Chapter 14-15-16: PNS Flashcards
PNS function
Bring the message into (sensory) and out of (motor) the central nervous system.
PNS location
The peripherial nerves come off the spinal cord and brain
What is a nerve?

“Nerve” refers to the PNS and is the name given for an organized bundle of axons.
Sensory neurons convey what type of information and in what direction?
Sensory neurons convey sensory information to the central nervous system
Motor neurons convey what type of informationa and in what direction
Motor neurons convey motor impulses from the central nervous system to the muscles and glands.
Nerves that have axons of both motor and sensory are called?
Mixed nerves
The three layers of a nerve are… (from superficial to deep)
- Epineurium
- Perineurium
- Endoneurium
There are how many pairs of nerves connected to the spinal cord?
31
The majority of nerves in your body are what type?
Mixed nerves
Sensory information travels into the spinal cord along the…
Posterior Root
Motor information travels out from the spinal cord along the…
Anterior Root
The axons of sensory neurons and the cell bodies of interneurons are located within what section of the gray matter within the spinal cord?
The axons of sensory neurons and the cell bodies of interneurons are located in the posterior horns
The anterior horns primarily house the cell bodies of…
Somatic motor neurons
identify 1-4 in this picture

- Spinal nerve
- Anterior (ventral) Root
- Posterior (dorsal) Root Ganglion
- Posterior (dorsal) Root
Identify 1-4 in this photo

- Anterior (Ventral) root
- Posterior (Dorsal) root
- Posterior Root Ganglion
- Spinal Nerves
The four major plexus (plexi??) are…
- Cervical
- Brachial
- Lumbar
- Sacral
Spinal nerves in certain areas of the spinal cord intertwine to create a network known as a…
Plexus
The thoracic spinal nerves are also known as…
Intercostal Nerves
C1-C5 form which plexus?
Cervical plexus
C6 through T1 form what plexus?
Brachial
C5 is unique in that it is apart of..
Both plexus (cervical and brachial)
Anterior rami of what nerves form the brachial plexus?
C5-T1
The phrenic nerve controls…
The diaphragm
Identify 1-3

- Right phrenic nerve
- Left Phrenic nerve
- Phrenic Nerve
Identify 1-3 in this picture

- Median Nerve
- Radial Nerve
- Ulnar Nerve
Identify 1-3

- Radial Nerve
- Median Nerve
- Ulnar Nerve
Identify 1-3

- Median Nerve
- Radian Nerve
- Ulnar Nerve
The three cords of the brachial plexus are..
Posterior, Lateral, Medial
The median nerve is formed from which section of the anterior rami?
C5-T1
The median nerve motor innervates…
Most anterior forearm muscles and Thenar (thumb muscles.
The cutaneous innervation of the median nerve is…
Palmar aspects and dorsal tips of lateral 3-1/2 digits (thumb, index finger, middle finger, and 1/2 of ring finger)
This is the cutaneous innervation of what nerve…

Median nerve
This is the cutaneous innervation of what nerve?

Ulnar Nerve
The median nerve is formed by what two cords of the brachial plexus?
Medial and lateral cords of the brachial plexus
The ulnar nerve is formed from the ___1__ cord of the ___2__ plexus
- Medial
- Brachial
The ulnar nerve is formed from anterior rami of…
C8-T1
The ulnar nerve motor innervates…
Anterior forearm muscles and intrinsic hand muscle
The cutaneous innervation of the ulnar nerve is…
Dorsal and plamar aspects of medial 1-1/2 digits (little finger, medial aspect of ring finger)
This is the cutaneous innervation of which nerve?

radial
The radial nerve is formed from what cord?
Posterior
The radial nerve is from from anterior rami…
C5-T1
The motor inntervation of the radial nerve is…
Posterior arm muscles (extend forearm) and Posterior forearm muscles (supinate forearm, extend wrist, digits, one muscle that abducts the tumb).
In general nerves from the ________ division of the brachial plexus tend to inntervate muscles that flex the parts of the upper limb.
anterior
Nerves from the ______ division of the brachial plexus tend to innervate muscles that extend parts of the upper limb
Posterior
The cutaneous innervation of the radial nerve:
Posterior region of arm
Posterior region of forearm
Dorsal aspect of lateral three digits(except their distal tips)
The two lower plexuses are…
Lumbar and Sacral
identify 1-3

- Femoral nerve
- Obturator nerve
- Sciatic nerve
What is unique about L4 nerve?
Shared between the lumbar and sacral plexuses
Identify this plexus

Lumbar
Identify this plexus

Sacral
Identify 1-3

- Femoral Nerve
- Obturator Nerve
- Saphenous Nerve
The femoral nerve is formed from anterior rami…
L2-L4
The femoral nerve motor innervates the…
Anterior thigh muscles
Cutaneous innervation of the femoral nerve is…
- Anterior thigh
- Inferomedial thigh
- medial side of leg
- most medial aspect of foot
This is the cutaneous innervation of…

Femoral Nerve
The obturator nerve is formed from anterior rami…
L2-L4
The obturator nerve motor innervates the…
medial thigh muscles (adductors of thigh)
The cutaneous inntervation of the superomedial thigh is through what nerve?
Obturator Nerve
This is the cutaneous innervation of what nerve?

Obturator Nerve
The lumbar plexus is formed by the anterior rami of…
L1-L4
The Sacral plexus is formed by the anterior rami of…
L4-S4
Identify the nerves in the picture

- Tibial Nerve
- Common Fibular Nerve
- Sciatic nerve
The sciatic nerve branches into two main divisions known as…
Common Fibular Division, Tibial Division
The Sciatic Nerve is formed by the anterior rami of…
L4-S3
The Tibial Nerve is formed by the anterior rami…
L4-S3
The tibia nerve motor innervates the…
- Posterior Thigh Muscles (extend thigh and flex leg)
- Posterior leg muscles (plantar flexors of foot, flexors of knee)
- Plantar foot muscles (via medial and lateral plantar nerve branches)
The cutaneous innervation of the tibial nerve:
Branches to heel and via its medial and lateral plantar nerve branches supply the sole of the foot.
This is the cutaneous innervation of the…

Tibial Nerve (picture really helped this time huh)
The common fibular nerve motor innervates the…
- Anterior leg muscles(dorsiflex foot, extend toes)
- Dorsum foot muscles(extend toes)
- Lateral Leg muscles(foot evertors and plantar flexors)
The cutaneous innervation of the common fibular nerve is…
Dorsal interspace between first and second toes
Anteroinferior part of leg; most dorsum of foot
This picture is the innervation of what nerve?

Common fibular nerve
The common fibular nerve is formed from the anterior rami of…
L4-S2