coordinated movement.
What type of neuron forms a synapse with an alpha motor neuron that supplies the flexor hamstring muscles?
Excitatory interneuron
This interneuron is part of the withdrawal reflex mechanism.
What is the term for the reflex that involves the flexor muscles contracting while the extensor muscles are inhibited?
Reciprocal innervation
This occurs during the withdrawal reflex.
Which reflex involves the sensory neuron stimulating muscles on the opposite side of the body?
Crossed extensor reflex
This reflex is activated when a pin pierces the foot, causing the opposite leg to extend.
What are the two branches of the sensory neuron that enters the spinal cord?
- Ascending axon
- Interneuron
The ascending axon travels to the brain while the interneuron connects to motor neurons.
What is the outer covering of a spinal nerve called?
Epineurium
It contains loose connective tissue.
List the types of spinal nerves.
- Cervical nerves
- Thoracic nerves
- Lumbar nerves
- Sacral nerves
- Coccygeal nerve
Each type has specific functions and innervates different body regions.
What is the function of the phrenic nerve?
Innervates the diaphragm
It is crucial for breathing.
Fill in the blank: The __________ is the tuft of nerves at the end of the spinal cord.
cauda equina
This structure is located at the level of L4.
What do the cervical nerves C1 through C4 primarily control?
Head movement and diaphragm movement
These nerves are essential for basic motor functions.
True or False: The radial nerve is responsible for extending the elbow and wrist.
True
The radial nerve innervates various muscles involved in extension.
What is the main function of the axillary nerve?
Innervates the teres minor and deltoid muscles
It is involved in arm movement.
Identify the components of the brachial plexus.
- C5-C6: Upper trunk
- C7: Middle trunk
- C8-T1: Lower trunk
- Anterior and posterior divisions
- Lateral, medial, and posterior cords
Each component gives rise to specific nerves.
What type of neuron carries sensory information into the spinal cord?
Sensory neuron
It enters through the dorsal root.
What is the primary role of the interneuron in spinal reflexes?
Connects sensory and motor neurons
It facilitates the reflex response.
What are the roots of the cervical plexus responsible for?
- Lesser occipital nerve
- Greater auricular nerve
- Transverse cervical nerve
- Phrenic nerve
These nerves control various neck and shoulder movements.
What does the medial cord of the brachial plexus give rise to?
- Medial brachial cutaneous nerve
- Medial antebrachial cutaneous nerve
- Ulnar nerve
These nerves provide sensory and motor innervation.
What anatomical structure do the spinal nerves emerge from?
Intervertebral foramen
This is the opening between vertebrae.
What is the function of the Extensor carpi radialis longus?
Extends and abducts wrist
This muscle assists in the movement of the wrist.
Which nerve innervates the coracobrachialis, biceps brachii, and brachialis?
Musculocutaneous Nerve
Originates from the lateral cord of the brachial plexus, C5–C7.
What is the cutaneous supply of the musculocutaneous nerve?
Antero posterolateral forearm
Provides sensory innervation to this area.
What muscles does the ulnar nerve supply?
- Flexor carpi ulnaris
- Flexor digitorum profundus
- Adductor pollicis
- Hypothenar muscles
- Dorsal and palmar interossei
- Two medial lumbricals
Innervates muscles responsible for finger movement and wrist flexion.
What is the sensory innervation area of the ulnar nerve?
Medial third of hand, little finger, and medial half of ring finger
This nerve provides sensory information to these specific areas.
Fill in the blank: The median nerve originates from the _______ and _______ cords of the brachial plexus.
medial, lateral
It includes nerve roots from C5 to T1.
Which muscles does the median nerve innervate?
- Palmaris longus
- Pronator teres
- Flexor carpi radialis
- Flexor digitorum superficialis
- Flexor digitorum profundus (part)
- Flexor pollicis longus
- Pronator quadratus
- Thenar muscles
- Two lateral radial lumbricals
These muscles are primarily responsible for flexion and pronation of the forearm and hand.
What is the cutaneous distribution of the median nerve?
Anteriorly and posteriorly lateral two-thirds of the hand
Provides sensory innervation to these areas.
Which nerve roots give rise to the obturator nerve?
L2, L3, L4
It emerges from the lumbosacral plexus.
What is the primary function of the femoral nerve?
- Flexes hip
- Extends knee
Innervates major muscles of the thigh including psoas major and quadriceps.
What area does the femoral nerve provide sensory innervation to?
Anteromedial thigh and leg
Supplies sensory information to these regions.
What muscles does the tibial nerve innervate?
- Adductor Magnus
- Biceps femoris (long head)
- Semimembranosus
- Semitendinosus
- Popliteus
- Gastrocnemius
- Soleus
- Flexor digitorum longus
- Flexor hallucis longus
- Tibialis posterior
Responsible for movements of the posterior thigh and leg.
What is the cutaneous innervation area of the tibial nerve?
Lateral foot anteriorly and posterior leg and foot
Provides sensory information to these areas.
Fill in the blank: The common fibular (peroneal) nerve originates from the _______ through _______ nerve root.
L4, S3
It is part of the lumbosacral plexus.
What muscles does the deep fibular nerve innervate?
- Tibialis anterior
- Fibularis tertius
- Extensor digitorum longus
- Extensor hallucis longus
- Extensor digitorum brevis
These muscles are primarily responsible for dorsiflexion and toe extension.
Which area does the superficial fibular nerve provide sensory innervation to?
Dorsal anterior third of leg and dorsum of the foot
Supplies sensory information to this region.
What is the origin of the iliohypogastric and ilioinguinal nerves?
L1
These nerves arise from the lumbar plexus.
What is the function of the superior gluteal nerve?
Innervates gluteus medius and minimus
Important for hip abduction.
What spinal levels does the Obturator nerve originate from?
L 2, L 3, and L 4
The Obturator nerve is responsible for innervating the medial compartment of the thigh.
Which spinal level does the lumbosacral trunk originate from?
L 5
The lumbosacral trunk contributes to the formation of the sacral plexus.
What are the spinal levels for the superior gluteal nerve?
L 5, S 1, and S 2
The superior gluteal nerve innervates the gluteus medius, gluteus minimus, and tensor fasciae latae.
From which spinal level does the inferior gluteal nerve originate?
S 1
The inferior gluteal nerve primarily innervates the gluteus maximus.
What are the spinal levels for the sciatic common fibular (peroneal) nerve?
L 4, L 5, S 1, and S 2
This nerve is responsible for innervating the muscles of the anterior and lateral compartments of the leg.
What spinal levels does the sciatic tibial nerve originate from?
L 5, S 1, S 2, and L 3
The tibial nerve innervates the posterior compartment of the leg and the plantar aspect of the foot.
Which spinal levels does the posterior femoral cutaneous nerve originate from?
S 2 and S 3
This nerve provides sensory innervation to the skin of the posterior thigh.
What are the spinal levels for the pudendal nerve?
S 2 and S 4
The pudendal nerve is crucial for innervating the perineum and external genitalia.
