Spinal Nerves (Exam 3) Flashcards
Type of motor response that occurs as the result of some type of sensory stimulus that takes place without conscious control
Reflexes
Simplest type of reflex
Monosynaptic reflex
A monosynaptic reflex involves a
Sensory neuron synapsing with a motor neuron
A monosynaptic reflex is also called a
Stretch reflex, initiated by the stretch of a skeletal muscle
In a motorsynaptic reflex an impulse is carried by the
Sensory neuron into spinal cord, sensory neuron synapses with motor neuron in anterior horn, motor neuron causes contraction
A polysynaptic reflex involves
3 neuron in series
In a polysynaptic reflex, a sensory neuron
Carries some kind of painful stimulus from skin to the spinal cord, interneurons recruit muscles to remove the body part from painful stimulus
Why do intercostal nerves remain segmented?
Intercostal muscles perform simple functions
The muscles of upper and lower extremities perform…
Complex, graded functions
Joining of spinal nerves to form nerves comprised of more than one level of the spinal cord
Nerve plexus
Brachial plexus delivers…
Motor to and sensory from the lower extremity
The lumbosacral plexus delivers motor to and sensory from the
Lower extremities
Plexuses are formed from
Mixed spinal nerves
The nerves plexuses produce are
Comprised of motor and sensory fibers
Brachial plexus is formed by the
Anterior rami of spinal nerves C5-T1
The brachial plexus extends from the
Lower neck, between clavicle and 1st rib, then to axilla
Innerverates the skeletal muscles of the upper extremity and carries sensation from skin of upper extremity
Brachial plexus
Anterior rami of C5 and C6 join to form the
Superior trunk
The anterior rami of C8 and T1 joint to form
Inferior trunk
The anterior ramus of _ forms middle trunk
C7
The posterior branches of all three trunks form…
Posterior cord
Anterior branches of the superior and middle trunks form
Lateral cord
The anterior branch of inferior trunk forms the
Medial cord
The posterior cord gives rise to the
Radial and axillary nerves
The lateral cord gives rise to the
Musculocutaneous nerve and part of median nerve
The medial cord gives rise to the
Ulnar nerve and part of the median nerve
Axillary nerve spinal cord levels
C5 and C6
Musculocutaneous nerve spinal cord levels
C5 C6 C7
Radial nerve spinal cord levels
C5, C6, C7, C8, T1
Median nerve spinal cord level
C6 C7 C8 T1
Ulnar nerve spinal cord level
C8, T1
Nerves of upper extremity: Axillary Nerve functions
Shoulder Abduction and shoulder external rotation;
Sensation of skin of lateral shoulder
Musculocutaneous nerve functions
Flexion at elbow, supination; sensory from skin of lateral forearm
Radial nerve function
Extension at elbow, wrist and fingers; supination of the forearm
Radial nerve sensory function
Sensory from skin of posterior arm, forearm, and hand
Functions of the median nerve
Flexion at wrist, flexion of fingers, and pronation
Median nerve sensory function
Sensory from skin of lateral palm, digits 1-3 and 1/2 of digit 4.
Ulnar nerve functions
Finger abduction and adduction
Ulnar nerve sensory function
Sensory from skin of medial palm,pinky, and 1/2 of ring finger
Combo of lumbar plexus and sacral plexus
Lumbosacral plexus
Femoral nerve spinal cord levels
L2-L4
Main functions of femoral nerve
Flex the hip and extend the knee
Sensory from skin of anterior thigh and medial leg
Spinal cord Levels of the obturator nerve
L2-L4
Fucntions of the obturator nerve
Hip adduction, sensory from skin of superior medial thigh
Main action performed by muscles innervated by obturator nerve
Hip adduction
Tibial nerve and common fibula nerve joined by connective tissue is known as
Sciatic nerve
Tibial nerve spinal cord levels
L4-S3
Main functions of the tibial nerve
Hip extension, knee flexion, plantar flexion, and toe flexion; sensory from skin of sole to foot
Common fibular (peroneal) nerve spinal cord levels
L4-S3
Common fibular (peroneal) nerve main function
Motor to short head of biceps femoral, flex leg
Superficial fibular (peroneal) nerve main functions
Eversion of foot, sensory from skin of dorsal foot except between first two toes
Deep fibular (peroneal) nerve functions
Dorsiflex and inverts foot, extends the toes; sensory from skin of first two toes
