Exam 3

What important function could be diminished if the cilia on ependymal cells were absent?

Circulation of cerebrospinal fluid could be negatively affected if cilia on ependymal cells were absent.

T/F - A neuron is a collection of nerve fibers in the PNS.

False

T/F - All arteries carry oxygen-rich blood, whereas veins carry oxygen-poor blood.

False

T/F- The correct sequence of heart wall layers from superficial to deep is epicardium, endocardium, and myocardium.

False

How are gray matter and white matter arranged in the CNS?

Gray matter is deep to the superficial white matter in the spinal cord.

Which of the following statements describes interneurons?

Interneurons are multipolar neurons that are confined to the CNS and are linked together in chains that form complex neuronal pathways.

Which valve(s) of the heart are forced closed when blood tries to flow back into the ventricles at the end of a cardiac cycle?

Pulmonary semilunar valve, Aortic semilunar valve

Which of these conduction sequences through the heart is correct?

SA node, AV node, AV bundle, bundle branches, Purkinje fibers

Which structure is responsible for formation of the regeneration tube following injury to an axon?

Schwann cells, The Schwann cells that surrounded the damaged axon form a regeneration tube and direct the route of the regrowing axon.

What is the common result of all types of anemia if medical treatment is not administered?

The blood's capacity for carrying oxygen is diminished.

Which numbered structure carries the efferent signal?

The efferent signal is carried on the motor axon from the CNS to the effector organ.

Which statement concerning the pulmonary arteries is FALSE?

The pulmonary arteries carry oxygenated blood back from the lungs to the heart.

What is SIMILAR between the pulmonary artery and a systemic artery?

They both have smooth muscle, They both lead away from the heart, They both are more elastic than veins

What is the function of valves in veins?

They counteract low venous pressure, and prevent backflow of blood away from the heart.

Which valve(s) of the heart functions to prevent blood from flowing into the right atrium when the right ventricle is contracting?

Tricuspid valve

What is the most likely function of the neuron illustrated here? (unipolar neuron)

a sensory neuron, Most sensory neurons (but not all) are unipolar neurons.

Which symptom is LEAST suggestive of a cerebellar disorder?

abnormal and painful sensations in one's legs and feet, While proprioception is monitored by the cerebellum, other sensory inputs such as pain are not. Painful sensations in the legs and feet suggest other problems, such as poor circulation.

Which of the following is associated with Alzheimer's disease?

accumulation of protein plaques around neurons

Blood moves from the left ventricle into what vessel?

ascending aorta

This tends to be the longest cytoplasmic projection from a neuron.

axon

Vesicles containing neurotransmitters are located in

axon terminals.

When the ventricles relax, intraventricular pressure falls and

blood is pushed against the semilunar valves, causing them to close

Which of these regions of the brain has frontal, parietal, temporal, and occipital lobes, as well as the insula?

cerebrum

Trace the path of circulation of cerebral spinal fluid (CSF) from production to absorption.

choroid plexus, ventricles of the brain, subarachnoid space, arachnoid villi, superior sagittal sinus, CSF is produced in the choroid plexus of each ventricle. It circulates through the CNS and is eventually reabsorbed into the vascular system at the arachnoid villi.

The basic components of the peripheral nervous system are __________ and __________.

cranial nerves; spinal nerves

Which layer of the heart wall is visceral pericardium?

epicardium, The epicardium is the visceral pericardium, the outer layer of the heart wall.

Which formed elements of blood are most abundant?

erythrocytes, Erythrocytes compose 45% of whole blood (blood cells and plasma) and make up the largest component of the formed elements.

Regeneration of peripheral axons requires

formation of a tube by Schwann cells to guide growth.

In which direction does the nerve signal pass at the synapse illustrated here?

from presynaptic axon terminal to postsynaptic dendrite, Neurotransmitters released from the axon terminal of the presynaptic neuron bind to the receptor sites on the dendrites (or on the soma) of the postsynaptic neuron, thus transmitting the signal from one neuron to the next.

Areas of the cerebral cortex involved with the initiation of motor impulses are localized to the posterior aspect of the __________.

frontal lobe

Which lobe of the cerebrum is responsible for planning and initiating voluntary motor movement?

frontal lobe, The premotor cortex and the primary motor cortex are located in the frontal lobe of the cerebrum.

The diencephalon develops into the thalamus, the epithalamus, and what other structure?

hypothalamus

The somatic sensory division of the PNS

includes general senses of pressure, pain, vibration, and temperature in body wall and limbs

The heart chamber that pumps oxygenated blood around the systemic circuit is the

left ventricle

The buffy coat that is present in a centrifuged tube of whole blood contains

leukocytes and platelets

Which part or parts of the neuron are found in the white matter of the central nervous system?

long axonal processes, The white matter of the CNS is composed of long myelinated and nonmyelinated axons. All neuronal cell bodies are located in gray matter in the CNS.

Which structure anchors the chordae tendinae of the atrioventricular valves?

papillary muscle, The papillary muscles are extensions from the ventricular wall that connect to the chordae tendinae. Upon ventricular contraction, the papillary muscles contract to prevent the atrioventricular valves from everting into the atria.

Cell fragments, also called thrombocytes, involved in clotting.

platelets

What is the function of the chordae tendineae and papillary muscles of the bicuspid and tricuspid valves?

preventing eversion of the valves into the atria

The valve responsible for preventing backflow of blood from the lungs into the heart.

pulmonary semilunar valve

Which vessel carries oxygenated blood?

pulmonary vein, Blood returning to the heart from the lungs is oxygenated.

Which of the following sequences puts the components of a reflex arc in the correct order of their activation?

receptor, sensory neuron, CNS integration center, motor neuron, effector

Where are blood cells produced postnatally?

red bone marrow located in spongy bone, After birth, blood cells are produced only in the red bone marrow found in spongy bone. The embryonic locations of blood cell formation, the spleen and liver, may become active postnatally in extreme situations.

Plasma minus clotting factors.

serum

Wide leaky capillaries found in bone marrow and spleen.

sinusoids

Which vessels drain into the right atrium?

superior and inferior vena cava and the coronary sinus

Which of these regions functions to direct nearly all sensory input, except olfactory impulses, to the cerebral cortex?

thalamus

Cell bodies of the sensory neurons of the spinal nerves are located in

the dorsal root ganglia external to the spinal cord.

The right ventricle pumps blood into which vessel?

the pulmonary trunk

Which of the following vessels does not carry oxygen-poor blood to the heart?

the pulmonary vein

In sickle cell disease

there is a genetic defect in the hemoglobin gene that results in a defective hemoglobin molecule

To what depth must an injection of anesthetic be inserted to numb the spinal cord and thus relieve pain caudal to that area?

to the depth of the epidural space, Anesthetics are injected at this depth to relieve pain inferior to the site of injection. For example, during labor, mothers will have an "epidural" to relieve the pain.

Which layer of blood vessels contains smooth muscle tissue?

tunica media

Microvasculature that provides nourishment to the outer walls of the aorta.

vasa vasorum

The semilunar valves prevent backflow of blood into the

ventricles, The pulmonary valve prevents backflow into the right ventricle; the aortic valve prevents backflow into the left ventricle.

If the beating heart makes a "lub-dup" sound, the "dup" sound is caused by

vibrations that result from the semilunar valves slamming shut.

Motor innervation to the stomach is classified as __________ .

visceral motor, Visceral motor neurons from the autonomic nervous system innervate the smooth muscle and glands of the stomach.