Spinal Nerves Flashcards
Steps of reflex arch
- ________ activates ________
- Nerve impulse travels through ________ ________ to ________
- ________ process information about stimulus
- ________ ________ send impulse to ________
- ________ brings response
- Stimulus, receptor
- Sensory neuron, CNS
- interneurons
- Motor neurons, effector
- Effector
________: both the receptor and effector organs are on same side
________: impulses initiation from a receptor cross the spinal cord to activate effector on opposite limb
________: sensory axons synapse directly on motor neurons, whose axons project to the effector
________: more complex pathways exhibit a number of synapse involving interneuron within the reflex arch
Ipsilateral
Contralateral
Monosynaptic
polysynaptic
Which two reflex arc types do not involve interneurons
Monosynaptic, polysynaptic
Withdrawal(flexor) reflex is an example of what reflex
Polysynaptic
Stretch reflex like a knee jerk is ________ reflex
Monosynaptic
Tendon reflex is ________ reflex
Monosynaptic
________ ________ organs are nerve endings in tendons near a muscle-tendon juntion
As a muscle contracts, force is exerted on tendon, causes tension in tendon, activation of ________ ________ organ
Nerve impulses signal ________ in the spinal cord which in turn inhibit the actions of the ________ neurons
Muscles relax, protecting the muscle and tendon from excessive tension
Golgi tendon
Golgi tendon
interneuron, motor
C1-C7 exit the ________ ________ above the vertebra of the same number
C8 exits above first ________ vertebrae
The remaining spinal nerves exit ________ vertebrae
Roots of ________ and ________ spinal nerves travel inferiorly to reach their intervertebral foramen
Intervertebral foramen
Thoracic
Below
Lumbar, Sacral
After leaving the intervertebral foramen, spinal nerve splits into branches called ________
The ________ramus innervates the deep muscles and skin of back
The ________ ramus innervates anterior and lateral portions of trunk and upper and lower lumbs
Many of anterior rami form ________ ________
The ________ ________ extend between the spinal nerves and the ________ ________ ________
Rami
Posterior
Anterior
Nervus plexuses
Rami communicantes, sympathetic trunk ganglie
A ________ is a segment of skin supplied by a SINGLE nerve
All spinal nerves except ________ innervate a segment of skin
Skin divided into sensory segments form a dermatome map
In ________ ________ pain, pain in one organ is mistakenly referred to a dermatome
Dermatome
C1
Referred visceral
Shingles is the reactivation of ________ ________.
During infection, virus moves from skin to ________ ________ ________. Remains dormant there until adulthood
Includes blisters along dermatomes because it travels along sensory nerve axons
Chickenpox
Posterior root ganglion
anterior rami of spinal nerves T- to T- are intercostal nerves
Spinal nerve T- is a subcostal nerve
T- is the only one that forms plexus
Part of T- helps form ________ plexus
Part of T- lies in first ________ space
T- innervates intercostal muscles of the second intercostal space and is sensory for axilla and ________ surface of arm
T- to T- innervate intercostal muscles and are sensory for ANTERIOR chest wall
T1-T11
T12
T1
T1, brachial
T1, intercostal
T2, medial
T3-T6
A nerve plexus is a network of interweaving ________ ________ of spinal nerves
Major plexuses:
Cervical plexus (C- to C-)
Brachial plexus (C- to T-)
Lumbar plexus (L- to L-)
Sacral (L- to S-)
Sciatic nerves:
Anterior rami
Cervical, brachial, lumbar, sacral
C1-C5: Ansa cervicalis, phrenic nerve
C5-T1: Musculocutaneous, axillary, median, radial, ulnar
L1-L4 Femoral, obturator
L4- S4 Superior gluteal, inferior gluteal
Common fibular, tibial
Left and right cervical plexuses are formed by anterior ramus of C- to C-
Innervates:
Phrenic originated from C-
- Travels through ________ cavity to innervate ________ (motor and sensory) and ________ ________, ________ ________, ________ ________ (sensory)
Motor branches:
Ansa cervicalis (C1, C2, C3) = ________ muscles
Segmental branches (C1-C4) = ________ and ________ muscles
Cutaneous branches:
________ _______ (C2-C3)
________ ________ (C2)
________ ________(C3-C4)
________ ________(C2-C3)
C1 to C4
C4
Thoracic, diaphragm, fibrous pericardium, mediastinal pleura, diaphragmatic peritoneum
Infrahyoid
Anterior and middle scalene
Great auricular
Lesser occipital
Supraclavicular
Transverse
The brachial plexus is formed by the anterior rami of spinal nerves C- to T-
Superior trunk: C- to C-
Middle trunk: C-
Inferior trunk: C- to T-
Erb’s point: C- to C-
Klumpke’s point: C- to T-
C5-T1
C5-C6
C7
C8-T1
C5-C6
C8-T1
5 branches of brachial plexus:
Nerve for skin on far lateral side of forearm:
Nerve for far medial side of forearm:
Nerve that is in the middle and goes through cubital fossa: and carpal tunnel
Nerve for armpit and deltoid and teres minor:
Nerve that does most muscles of back of arm:
Musculocutaneous
Ulnar
Median
Axillary
Radial
Axillary nerve
Terminal branch:
Anterior Rami:
Motor innervation:
Cutaneous innervation:
Posterior cord, posterior division of brachial plexus
C5-C6
Deltoid (arm abduction), Teres minor (lateral rotation)
Superolateral arm
Radial nerve
Terminal branch:
Anterior Rami:
Motor innervation:
Cutaneous innervation:
Posterior cord, posterior division of brachial plexus
C5-T1
Posterior arm muscles (triceps brachii, anconeus), posterior forearm muscles (supinate forearm, extend wrist, digits, abducts thumb, brachioradialis),
Posterior region of arm, forearm, dorsal aspect of lateral 3 digits
Musculocutaneous nerve
Terminal branch:
Anterior Rami:
Motor innervation:
Cutaneous innervation:
Lateral cord of anterior division of brachial plexus
C5-C7
Anterior arm muscles (coracobrachialis, biceps brachii, brachialis)
Lateral region of forearm
Median nerve:
Terminal branch:
Anterior Rami:
Motor innervation:
Cutaneous innervation:
Medial and lateral cords, anterior division of brachial plexus
C6-T1
Most anterior forearm muscles (flexors, pronators), Thenar muscles, Lateral 2 lumbricals
Palmar and dorsal tips of lateral 3 fingers and half of ring finger
Ulnar Nerve
Terminal branch:
Anterior Rami:
Motor innervation:
Cutaneous innervation:
Medial cord, anterior division
C8-T1
Anterior forearm muscles, intrinsic hand muscles
Palmar and dorsal of medial 1 digit (pinky) and half of ring finger
Dorsal scapular nerve:
Levator scapulae, rhomboid major, rhomboid minor
Long thoracic nerve
Serratus anterior
Suprascapular
Supraspinatus, infraspinatus
Lateral pectoral nerve
Pectoralis major
Upper subscapular, lower subscapular, thoracodorsal nerves
Subscapularis, teres major, latissimus dorsi
Medial pectoral nerve
Pectoralis major, pectoralis minor
Axillary nerve
Deltoid, teres minor
Radial nerve:
brachioradialis, triceps brachii, anconeus, supinator, extensors in forearm
Musculocutaenous nerve:
Biceps brachii, coraco brachialis, brachialis
Medial nerve
Most flexors in forearm
Ulnar nerve
Flexor carpi ulnaris
Superior trunk injury affects C- and C- (________ palsy)
- ________ ________ position
- Because of excessive lateral flexion or separation of neck and shoulder
- Shoulder adducted, arm medially rotated, elbow extended, wrist flexed
Inferior trunk injury affects C- to T- ( ________ palsy)
-Arm is excessively abducted
- Can affect ______ muscle function or show as ________ hand
Axillary nerve injury
- ________ palsy
- Affects ________ muscle and causes difficulty in abducting the arm
Winge scapula
- ________ ________ nerve is injured and ________ ________ muscle is affected
- Medial border of scapula protrudes
C5 and C6, Erb’s
- Waiter’s tip
C8 and T1, Klumpke’s
- Scalene, claw hand
- Crutch
- Deltoid
- Long thoracic, serratus anterior
A wrist drop is a ________ injury
Ulnar injury loses function of ________ muscles and ulnar ________ lumbars
- Claw hand is an ________ injury
________ injury is lost function of thumb and can’t flex digits 2 and 3 when making a fist
Radial
Ulnar
Median
Lumbar plexus formed by L- to L-
posterior division is the ________ nerve
Anterior division is the ________ nerve
Illiohyogastric nerve (L-)
Motor = Partial innervation of ________ muscles
Cutaneous = Superior lateral ________ region and inferior ________ wall
Ilioinguinal nerve (L-)
Motor = Partial innervation of ________ muscles
Cutaneous = ________ abdominal wall. ________ (males) are ________ ________ (female)
Genitofemoral nerve (L-, L-)
Cutaneous = skin over ________ ________
Lateral femoral cutaneous nerve (L-, L-)
Cutaneous = Skin of ________ ________
Femoral
Obturator
L1, abdominal, gluteal, abdominal
L1, Abdominal, inferior, scrotum, labia majora
L1, L2, femoral triangle
L2, L3, anterolateral thigh
Femoral nerve passes through ________ ________
Obturator nerve passes through ________ ________
Femoral triangle
obturator foramen
Femoral nerve:
Anterior Rami
Motor innervation
Cutaneous innervation
L2-L4
Quadriceps, Iliapsoas
Saphenous nerve: medial aspect of fit
Obturator nerve:
Anterior Rami
Motor innervation
Cutaneous innervation
L2-L4
Medial thigh muscles
Superomedial thigh
Sacral plexus
Formed by L- to S-
The _______ nerve is the largest and longest nerve in sacral plexus
Superior to _______ _______, divisions split into two nerves:
- _______ nerve
- _______ _______ nerve
Along the lateral knee, the common fibular nerve splits into the _______ and _______ fibular nerve
L4-S4
Sciatic
Popliteal fossa
- Tibial
- Common fibular
Deep, superficial `
Sciatic nerve exits the _______ _______ foramen next to _______ muscle
_______ _______ nerve: L- to S-
Motor to gluteus medius, gluteus maximus TFL
_______ _______ nerve: L- to S-
Motor to gluteus maximus
_______ _______ nerve: S- to S- skin on _______ thigh
_______ nerve: S- to S-
motor to muscles of _______
Cutaneous to skin of external _______
Greater sciatic, piriformis
Superior gluteal, L4-S1
Inferior gluteal, L5-S2
Posterior femoral cutaenous, S1-S3 posterior
Pudendal, S2-S4
Perineum, gentalie
Sural is purely _______
Cutaneous
Tibial nerve
Rami:
Motor:
Cutaneous:
L4-S3
Posterior thigh muscles, Posterior leg muscles, plantar foot muscles
Sural nerve
Common fibular
Rami:
Motor:
Cutaneous:
L4-S2
Short head of biceps femoris
head of fibula
Deep fibular
Rami:
Motor:
Cutaneous:
L4-S1
Anterior leg muscles, dorsum foot
Dorsal interspace between first and second toes
Superficial fibular
Rami:
Motor:
Cutaneous:
L5-S2
Lateral leg muscles
Anteroinferior part of leg, dorsum of foot7
Femoral
obturator
Superior gluteal:
Inferior gluteal:
Tibial:
Common fibular:
Superficial fibular:
Deep fibular:
Pudendal:
Iliacus, quadriceps, sartorius
adductors
TFL, gluteus medius
Gluteus maximus
Long hamstrings, popliteus, calf muscles
Biceps femoris short head
Fibularis long, brevis
Tibialis anterior, fibularlis tertius
Muscles of perineum
