Peripheral Nerves 1 (part 2) Flashcards
8 Cervical
12 Thoracic
5 Lumbar
5 Sacral
1 Coccygeal
Spinal Cord Segments (31 total)
Spinal Cord rootlets gather together to make a spinal root (dorsal or ventral). The spinal roots then join peripherally into a spinal nerve.
Rootlets -> Roots -> Nerve
Spinal Cord Segments
Sensory. Cell bodies are located peripherally in a dorsal root ganglion.
-Bring sensory (afferent) fibers to the spinal cord
-GSA/GVA fibers
Dorsal Spinal Root
Motor. Cell bodies are located within the Ventral Gray Horn of the spinal cord
-Carry motor (afferent) fibers away from the spinal cord
-SE/GVE fibers
Ventral Spinal Root
As soon as the spinal nerve is formed, it branches into Dorsal and Ventral ____ ____.
Primary Rami
Mixed fibers
-Medial: Sensory
-Lateral: Motor
Dorsal Primary Rami
Formed by the VPR of Spinal Nerves.
-Mixing of Axons gives the upper limbs their variability, excitability, and ability to carry out different tasks
Brachial Plexus
A high block that uses a Cervical Approach via the Cricoid Cartilage (C4-C6). Injection goes into the interscalene gap (between the anterior and middle scalene)
-Provides anesthesia for the proximal upper limb (shoulder surgeries)
Interscalene Block
A block that goes over the top of the clavicle to anesthetize the elbow region (upper limb)
Supraclavicular Approach
A block done to anesthetize the wrist/hand (distal limb)
Axillary Approach
A layer of connective tissue that is wound around the brachial plexus (Saran wrap). Keeps everything held together.
-Used in anesthesia: Inject medication into the space between this and the brachial plexus
-This holds the anesthesia in place like a bag around the brachial plexus
Axillary Sheath
Where the proximal portion of the Brachial Plexus sits. Right behind the SCM, between the Anterior and Middle Scalene muscles
-Also contains the Subclavian Artery
Scalene Gap (notch/opening)
About halfway down the SCM, where you can see C5-C8 & T1
Erb’s Point
C5 & C6 VPR make the Upper
C7 VPR makes the Middle
C8 & T1 VPR make the Lower
Trunks
The posterior divisions of the Upper, Middle, and Lower Trunks
Posterior Cord of the Brachial Plexus
The anterior division of the upper trunk and the anterior division of the middle trunk
Lateral Cord of the Brachial Plexus
The division of the lower trunk continues forward to the form the ____.
Medial Cord of the Brachial Plexus
If you have C4 giving a contribution to C5
Pre-fixed Brachial Plexus
If you have T2 giving a contribution to T1
Post-fixed Brachial Plexus
As soon as the Subclavian Artery passes through the Scalene Gap and touches the lower border of the first rib, it changes into the ____.
Axillary Artery
When the Axillary Artery gets to the lower border of the Teres Major muscle, it turns into the ____.
Brachial Artery
The part of the Axillary artery from the 1st rib to the Pectoralis Minor muscle
1st part
The part of the Axillary Artery that is covered by the Pectoralis Minor Muscle
2nd part
The part of the Axillary Artery that is from the lower border of the Pectoralis Minor muscle to the Teres Major muscle.
3rd Part
The artery beyond the lower border of the Teres Major muscle
Brachial Artery
One of the terminal branches of the Posterior Cord.
-Runs through the Axilla
-Can be damaged with crutch-use
Axillary nerve
A terminal branch of the Posterior Cord
Radial Nerve
A distal extension of the Lateral Cord.
-Has to be anesthetized on its own. Lies outside of the Axillary Sheath
Musculocutaneous Nerve
Formed by contributions from the Lateral and Medial Cord.
-Where the Lateral and Medial Cords join together at the midline
Median Nerve
An extension of the Medial Cord
Ulnar Nerve
Formed by C5, C6, and C7. Runs down the mid-axillary line
-Avoid this area with chest tubes
Long Thoracic Nerve
A tiny nerve that comes off of C5.
-Pierces the Middle Scalene Muscle
-Innervates the Levator Scapulae and Rhomboids Major and Minor muscles
Dorsal Scapular Nerve
A very small nerve coming off of the Upper Trunk.
-Innervates a muscle that exists between the 1st rib and clavicle to stabilize these two structures against each other
Nerve to the Subclavius Muscle
A nerve that comes off of the Upper Trunk that innervates the Supraspinatus and Infraspinatus muscles (above and below the spine of the scapula).
Suprascapular Nerve
A branch off of the Lateral Cord that innervates the Pectoralis Major Muscle
Lateral Pectoral Nerve
A nerve that comes off of the Posterior cord and can have multiple branches.
-Innervates the Subscapularis Muscle
Upper Subscapular Nerve
A nerve that comes off of the Posterior Cord and runs across the back of the chest.
-Innervates Latissimus Dorsi muscle.
Thoracodorsal Nerve
A nerve that comes off of the Posterior Cord (most distal of the three branches)
-Innervates the Subscapularis and Teres Major muscles
Lower Subscapular Nerve
A nerve that comes off of the Medial Cord that innervates the Pectoralis Minor and Major muscles.
Medial Pectoral Nerve
A nerve that comes off of the Medial Cord that supplies general sensation to the medial aspect of your arm.
Medial Brachial Cutaneous nerve
A nerve that comes off of the Medial Cord that supplies general sensation to the medial part of the forearm.
Medial Antebrachial Cutaneous nerve
Nerve that is derived from T2 (not in the Brachial Plexus)
-Responsible for general sensation to the very anterior edge of the axillary region (proximal, medial portion of the arm)
-Has to be blocked separately because it’s not a part of the Brachial Plexus
-Joins on with the Medial Brachial Cutaneous nerve later on
Intercostobrachial Cutaneous nerve
An upper limb muscle that is innervated by CN XI (Spinal Accessory Nerve)
-Has 3 parts: Upper, Middle, and Lower
-Helps form the pectoral girdle with the shoulder, clavicle, and scapula.
-Forms a U-shape on the lateral side of the shoulder where muscles attach.
-Moves the shoulder girdle around to do work.
Trapezius muscle
Origin: Superior Nuchal Line
Insertion: Shoulder
-Contracts to pick the shoulder up
-Can reverse origin/insertion to extend the head back as well
-CN XI
Upper Trapezius muscle
Origin: Upper Thoracic Vertebra
Insertion: Scapula (pectoral girdle)
-Contracts: fibers run horizontally, so it retracts the scapula (pulls it back and into attention)
Middle Trapezius muscle
Muscle that causes scapular depression (down) and also at the same time, flips the scapula up (upward rotation)
Lower Trapezius muscle
