Histology Midterms

Question 1

The basal lamina of a muscle fiber is part of which structure?
a. Perimysium
b. Epimysium
c. Fascia
d. Endomysium
e. Sarcoplasmic reticulum

Answer 1

d. Endomysium

Question 2

With the transmission electron microscope skeletal muscle fibers can be seen to contain structures called triads. What do the two lateral components of a triad represent?
a. Attachment sites for thick myofilaments
b. Sites for calcium sequestration and release
c. Sites for impulse conduction into the fiber
d. Sites for ATP production
e. Sites for synthesis of proteins to be secreted outside the cell

Answer 2

b. Sites for calcium sequestration and release

Question 3

Which characteristic is unique to cardiac muscle?
a. Contain centrally located nuclei
b. Striated
c. Often branched
d. Multinucleated
e. Lack T-tubules

Answer 3

c. Often branched

Question 4

In smooth muscle calcium released by the smooth ER initiates contraction by binding to what protein?
a. Actin
b. Calmodulin
c. Desmin
d. Myosin light chain kinase
e. Tropomyosin

Answer 4

b. Calmodulin

Question 5

Which feature typifies T-tubules?
a. Evaginations of the sarcoplasmic reticulum
b. Sequester calcium during muscle relaxation, releasing it during contraction
c. Carry depolarization to the muscle fiber interior
d. Overlie the A-I junction in cardiac muscle cells
e. Rich supply of acetylcholine receptors

Answer 5

c. Carry depolarization to the muscle fiber interior

Question 6

Which characteristic is unique to smooth muscle?
a. T-tubules lie across Z lines
b. Each thick filament is surrounded by six thin filaments
c. Thin filaments attach to dense bodies
d. Cells are multinucleated
e. Cells have centrally located nuclei

Answer 6

c. Thin filaments attach to dense bodies

Question 7

In one type of muscle, numerous gap junctions, desmosomes, and adherens junctions are specifically localized in which structures?
a. Myofilaments
b. Dense bodies
c. Sarcomeres
d. Neuromuscular spindles
e. Intercalated discs

Answer 7

e. Intercalated discs

Question 8

A 66-year-old man who lives alone has a severe myocardial infarction and dies during the night. The medical examiner’s office is called the following morning and describes the man’s body as being in rigor mortis. This state of rigor mortis is due to which one of the following?
a. Inhibition of Ca2+ leakage from the extracellular fluid and sarcoplasmic reticulum
b. Enhanced retrieval of Ca2+ by the sarcoplasmic reticulum
c. Failure to disengage tropomyosin and troponin from the myosin active sites
d. Absence of ATP preventing detachment of the myosin heads from actin
e. Increased lactic acid production

Answer 8

d. Absence of ATP preventing detachment of the myosin heads from actin

Question 9

A 5-year-old boy sustains a small tear in his gastrocnemius muscle when he is involved in a bicycle accident. Regeneration of the muscle will occur through which of the following mechanisms?
a. Dedifferentiation of muscle cells into myoblasts
b. Differentiation of muscle satellite cells
c. Fusion of damaged myofibers to form new myotubes
d. Hyperplasia of existing muscle fibers
e. Differentiation of fibroblasts to form myoblasts

Answer 9

b. Differentiation of muscle satellite cells

Question 10

A healthy 32-year-old man lifts weights regularly as part of his workout. In one of his biceps muscle fibers at rest, the length of the I band is 1.0 μm and the A band is 1.5 μm. Contraction of that muscle fiber results in a 10% shortening of the length of the sarcomere. What is the length of the A band after the shortening produced by muscle contraction?
a. 1.50 μm
b. 1.35 μm
c. 1.00 μm
d. 1.90 μm
e. 0.45 μm

Answer 10

a. 1.50 μm

Question 11

Vasa vasorum serve a function analogous to that of which of the following?
a. Valves
b. Basal lamina
c. Coronary arteries
d. Endothelial diaphragms
e. Arterioles

Answer 11

c. Coronary arteries

Question 12

What tissue is directly associated with and extends into the heart valves?
a. Myocardium
b. Epicardium
c. Atrioventricular bundle of His
d. Cardiac skeleton
e. Pericardium

Answer 12

d. Cardiac skeleton

Question 13

Which of the following is true for ventricles?
a. Located at the base of the heart
b. Myocardial cells contains abundant granules
c. Receive blood directly from the venae cavae and pulmonary veins
d. Walls contain Purkinje fibers of the right and left branches from the atrioventricular bundle
e. Contain more elastic fibers than the atria

Answer 13

d. Walls contain Purkinje fibers of the right and left branches from the atrioventricular bundle

Question 14

Individuals with Marfan syndrome have mutations in the fibrillin gene and commonly experience aortic aneurisms. What portion of the arterial wall is most likely to be affected by the malformed fibrillin?
a. Endothelium
b. Tunica intima
c. Tunica media
d. Tunica adventitia
e. Vasa vasorum

Answer 14

c. Tunica media

Question 15

Which description is true of continuous capillaries?
a. Unusually wide lumens
b. Most common in both brain and muscle
c. Abundant fenestrations
d. Lack a complete basement membrane
e. Phagocytic cells often seen inserted in the intercellular clefts

Answer 15

b. Most common in both brain and muscle

Question 16

Which of the following is true of pericytes?
a. Are associated with the basal lamina of capillary endothelial cells
b. Have similar histological features as contractile cells of the myocardium
c. Form a layer of cells joined by gap junctions
d. Are terminally differentiated
e. Capable of forming multinucleated muscle fibers

Answer 16

a. Are associated with the basal lamina of capillary endothelial cells

Question 17

During light microscopic examination of a tissue, you note a vessel that has no smooth muscle but a large amount of connective tissue at its periphery. Which of the following vessels are you examining?
a. Arteriole
b. Venule
c. Elastic artery
d. Capillary
e. large vein

Answer 17

b. Venule

Question 18

A 43-year-old woman notices a lump in her left breast which upon pathological examination of a needle biopsy is diagnosed as stage 3 adenocarcinoma of the mammary gland. She elects to have a single mastectomy and the surgeon also removes several axillary lymph nodes to be examined to determine the tumor’s state of metastasis. The patient recovers well from the surgery, but at a 6-month followup visit at the clinic her upper left arm is seen to be swollen and the surgeon prescribes a bandage wrap for “lymph edema.” This condition likely resulted from which of the following?
a. Angiogenesis from arterial branches that brought blood to the left breast
b. Growth of cancer cells and blockage of lymphatic drainage from the left arm
c. Surgical disruption of the left arm’s lymphatic drainage by removal of lymph nodes
d. Surgical damage to the thoracic duct during lymph node removal
e. Hypertrophy of the vessels in the upper arm to accommodate blood otherwise flowing to the left breast

Answer 18

c. Surgical disruption of the left arm’s lymphatic drainage by removal of lymph nodes

Question 19

A 66-year-old man diagnosed with type II diabetes 10 years earlier presents with an aching pain in the muscles of his lower extremities. He says the pain is relieved by rest and worsened by physical activity. His lower limbs appear cold, pale, discolored, and he has a sore on the skin of his left heel. He has a weak tibial pulse on both sides and poor skin filling from dermal capillaries. The problems with blood distribution in this patient’s leg are most likely associated with what vascular structures?
a. Veins and venules
b. Arterioles
c. Branches of the aorta
d. Lymphatic vessels
e. Ventricles

Answer 19

b. Arterioles

Question 20

A 62-year-old African American man presents with exerciseinduced angina. His serum cholesterol is 277 mg/dL (normal < 200), LDL is 157 (normal < 100), HDL is 43 (normal > 35), and triglycerides 170 (normal < 150). His body mass index (BMI) is 34 and his coronary risk ratio is 6.84 (normal < 5). Cardiac catheterization reveals an occlusion of the left anterior descending and the origin of the right coronary artery. This disease process initially involved which one of the following?
a. Smooth muscle cell proliferation
b. Formation of an intimal plaque
c. Intimal thickening through addition of collagen and elastin
d. Adventitial proliferation of fibroblasts
e. Injury to endothelial cells

Answer 20

e. Injury to endothelial cells

Question 21

Which biochemical component of the erythrocyte cell surface is primarily responsible for determining blood type (eg, the A-B-O system).
a. Fatty acid
b. Carbohydrate
c. Nucleic acid
d. Protein
e. Cholesterol

Answer 21

b. Carbohydrate

Question 22

What cell in circulating blood is the precursor to microglia and most antigen-presenting cells?
a. Eosinophil
b. Basophil
c. Lymphocyte
d. Monocyte
e. Mast cell

Answer 22

d. Monocyte

Question 23

What is the approximate life span of a circulating erythrocyte?
a. 8 days
b. 20 days
c. 5 weeks
d. 4 months
e. 1 year

Answer 23

d. 4 months

Question 24

Which cell type has cytoplasmic granules that contain heparin and histamine?
a. Eosinophils
b. Basophils
c. Lymphocytes
d. Monocytes
e. Neutrophils

Answer 24

b. Basophils

Question 25

A differential cell count of a blood smear from a patient with a parasitic infection is likely to reveal an increase in the circulating numbers of which cell type? a. Neutrophils b. Lymphocytes c. Monocytes d. Basophils e. Eosinophils

Answer 25

e. Eosinophils

Question 26

Which of the following blood cells differentiate outside of the bone marrow? a. Neutrophils b. Basophils c. Eosinophils d. T lymphocytes e. Megakaryocytes

Answer 26

d. T lymphocytes

Question 27

Examination of a normal peripheral blood smear reveals a cell more than twice the diameter of an erythrocyte with a kidney-shaped nucleus. There cells are < 10% of the total leukocytes. Which of the following cell types is being described? a. Monocyte b. Basophil c. Eosinophil d. Neutrophil e. Lymphocyte

Answer 27

a. Monocyte

Question 28

A 43-year-old anatomy professor is working in her garden, pruning rose bushes without gloves, when a thorn deeply penetrates her forefinger. The next day the area has become infected. She removes the tip of the thorn, but there is still pus remaining at the wound site. Which of the following cells function in the formation of pus? a. Cells with spherical nuclei and scant cytoplasm b. Biconcave cells with no nuclei c. Cells with bilobed nuclei and many acidophilic cytoplasmic granules d. Very small, cell-like elements with no nuclei but many granules e. Cells with polymorphic, multiply lobed nuclei

Answer 28

e. Cells with polymorphic, multiply lobed nuclei

Question 29

A 35-year-old woman’s physician orders laboratory blood tests. Her fresh blood is drawn and centrifuged in the presence of heparin as an anticoagulant to obtain a hematocrit. From top to bottom, the fractions resulting from centrifugation are which of the following? a. Serum, packed erythrocytes, and leukocytes b. Leukocytes, erythrocytes, and serum proteins c. Plasma, buffy coat, and packed erythrocytes d. Fibrinogen, platelets, buffy coat, and erythrocytes e. Albumin, plasma lipoproteins, and erythrocytes

Answer 29

c. Plasma, buffy coat, and packed erythrocytes

Question 30

A hematologist diagnoses a 34-year-old woman with idiopathic thromobocytic purpura (ITP). Which of the following symptoms/characteristics would one expect in this patient? a. Normal blood count b. Hypercoagulation c. Decreased clotting time d. Abnormal bruising e. Light menstrual periods

Answer 30

d. Abnormal bruising

Question 31

In which of the following cells involved in erythropoiesis does hemoglobin synthesis begin? a. Orthochromatic erythroblast b. Polychromatophilic erythroblast c. Reticulocyte d. Basophilic erythroblast e. Proerythroblast

Answer 31

d. Basophilic erythroblast

Question 32

Which of the following can be used to describe megakaryocytes? a. Multinucleated b. Formed by fusion of haploid cells c. Precursors to bone marrow macrophages d. A minor but normal formed element found in the circulation e. Possess dynamic cell projections from which one type of formed element is released

Answer 32

e. Possess dynamic cell projections from which one type of formed element is released

Question 33

Which cytoplasmic components are the main constituents of the dark precipitate that forms in reticulocytes upon staining with the dye cresyl blue? a. Golgi complexes b. Hemoglobin c. Nucleoli d. Nuclear fragments e. Polyribosomes

Answer 33

e. Polyribosomes

Question 34

Which process occurs during granulopoiesis but not during erythropoiesis? a. Cells lose their capacity for mitosis b. Euchromatin content increases c. Nucleus becomes increasingly lobulated d. Overall cell diameter decreases e. Overall nuclear diameter decreases

Answer 34

c. Nucleus becomes increasingly lobulated

Question 35

What fate often awaits granulocytes that have entered the marginating compartment? a. Undergo mitosis b. Crossing the wall of a venule to enter connective tissue c. Cannot reenter the circulation d. Differentiate into functional macrophages e. Begin to release platelets

Answer 35

b. Crossing the wall of a venule to enter connective tissue

Question 36

What is the earliest stage at which specific granulocyte types can be distinguished from one another? a. Myelocyte b. Band form c. Reticulocyte d. Metamyelocyte e. Promyelocyte

Answer 36

a. Myelocyte

Question 37

Which cell type is capable of further mitosis after leaving the hemopoietic organ in which it is formed? a. Basophil b. Eosinophil c. Reticulocyte d. Lymphocyte e. Neutrophil

Answer 37

d. Lymphocyte

Question 38

Shortly after her birth a baby is diagnosed with a mutation in the erythropoietin receptor gene which leads to familial erythrocytosis (familial polycythemia). During the seventh to ninth months of fetal development, the primary effect on her red blood cell production was in which of the following? a. Liver b. Yolk sac c. Spleen d. Thymus e. Bone marrow

Answer 38

e. Bone marrow

Question 39

A 54-year-old man presents with recurrent breathlessness and chronic fatigue. After routine tests followed by a bone marrow biopsy he is diagnosed with lymphocytic leukemia. Chemotherapy is administered to remove the cancerous cells, which also destroys the precursor cells of erythrocytes. To reestablish the erythrocytic lineage, which of the following cells should be transplanted? a. Reticulocytes b. Orthochromatophilic erythroblasts c. Megakaryoblasts d. Basophilic erythroblasts e. Metamyelocytes

Answer 39

d. Basophilic erythroblasts

Question 40

A smear of blood from a 70-year-old leukemia patient reveals a larger than normal population of cells that have large, round nuclei with 1 or 2 nucleoli. The cytoplasm of these cells shows azurophilic granules. Which of the following forms of leukemia would you suspect? a. Promyelocytic leukemia b. Basophilic leukemia c. Lymphoblastic leukemia d. Stem cell leukemia e. Eosinophilic leukemia

Answer 40

a. Promyelocytic leukemia

Question 41

Which function is carried out by all lymphoid tissues and organs? a. Filtration of lymph b. Filtration of blood c. Extramedullary hemopoiesis d. Production of lymphocytes e. Destruction of old erythrocytes

Answer 41

d. Production of lymphocytes

Question 42

Which structure is partly encapsulated and covered by nonkeratinized stratified squamous epithelium? a. Appendix b. Lymph node c. Palatine tonsil d. Peyer’s patch e. Thymic (Hassal’s) corpuscle

Answer 42

c. Palatine tonsil

Question 43

Which cell type gives rise to both memory and effector cells and is primarily associated with humoral immunity? a. B lymphocyte b. NK cell c. Macrophage d. T lymphocyte e. Reticular cell

Answer 43

a. B lymphocyte

Question 44

Recycling of iron and heme, the major complex containing iron, occurs most actively in which lymphoid organ(s)/tissue(s)? a. Lymph nodes b. Peyer’s patches c. Tonsils d. Spleen e. Lymphatic vessels

Answer 44

d. Spleen

Question 45

Which description is true of all secondary (peripheral) lymphoid organs? a. Capable of antigen-independent lymphopoiesis b. Contain crypts c. Contain epithelial-reticular cells d. Lack connective tissue capsules e. Contain lymphoid nodules

Answer 45

e. Contain lymphoid nodules

Question 46

Which structure would be most heavily labeled by an immunohistochemical method targeting the CD8 surface antigen? a. Germinal centers b. Paracortex c. Peyer’s patch d. Sheathed arterioles e. Splenic cords

Answer 46

b. Paracortex

Question 47

A baby is born with a cleft palate and a condition called DiGeorge syndrome, which involves failure of third and fourth pharyngeal pouch derivatives to develop properly. The palate defect is corrected surgically, but regarding the pharyngeal pouch defect the parents are advised that the growing child may expect which of the following health problems? a. Insufficient B-cell production by lymph nodes in the head and neck b. Inability to secrete IgA c. Excessive numbers of circulating but defective erythrocytes d. Increased oral infections due lack of palatine and pharyngeal tonsils e. Conditions related to autoimmunity

Answer 47

e. Conditions related to autoimmunity

Question 48

Many immune-related cellular activities are often impaired in aged patients. Which lymphoid organ(s) normally develop less functionality and increasing amounts of adipose tissue with age? a. Axillary lymph nodes b. Lingual tonsils c. Thymus d. Splenic white pulp e. Splenic red pulp

Answer 48

c. Thymus

Question 49

A 12-year-old African-American girl presents with anemia and a large percentage of her peripheral erythrocytes appear sickle-shaped. Genetic testing reveals homozygosity for sickle cell disease. In which of the following sites will the abnormal RBCs be removed from the circulation? a. Thymic cortex b. Periarteriolar lymphoid sheathes of splenic white pulp c. Medullary sinuses of lymph nodes d. Thymic medulla e. Splenic cords (of Billroth)

Answer 49

e. Splenic cords (of Billroth)

Question 50

A 6-year-old boy is brought to the clinic where his mother reports that was bitten by a neighbor’s dog two days earlier. The child’s right hand is lacerated between the thumb and index finger and this area is inflamed but healing. The doctor’s examination reveals small but painless swellings beneath the skin inside the right elbow and arm pit and he explains to the mother that these are active lymph nodes enlarged in response to the infection in the hand. What has produced the swelling? a. Increased flow of lymph through the nodes’ afferent lymphatics b. Formation of germinal centers for B-cell proliferation in each node’s cortex c. Arrival of antigen-presenting cells in each node’s medulla d. Enlargement and increased activity of the nodes’ high endothelial venules e. Increased thickness of each node’s paracortex

Answer 50

b. Formation of germinal centers for B-cell proliferation in each node’s cortex