Chapter 17 & 15 Mastering A&P

How many oxygen molecules can be transported by one hemoglobin molecule?

4

Ling, a 75-year-old grandmother, complained that her vision was becoming obscured. Upon examination by an ophthalmologist she was told she had cataracts. What are cataracts, how do they occur, and how are they treated?

A cataract is a clouding of the lens. Some cataracts are congenital, but most are due to age-related hardening and thickening of the lens, diabetes mellitus, or exposure to UV rays over time. The lens can be removed and replaced with an artificial lens.

Which part of the inner ear houses receptors for angular (rotational) movement of the head? Select from choices A-D.

A,

Which of these parts of the ear can be affected by otitis media?

A, inner ear

Which plasma constituent is the main contributor to osmotic pressure?

Albumin Albumin, produced by the liver, makes up 60% of plasma proteins and is the main contributor to osmotic pressure.

Helps maintain the intraocular pressure; located in the anterior part of the eye.

Aqueous humor

Which of the following scenarios would most likely result in HDN (hemolytic disease of the newborn)?

B- female pregnant with an AB+ baby Hemolytic disease of the newborn (HDN) can develop when an Rh- mother carries an Rh+ fetus. HDN is unlikely to develop in an Rh- female's first pregnancy with an Rh+ baby. Rather, it is in a subsequent pregnancy with an Rh+ baby that HDN can develop.

Which of the following statements does not describe blood? Blood pH is normally between 7.35 and 7.45. Blood is denser and more viscous than water. Blood carries body cells to injured areas for repair. Blood varies from bright red to a dark red color.

Blood carries body cells to injured areas for repair.

Which of the following statements is true? Contraction of the ciliary muscles is required for myopic individuals to clearly see distant objects. Relaxation of the ciliary muscles is required for hyperopic individuals to clearly see nearby objects. Contraction of the ciliary muscles is required for hyperopic individuals to clearly see distant objects. All of the listed responses are true.

Contraction of the ciliary muscles is required for hyperopic individuals to clearly see distant objects. Persons who are farsighted (hyperopia) can see distant objects because their cillary muscles are in a state of continuous contraction that moves the object forward to focus it on the retina.

Choose the compatible transfusion. Donate type AB blood to a recipient with type B blood; Donate type A blood to a recipient with type B blood; Donate type O blood to a recipient with type AB blood; Donate type B blood to a recipient with type O blood.

Donate type O blood to a recipient with type AB blood. Type O is the universal donor since these RBCs would lack A and B agglutinogens. People with type O blood can give blood to all the ABO blood groups.

Which of the following is true of the structure of an erythrocyte? Erythrocytes are cell fragments. Erythrocytes are nucleated cells. Erythrocytes are a fixed shape and cannot change shape. Erythrocytes are shaped like biconcave discs.

Erythrocytes are shaped like biconcave discs.

Each hemoglobin molecule can transport two molecules of oxygen.

False

Hemoglobin is made up of the protein heme and the red pigment globin.

False

Sound is generally perceived in the occipital lobe of the cerebral cortex.

False

The anterior chamber of the eye is filled with vitreous humor

False

The process of fibrinolysis disposes of bacteria when healing has occurred.

False

The normal RBC "graveyard" is the liver.

False, spleen

Which of the following does NOT stimulate erythrocyte production?

Hyperventilating Hyperventilating leads to an above-normal level of oxygen in the blood, which would not stimulate RBC production.

Even though we have two eyes, why do we normally see only one image?

Information from each eye goes to both hemispheres for processing. Notice that both eyes are set anteriorly and look in approximately the same direction. Their visual fields, each about 170 degrees, overlap to a considerable extent, and each eye sees a slightly different view. The visual cortex fuses the slightly different images delivered by the two eyes, providing us with a single image and depth perception (or three-dimensional vision), an accurate means of locating objects in space.

What structure regulates the amount of light passing to the visual receptors of the eye?

Iris

Which of the following is true about blood plasma? It contains about 20 dissolved components. The main protein component is hemoglobin. It is about 90% water. It is the same as serum but without the clotting proteins.

It is about 90% water.

Which of the following is a role of the vitreous humor? It supplies oxygen to the cornea. It carries away the metabolic waste of retinal cells. It supports the posterior surface of the lens. It supplies nutrients to the lens of the eye.

It supports the posterior surface of the lens. The posterior segment of the eye is filled with a clear gel called the vitreous humor that binds tremendous amounts of water. Functions of vitreous humor include: transmitting light; supporting the posterior surface of the lens and holding the neural layer of the retina firmly against the pigmented layer; and contributing to intraocular pressure, helping to counteract the pulling force of the extrinsic eye muscles. The vitreous humor forms in the embryo and lasts for a lifetime.

The structure most responsible for focusing light rays that enter the eye.

Lens

In a cancer patient undergoing chemotherapy, the decision to utilize a CSF capable of specifically stimulating the production of only the granular leukocytes would require that the CSF acts exclusively on ______.

Myeloblasts. Myeloblasts are the precursor cells that ultimately form basophils, eosinophils, and neutrophils.

Tinnitus, vertigo, and gradual hearing loss typify the disorder called ________.

Ménière's syndrome

Which leukocyte functions in phagocytizing bacteria?

Neutrophil Neutrophils phagocytize bacteria.

When neither anti-A serum nor anti-B serum cause clumping (agglutination) of donor cells on a slide, the blood type is ________.

O

Which ABO blood type is considered to be the universal donor?

O

A person who lacks agglutinogens A and B would have blood type __________.

O Agglutinogen are glycoprotein found on the surface of erythrocytes. A person with type O blood lacks agglutinogen A and B on their red blood cells.

Which of the following represents a difference between extrinsic and intrinsic blood clotting pathways?

One is faster than the other. The extrinsic pathway is faster than the intrinsic pathway.

Which of the following is correctly matched?

Pernicious anemia: results from a vitamin B12 deficiency

Dancers will use a technique called "spotting" when they perform spins of the body. By holding their head and eyes on a fixed point in front of them as their body spins they reduce the amount of head spinning and this prevents dizziness. Which of the following is the most likely explanation for why this works?

Reducing the inertia of head spin will reduce the flow of endolymph that deflects the hair cells of the crista ampullaris.

A total WBC count and a differential WBC count have been ordered for Mrs. Johnson. What information is obtained from the differential count that the total count does not provide?

The differential count determines the relative proportion of individual leukocyte types. The total WBC count indicates an increase or decrease in number of WBCs.

Which of the following is characteristic of all leukocytes? They are phagocytic. They are the most numerous of the formed elements in the blood. They are nucleated. They have cytoplasmic granules.

They are nucleated.

All lymphocytes are leukocytes, but not all leukocytes are lymphocytes.

True

In order for sound to reach the spiral organ (of Corti), the auditory ossicles must vibrate the oval window and set the endolymph in motion.

True

Leukemia refers to cancerous conditions involving white blood cells.

True

Leukopenia is an abnormally low number of leukocytes.

True

The function of the lens of the eye is to allow precise focusing of light on the retina.

True

The optic disc forms a blind spot where the optic nerve leaves the eyeball

True

When we move from darkness to bright light, retinal sensitivity is lost, but visual acuity is gained.

True

Without a functioning crista ampullaris, the semicircular canals would not function.

True

Fetal hemoglobin has a higher affinity for oxygen than does adult hemoglobin.

True.

What is an embolus?

a blood clot that has broken loose and is floating freely in the blood stream An embolus is a blood clot (thrombus) that has broken away from the vessel wall and is floating freely in the bloodstream.

Which blood component primarily contributes to plasma osmotic pressure?

albumin

During erythroblastosis fetalis, a Rh- mother's anti-Rh antibodies that have crossed the placenta will cause agglutination of the fetus's Rh+ RBCs. However, the reverse problem never happens when a Rh+ mother is pregnant with a Rh- fetus, that is, antibodies produced by the fetus cannot cause agglutination of the mother's Rh+ RBCs. This is true because ______.

antibodies that can cause this agglutination are not produced by a fetus The fetus does not produce antibodies because the immune system is immature.

When we take anti-histamines, we are countering the effects of which type of leukocyte?

basophils

Specifically, what is the production of red blood cells called?

erythropoiesis

Which of the following is not a phase of hemostasis? fibrinolysis platelet plug formation coagulation vascular spasm

fibrinolysis

Area of greatest visual acuity

fovea centralis

Which pairing of terms is incorrectly related?

frequency of sound waves: loudness of the sound

The cells of the retina in which action potentials are generated are the ________.

ganglion cells

Which of the following is NOT a function of blood?

hormone production The blood does not produce hormones.

Farsightedness is more properly called ________.

hyperopia

Which region of the ear is involved in detection of both hearing and equilibrium?

inner ear, C

During otitis media, large amounts of fluid or pus may accumulate in the tympanic cavity; the fluid is primarily ______.

interstitial fluid Interstitial fluid is the fluid between cells. Pus is a thin, protein-rich fluid that consists of tissue fluid, dead cells, and immune cells found at a sight of inflammation.

If the optic chiasma is destroyed but the rest of the visual pathway to the brain is not damaged, the result would be ______.

loss of peripheral vision on both the far right and far left sides of the visual field At the optic chiasm, the nerves from the medial aspect of each optic nerve (retina) cross to the opposite side. The lens system reverses all images so the medial half of each retina receives light rays from the most lateral part of the visual field and the lateral retina receives images from the most medial visual field.

All of the following can be expected with polycythemia except ________. high hematocrit increased blood volume high blood pressure low blood viscosity

low blood viscosity

Which type of leukocyte is responsible for antibody production?

lymphocytes

The receptor for static equilibrium is the ________.

macula

What condition results when distant objects focus in front of the retina, rather than on it?

myopia

When a person has an acute bacterial infection, such as meningitis or appendicitis, which type of leukocyte increases in number?

neutrophils

The most abundant leukocytes are __________.

neutrophils Neutrophils are the most numerous of the circulating leukocytes at 50-70%.

Visual processing in the thalamus does not contribute significantly to ________.

night vision

Most newborns ________.

often use only one eye at a time.

What part of the eye constitutes the blind spot?

optic disc The optic disc, where the optic nerve exits the eye, is a weak spot in the posterior wall of the eye because it is not reinforced by the sclera. The optic disc is also called the blind spot because it lacks photoreceptors, so light focused on it cannot be seen. Nonetheless, we do not usually notice these gaps in our vision because the brain uses a sophisticated process called filling in to deal with absence of input.

Blood volume restorers include all of the following except ________. packed cells albumin dextran saline solutions

packed cells

Which of the following structure is NOT part of the external ear? pinna tympanic membrane external acoustic meatus pharyngotympanic tube

pharyngotympanic tube

The majority of whole blood is __________.

plasma

What "clot buster" enzyme removes unneeded clots after healing has occurred during fibrinolysis?

plasmin

An abnormal excess of erythrocytes is called __________.

polycythemia. An abnormal excess of erythrocytes is called polycythemia.

What triggers erythropoietin (EPO) production to make new red blood cells?

reduced availability of oxygen

The sensory layer of the eye

retina

Which of the following is NOTan accessory structure of the eye? conjunctiva retina eyelid lacrimal apparatus extrinsic eye muscles

retina The retina is a part of the eye (not an accessory structure). The accessory structures of the eye include the eyebrows, eyelids, conjunctiva, lacrimal apparatus, and extrinsic eye muscles.

During dark adaptation ________.

rhodopsin accumulates in the rods

Identify the region that belongs to the fibrous layer of the eye

sclera

If you shine a light into one eye both pupils will constrict. The best explanation for this is ________.

sensory input from the retinas of both eyes converges at the optic chiasm and information from each eye is delivered to both the left and right sides of the brain.

Which of the following would not be a possible cause of sickling of red blood cells in someone with sickle-cell anemia? sleeping in a well-ventilated room vigorous exercise malaria and travel at high altitude travel at high altitude

sleeping in a well-ventilated room

Which of the following is the receptor organ for hearing?

spiral organ (of Corti) The cochlear duct (of the cochlea) houses the receptor organ of hearing, called the spiral organ or the organ of Corti. It responds to fluid movement (vibration) in the cochlea generated by the tympanic membrane and transmitted by the middle ear ossicles.

Hemostasis leads to __________.

stoppage of bleeding Hemostasis leads to stoppage of bleeding. The hemostasis response is fast, localized, and controlled. It involves clotting factors and substances released by damaged tissue and platelets.

Congenital sensorineural deafness most commonly involves damage to ______.

the cochlear hair cells The mesenchyme of the ectoderm will eventually form the bony labyrinth of the inner ear. Sound waves distort the cochlear hair cells, resulting in stimulation of the cochlear nerve. Loss of these hairs results in deafness.

Which of the following is not a distribution function of blood? transport of salts to maintain blood volume transport of hormones to their target organs transport of metabolic wastes from cells delivery of oxygen to body cells

transport of salts to maintain blood volume

The first step in hemostasis is __________.

vascular spasm The first step of hemostasis is vascular spasm. In this step, the damaged vessel constricts to limit blood loss.

What is the main function of the rods in the eye?

vision in dim light

In a centrifuged sample of blood, what makes up the buffy coat?

white blood cells and platelets The buffy coat (the creamy white zone between the yellowish plasma and the red erythrocytes) consists of white blood cells and platelets. It constitutes less than 1% of whole blood.