histo review jung Flashcards
1
Q
Question 8 of 230
Which structure in the cochlea is analogous in composition and function to the cupola of each semicircular canal?
A
Tectorial membrane
The tectorial membrane (TM) is an extracellular connective tissue that covers the mechanically-sensitive hair bundles of the sensory receptor cells in the inner ear. It occupies a strategic position, playing a key role in transforming sound to mechanical stimulation.
2
Q
Chylomicrons
Chylomicrons are formed in the endoplasmic reticulum in the absorptive cells (enterocytes) of the small intestine. The villi, lined with the microvilli of the brush border, provide a lot of surface area for absorption.
A
Question 9 of 230
What are the relatively large particles formed in the intestinal epithelial cells and rich in ingested lipids?
Chylomicrons are large micellar lipoproteins, having a diameter of 75 to 1200 nm, and are primarily composed of TG (85%) and contain some cholesterol and cholesteryl esters. They are surrounded by a surface monolayer of phospholipids, unesterified cholesterol and specific apoproteins.
3
Q
Which of the following is a characteristic of the connective tissue layer that surrounds individual fascicles in large peripheral nerves?
A
Important as part of the blood-nerve barrier in the nerve
A blood-nerve barrier is formed by tight junctions in the inner layers of the perineurium and tight junctions in endoneurial capillaries.
4
Q
Myoepithelial cells aid in the secretory process of which of the following?
Eccrine is a term specifically used to designate merocrine secretions from sweat glands.
found in large numbers on the soles of the feet, the palms, the forehead and cheeks, and in the armpits. Eccrine glands secrete an odorless, clear fluid that helps the body to control its temperature by promoting heat loss through evaporation.
A
Eccrine sweat glands
Eccrine glands secrete an odorless, clear fluid that helps the body to control its temperature by promoting heat loss through evaporation. In general, the type of sweat involved in hyperhidrosis is eccrine sweat. The other type of sweat gland is called an “apocrine” gland.
5
Q
Functions of the basement membrane do not include
A
Molecular filtering
6
Q
Which of the following separates the hair follicle from the connective tissue of the dermis?
inner basement membrane called the hyaline or vitreous (glassy) membrane and an outer connective tissue sheath.
A
Glassy membrane
The perifollicular sheath envelops the epithelial components of the hair follicle and consists of an inner basement membrane called the hyaline or vitreous (glassy) membrane and an outer connective tissue sheath. … It is most prominent around the outer root sheath at the bulb in anagen hairs
7
Q
What is an important part of the role played by macrophages during maintenance and renewal of strong extracellular fibers in connective tissue?
A
Secretion of MMPs
metalloproteinases
8
Q
What is the most important form of lipid storage in both white and brown adipocytes?
A
triglicerides
9
Q
Which description is true of the bile canaliculi?
Kupffer cells are the resident macrophages of the liver and are typically found within the lumen of the sinusoids.
A
Lumens are entirely sealed by junctional complexes
The perisinusoidal space (or space of Disse) is a location in the liver between a hepatocyte and a sinusoid. It contains the blood plasma. Microvilli of hepatocytes extend into this space, allowing proteins and other plasma components from the sinusoids to be absorbed by the hepatocytes.
10
Q
Which of the following most accurately describes the endosteum?
Sharpey’s fibres (bone fibres, or perforating fibres) are a matrix of connective tissue consisting of bundles of strong predominantly type I collagen fibres connecting periosteum to bone. … Each fibre is accompanied by an arteriole and one or more nerve fibres.
A
NOT - Attached to the bone surface by collagen bundles called Sharpey fibers
D YES _
Lines the medullary cavity
11
Q
Which of the following is true for ventricles?
A
Walls contain Purkinje fibers of the right and left branches from the atrioventricular bundle
NOT
Contain more elastic fibers than the atria
12
Q
Blood in the renal arcuate arteries flows next into which vessels?
renal artery, then reaches the interlobar arteries, then goes to the arcuate arteries, then the interlobular arteries, and finally goes to the afferent arteriole, which supplies the nephron with blood.
A
Interlobular arteries
13
Q
An intermediate filament protein found in cytoplasm of most epithelial cells is which of the following?
A
keratin
14
Q
night vision problems - and even during day?
A
Closing of Na+ channels
15
Q
Besides saving much time by avoiding fixation and procedures required for paraffin embedding, frozen sections retain and allow study of what macromolecules normally lost in the paraffin procedure?
A
lipids
16
Q
Which of the following facilitates breakdown of the nuclear envelope during the onset of mitosis?
A
Phosphorylation of lamin subunits by a CDK
During what phase of mitosis does the nuclear envelope first start to break down?
prophase
The first and longest phase of mitosis is prophase. During prophase, chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell.
17
Q
Which description is true of the gallbladder?
A
Secretes mucus
Once the pressure in the CBD exceeds the resting pressure of the gallbladder (~10 mm Hg), bile flows into the gallbladder. The peribiliary mucous glands in the neck and the surface epithelial cells produce mucin, most of which is neutral, heavily sulphated, and contains a few sialic residues.
18
Q
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
Basophilic erythroblasts
Erythropoietin
Erythropoietin is a hormone, produced mainly in the kidneys, which stimulates the production and maintenance of red blood cells.
19
Q
In transmission EM preparations of cells the cell membrane often appears as a trilaminar structure having two parallel dark-staining components on either side of an unstained middle layer. This central poorly stained region of the membrane is primarily responsible for which of the following functions?
A
Creation of a barrier to water-soluble molecules
20
Q
What is the first step of collagen production that occurs after the protein undergoes exocytosis?
A
Removal of the terminal nonhelical domains by peptidases
21
Q
Chaperonins are cytoplasmic proteins most likely to be found in which of the following organelles?
A
Rough endoplasmic reticulum
Chaperonins are a class of molecular chaperone composed of oligomeric double-ring protein assemblies that provide essential kinetic assistance to protein folding by binding non-native proteins and allowing them to fold in the central cavities of their rings.
22
Q
What tissue is directly associated with and extends into the heart valves?
A
Cardiac skeleton
23
Q
In which of the following structures of the oral cavity would taste buds be localized in the highest concentration?
A
Vallate papillae
24
Q
The pars distalis is not a good candidate for transplantation studies for which one of the following reasons?
A
Its cells stop functioning when separated from the hypothalamo-hypophyseal portal system.
25
Transitions in the cell cycle from one phase to the next are regulated by protein kinases whose activity depends on what other proteins
cyclins
26
While studying a germ cell line developed from a patient’s testicular biopsy, the researcher notes that colchicine-treated cells blocked in metaphase have 46 chromosomes. From which of the following regions of the male genital tract would you expect these cells to have originated?
At the basal lamina of the seminiferous tubule
27
Which of the following cellular features is used in naming types of epithelia?
number of cell layers
28
in the diaphysis of a typical long bone which of the following structures is in closest proximity to the trabeculae of cancellous bone?
Cancellous Bone or Spongy Bone
It typically occurs at the ends of long bones, proximal to joints and within the interior of vertebrae. For example, distal end radius, proximal humerus or proximal femur, all are examples of cancellous bone.
Inner circumferential lamellae
Cancellous Bone or Spongy Bone. Cancellous bone is also called trabecular bone or spongy bone. Compared to compact bone, which is the other type of osseous tissue, it has a higher surface area but is less dense, softer, weaker, and less stiff.
29
The major lubricant for diarthrotic joints is synthesized by cells located in which joint structure?
Synovial membrane
30
56-year-old man has been taking atorvastatin because of a poor lipid profile and a family history of cardiovascular disease. The statin family of drugs enhances endocytosis of low-density lipoprotein (LDL) from the blood. Endocytosis of LDL differs from phagocytosis of bacterial cells in which of the following ways?
Use of clathrin-coated pits
Coated pits are regions of the cell membrane specialized in receptor-mediated endocytosis. Their cytoplasmic surface is coated with a bristlelike structure made of clathrin.
31
In a light microscope used for histology, resolution and magnification of cells are largely dependent on which component?
Objective lens
32
Polarity in microtubules is important in determining which of the following?
The direction of vesicular transport along microtubules
33
Which if the following most accurately describes compact bone?
NOT
B
Also known as cancellous bone
C
| Characterized by the presence of osteons
34
The pulmonary (functional) and bronchial (nutritive) arterial systems enter the lungs separately at the hilus but anastomose into a single system at which level?
Respiratory bronchioles
35
A 9-year-old girl, the youngest of four daughters, is taken to the pediatrician by her mother, who indicates that for at least 4 months the child has seemed “hyperactive,” unable to sleep soundly because “she says her room is too hot,” and no longer able to concentrate in school. Upon questioning, the mother also remembers that her daughter’s periods also began within the past few months. Blood tests indicate high levels of estrogen-related hormones and cortisol. Which of the following tentative diagnoses is consistent with all of these symptoms?
A benign tumor involving cells in the adenohypophysis
36
Which of the following staining procedures relies on the cationic and anionic properties of the material to be stained?
H&E staining
37
Fully differentiated white adipocytes are large cells, typically having diameters of approximately what size?
100 μm
38
channels that connect the testis to the epididymis. What is the name of these channels?
Efferent ductules
39
antibodies to a subfamily of CADHERINS and immunohistochemical staining of a biopsy from the oral mucosa shows distribution of the antigen throughout the epithelium. In what structures is the defect that is causing this patient’s condition?
Desmosomes
40
A glucagonoma is a malignant tumor consisting of what cells?
A or α cells
41
Which of the following components of the epidermis provides sealant between adjacent cells?
Glycolipids and lipids
42
Which feature typifies T-tubules?
NOT
Evaginations of the sarcoplasmic reticulum
Carry depolarization to the muscle fiber interior
43
Which of the following is the thickest component of the cornea?
Stroma
44
Which of the following proteins is/are most likely to have initially contained a “signal peptide” that bound a “signal recognition particle” during its translation?
Proteins in secretory granules
45
the epithelial cells within the organ of Corti are supported by which of the following structures?
Basilar membrane
The organ of Corti is a specialized sensory epithelium that allows for the transduction of sound vibrations into neural signals. The organ of Corti itself is located on the basilar membrane. The organ of Corti rests on the basilar membrane and contains two types of hair cells: inner hair cells and outer hair cells.
46
During an eye examination a 55-year-old man is found to show intraocular pressure exceeding 40 mm Hg and blockage of fluid flow within the eye is suspected. Such a diagnosis would involve a blockage at which of the following sites?
Trabecular meshwork
47
A 66-year-old man who suffered from severe osteoarthritis is referred to an orthopedic surgeon for replacement of his right knee. He had been actively involved in both high school and intercollegiate football and had continued running until about the age of 45 as a form of relaxation and exercise. With the patient’s permission the removed joint is used by investigators performing a proteomic analysis of different joint tissues. The meniscus was found to contain almost exclusively type I collagen and aggrecan was undetectable. What is the most likely explanation for this result?
The meniscus had undergone repeated rounds of repair due to wear-and-tear during which its hyaline cartilage component was replaced by dense connective tissue.
48
n situ hybridization is a histologic technique used to visualize what type of macromolecule?
Nucleic acids
49
Which step occurs first in chondrogenesis?
NOT
Conversion of chondroblasts to chondrocytes
C
Formation of mesenchymal condensations
50
Which of the following accurately describes glucocorticoids?
NOT
Are produced primarily by the zone glomerulosa
Which is a difference between the anterior pituitary and the posterior pituitary?
The pituitary glands are made of the anterior lobe and posterior lobe. The anterior lobe produces and releases hormones. The posterior lobe does not produce hormones per se—this is done by nerve cells in the hypothalamus—but it does release them into the circulation
Are produced in response to stimulation by ACTH
drenocorticotropic hormone (ACTH) is a hormone produced in the anterior, or front, pituitary gland in the brain. The function of ACTH is to regulate levels of the steroid hormone cortisol, which released from the adrenal gland. ... highly-sensitive ACTH. corticotropin.
51
About 3 years ago, a 39-year-old construction worker became increasingly uncoordinated. His wife describes bouts of depression and apathy beginning about a decade ago. Laboratory tests are normal. MRI and CT reveal striatal and caudate atrophy with “boxcar ventricles.” His mini-mental status examination score is 24/30. The cranial nerve examination shows dysarthria, saccadic extraocular eye movements, and a hyperactive gag reflex. There is increased tone in all extremities. Polymerase chain reaction reveals one normal band with 20 CAG (trinucleotide) repeats and the other with 49 CAG repeats. Modulation of respiration and mitochondrial membrane potential, and bioenergetic failure are associated with the abnormal gene in this disease. Which of the following mechanisms used to establish the mitochondrial electrochemical gradient may be altered in this disease?
Proton-translocating activity in the inner membrane
52
Exocrine glands in which the acini all produce a secretion of heavily glycosylated, hydrophilic proteins are an example of which type of gland?
mucous gland
53
Important target cells of leptin are found in which organ?
A
Hypothalamus
54
In the choroid plexus water from capillaries is transported directly into the cerebrospinal fluid by what structure(s)?
A
Ependyma
Lining the CSF-filled ventricles, and spinal canal, the ependymal cells play an important role in the production and regulation of CSF. Their apical surfaces are covered in a layer of cilia, which circulate CSF around the CNS. Their apical surfaces are also covered with microvilli, which absorb CSF.
55
A newborn boy is diagnosed with Apert syndrome. He has craniosynostosis, hypoplasia of the middle part of the face with retrusion of the eyes, and syndactyly that includes fusion of the skin, connective tissue, and muscle of the first, middle, and ring fingers with moderate fusion of those digits. There is very limited joint mobility past the first joint. Which one of the following is most likely decreased in cells of the interdigital regions of the developing hand of this newborn child?
E
DNA degradation by endonucleases
56
Which cytoplasmic components are the main constituents of the dark precipitate that forms in reticulocytes upon staining with the dye cresyl blue?
A
Polyribosomes
57
Which feature is characteristic of the endometrium’s basal layer but not of its functional layer?
C
Contains cells that replace the surface epithelium after menstruation
58
The release of lipid droplets from cells is which type of secretion?
Apocrine
59
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?
Sites for calcium sequestration and release
When the muscle is stimulated, calcium ions are released from its store inside the sarcoplasmic reticulum, into the sarcoplasm (muscle ). ... The two terminal cistemae of the SR together with their associated T tubule are known as a triad.
60
Resolution in electron microscopy greatly exceeds that of light microscopy due to which of the following?
A
The wavelength of the electrons in the microscope beam is shorter than that of a beam of light.
61
Osteoarthritis is characterized by the progressive erosion of articular cartilage. The matrix metalloproteinases involved in this erosion primarily act on which matrix component?
Fibril-forming collagen
62
Which biochemical component of the erythrocyte cell surface is primarily responsible for determining blood type (eg, the A-B-O system).
carbohy
63
sulfated GAGs are important constituents of what extracellular structures?
Proteoglycans
Because GAGs are highly polar and attract water, they are used in the body as a lubricant or shock absorber. Mucopolysaccharidoses are a group of metabolic disorders in which abnormal accumulations of glycosaminoglycans occur because of enzyme deficiencies.
64
What term applies to collections of neuronal cell bodies (somata) in the central nervous system?
nuclei
65
Dense regular connective tissue typically involves which of the following features?
Predominantly located in tendons and ligaments
66
the basal lamina of a muscle fiber is part of which structure?
Endomysium
67
Which area in cartilage is relatively collagen-poor and proteoglycan-rich?
he darker staining matrix immediately surrounding the capsule is called territorial matrix , while the matrix that occupies the majority of space between chondrocytes is interterritorial matrix .
Territorial matrix
Note that the cartilage matrix is relatively homogeneous and basophilic. This is due to the masking of the collagen fibers by the high concentration of the glycosaminoglycans in the ground substance. The matrix immediately surrounding the lacunae is more intensely basophilic. This zone is the territorial matrix.
68
Which function is carried out by all lymphoid tissues and organs?
NOT
Filtration of lymph
Production of lymphocytes
69
A 46-year-old woman presents with pain in the left leg that worsens on weight bearing. An x-ray shows demineralization, and a bone biopsy decalcified with EDTA shows reduction in bone quantity. The patient had undergone menopause at age 45 without estrogen replacement. She reports long-standing diarrhea. In addition, laboratory tests show low levels of vitamin D, calcium, and phosphorus, and elevated alkaline phosphatase. A second bone biopsy was taken but not decalcified, which showed extensive deposition of uncalcified osteoid on all the bone surfaces. On the basis of these data, the best diagnosis would be which of the following
Osteomalacia
D
Rickets
70
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 one or two nucleoli. The cytoplasm of these cells shows azurophilic granules. Which of the following forms of leukemia would you suspect?
A
Promyelocytic leukemia
71
Ten days after birth a full-term newborn boy develops firm, erythematous nodules, and plaques over his trunk, arms, buttocks, thighs, and cheeks. His mother’s pregnancy was complicated by placenta previa and his airway was cleared of aspirated meconium immediately after birth. A biopsy of subcutaneous tissue shows necrosis within the brown adipose tissue. What metabolic activity is liable to be affected in this patient?
Oxidation of fatty acids for thermogenesis
72
Which cell type comprises the visceral layer of Bowman capsule?
podocytes
73
Which feature is typical of elastic cartilage?
Collagen is mainly type II
74
dding heavy metal compounds to the fixative and ultrathin sectioning of the embedded tissue with a glass knife are techniques used for which histologic procedure?
TEM
75
Binding of histone H1 proteins to importins is important for which of the following?
A
| Transport through the nuclear pores complexes
76
In preparing tissue for routine light microscopic study, which procedure immediately precedes clearing the specimen with an organic solvent?
Dehydration
77
Which description is true of pancreatic zymogens?
Are inactive until they reach the duodenal lumen
78
Urinalysis shows elevated levels of desmosine and isodesmosine. These excreted compounds normally contribute to efficient lung function by which of the following mechanisms?
Cross-linking elastin
79
The mucosa and submucosa are poorly preserved, with only the thick muscularis well-stained, showing striated fibers. The slide most likely shows a biopsy of which region of the GI tract?
Esophagus
80
Epithelial cell membrane domains containing many stiffened plaques of protein are an important feature in which part of the urinary system?
Bladder mucosa
81
What is the earliest stage at which specific granulocyte types can be distinguished from one another?
NOT
Band form
C
Reticulocyte
D
Metamyelocyte
E
Promyelocyte
Myelocyte
82
he teniae coli of the large intestine represent an organ-specific specialization of which layer of the intestinal tract wall?
A
Epithelium
B
Lamina propria
C
Muscularis mucosa
D
Muscularis externa
83
A parotid gland biopsy shows inflammatory infiltrates in the interlobular connective tissue with damage to the acinar cells and striated ducts. In this case, resorption of which of the following will be most altered by destruction of those ducts?
A
| Na+
84
An individual genetically unable to synthesize normal occludin is likely to have epithelia with defective regulation in which of the following?
Material crossing the epithelium between the cells (paracellular movement)
85
Which component of bone impedes the distribution of nutrients and oxygen to osteocytes?
A
ECM
86
Which of the following is found during meiosis but not mitosis?
Synapsis
87
Which of the following accurately describes spermiogenesis?
C
Involves cytodifferentiation of early spermatids
88
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
89
A report from a hospital pathology laboratory indicates that a microscope slide with a small specimen of neural tissue contains “numerous GFAP-positive” cells. What is the most likely source of this specimen?
A region of gray matter
90
Question 174 of 230
Which description is true for the hepatic space of Disse?
NOT
Is surrounded by the hepatic sinusoid
B
Contents flow toward the central vein
C
D
Lumen sealed by junctional complexes
Is directly contacted by hepatocytes
91
Which of the following hormones is primarily responsible for inducing ovulation?
LH
LH
92
Which cell type has cytoplasmic granules that contain heparin and histamine?
B
| Basophils
93
Which part of meiosis is most closely associated with recombination?
Prophase I
94
What substance, released from the adrenal gland and some autonomic neurons, increases lipolytic activity in white adipocytes?
Norepinephrine
95
In healthy bone canaliculi are likely to contain which one of the following?
Osteocytic processes
96
The hormone-sensitive lipase in the cells of adipose tissue acts primarily on what substrate?
Triglycerides
97
Which description is accurate for lens fibers?
Derived from epithelial cells that produce proteins called crystallins
98
Which characteristic is unique to smooth muscle?
Thin filaments attach to dense bodies
99
A young child presents with hepatomegaly and renomegaly, failure to thrive, stunted growth, and hypoglycemia. A deficiency in glucose-6-phosphatase is identified and the diagnosis of von Gierke disease is made. What cellular structures would be expected to accumulate in hepatocytes during progression of this disorder?
B
| Glycogen granules
100
A 45-year-old man presents with nephrolithiasis or kidney stones. The process of calcium oxalate stone formation as seen in this patient begins with Randall plaques found in the basement membranes of which one of the following structures found only in the renal medulla?
Collecting ducts
101
Air moving rapidly across the vocal cords and causing them to vibrate and produce sound is contacting what type of epithelium?
Stratified squamous nonkeratinized
102
Which of the following is true of the absorptive cells of the small intestine?
Synthesize triglycerides from absorbed lipids
103
A renal biopsy is prepared for light microscopy, and an infiltrate containing lymphocytes, plasma cells, and eosinophils is found among tubules having cells with prominent brush borders. Which one of the following statements correctly pertains to these epithelial cells?
The primary site for the reduction of the tubular fluid volume
104
Which of the following is characteristic of the chromatophilic material called Nissl substance in neural tissue?
Site of mRNA translation for proteins of the axolemma
105
In a liver biopsy from a long-time drug user which of the following hepatocyte organelles would be expected to be more extensive than normal?
Smooth endoplasmic reticulum
106
A 14-year-old boy is diagnosed with epidermolysis bullosa simplex (EBS). His skin blisters easily with rubbing or scratching. Blisters occur primarily on his hands and feet and heal without leaving scars. Genetic analysis shows mutations in the KRT5 and KRT14 genes, which code keratin 5 and keratin 14. What is the primary function of those proteins?
Provide mechanical stability
107
Question 203 of 230
Key differences between apoptotic and necrotic cell death include which of the following?
A
Apoptotic cells do not release factors that induce inflammation.
108
The molecular basis for the shock absorbing properties of cartilage involves which of the following?
Hydration of glycosaminoglycans
109
A 42-year-old woman visits her physician complaining of recurrent vaginal yeast infections. The doctor explains the likelihood that the woman’s vaginal lining is temporarily out of proper acid-base balance, leading to the increased susceptibility to yeast infections. The normally low pH in the vagina is maintained by which of the following?
Bacterial metabolism of glycogen to produce an organic acid
110
To identify and localize a specific protein within cells or the ECM, one would best use what approach?
Immunohistochemistry
111
Mitotic figures visible in a tissue section from the lining of the small intestine are most likely to belong to which of the following categories?
Progenitor cells
112
Autoantibodies are detected against a cell type located in one region of the GI tract. In which regions would those cells be found?
What stomach cells produce intrinsic factor? and where located?
Body of the stomach
parietal. In humans, it has an important role in the absorption of vitamin B12
113
protein connexin
gap junctions
114
A 39-year-old man undergoing an extensive series of tests for infertility is found to have a genetic mutation preventing formation of a functional synaptonemal complex during meiosis, causing almost complete failure of sperm formation. Which cells would be directly affected by this mutation?
A
Primary spermatocytes
This is when they are reduced -
What does the Synaptonemal complex do in meiosis?
The synaptonemal complex (SC) is a protein structure that forms between homologous chromosomes (two pairs of sister chromatids) during meiosis and is thought to mediate synapsis and recombination during meiosis I in eukaryotes.
115
Which cells transmit visual signals from the retina to the brain?
Ganglion cells
116
Which structure is the most anterior extension of the eye’s vascular layer?
Iris
117
Question 218 of 230
A 15-year-old male presents with hematuria, hearing loss, lens dislocation, and the onset of cataracts. Genetic analysis reveals a mutation in the COL4A5 gene. Transmission EM examination of a renal biopsy confirms that the disorder has affected a component of the renal corpuscles in which damage disrupts normal glomerular filtration. Which one of the following structures would most likely be abnormal in the TEM of this patient’s biopsy?
D
Glomerular basement membranes??
118
Secretion, chemical modification and storage, reuptake, and digestion of a protein occur in epithelial cells of what endocrine tissue?
Thyroid gland
thyroid gland
119
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?
Conditions related to autoimmunity
120
Which structure would be most heavily labeled by an immunohistochemical method targeting the CD8 surface antigen?
paracortex
121
Which of the following contains binding sites for integrins and is an important part of the ECM in both loose connective tissue and dense irregular connective tissue?
fibronectin
FN is involved in many cellular processes, including cell adhesion, growth, migration, and differentiation.
122
hair cells for color where located?
The hair matrix (zone of dividing and differentiating cells) of the hair bulb
123
Applied to adipocytes, the term “multilocular” refers to which of the following?
A
The large number of small cytoplasmic lipid droplets
The large number of small cytoplasmic lipid droplets
124
In which of the following cells involved in erythropoiesis does hemoglobin synthesis begin?
Basophilic erythroblast
125
Microscopic autoradiography uses radioactivity and can be employed to study what features in a tissue section?
Cellular sites where various macromolecules are synthesized
126
hey have developed a novel peptide-based drug, potentially deliverable therapeutically, that disrupts the tumor cells’ ability to adhere to the ECM, which in turn triggers apoptosis. Which of the following is a most likely target of such drugs?
Integrins
127
In which of the following structures is perilymph normally found?
Scala tympani
128
The mitochondrial protein, Bax, promotes apoptosis by binding and inactivating which anti-apoptotic protein?
BCL-2 family proteins are the regulators of apoptosis, but also have other functions. This family of interacting partners includes inhibitors and inducers of cell death. Together they regulate and mediate the process by which mitochondria contribute to cell death known as the intrinsic apoptosis pathway.
BAX vs Bcl2
Bax and Bak are two nuclear-encoded proteins present in higher eukaryotes that are able to pierce the mitochondrial outer membrane to mediate cell death by apoptosis. Thus, organelles recruited by nucleated cells to supply energy can be recruited by Bax and Bak to kill cells.
129
How does Bcl 2 prevent apoptosis?
The anti-apoptotic members of this family, such as Bcl-2 and Bcl-XL, prevent apoptosis either by sequestering proforms of death-driving cysteine proteases called caspases (a complex called the apoptosome) or by preventing the release of mitochondrial apoptogenic factors such as cytochrome c and AIF (apoptosis-inducing
130
centriole
is a cylindrical organelle composed mainly of a protein called tubulin. Centrioles are found in most eukaryotic cells. A bound pair of centrioles, surrounded by a highly ordered mass of dense material, called the pericentriolar material, makes up a structure called a centrosome.
131
centrosomes - during mitosis - two form - these "zomes" (zones) control the mitotic spindle
they go to the far ends and pull the sister chromatids aparts - out of them comes a ton of + pointed microtubules pulling the sisters apart - plus end, minus end a and b - tubules 13 around
132
cytoskeleton - 3
actin filaments (determine shape)
intermediate (structure of cell)
microtubules - organizing
133
mitotic spindle - tubulin beta end is plus end - grows more here
made of microtubules - hollow tubular structure - 13 protofilaments - dimer - alpha beta tubulin
134
microtubules grow out of MTOC
microtubule organizing center - located near nucleus - called CENTROSOME
135
Pair CENTRIOLES in each centrosome - at right angles, 9 triplets
minus ends plugged into centrosome, plus ends reach out
microtubules during mitosis - grow out from centrosomes - grab the sisters
136
Apoptosis vs necrosis
apop - no inflamation, programmed
BAK, BAX - destroy
BCL (2 types) BROCOLI - keep apoptosis from happening
BAK makes holes in cells - releases - cytochrome C - > caspases
intrinsic pathway - re above
Extrinsic - two ways
FAS
Cytotoxic C cells - GRANzyme - Perforin
137
DesMin - muscle
ViMEntin
mesenchymal - fibroblasts, endothelial, macrophages
138
Gfap
Glial cells - astocytes, Schwann, oligodendrocytes (most numerous)
139
Tight junctions
claudins, occludins
140
adherens - BELT - CADhereins
CA dependent ADhension protein CAD
141
Desmosomes - spot - macula adherens - Intermediate filament
pemphigus vulgaris
142
GAP junctions - CONNECONS
permit electrical and chem communication between cells
143
Hemidesmosome - connects Keratin in basal cells to basement
BULLous pemphigoid (hemides are BULLow
144
Integrins - bind to COLLAGEN, LAMININ, and FIBRONECTIC in basement membrane -
maintain INTEGRITY of basolateral membrane
145
3 types of cartilage -
There are three different types of cartilage: elastic (A), hyaline (B), and fibrous (C). In elastic cartilage the cells are closer together creating less intercellular space. Elastic cartilage is found in the external ear flaps and in parts of the larynx. ... Fibrous cartilage is found in the spine and the menisci.
There are three types of cartilage: hyaline, fibrous, and elastic cartilage.
Hyaline cartilage is the most widespread type and resembles glass. In the embryo, bone begins as hyaline cartilage and later ossifies. Fibrous cartilage has many collagen fibers and is found in the intervertebral discs and pubic symphysis
146
EAlastic cartilge
EAR
147
Fibrous cartilage? Structurally intermediate between dense connective tissue and cartilage
spine and menici - and pubic symphysis
148
growth plate cartilage? Hyaline
The epiphyseal plate is the area of growth in a long bone. It is a layer of hyaline cartilage where ossification occurs in immature bones. On the epiphyseal side of the epiphyseal plate, cartilage is formed. On the diaphyseal side, cartilage is ossified, and the diaphysis grows in length.
149
eye's tunica fibrosa?
cornea
150
Which structures consist primarily of actin or actin-like proteins? think Muscle, actin, myosin
One of the most important roles of microfilaments is to contract muscles. There is a high concentration of microfilaments in muscle cells, where they form myofibrils, the basic unit of the muscle cell. ... In muscle cells, actin works together with the protein myosin to allow the muscles to contract and relax.
microfilaments -
Microfilaments assist with cell movement and are made of a protein called actin. Actin works with another protein called myosin to produce muscle movements, cell division, and cytoplasmic streaming. Microfilaments keep organelles in place within the cell.
151
cilia structure 9 + 2
Cilia and flagella are projections from the cell. They are made up of microtubules
Cilia and flagella have a core composed of microtubules that are connected to the plasma membrane and arranged in what is known as a 9 + 2 pattern. ... Movement is produced when the nine paired microtubule sets of the axoneme slide against one another causing cilia and flagella to bend.
152
Which vessels lie at the border between the renal cortex and medulla?
A
Arcuate arteries and veins
153
Which cells are the primary cellular components of the stroma of the splenic lymphoid nodules?
reticular
154
crystalline nucleoid (dense core) of peroxisomes is composed of which substance?
urate oxidase
155
Which of the following is true of glucocorticoids?
The adrenal cortex comprises three zones, or layers: Zona glomerulosa (outer), Zona fasciculata and Zona reticularis. The outermost layer, the zona glomerulosa, is the main site for production of mineralocorticoids, mainly aldosterone.
Are produced in response to stimulation by ACTH
Adrenocorticotropic hormone (ACTH) is a hormone produced in the anterior, or front, pituitary gland in the brain. The function of ACTH is to regulate levels of the steroid hormone cortisol, which released from the adrenal gland. ACTH is also known as: adrenocorticotropic hormone.
156
Which feature typifies tropocollagen?
found in ECM Tropocollagen is the basic structural unit of collagen,
157
(ECM)
is a three-dimensional network of extracellular macromolecules, such as collagen, enzymes, and glycoproteins, that provide structural and biochemical support to surrounding cells.
158
Which feature of skeletal muscle is most directly proportionate to the strength of contraction?
fiber diameter
NOT size of motor unit!
159
Which hormone is most responsible for increasing osteoclast number and activity?
PTH
160
Which protein anchors the nuclear pore complex in the nuclear envelope?
A
gp210
161
Which cell-cycle phase is the longest and most variable in continuously dividing cells?
G1
162
source of Kupffer cells.
mesoderm
163
Which feature typifies dendrites?
may contain nissi bodies
is a large granular body found in neurons. These granules are of rough endoplasmic reticulum (RER) with rosettes of free ribosomes, and are the site of protein synthesis.
164
parietal cells secrete? in BODY (fundus)
gastric acid, i.e. hydrochloric acid and secrete intrinsic factor, which is a vitamin B12-binding protein.
Zollinger-Ellison syndrome (gastrinoma) involves a hypersecreting tumor of the δ cells in the pancreatic islets of Langerhans (21.III.C). The tumor cells secrete excess gastrin, which causes excess HCl release by the parietal cells in the gastric mucosa. Excess HCl secretion is a common cause of duodenal ulcers.
Gastric chief cells are less directly responsive to gastrin secretion; moreover, without adequate HCl, the pepsinogen they secrete cannot be converted to the active proteolytic enzyme known as pepsin (15.VI.B.5.b).
Paneth's cells secrete lysozyme, an antibacterial enzyme, and occur mainly in the ileum (15.VII.B.6).
Excess secretion by duodenal goblet cells is more likely to protect against ulceration than to cause it (15.VII.B.4).
Pancreatic acinar cells (16.III.B.1) and δ cells (21.III.C) are not components of the digestive tract mucosa.
165
Which process best accounts for the pale staining of the germinal centers of lymphoid nodules?
Blast transformation
166
tubuloacinar glands
Examples include secretory cells of the salivary glands, esophageal glands, stomach surface, pyloric glands, and Brunner's glands of the duodenum. These cells are typically organized into tubular secretory units
167
Which description is true of the muscularis mucosa of the upper esophagus?
Innervated by postganglionic autonomic fibers
168
cck Is produced by enteroendocrine cells in the intestinal mucosa
Cholecystokinin plays a key role in facilitating digestion within the small intestine. It is secreted from mucosal epithelial cells in the first segment of the small intestine (duodenum), and stimulates delivery into the small intestine of digestive enzymes from the pancreas and bile from the gallbladder.
169
What effect does colchicine use in gout and cancer chemotherapy have on adult neurons?
Gout is caused by too much uric acid in the blood. When uric acid levels in the blood are too high, the uric acid may form hard crystals in your joints. Colchicine works by decreasing swelling and lessening the build up of uric acid crystals that cause pain in the affected joint(s).
Inhibits axonal regeneration - lessening the build up of uric acid crystals
Colchicine is a classical anti-mitotic drug which blocks mitotic cells in metaphase. It binds to soluble tubulin to form tubulin-colchicine complexes in a poorly reversible manner, which then binds to the ends of microtubules to prevent the elongation of the microtubule polymer
170
Which hormone, produced by the adrenal medulla, and by certain autonomic neurons, has a dramatic lipolytic effect in adipose tissue?
Leptin is a hormone predominantly made by adipose cells and enterocytes in the small intestine that helps to regulate energy balance by inhibiting hunger, which in turn diminishes fat storage in adipocytes.
leptin
a hormone predominantly made by adipose cells and enterocytes in the small intestine that helps to regulate energy balance by inhibiting hunger, which in turn diminishes fat storage in adipocytes.
Leptin is a hormone released from fat cells in adipose tissue. Leptin signals to the brain, in particular to an area called the hypothalamus. Leptin does not affect food intake from meal to meal but, instead, acts to alter food intake and control energy expenditure over the long term.
171
brain sand - May serve as a landmark for radiologists
calcified structures in the pineal gland and other areas of the brain such as the choroid plexus. Older organisms have numerous corpora arenacea, whose function, if any, is unknown.
172
Which collagen type occurs only in hypertrophic cartilage?
X Zone of hypertrophy: Chrondrocytes and their lacunae increase in size. Zone of calcification: Deposition of minerals in the matrix surrounding the enlarged lacunae causing cell death. Zone of ossification: Osteoblasts deposit bone matrix on the exposed plates of calcified cartilage.
173
What are the two types of cartilage growth?
Interstitial growth which includes: Cell division of the chondrocytes. Synthesis of the extracellular matrix. ...
Appositional growth which includes: Differentiation of the chondroblasts or perichondrial cells. Synthesis of the extracellular matrix.
As the inner cartilage hypertrophies and the ossification front extends farther outward, the remaining cartilage in the epiphyseal growth plate proliferates. As long as the epiphyseal growth plates are able to produce chondrocytes, the bone continues to grow.
174
Nondisjunction (failure of chromosomes to separate normally) during the first meiotic division in the seminiferous epithelium results in abnormal numbers of chromosomes in which cell type?
secondary spermatocyte
175
Which structure forms the border between the eye's anterior and posterior chambers?
iris
176
B-cell derivatives.
gamma globulins are one
nteraction of a B-cell with antigen results in clonal expansion, as does activation by T-cells. The majority of B-cell clones mature into plasma cells. Plasma cells are found in the splenic red pulp, lymph node medulla and bone marrow. Plasma cells are the terminal differentiation state of B-cells.
177
Sensory nerve fibers enter arteries through the adventitia and extend further. As far as which layer do they penetrate?
tunica intima
178
Which description is true of the retina's pigmented epithelium?
Derives from the outer wall of the embryonic optic cup
179
Where is type IV collagen found?
Collagen IV is the primary collagen found in the extracellular basement membranes separating a variety of epithelial and endothelial cells. It is a major component of the dermal–epidermal junction, where it is mostly found in the lamina densa.
180
multilocular. adipose produces heat
White fat cell and brown fat cell. ... The lipid droplets in adipose tissue can be unilocular and/or multilocular. Unilocular cells contain a single large lipid droplet which pushes the cell nucleus against the plasma membrane, giving the cell a signet-ring shape
181
null cells examples
NK cells are part of a group of lymphocytes called null cells. Unlike other lymphocytes, such as T and B cells, they do not have to find their specific match to identify an invader. ... They are 'null' of both specificity and memory, allowing them the freedom to react to any tumor cell or cell infected with a virus.
Non–T, non–B, lymphocytes
A null cell is a large agranular lymphocyte that develops inside the bone marrow. Null cells lack the common characteristic surface markers that can be found in mature B-cells and T-cells.
182
absorptive cells of the small intestine
Synthesize triglycerides from absorbed lipids
183
In which location are mitotic figures most likely to be found?
A
Neck of the stomach's fundic glands
Mucous neck cells are found in the upper parts (isthmus and neck) of the gastric glands (SEM). They are smaller than surface mucous cells. They secrete an acidic fluid containing mucin proteins. This differs from the mucus produced by surface mucous cells which is alkaline.
184
Which structures form the purse-string constriction at the equator of mitotic cells?
Microfilaments
Cell division begins along the cell's equator, between the two chromosomal poles that form during nuclear division. Microfilaments help the cell lay down new membrane and divide into two daughter cells.
185
Which cells contain abundant basal mitochondria between infoldings of the basal plasma membrane?
A
Ion-transporting cells
186
What are Rathke cleft cysts?
Rathke cleft cysts (RCCs) are benign (non-cancerous) fluid-filled growths that develop between the parts of the pituitary gland at the base of the brain. T
187
Which description is true of the wall of the stomach
Three layers of skeletal muscle in the muscularis externa
188
Which description is true of type-III cells of taste buds?
Are innervated by several sensory fibers
189
Proprioceptor
a sensory receptor which receives stimuli from within the body, especially one that responds to position and movement.
190
Which description is true of thick filaments?
Contain ATPase
ATPases are a class of enzymes that catalyze the decomposition of ATP into ADP and a free phosphate ion or the inverse reaction. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur.
191
A decrease in the number of neutrophils in which compartment acts as a potent stimulus for neutrophilopoiesis?
Neutrophils in the blood stream can be divided into circulating granulocyte pool (CGP) and marginating granulocytic pool (MGP). The white blood cell count reflects the cells in the circulating pool. The cells in the marginating pool move quickly into the circulating pool when needed.
A
Circulating compartment
After maturation in the bone marrow, neutrophils are stored, awaiting release into the circulation. To exit the bone marrow, the neutrophils have to migrate across the bone marrow endothelium that separates the marrow from the circulation.
192
left shift?
Increase in band neutrophils, immature, can mean an infection or disease
193
hemophilia- what clotting factor
VIII
194
Which protein is more likely to inhibit the rapid growth of a malignant tumor?
Angiostatin
It is an endogenous angiogenesis inhibitor (i.e., it blocks the growth of new blood vessels).
195
Hassall's corpuscles - medulla - hormone secretor? unclear
(or thymic corpuscles (bodies)) are structures found in the medulla of the human thymus, formed from eosinophilic type VI epithelial reticular cells arranged concentrically.
196
thymic cortex?
The functional blood-thymus barrier consists of epithelial reticular cells, their basal laminae, and endothelial cells joined by tight junctions. This barrier keeps antigens in blood vessels from entering the thymus, preventing reaction with developing T-cells.
Site of the blood–thymus barrier
The blood–thymus barrier is a functional and selective barrier separating T-lymphocytes from blood and cortical capillaries. In the cortex, capillaries, which are rarely fenestrated, form the barrier together with perivascular lymphocytes, macrophages, and reticular epithelia cells.
197
thyroid in embryology
one of first endocrine glands in fetus to start working - as need these things to develop
198
Which structures consist primarily of actin or actin-like proteins?
microfilaments
199
Which feature is true of the uterine tube's ampulla but not of its isthmus?
Contains large, branched mucosal folds
200
Peg cells in fallopian tubes do what?
The peg cells capacitate spermatozoa, making them capable of fertilizing an ovum in the ampulla. Nutrients secreted by the peg cells aid in maintenance of the spermatozoa and the ovum.
201
Which description is true of the lens fibers?
Contain abundant proteins called crystallins
202
Identify the cell type that exhibits both exocrine and endocrine secretory activity.
Hepatocyte
203
Which of the following comprises every third amino acid in collagen?
Glycine
204
Which enzyme is used during DNA cloning procedures to isolate specific genes by cutting DNA at specific nucleotide sequences?
Restriction nuclease
205
Which structure is typically found in the connective tissue of a portal triad?
Portal triads are composed of three major tubes. Branches of the hepatic artery carry oxygenated blood to the hepatocytes, while branches of the portal vein carry blood with nutrients from the small intestine. The bile duct carries bile products away from the hepatocytes, to the larger ducts and gall bladder.
Branch of the hepatic artery
A distinctive component of a hepatic lobule, found running along each of the lobule's corners, that consists of branches of the hepatic artery proper, hepatic portal vein and bile ducts, as well as other structures.
206
serous demilunes?
Produce lysozyme
escents of Giannuzzi or Demilunes of Heidenhain, are cellular formations in the shape of a half-moon on some salivary glands. Serous demilunes are the serous cells at the distal end of mucous tubuloalveolar secretory unit of certain salivary glands
207
Which structures comprise the placenta?
A
Decidua basalis and chorion frondosum
208
Identify the source of goblet cells.
endoderm
209
Which cell type typically releases its lysosomal contents into the extracellular space?
osteoclasts
210
Which feature is true of both endocrine and exocrine glands?
Have secretory cells that derive from lining epithelia
211
Which term is used to designate the short oligonucleotide sequences that hybridize to the beginning and ending portions of DNA sequences targeted for rapid copying using the polymerase chain reaction?
primer
212
Which cell type typically contains the largest and most easily visualized nucleolus?
Proerythroblast
213
he production of which hormone is influenced by visual stimuli?
Melatonin is a hormone primarily released by the pineal gland that regulates the sleep–wake cycle.
214
CCK produced?
Is produced by enteroendocrine cells in the intestinal mucosa
stimulates delivery into the small intestine of digestive enzymes from the pancreas and bile from the gallbladder.
215
Which structure surrounds a muscle fascicle?
Perimysium
216
The patient's loose teeth reflect the importance of diet in providing a cofactor for enzymes that hydroxylate which amino acids?
Lysine and proline
217
In which order do the phases of intrauterine hematopoiesis occur?
Primordial, hepatosplenothymic, medullolymphatic
218
Which cell type surrounds neuronal perikarya located in ganglia?
satellite cells
219
The intense basophilia of the capsular matrix in hyaline cartilage is caused mainly by the synthetic activity of which chondrocyte organelle?
B
Golgi complex
220
Which term applies to the connective tissue sheath surrounding each seminiferous tubule?
Tunica propria
221
On which cellular component is protein synthesis initiated?
Free polyribosomes
222
The pulmonary (functional) and bronchial (nutrient) arterial systems enter the lungs separately through the hilus but anastomose into a single system at which level?
Respiratory bronchiole
223
Which feature typifies dense regular connective tissue?
TENDONS
224
Which feature typifies the zonula occludens?
A
Fusion of the outer leaflets of adjacent trilaminar unit membranes into one pentalaminar unit
225
Hormones produced by the pituitary gland
```
Adrenocorticotrophic hormone (ACTH)
Thyroid-stimulating hormone (TSH)
Luteinising hormone (LH)
Follicle-stimulating hormone (FSH)
Prolactin (PRL)
Growth hormone (GH)
Melanocyte-stimulating hormone (MSH)
```
226
ACTH?
Adrenocorticotropic hormone (ACTH) is a hormone produced in the anterior, or front, pituitary gland in the brain. The function of ACTH is to regulate levels of the steroid hormone cortisol, which released from the adrenal gland. ACTH is also known as: adrenocorticotropic hormone.
Enhances the production of mineralocorticoids by the adrenal cortex
The outermost layer, the zona glomerulosa, is the main site for production of mineralocorticoids, mainly aldosterone, that are largely responsible for the long-term regulation of blood pressure. ... The major stimulus to produce aldosterone is angiotensin II, as ACTH from the pituitary only produces a transient effect
227
Which organ has both adventitial and serosal coverings.
Ascending colon
228
Which cell type produces and maintains all extracellular matrix components of connective tissue?
A
| Fibroblast
229
A cascade of interactions between which two tissues is primarily responsible for tooth formation?
C
Ectomesenchyme and epithelium
230
Which organ typically contains the most goblet cells in the mucosa covering its villi?
Ileum
231
Which of the following is true of synapses?
Contain some basal lamina in the synaptic cleft
232
Which connective tissue component is a part of the extracellular matrix but not of the ground substance?
Collagen fibers
233
Which of the following tests would provide the most reliable information for distinguishing among sickle cell disease, sickle cell trait, and other possible hemoglobinopathies?
C
Isoelectric focusing
234
Which process occurs in response to the neural stimulation during suckling?
Contraction of the myometrium
235
2-week history of frequent urination (every 1–2 hours) and excessive thirst.
Renal collecting ducts problem -
This patient's frequent voiding of dilute urine (polyuria) and excessive thirst (polydipsia) are classic symptoms of diabetes insipidus (DI). The most common cause of DI is a chronic or temporary loss (or reduction) of the pars nervosa's ability to produce arginine vasopressin (AVP), also known as antidiuretic hormone (ADH; 20.IV.A.1), in response to a hypovolemic or hyperosmotic challenge. The normal-to-elevated levels of serum AVP, and the evidence of normal pituitary structure and function, indicate that factors regulating AVP production (including the pituitary and hypothalamus) are not affected in this case. Thus, the hormone's target cells become candidates for the location of the lesion causing this patient's symptoms. B
236
Identify the source of the ganglion cells in the myenteric plexus.
neural crest
237
Which procedure entails impregnating a specimen with a solvent of the embedding medium?
A
Clearing
238
Antibiotic therapies that slow the replacement of the cells lining the small intestine may cause the loss of what tissue type?
simple columnar
239
What is the function of the Fovea Centralis?
Thinnest part of the neural retina
The fovea is responsible for sharp central vision (also called foveal vision), which is necessary in humans for reading, driving, and any activity where visual detail is of primary importance.
240
Which description is true of thin filaments?
Found in the A band
Actin filaments, the thin filaments, are the major component of the I-band and extend into the A-band. Myosin filaments, the thick filaments, are bipolar and extend throughout the A-band. They are cross-linked at the centre by the M-band.
241
Which technique is most commonly used to locate glycogen in cells?
Periodic acid–Schiff (PAS) reaction
242
Which characteristic is unique to smooth muscle?
C
Thin filaments attach to dense bodies
243
skin's pale, clammy condition?
Reticular dermis
Hypovolemic shock caused by internal bleeding from liver trauma is strongly suggested in this case. The pale clammy skin reflects the reflex response to reduced venous return to the heart. This response involves the shunting of blood from peripheral vascular beds (e.g., skin) to vital internal organs to protect oxygen supply to the brain and heart (18.IV.D). The skin's coolness and paleness is caused by the lack of blood in the papillary capillaries. Its moistness is caused by the consequent reduction in the evaporation of sweat (18.VIII.A.3) and by increased sweating in response to sympathetic stimulation of the sweat glands. Sympathetic stimulation also causes smooth muscle contraction in the metarterioles that feed the dermal capillaries and thus prevents blood from entering the capillary beds. This process increases the blood volume flowing directly from the arteries to the veins through arteriovenous anastomoses (shunts). The skin's main arteriovenous anastomoses are located in the superficial and deep vascular plexuses at the borders between the reticular dermis and the papillary dermis and at the border between the reticular dermis and the hypodermis, res
244
Which structure produces the eye's aqueous humor?
ciliary body
245
Which of the following is true of motile cilia?
Covered by plasma membrane
246
Which hormone, produced by the adrenal medulla, and by certain autonomic neurons, has a dramatic lipolytic effect in adipose tissue?
Leptin
247
When the oxygen tension in the blood of sickle cell anemia patients decreases, as it does at high altitudes, which of the following changes occurs?
Hematocrit values decrease owing to hemolysis
248
Which description is true of the hepatic sinusoids?
Are surrounded by the space of Disse
Are surrounded by the space of Disse
249
Which protein accumulates in cells in response to DNA damage ?
p53
250
Leptin goes to what hypothalmus from ? why?
Leptin is a hormone released from fat cells in adipose tissue. Leptin signals to the brain, in particular to an area called the hypothalamus. Leptin does not affect food intake from meal to meal but, instead, acts to alter food intake and control energy expenditure over the long term.
251
Which of the following is true of the Barr body?
Member of a homologous chromosome pair in normal females
252
The basal lamina of a muscle fiber is a part of which structure?
endomesium
253
Which description is true for sweat glands but not sebaceous glands?
Apocrine sweat glands, which are usually associated with hair follicles, continuously secrete a fatty sweat into the gland tubule. Emotional stress causes the tubule wall to contract, expelling the fatty secretion to the skin, where local bacteria break it down into odorous fatty acids
contain clear and dark cells
Eccrine glands are found all over the body and secrete a watery product that cools the skin. Apocrine sweat glands are mainly found in the armpits and perianal area, and secrete a more viscous, odorous product.
254
Which feature typifies unmyelinated axons of the central nervous system?
Occur in gray matter and white matter
255
Which filamentous protein winds around F-actin and lies in grooves in its surface?
Tropomyosin
256
Which structure is partly lined by nonkeratinized stratified squamous epithelium?
larynx
257
Hypersecretion of dopamine by neurons of the arcuate nucleus of the hypothalamus is likely to elicit which effect?
A
Hyposecretion of prolactin
258
Which collagen type occurs only in hypertrophic cartilage?
X during bone growth - chondrocyte differentiation pathway, and are essential for bone growth.
259
Which type of epithelium lines the thin loop of Henle?
simple squamous
260
Which cross-linked amino acid is characteristic of elastin?
A
| Desmosine
261
What shortens during muscle contraction?
When a muscle contracts, the actin is pulled along myosin toward the center of the sarcomere until the actin and myosin filaments are completely overlapped. In other words, for a muscle cell to contract, the sarcomere must shorten.
For a muscle cell to contract, the sarcomere must shorten. However, thick and thin filaments—the components of sarcomeres—do not shorten. Instead, they slide by one another, causing the sarcomere to shorten while the filaments remain the same length.
262
Which description is true of the muscularis mucosa of the upper esophagus?
Innervated by postganglionic autonomic fibers
263
Muscle contraction - great explanation
| I and H shorten, z lines come closer together
When a sarcomere shortens, some regions shorten whereas others stay the same length. A sarcomere is defined as the distance between two consecutive Z discs or Z lines; when a muscle contracts, the distance between the Z discs is reduced. The H zone—the central region of the A zone—contains only thick filaments (myosin) and is shortened during contraction. The H zone becomes smaller and smaller due to the increasing overlap of actin and myosin filaments, and the muscle shortens. Thus when the muscle is fully contracted, the H zone is no longer visible. The I band contains only thin filaments and also shortens. The A band does not shorten—it remains the same length—but A bands of different sarcomeres move closer together during contraction, eventually disappearing. Thin filaments are pulled by the thick filaments toward the center of the sarcomere until the Z discs approach the thick filaments. The zone of overlap, in which thin filaments and thick filaments occupy the same area, increases as the thin filaments move inward.
264
stomach zones
The pylorus, the lowest section of the stomach which attaches to the duodenum via the pyloric canal, contains countless glands which secrete digestive enzymes including gastrin. After an hour or two, a thick semi-liquid called chyme is produced.
The pylorus is the narrow region that connects the stomach to the duodenum. The cardia and pylorus contain branched coiled tubular glands that secrete mucus. In contrast, the mucosa of the fundus/body contains long, branched tubular gastric glands with several cell types that secrete substances that aid in digestion.
265
fundus of stomach (body)
Pepsin is a proteolytic digestive enzyme (protease), thereby contributing to digestion. The distribution of the glandular epithelial constituents varies by region of the glandular stomach. The fundus contains large numbers of parietal cells, whereas the pylorus is rich in mucus cells but contains few parietal cells.
266
Which collagen type predominates in hematopoietic tissues?
type 3 III
267
Which description is true of the smooth muscles of the iris?
ectodermal origin
268
Which fiber type forms a fine supportive network in the body's soft tissues?
reticular fibers
269
proliferative vs secretory stage
The progesterone surge of ovulation ends the proliferative phase, and the endometrium moves into the secretory (or luteal phase) of development. Under normal conditions the secretory phase is 14 days in length, and the endometrium moves through an orderly sequence of morphologic changes
270
Which hormone is carried to its target(s) by the hypophyseal portal system?
The main hormones transported by the system include gonadotropin-releasing hormone, corticotropin-releasing hormone, growth hormone–releasing hormone, and thyrotropin-releasing hormone.
271
What is Hypothalamo hypophyseal portal system?
GONADS
The hypothalamic-pituitary-gonadal axis (HPG axis) alludes to the connection between the hypothalamus, pituitary gland, and gonads. It is an important control mechanism mainly involved in the development and regulation of the reproductive system and immune system.Ja
272
Which description is true of endosteum?
lines the marrow cavity
273
Which feature typifies mucous connective tissue?
Is sometimes referred to as Wharton's jelly
274
Which pair of structures regulates the distribution of vesicles and organelles through their influence on microtubule polymerization?
A
Centrioles and satellite bodies
275
Where is ribosomal RNA (rRNA) synthesized?
Nucleolus
276
What sequence does membrane depolarization follow in skeletal muscle fibers after acetylcholine binds to its receptor?
Sarcolemma, T tubule, terminal cisternae, sarcoplasmic reticulum
277
Which description is true of the cells lining striated ducts?
A
Have basal plasma membranes containing numerous infoldings
278
Which bone marrow component increases in abundance as hematopoietic activity declines?
A
Adipocytes
279
Which pituitary hormone maintains progesterone secretion in the corpus luteum of menstruation?
LH
280
In which location are hepatocytes the first to be destroyed by hepatotoxic substances in the blood?
A
Zone I of hepatic acinus
281
Which term refers to a large, fat-containing particle formed by the intestinal epithelium?
A
Chylomicron
282
hich substance is an endocrine secretory product of the liver?
A
Albumin
B
Bile acids
C
Bilirubin glucuronide
D
Cholecystokinin
Albumin
283
Which receptor class includes the olfactory epithelium?
A
Chemoreceptor
284
Which structures are important components of axonemes?
microtubues - its the main
the central strand of a cilium or flagellum. It is composed of an array of microtubules, typically in nine pairs around two single central ones. this is an axoneme
285
Which feature of brown adipose tissue is not shared by white or yellow adipose tissue?
can generate heat
Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). In addition to heat produced by shivering muscle, brown adipose tissue produces heat by non-shivering thermogenesis
286
Which description is true of tears?
has lysosomes, lacrimal glands are paired, almond-shaped exocrine glands, one for each eye, that secrete the aqueous layer of the tear film. They are situated in the upper lateral region of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone.
287
Which description is true of ciliary muscle contraction?
contraction - viewing NEAR - lens thickens
pulls the muscle forward -
Contraction is to decrease the diameter of the ring of ciliary muscle causing relaxation of the zonule fibers, the lens becomes more spherical, increasing its power to refract light for near vision.
288
Which histone is typically associated with the nucleosome's linker region?
A
| H1
289
plasma vs serum
Which substance is present in higher concentrations in plasma than in serum?
Fibrinogen
plasma contains fibrinogen which is absent in serum. ... Plasma on the other hand, is mostly used for blood-clotting related problems.
Serum and plasma both come from the liquid portion of the blood that remains once the cells are removed, but that's where the similarities end. Serum is the liquid that remains after the blood has clotted. Plasma is the liquid that remains when clotting is prevented with the addition of an anticoagulant.
290
Which organelle is the site of actin and tubulin synthesis?
Free polyribosomes
291
Which cell type comprises the visceral layer of Bowman's capsule?
Podocyte
Bowman's capsule
The visceral layer is formed by podocytes – epithelial cells with pedicles surrounding glomerular capillaries.
292
Which fibroblast secretion is synthesized mainly in the Golgi complex?
Glycosaminoglycan
293
Which description is true of intramembranous bone formation?
Process by which the periosteal bone collar is formed
The direct conversion of mesenchymal tissue into bone is called intramembranous ossification. This process occurs primarily in the bones of the skull. ... The process by which a cartilage intermediate is formed and replaced by bone cells is called endochondral ossification.
294
Which description is true of pancreatic zymogens?
Are inactive until they reach the duodenal lumen
The pancreas secretes zymogens partly to prevent the enzymes from digesting proteins in the cells in which they are synthesised. Enzymes like pepsin are created in the form of pepsinogen, an inactive zymogen.
295
Eye - 1) Tunica fibrosa
Cornea +
It is outer fibrous layer including sclera and cornea. ... It is composed of 5 layers: corneal epithelium, Bowman's membrane, corneal stroma, Descemet's membrane, corneal endothelium.
296
Which feature typifies resting-state axons?
Depolarization is caused when positively charged sodium ions rush into a neuron with the opening of voltage-gated sodium channels.
Transmission of a signal within a neuron (from dendrite to axon terminal) is carried by a brief reversal of the resting membrane potential called an action potential. When neurotransmitter molecules bind to receptors located on a neuron's dendrites, ion channels open
The K+ concentration inside the axon is greater than that outside the axon
n action potential is caused by either threshold or suprathreshold stimuli upon a neuron. It consists of four phases; hypopolarization, depolarization, overshoot, and repolarization. An action potential propagates along the cell membrane of an axon until it reaches the terminal button.
297
Which cell type secretes lysozyme.
paneth cells
298
different types of glands
Compound tubular glands are glands that have branched ducts. So the duct of a compound gland branches repeatedly. This in contrast to simple glands that consist of a single secretory passage / an unbranched common duct.
Depending on the shape of the secretory portions they can be further divided into:
Compound tubular glands e.g. in testis and kidney
Compound alveolar glands e.g. in pancreas
Compound tubulo-alveolar glands e.g. salivary gland (see image), mammary gland
299
Which description is true of skeletal muscle myosin?
Head includes an actin-binding site
300
Which cells contain secretory granules containing thymic hormones?
Epithelial reticular cells
301
electron-transport system located?
Cristae
302
Which pair of functions is associated with the Golgi complex?
NOT
Glycogen synthesis and packaging of secretions
Glycosylation and sulfation of secretory products
303
Which cells produce cholecystokinin?
neural crest derived cells
304
Which description is true of thymic epithelial reticular cells?
Components of the blood–thymus barrier
305
After transecting an axon, which change occurs distal to the injury?
Complete axonal degeneration
Chromatolysis is the dissolution of the Nissl bodies in the cell body of a neuron. It is an induced response of the cell usually triggered by axotomy, ischemia, toxicity to the cell, cell exhaustion, virus infections, and hibernation in lower vertebrates.
306
Which feature typifies specific granules?
Contain phagocytins or major basic protein
307
The sarcoplasmic reticulum (SR)
Is a specialized form of SER
is a membrane-bound structure found within muscle cells that is similar to the endoplasmic reticulum in other cells. The main function of the SR is to store calcium ions (Ca2+).
308
Which structure has an epithelial lining in which cilia are present but goblet cells are absent?
Respiratory bronchiole
309
Which of the following is true of Nissl bodies?
Undergo chromatolysis after injury
310
kinetochore
a complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach.
311
Which feature is true of the cytotrophoblast but not of the syncytiotrophoblast?
Disappears during late pregnancy
312
Where are the Krebs cycle enzymes and mitochondrial DNA located?
Mitochondrial matrix
313
Which protein in the troponin complex inhibits the binding of myosin to actin?
Tnl - Tropomyosin blocks myosin binding sites on actin molecules, preventing cross-bridge formation, which prevents contraction in a muscle without nervous input. The protein complex troponin binds to tropomyosin, helping to position it on the actin molecule
314
What are the 6 steps of muscle contraction?
Terms in this set (6)
Ca2+ release from SR terminal Cisterinae binding site exposure.
Myosin head binding to actin binding sites.
Release of ADP & Pi Causes power stoke.
ATP causes Myosin head to be released.
ATP is hydrolyzed, re-energizes the Myosin head.
Ca2+ pumped back into SR terminal cisterine.
315
hypertonic filtrate?
allows water to filter thru
316
steps in muscle contraction
The process of muscular contraction occurs over a number of key steps, including:
Depolarisation and calcium ion release.
Actin and myosin cross-bridge formation.
Sliding mechanism of actin and myosin filaments.
Sarcomere shortening (muscle contraction)
317
Which structure is the site of secretory-protein core glycosylation?
RER
318
Which protein anchors the nuclear pore complex in the nuclear envelope?
A
gp210
319
oxiphil cells
In the parathyroid gland, the parathyroid oxyphil cell is larger and lighter staining than the parathyroid chief cell. These cells can be found in clusters in the center of the section and at the periphery. Oxyphil cells appear at the onset of puberty, but have no known function.
320
Which structure is the smallest chromatin subunit in eukaryotic cells?
nucleosome
321
does placenta release hormones?
Yes, after 12th week
322
Which of the following is true of the fetal (provisional) adrenal cortex?
Produces sulfated androgens
323
Ubiquitin
is best known for its function in targeting proteins for degradation by the proteasome.
324
How does MPF regulate the cell cycle?
Maturation promoting factor (MPF) is a cell cycle checkpoint that regulates the passage of a cell from the G2 growth phase to the M phase. It is also known as the G2 checkpoint, and ensures that DNA replication during the S phase did not produce any mistakes.
325
hich protein specifically promotes passage through the G1 checkpoint?
Cyclin D
326
Which protein increases in concentration during G2 and is degraded in M?
Cyclin B
327
Which of the following is true of releasing and inhibiting hormones?
Are released by axon terminals located near the primary capillary plexus
328
hering bodies
Herring bodies or neurosecretory bodies are structures found in the posterior pituitary. They represent the terminal end of the axons from the hypothalamus, and hormones are temporarily stored in these locations. They are neurosecretory terminals.
329
fibrocartilage - type of collagen
type 1
330
Which cells in the lymph nodes are nonphagocytic, bind antigen on their surfaces, and present them to lymphocytes for recognition and stimulation?
A
Dendritic cells
Dendritic cells (DCs) are antigen-presenting cells (also known as accessory cells) of the mammalian immune system. Their main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They act as messengers between the innate and the adaptive immune systems.
Dendritic cells (DCs), monocytes and macrophages are members of the mononuclear phagocyte system (MPS) that exhibit multiple functions during immune responses. ... By contrast, DCs are usually defined as cells with a stellate morphology that can efficiently present antigens on MHC molecules and activate naive T cells7,8.
331
Which of the following is true of the fibroblasts of a normal neurohypophysis?
A
derive from neural crest
332
Zollinger-Ellison syndrome - gastrin comes from
D cells in stomach
333
Which cells often contain mitochondria with tubular cristae?
Steroid-secreting cells
334
Question 522 of 569
| Select the adult dental formula.
2 incisors, 1 canine, 2 premolars, 3 molars
335
Which description is true of megakaryocytes?
Network of intracellular membranes
336
serous demilunes
sublingual
337
Which cells are the primary cellular components of the stroma of the splenic lymphoid nodules?
reticular cells
338
he capillaries of the adrenal medulla receive their double blood supply directly from which vessels?
Cortical capillaries and medullary arteries
NO medullary rays in medulla FYI
339
A 15-year-old male patient visits his family physician for the checkup required to join his high school football team. Giemsa staining of a standard smear of his blood reveals that most of his mature RBCs lack ribosomes. From this information, and from knowledge of ribosome function and distribution, the physician can deduce which conclusion?
Mature RBCs are incapable of protein synthesis
They also lack the components to express genes and synthesize proteins.
