Human Anatomy Chapter 12

There is/are _______ pair(s) of cervical nerve(s), _____ pair(s) of thoracic nerve(s), ____ pair(s) of lumbar nerve(s), ____ pair(s) of sacral nerve(s) and 1 pair of coccygeal nerve.

8 12 5 5

What is a nerve fasicle?

A bundle of axons bound together by connective tissue.

Match the term on the right with the corresponding letter on the left. Ventral root Dorsal root ganglion Spinal nerve Ganglion of sympathetic chain

A: Ventral root B: Dorsal root ganglion C: Spinal nerve D: Ganglion of sympathetic chain

List the components of a stretch reflex

Alpha motor neuron Gamma motor neuron Muscle spindle

Identify the characteristics of reflexes.

Are homeostatic Automatic responses Involuntary Produce consistent results Integrated within the CNS Can be influenced by higher brain centers

The CNS consists of the

Brain and spinal cord

The bundle of spinal nerves extending inferiorly from the conus medullaris is called the ______.

Cauda equina

The hollow space in the center of the gray commissure of the spinal cord that helps to circulate CSF is called the ________.

Central canal

Stretch reflexes cause muscles to ____ and Golgi tendon reflexes cause muscles to ____.

Contract; relax

Match the structures with the correct letters as labeled on the diagram.

Conus medullaris: D Cauda equina: E Filum: F Brain: A Spinal nerves: B Spinal cord: C

Match the structure in the left column to the correct labeled structure in the image.

Denticulate ligament: A Dura mater: C Pia mater: B

An area of the skin supplied with sensory innervation is called a(n) _____.

Dermatome

The ____ rami of spinal nerves innervate most of the deep muscles of the back of the trunk responsible for moving the vertebral column and the _____ rami of spinal nerves innervate the ribs, the intercostal muscles and the skin of the thorax.

Dorsal Ventral

The space between the dura mater and the periosteum of the vertebral canal is the _______ space.

Epidural

List the functions of the spinal cord.

It integrates incoming information. It produces responses through reflex mechanisms. It serves as the link b/t the brain and the PNS.

Match the sensory receptor with the correct reflex.

Pain receptor: Withdrawal reflex Muscle spindles: Stretch reflex Golgi tendon organ: Golgi tendon reflex

Nerve fascicles are surrounded by a connective tissue layer called the _______.

Perineurium

A ______ _______ is the smallest, simplest portion of the nervous system capable of receiving a stimulus and producing a response.

Reflex arc

The basic functional unit of the nervous system is the _____.

Reflex arc

What is the conus medullaris?

Region of the spinal cord where it tapers to a point.

The space between the arachnoid mater and pia mater is the _____ space.

Subarchnoid

The space related to the meninges that contains a small amount of serous fluid is the _______.

Subdural space

The coccygeal plexus innervates _____.

The muscles of the pelvic floor

Place the events of a basic reflex arc in order in which action potentials will pass through.

(1) Sensory receptor detects a stimulus. (2) Sensory neuron conducts action potential to the CNS. (3) Synapse with an interneuron. (4) Synapse with a motor neuron. (5) Motor neuron conducts action potential to an effector organ.

Place the events of a stretch reflex in chronological order.

(1) Muscle spindles detect stretch (2) Sensory neurons conduct action potential to spinal cord. (3) Sensory neurons synapse with an alpha motor neuron. (4) Alpha motor neuron conducts action potential to muscle. (5) Muscle contracts and resists stretching

Identify the largest peripheral nerve.

Sciatic nerve

Dorsal roots consist of only _______ fibers (axons).

Sensory

List the events that occur in withdrawal reflex

Sensory neurons conduct action potentials to the spinal cord. Withdrawal of a body part from the painful stimulus Muscle contraction. Pain receptors detect a painful stimulus.

Place the events of a Golgi tendon reflex in chronological order.

1) Golgi tendon organ detects intense tension applied to tendon. 2) Sensory neuron conducts action potential to spinal cord. 3) Sensory neuron synapses with inhibitory interneurons. 4) Interneurons synapse with alpha motor neuron. 5) Inhibition of alpha motor neurons. 6) Muscle relaxation.

Place the events of a withdrawal reflex in chronological order

1) Pain receptors detect a painful stimulus. 2) Sensory neurons conduct action potentials to the spinal cord 3) Sensory neuron synapses with an excretory interneuron. 4) Excitatory interneuron synapses with an alpha motor neuron 5) Muscle contacts 6) A body part is withdrawn from the painful stimulus

The spinal cord gives rise to _______ pairs of spinal nerves.

31

What is a plexus?

An intermingling of nerves.

Match the structure in the left column with the correct label in the right column.

Anterior median fissure: N Posterior median sulcus: F Lateral column: D Lateral horn: K Dorsal root ganglion: H Ventral root: I Spinal nerve: E Gray commissure: M

The muscles of the hyoid, skin of the neck, the posterior portion of the head and the diaphragm are innervated by the _______ plexus.

Cervical

Identify the regions of the spinal cord.

Cervical Sacral Thoracic Lumbar

Identify the nerves that combine to form the sciatic nerve.

Common fibular nerve Tibial nerve

Collection of cell bodies of sensory neurons that form bulges on the dorsal root are called the _______.

Dorsal root ganglion

Match the structure in the left column with the type of axons found within the structure in the right column. Dorsal root Ventral root Spinal nerve

Dorsal root: Axons of unipolar neurons Ventral root: Axons of multipolar neurons Spinal nerve: Axons of both unipolar and multipolar neurons

Indicate the correct order of meninges from superficial to deep. arachnoid mater dura mater pia mater

Dura mater Arachnoid mater Pia mater

Match the structure to its correct description: Dura mater Arachnoid mater Pia mater Subarachnoid space Subdural space Epidural space

Dura mater: The thickest layer of the meninges Arachnoid mater: A thin, web-like layer of the meninges Pia mater: A thin layer of meninges that adheres tightly to the spinal cord. Subarachnoid space: A space filled with blood vessels and cerebrospinal fluid Subdural space: A space containing serous fluid Epidural space: A space containing spinal nervous roots, blood vessels, areolar connective tissue and adipose tissue

Match the connective tissue component of a nerve with the correct description: Endoneurium Perineurium Epineurium

Endoneurium: Delicate layer of connective tissue surrounding a single axon and its Schwann cell sheath. Perineurium: Layer of connective tissue surrounding a nerve fasicle. Epineurium: A layer of dense connective tissue surrounding a nerve.

Two areas of the spinal cord are thicker than the rest. These areas give rise to the nerves leading to the limbs. These areas are called the cervical and lumbar

Enlargements

Identify the layers of meninges and the related spaces from most superficial to deepest.

Epidural space Dura mater Subdural space Arachnoid mater Subarachnoid space Pia mater

The layer of dense connective tissue binding fascicles together to form a nerve is the _______.

Epineurium

List the layers of connective tissue surrounding nervous tissue starting with the most superficial layer and ending with innermost layer surrounding an individual Schwann cell sheath.

Epineurium Perineurium Endoneurium

Match the term on the right with the corresponding letter on the left. Epineurium Fasicle Schwann cell Endoneurium Perineurium

Epineurium: A Fasicle: D Schwann cell: E Endoneurium: C Perineurium: B

Identify the functions of the ventral rami

Innervate intercostal muscles. Innervate skin over thorax Form nerve plexuses

In an adult, the spinal cord extends down the vertebral column to the level of which vertebrae?

L1-L2

The connective tissue membrane that surrounds the brain and the spinal cord is called ________.

Meninges

Identify characteristics of stretch reflexes

Monosynaptic Helps to control posture Promotes muscle contraction. Does not involve an interneuron.

Ventral roots consist of only ____ fibers (axons).

Motor

The basic structural unit of the nervous system is the _____ and the basic functional unit of the nervous system is the _____ ___.

Neuron Reflex arc

Twelve pairs of cranial nerves and 31 pairs of spinal nerves with their ganglia make up the ________.

Peripheral nervous system

The deepest meningeal layer that is tightly attached to the spinal cord is called the ____ ___.

Pia mater

A complex pathway consisting of two or more interneurons b/t motor neurons is called a ______ reflex.

Polysynaptic

Identify characteristics of Golgi tendon reflexes.

Polysynaptic Prevents excessive damage to tendons.

Which of the following statements correctly describe spinal reflexes.

Spinal reflexes can be influenced by descending tracts. Spinal reflexes can interact with ascending tracts.

What type of reflex helps control posture?

Stretch reflex

The spaces related to the layers of the meninges of the spinal cord include the: _______ space that contains cerebrospinal fluid, the _______ space that contains serous fluid, and the ______ space that contains adipose tissue.

Subarachnoid Subdural Epidural

Match the list of terms on the left with the letters in the picture on the right

Ventral root: J Spinal nerve: I Dorsal root ganglion: H Denticulate Ligament: C Epineurium of spinal nerve: G

The _____ matter of the spinal cord consists of myelinated axons and the ____ matter consists of cell bodies of neurons and dendrites.

White Gray

Match the reflex with the correct function. Withdrawal reflex Stretch reflex Golgi tendon reflex

Withdrawal reflex: Protects structures from painful stimuli by promoting removal of body parts. Stretch reflex: Aids in maintaining posture by promoting muscular contraction when muscles are stretched. Golgi tendon reflex: Prevents damage caused by excessive tension by inhibiting muscular contraction.