Spinal Nerves and Plexuses Flashcards

Questions and Answers

Spinal nerves are part of the __ nervous system.

peripheral

How many pairs of spinal nerves are there?

Most spinal nerves exit through __.

intervertebral foramen

Identify the spinal cord levels for the cervical plexus.

C1-C5 Signup and view all the answers

Identify the spinal cord levels for the brachial plexus.

C5-T1 Signup and view all the answers

Identify the spinal cord levels for the lumbar plexus.

L1-4/5 Signup and view all the answers

Identify the spinal cord levels for the sacral plexus.

L4-S3 Signup and view all the answers

Nerve plexuses contain __ rami.

ventral Signup and view all the answers

Spinal nerves contain what type of axons?

Motor, sensory, and autonomic Signup and view all the answers

The plexus that supplies sensory and motor nerves to the upper extremities is called?

Brachial Signup and view all the answers

An individual muscle receives innervation from more than one spinal cord level.

True Signup and view all the answers

Most branches of the cervical plexus are (motor/sensory).

sensory Signup and view all the answers

The most important nerve of the cervical plexus is?

Phrenic Signup and view all the answers

The phrenic nerve contains fibers from spinal cord levels and innervates the .

C3-C5, diaphragm Signup and view all the answers

What is the sequence for the parts of the brachial plexus?

Roots, Trunks, Divisions, Cords Signup and view all the answers

The five major nerves of the brachial plexus that supply innervation to the arm, forearm, and hand are?

Axillary, Musculocutaneous, Radial, Ulnar, Median Signup and view all the answers

Motor innervation to the deltoid muscle is from the __ nerve.

axillary Signup and view all the answers

Motor innervation to the biceps brachii muscle is from the __ nerve.

musculocutaneous Signup and view all the answers

Motor innervation to the extensor muscles of the arm is from the __ nerve.

radial Signup and view all the answers

The largest nerve of the brachial plexus is?

Radial nerve Signup and view all the answers

Motor innervation to most of the intrinsic muscles of the hand is from the __ nerve.

ulnar Signup and view all the answers

The largest branch of the lumbar plexus is the nerve, which innervates the .

femoral, quad Signup and view all the answers

The sciatic nerve terminates in the lower leg as the and nerves.

tibial and fibular Signup and view all the answers

Which plexus supplies the anterolateral abdominal wall, external genitals, and part of the lower extremity?

Lumbar plexus Signup and view all the answers

Which plexus supplies skin and muscles of the head, neck, and superior part of shoulders and chest?

Cervical plexus Signup and view all the answers

Which plexus supplies the buttocks, perineum, and lower extremities?

Sacral plexus Signup and view all the answers

The sciatic nerve is a part of what plexus?

Sacral Signup and view all the answers

The area of the skin that provides sensory input to the CNS via one pair of spinal nerves is called?

Dermatomes Signup and view all the answers

The levels of spinal cord that contribute to the innervation of skeletal muscles are called?

Myotomes Signup and view all the answers

C5 is involved in the nerve to the biceps, the reflex, and the __ nerve to the lateral arm.

musculocutaneous, biceps, axillary Signup and view all the answers

Study Notes

Overview of Spinal Nerves

Spinal nerves are part of the peripheral nervous system.
There are 31 pairs of spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal.
Most spinal nerves exit through intervertebral foramen.

Plexuses and Their Levels

Cervical Plexus: Spinal cord levels C1-C5.
Brachial Plexus: Spinal cord levels C5-T1.
Lumbar Plexus: Spinal cord levels L1-L4/5.
Sacral Plexus: Spinal cord levels L4-S3.

Nerve Plexus Structure

Nerve plexuses contain ventral rami.
Each spinal nerve contains motor, sensory, and autonomic axons.

Functions and Major Nerves

The brachial plexus supplies sensory and motor nerves to the upper extremities.
An individual muscle receives innervation from more than one spinal cord level, emphasizing the importance of nerve redundancy.
Most branches of the cervical plexus are sensory.
The phrenic nerve, arising from C3-C5, innervates the diaphragm.

Brachial Plexus Structure

Sequence of parts: Roots, Trunks, Divisions, Cords.
Five major nerves of the brachial plexus include:
- Axillary nerve (deltoid muscle innervation),
- Musculocutaneous nerve (biceps brachii muscle innervation),
- Radial nerve (extensor muscles of the arm),
- Ulnar nerve (intrinsic muscles of the hand),
- Median nerve.

Lumbar and Sacral Plexus

The largest nerve of the lumbar plexus is the femoral nerve, which innervates the quadriceps muscle.
The sciatic nerve, originating from the sacral plexus, splits into the tibial and fibular nerves in the lower leg.
The lumbar plexus innervates the anterolateral abdominal wall, external genitals, and part of the lower extremity.
The cervical plexus supplies the skin and muscles of the head, neck, and upper chest area.
The sacral plexus innervates the buttocks, perineum, and lower extremities.

Sensory Input Regions

Dermatomes refer to areas of skin providing sensory input to the central nervous system via one pair of spinal nerves.
Myotomes represent muscle groups innervated by specific spinal cord levels.

Specific Nerve Functions

C5 contributes to:
- Musculocutaneous nerve innervating the biceps,
- The biceps reflex,
- Axillary nerve innervation to the lateral arm.
The radial nerve is the largest branch of the brachial plexus.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on spinal nerves and nerve plexuses with these flashcards. This quiz covers the basic anatomy of spinal nerves, their distribution, and the specific plexuses they form. Perfect for students of anatomy and neuroscience.