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
