A&P Lecture Exam 3

Examine the cross section through the lumbar section of the spinal cord and the two patellar reflex pathways shown. What identifies these synapses?

1. Pathways will activate one muscle and simultaneously inhibit its antagonist muscle. 2. Afferent impulses synapse with motor neurons and interneurons.

Select the true statements (more than one) about the characteristics of sensory neurons in the stretch reflex.

1. These sensory neurons transmit afferent impulses toward the spinal cord (CNS). 2. When a stretch activates the muscle spindle, these sensory neurons transmit impulses at a higher frequency.

How many ribs make up the rib cage?

24

How many pairs of ribs are considered false ribs?

5

How many pairs of ribs articulate directly with the sternum?

7

The synapse between which of the following two neurons is a part of a monosynaptic reflex arc?

A and B

Examine and characterize the two motor pathways in the stretch patellar reflex.

Alpha motor neurons send efferent messages to the quadriceps, while parallel efferent messages to the hamstrings are reduced.

Order the following terms as they would occur in a typical stretch reflex. Some items may be placed equivalently (in sequential order from left to right); some events may occur simultaneously (statements overlapping).

Answer below

What is the name of the first cervical vertebra?

Atlas

Which vertebra lacks both a body and spinous process?

Atlas

Identify the articulation site that allows us to rotate our head, e.g. shaking the head "no".

Atlas - axis

What is the name of the second cervical vertebra?

Axis

Choose the FALSE statement about nerves.

Axons make up a majority of the matter in a nerve.

Identify the central portion of the sternum.

Body

Which part of a vertebra is known as the centrum?

Body

Severe whiplash, or acceleration flexion-extension neck injury, may cause numbness, tingling, or weakness in an accident victim's arms. Most injuries happen in the C_5 and C_6 region. Which nerve plexus would this injury most likely involve?

Brachial

In which area of the neuron is an action potential initially generated?

C

Remodeling a kitchen to add additional cabinets to existing ones also means adding extra support. In a similar respect, bone remodeling alters bone structure without adversely affecting bone strength. What divalent cation is required to create additional bone matrix support?

Calcium

The groove indicated by C is the __________.

Central sulcus

Mechanical stress on weight-bearing bones plays a large part in bone remodeling. What single factor plays the largest role in maintaining adequate bone strength?

Gravity

Identify the part of a rib that articulates in the demi-facets of the thoracic vertebra.

Head

Name the type of connective tissue that anchors the ribs onto the sternum.

Hyaline cartilage

Individual vertebrae articulate with each other forming the vertebral column. Identify the part of a vertebra that articulates immediately with the vertebra below it.

Inferior articular processes

Which of the following is NOT required for a reflex arc?

Interneurons

Which is the true statement about the synapses in the spinal cord in the stretch reflex?

Interneurons make inhibitory synapses with neurons that prevent contraction of the antagonist muscle.

Which of the following structures would not be found within a vertebral foramen?

Intervertebral discs

What is the largest danger associated with a blood clot that's lodged in a cerebral artery?

Lack of oxygen

Which of these regions of the vertebral column would be most accessible from a posterior surgical approach?

Lamina

Identify the shield shaped top of the sternum.

Manubrium

A Morton's (plantar) neuroma is a foot condition due to swelling of the common plantar digital nerve. It can cause excruciating pain felt between the third and fourth metatarsal bones when walking. Which of the following would NOT be a factor responsible for this disorder?

Nerve thinning

Identify the articulation site that allows us to nod our head "yes".

Occipital bone - atlas

Identify the region of the skull that articulates with the atlas.

Occipital condyles

Which of the following pairings is correct?

Paget's disease; excessive and haphazard bone deposition and resorption

__________ is a progressive degenerative disease of the basal nuclei that affects the dopamine-secreting pathways.

Parkinson's disease

Region A includes which of the following?

Prefrontal cortex

Which of the following is the best description of the function of region B?

Region B includes neurons whose axons carry motor commands from the cerebrum.

Which of the following is NOT one of the basic functions of the nervous system?

Release hormones into the bloodstream to communicate with other cells in the body.

Name the vertebral projection oriented in a median plane.

Spinous process

The letter A in the figure indicates which of the following structures?

Thalamus

A patient sustains a ventral horn injury to the lumbar region of the spine. This injury has damaged the cell bodies of several afferent nerves within the region. Predict how the patient's patellar reflex might be affected.

The patient's patellar reflex would be absent or weak.

Identify a lateral projection of a vertebra.

Transverse process

Identify the region of a rib that articulates with the transverse process of a vertebra.

Tubercle

What part of the sternum is palpated prior to giving CPR?

Xiphoid Process

What type of stimulus is required for an action potential to be generated?

a threshold level depolarization

Classify the neuron at A.

afferent sensory neuron

Which areas of this neuron would be classified as receptive regions?

both A and B

What is the structure at A?

dendrite

Which type of glial cells are shown in this figure?

ependymal cells

Suppose a patient produced more fluid in the structure shown in the figure than could be distributed throughout the ventricles and extracellular fluid. What condition would result?

hydrocephalus

Which of the following refers to a bone disorder found most often in the aged and resulting in the bones becoming porous and light?

osteoporosis

What is the designation of the area at D?

primary visual cortex

The cortical regions indicated by E are involved in what functions?

the production and interpretation of language

Why would imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) be recommended for a patient experiencing sudden aphasia?

to rule out other causes of brain injury