Fundamentals of A&P Chapter 13 (spinal cord)

What types of neurons contain the anterior, posterior and the lateral gray horn?

-Anterior: somatic motor nuclei -Posterior: somatic and visceral sensory nuclei -Lateral (located only in the thoracic and lumbar segments) : visceral motor nuclei

The sacral plexus consists of

Anterior rami of S2-S4

Lumbar plexus consists of

Anterior rami of spinal nerves T12-L4

Name the branches of the sciatic nerve

As it approaches the knee, the sciatic nerve divides into: Fibular nerve Tibial nerve

What is quadriplejia?

Quadriplegia: also known as tetraplegia, is a paralysis of the four limbs Paraplegia: impairment in motor or sensory function of the lower extremities

What is the subarachnoid space?

Region between arachnoid mater and pia mater, and it is filled with CSF

The ascending tracts carry information to the .......

Sensory information to the brain

Name the specialized membranes that protect the spinal cord. Name the membranes that protect the brain. Name the meninges in order.

Spinal meninges are a series of specialized membranes surrounding the spinal cord and are continuos with the cranial meninges. 1. Dura mater 2. arachnoir mater 3. Pia mater

A Babinski reflex is a sign of injury to descending spinal tracts, it is normal in newborns, it is abnormal in adults. It is the flaring of the toes when the sole is stroked. (T, F)?

TRUE

A viral disease that destroys the cells of the anterior gray horn will lead to muscle weakness or paralysis (T, F)

TRUE

Each segment is associated with a pair of dorsal root ganglia (true or false)

TRUE

Each segment is designated by a letter and number (true or false)

TRUE

Enlargements of the spinal cord occur in the spinal segments that control the limbs(T,F)

TRUE

Every spinal cord segment is connected to a pair of spinal nerves (true or false)

TRUE

Every spinal nerve is surrounded by a layer of connective tissue named epineurium(T, F)?

TRUE

If the dorsal root of the spinal nerve is injured, sensory input would be blocked (T, F)

TRUE

Plexuses are complex, interwoven networks formed by contributions from the ventral rami of neighboring spinal nerves (T,F)

TRUE

The anterior gray horn contain somatic motor neurons (T, F)

TRUE

The brachial plexus consists of ventral rami from C5 to T 1 (T, F)

TRUE

The dorsal root ganglia mainly contain cell bodies of Sensory neurons (T, F)?

TRUE

The femoral nerve belongs to the lumbar plexus (T, F)?

TRUE

The flexor reflex moves a limb away from a painful stimulus (T,F)?

TRUE

The gray matter contains mainly cell bodies (T,F)

TRUE

The inferior limit of the Spinal cord is: LI or L II (true or false

TRUE

The lateral gray horn contain neurons that control visceral portion of the nervous system (T,F)

TRUE

The outward projections from the gray matter of the spinal cord are called Horns (T, F).

TRUE

The post ganglionic fibers that connect an autonomic ganglion in the thoracic or lumbar regions of the spinal cord are gray rami communicants (true or false)

TRUE

The posterior gray horn of the spinal cord contain mainly somatic sensory neurons (T,F )

TRUE

The preganglionic fibers connect a spinal nerve with an autonomic ganglion (true or false)

TRUE

The sciatic nerve belongs to the sacral plexus (T, F)?

TRUE

The spinal cord is shorter than the spinal canal (true or false)

TRUE

The spinal nerve forms lateral to the intervertebral foramen (true or false)

TRUE

The subdural space lies between the duramatter and the arachnoid matter (T,F)?

TRUE

The ventral rami form plexuses (T, F)?

TRUE

The ventral rami innervate the ventrolateral body surfaces and limbs (T, F)?

TRUE

The white matter contains mainly Myelinated axons (T,F)

TRUE

The white matter of the spinal cord contains bundles of axons that share common origins destinations and functions, they are called tracts (t,f)

TRUE

The withdrawn of the CSF in performed in the subarachnoid space (T, F)?

TRUE

When the dorsal and ventral roots unite, they form the Spinal nerve (T, F)?

TRUE

The epidural space contains connective tissue (adipose and blood vessels) (T,F)? The epidural space is used to

TRUE Anesthetics are often injected into the epidural space

The white matter contains bundles of axons with common origin, destination and function (T, F).

TRUE Each column of the white matter contain tracts, whose axons share functional and structural characteristics.

What is the gray commisure? Axons crossing from one side of the spinal cord to the other within the gray matter are found here (T,F)?

TRUE Narrow bridge of gray matter

What is a plexus? The plexuses are networks of ventral rami only (true or false)

TRUE Plexuses are a complex interwoven network of nerves.

The dorsal root consists of the axons of sensory neurons. (T, F)? What type of information is carried by the dorsal or posterior root?

TRUE Posterior roots bring sensory information into the spinal cord

The spinal cord continues to elongate and enlarge until what age?

4 years

Describe the spinal cord, including location, length, width and limits

45 cm (18 in) long width of 14 mm (0.55 in) it extends from the brain to L1-L2

In the thoracic region the ventral rami of the spinal nerves do not form plexus(T,F)?

TRUE

The cervical plexus consists of the ventral rami from C1-C5 (true or false)

TRUE

Dorsal ramus innervate skin and muscles of the back (T, F)?

TRUE

What is an innate reflex?

basic neural reflexes formed before birth

The bundle of axons is surrounded by the

perineurium

What are the nuclei? What are the ganglia? What is a nerve? What is a tract?

-Ganglia: contain cell bodies of sensory neurons. Associated with every spinal segment. -Nerve: distal to each spinal ganglion, the sensory and motor roots are bound together to form a single spinal nerve. - Nuclei: masses of gray matter within the CNS. There are both sensory and motor -Tract: Bundle of axons in the CNS.

How many pairs of spinal nerves are there?

31 pairs

How many plexuses are there? Name them

4 plexuses: cervical, brachial, lumbar, sacral

The cervical portion consists of ------------segments

8 segments

What is a neural reflex? Characteristics of the neural reflex

A reflex is a rapid and automatic response to a specific stimulus. In a neural reflex, sensory fibers deliver information from peripheral receptos to an integration center in the CNS, and motor fibers carry motor commands to peripheral effectors

Every individual axon is surrounded by

Endoneurium

What is the denticulate ligament? Function of it

Extend from piamater to duramater Prevent side-to-side movements

The cervical plexus innervates muscles of the neck and shoulder (T, F)

FALSE The cervical plexus innervates the mucles of the neck and extend into the thoracich cavity where they control the diaphragm

What is a neuronal pool? Name the neuronal circuit patterns

Functional groups of interconnected neurons. Five ciurcuit patterns: divergence, convergence, serial processing, parallel processing and reverberation

Describe the position of the white matter in the spinal cord. Describe the position of the gray matter in the spinal cord.

GRAY MATTER: forms an H surrounding the central canal. Formed by cell bodies. WHITE MATTER: has three regions (columns): posterior, anterior and lateral. Formed by axons

Structures innervated by the communicantes rami

Innervate glands and smooth muscles in the body wall and limbs

The spinal tap is performed at what level? Cervical, thoracic, lumbar, sacral? Why?

It is also called lumbar puncture, and is a procedure to withdraw CSF from the subarachnoid space

Functions of the epidural block?

It is commonly used as a method of pain control during labor and delivery. Provides mainly sensory anesthesia. Affects only the spinal nerves in the immediate area of the injection.

Name the nerves of the brachial plexus.

Musculocutaneous nerve (lateral cord) Median nerve (lateral and medial cords) Ulnar nerve (medial cord) Axillary nerve (posterior cord) Radial nerve (posterior cord)

What is a shingle? In the condition, a virus infects dorsal root ganglia causing a painful rash whose distribution corresponds to that of the affected sensory nerves as seen in their dermatomes (T.F)?

TRUE Shingles are caused by the varicella-zoster virus, the same that causes chickenpox.

The subarachnoid space contains CSF. Function of the CSF.

TRUE The CSF acts as a shock absorber and a diffusion medium for dissolved gases, nutrients, chemical messengers and wastes

The anterior root consists of the axons of motor neurons. (T, F)? What type of information is carried by the anterior or ventral root?

TRUE The anterior root contains the axons of motor neurons that extend into the periphery.

Where are found the blood vessels that supply directly the spinal cord? The piamater is the layer that is in direct contact with the spinal cord. (T,F)?

TRUE The blood vessels that supply the spinal cord run along the surface of the pia mater, within the subarachnoid space

What is the conus medullaris? In an adult the conus medullaris ends at the level of the LI or LII (true or false)

TRUE The conus medullaris is a region inferior to the lumbosacral enlargement, where the spinal cord becomes tapered and conical

What is the fillum terminalis? Function of the fillum terminalis. It provides longitudinal support as a component of a coccygeal ligament (T,F)

TRUE The fillum terminalis is a slender strand of fibrous tissue that extends from the tip of the conus medullaris. It continues as far as the second sacral vertebra and provides longitudinal support.

Phrenic nerve is one of the nerves of the cervical plexus. The phrenic nerve innervates the diaphragm. If a person has a crush injury to the CIII- C IV spinal segments. You would expect that he might be unable to breathe on his own. Why?

TRUE The phrenic nerve originates between c3-c5 and innervates the diaphragm

Post ganglionic fibers of the Autonomic Nervous System that innervate internal organs do not rejoin the spinal nerve but form the Autonomic Nerves (T, F)?

TRUE They form sympathetic nerves

The though fibrous, outermost covering of the spinal cord is the duramater (T,F)?

TRUE This is the outermost membrane

What is the meningitis? Bacterias, viruses can be the cause of the inflammation of the meninges. The cerebro spinal fluid flow can be disrupted (T, F)?

TRUE is a rare infection that affects the meninges. There are several types of this disease, including bacterial, viral, and fungal

What type of information carries the spinal nerve? It is mixed information (T, F)?

TRUE they contain both afferent (sensory) and efferent (motor) fibers.

The gray horns of the spinal cord contain mainly cell bodies (T,F)

TRUE. Masses of gray matter are called nuclei. (sensory or motor)

What is the cervical enlargement? Importance of the cervical enlargement. What is the lumbar enlargement? Importance of the lumbar enlargement

The enlargements are segments where the amount of gray matter is greater. Dedicated to sensory and motor control of the limbs. -Cervical enlargement: supplies nerves to the shoulder and upper limbs -Lumbar enlargement: supplies nerves to the pelvis and lower limbs.

The spinal cord consists of how many segments. What is a spinal segment?

The spinal cord is divides into 31 segments on the basis of the origins of the spinal nerves

How many segments contain the thoracic, lumbar, sacral and coccigeal portion?

Thoracic: 12 segments lumbar: 5 segments sacral: 5 segments coccigeal: 1 segment

Name the branches of the spinal nerve

Ventral rami Dorsal rami. Communicans (White and Gray ramus)

What are the white and the gray rami communicants?

White ramus communicans contain myelinated axons Gray ramus communicans contain unmyelinated fibers.

Number of cervical, thoracic, lumbar, sacral and coccigeal spinal nerves

cervical: 8 nerves thoracic: 12 nerves lumbar: 5 nerves sacral: 5 nerves coccigeal: 1 nerve

The descending tracts carry motor commands to the---

motor command to the spinal cord