Histology NBME Review Flashcards by Deleted Deleted

The intercellular passage of ions from the luminal surface of the intestines to the lamina propria is prevented by the presence of …

Desmosomes
Belt desmosomes
Hemidesmosomes
Gap junctions
Tight Junctions/Zonulae Occludens

Tight Junctions

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Emphysema is characterized by overdistention & destruction of which of the following structures?

Trachea
Bronchi
Bronchioles
Terminal bronchioles
Alveolar ducts

Aveolar ducts- duct that carries into alveoli

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A diurnally secreted biogenic amine synthesized in pinealocytes is?

Dopamine
Epinephrine
norepinephrine
Melatonin
serotonin

Pinealocytes are in pineal glad -MELATONIN- induce sleepiness

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In the renal cortex, the labyrinth of capillaries that carry resorbed glucose out of the kidney arises directly from?
Afferent arterioles
Arcuate arteries
Capsular plexus
Efferent arterioles 
Intralobular arteries

EFFERENT ARTERIOLES directly connects to capillaries

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The proliferation of uterine endometrium depends on?
Cortisol 
Estrogen
Luteinizing hormone
Progesterone
Prolactin

Proliferation is the follicular phase which secretes ESTROGEN luteal phase is progesterone

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Which of the following cell types are found exclusively in the basal compartment of seminiferous tubules?
Primary spermatocytes
Secondary spermatocytes
Spermatids
Spermatogonia
Spermatozoa

SPERMATOGONIA are exclusively found in basal. The rest are found in luminal compartment

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A suitable marker for determining that cells have differentiated into epidermal epithelial tissue is expression of?
Desmin
Keratin
Vimentin
Histone H variant

Epithelial tissue to do with intermediate filaments. KERATIN or cytokeratin

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A patient ingests an overdose of barbiturates.  Which of the following will show greatest increase in hepatocytes 2 days later?
Centrioles
Glycogen
Golgi cisternae
Lysosomes
Smooth endoplasmic reticulum

Processing of drugs happens in the liver by SMOOTH ENDOPLASMIC RETICULUM

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During the final stage of secretory glycoprotein formation, before exocytosis, glycoproteins are found in the?
Cisternae of rough endoplasmic reticulum
Cis golgic complex 
Trans golgi complex
Lysosomes
Polysomes in the cystosol
TR

TRANS GOLGI COMPLEX
Nucleus-> RER -> Golgi complex -> plasma membrane
Modifications occur at the golgi complex. Cis phase, medial phase, trans phase (L-R as proteins go throguh golgi)

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The synthesis of rRNA is associated most specifically with which of the following cell structures?
Kinetochores
Nucleus envelope
Nucleolus
Ribosomes
Rough endoplasmic reticulum

NUCLEOLUS - Where ribosomal subunits initially are

They may give a drawn picture and ask to identify the are. Nucleoulus is the dense region in the center of the nucleus

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Beating of cilia is mediated by?
Dynein arms
Microfilaments
Nexin links
Reversible assembly-disassembly of microtubules
Triplet microtubule units

DYENIN ARMS- associated with microtubules

Cilia associated with epithelial cells in trachea (9+2 dyenin arms)

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A 26-yr. old woman with irregular menstrual cycles undergoes diagnostic endometrial biopsy. Histologic examination of the specimen shows long straight endometrial glands with narrow lumens that are embedded in a thick stratum functionale of the endometrium. These changes are most considered with which of the following findings?
Decreasing serum estrogen concentration stimulation release if luteinizing hormone releasing hormone from the hypothalamus
Diminishes activity of granulosa lutein cells in the ovary
Increasing secretion of pituitary FSH correlated with decreasing secretion of pituitary luteinizing hormone
Presence of a primary oocyte still encoded within the cumulus oophorous undergoing maturation prior to ovulation
Rapidly increasing viscosity and pH of vaginal secretions

DIMINISHES ACTIVITY OF GRANULOSA LUTEIN CELLS IN THE OVARY

Associated with proliferative phase. Estrogen is increasing because of proliferation of granulosa cells along with FSH

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The blood brain barrier excluded which of the following molecules from the brain parenchyma?
Albumin
Choline
Estrogen 
glucose
tyrosine

ALBUMIN- cannot pass because of size

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A substance of low molecular weight is injected into a cell.  A short time later, the substance can be identified in the injected cell and in an adjacent cell.  There is also evidence that the two cells are electrically coupled.  EM is most likely to disclose which of the following structural specializations between these 2 cells?
Chemical synapses 
Desmosomes (maculae adherents)
Gap junctions 
Tight junctions (zonulae occludentes)

GAP JUNCTIONS- or connexons-> connexin protein (transmembrane protein)

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Fenestrated capillaries are found in which of the following sites?
Central nervous system
lung
Muscle
Thymus
Thyroid gland

THYROID GLANDS

Blood barrier in CNS (blood brain), lung, muscle, thymus (blood thymic barrier)

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Which of the following differentiates capillaries in the brain from those in the gut?
Absence of a basement membrane
Absence of endothelial cell membrane fenestrations
Absence of a saturable transport mechanism for glucose
Presence of multiple endothelial cell nuclei
Presence of valves in the lumen

ABSENCE OF ENDOTHELIAL CELL MEMBRANE FENESTRATIONS

Blood brain barrier in the brain so close contact with epithelial cells with continuous basal membrane

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In contrast to extrafusal muscle fibers, infrafusal fibers contain?
A bands
Motor nerve endings 
Sarcolemma 
Satellite cells
Stretch-sensitive nerve endings

STRETCH-SENSITIVE NERVE ENDINGS

Muscle spindles- sensory receptors associated with skeletal muscle fibers which detect tension

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The diagram represents the cytosolic surface of a normal erythrocyte PM Various proteins associated with the membrane are lettered A-E. A point mutation in which labeled protein results in spherocytosis

The rope shaped item is spectrin- A LETTER

Spectrin gives normal architecture to red blood cells - cytoskeletal protein

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Cells will accumulate in which of the following phases of the cell cycle if they are cultivated in the presence of a chemical agent that is capable of blocking the cell cycle immediately after DNA synthesis has been completed?
Metaphase of mitosis
Anaphase of mitosis
G1
S
G2

G2 PHASE- is immediately after DNA synthesis

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A tumor stained with a panel of monoclonal antibodies directed against various classes of intermediate filaments.  The tumor stained positively with antiglial fibrillary acidic protein (anti-GFAP), indicating its derivation from?
Astrocytes
Endothelial cells of the brain
Microglial precursors
Oligodendrocytes 
Stromal fibroblasts of brain meninges

Anti-GFAP is an intermediate filament associated with ASTROCYTE

They may flip the question and ask what is the IF associated with astrocyte

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To demonstrate graft versus host rejection to her students, an immunologist grafts the skin of a black male mouse onto an albino female mouse.  The graft is rejected.  Which of the following cell types present in the skin adjacent to the graft migrate into the graft to initiate an immunological response?
Keratinocytes
Langerhans’ cells
Lymphocytes
Melanocytes
Merkel cells

LYMPHOCYTES are the T CELLS responsible for graft rejection

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The dense spherical granules in this micrograph of a mammalian heart are likely sites for storage of?AcetylcholineAtrial natriuretic peptideCa2+ ATPaseGalactosyltransferaseGlobular actin

Refer to picture with lobule shaped with lots of dots- cardia cell

ATRIAL NATRIURETIC PEPTIDE- decreases blood pressure

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The diagram is of the olfactory epithelium. The structures label X are?absorptive cellsGoblet cellsMitral cellsOlfactory receptors cellsSupporting cells

OLFACTORY RECEPTOR CELLS- the one with an X

Has pseudostratified epithelial cells- columnar cells, basal cells, olfactory epithelium

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For the oocyte, meiosis is completed at the time of which of the following events?
Extrusion of the first polar body
Midcyle peak serum luteinizing hormone
Peak serum follicle-stimulating hormone
Peak serum inhibin
Sperm entry into the secondary oocyte

SPERM ENTRY INTO THE SECONDARY OOCYTE- during this process there is completely of second meiotic division

Meiosis is complete in oocyte. Completion happens during fertilization.

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``` Drugs, including alcohol, increase the number of detoxifying enzymes in the liver by extensive proliferation of which of the following cellular components? Golgi complex Lysosomes Mitochondria Rough endoplasmic reticulum smooth endoplasmic reticulum ```

SMOOTH ENDOPLASMIC RETICULUM

Which lettered structure on the diagram of muscle is most active during generation of energy necessary for contractions?

Skeletal muscle fiber- referring to mitochondria LETTER C= MITOCHONDRIA

``` The most abundant type of cell within the fovea of the retina centralis? Bipolar Cone Ganglion Horizontal Rod ```

CONE- most abundant In the eye

``` The cell type most responsible for recognition and rejection of foreign tissue in organ transplants? B lymphocyte T lymphocyte Macrophage Natural killer cell Neutrophil ```

T LYMPHOCYTES

``` Axons are characterized by the absence of which of the following organelles? Intermediate filaments Microtubules Mitochondria Rough endoplasmic reticulum Vesicles ```

ROUGH ENDOPLASMIC RETICULUM

``` An a 11yr old girl has severed her ulnar nerve. Which of the following cell types is important in promoting axonal regrowth? Epinerulial cells Fibroblasts Oligodendrocytes Perineurial cells Schwann cells ```

SCHWANN CELLS- process of nerve regeneration- promoting axonal growth

``` A recessive genetic mutation, white belly spot and tall (bst) is associated in mice with a failure of neural crest cells to migrate into the area of the umbilicus & the distal tail. The skin in these regions on infected mice lacks a population of cells that are devoid of desmosomes & keratin fibrils. Which of the following cell populations is most likely to be affected? Keratinocytes Langerhans’ cells Lymphocytes Melanocytes Merkel’s cell ```

MELANOCYTES- white belly spot because of failure of migration

``` A core of helical F-actin filaments provides the skeletal framework for? Ciliary axonemes Desmosomes Microvilli Nuclear laminae Nucleosomes ```

MICROVILLI- actin filaments are associated with these

``` The chart represents the changing amounts of RNA and hemoglobin in the erythroblast during erythrocyte formation. Which point best characterizes the condition found in the basophilic erythroblast? Point W Point X Point Y Point Z ```

POINT W

``` The vibrations of a tuning fork are most likely detected by? Bare nerve endings Golgi tendon organs Merkel’s cell receptors Muscle spindles Pacinian corpuscles ```

PACINIAN CORPUSCLES

``` Taste buds on the anterior 2/3 of the tongue are innervated by processes of cells in which the following ganglia? Geniculate Otic Pterygopalatine Submandibular Trigeminal ```

GENICULATE

``` The arrows in the photomicrograph indicate structures that are directly regulated by secretions? Chief cells of the parathyroid Chromaffin cells of the adrenal medulla Follicular cells of the Thyroid Glomerulosa cells of the adrenal cortex Pituicytes of the Neurohypophysis ```

CHEIF CELLS OF THE PARATHYROID- secretes parathyroid hormones Photo will be in color- bone matrix is long gray region with circle center

``` Cells of which of the following hypothalamic nuclei secrete oxytocin into circulation? Mammillary Supreachiasmatic Supraoptic Tuberal Ventromedial ```

SUPRAOPTIC- secreted from hypothalmus (paraventricular (oxytocin) and supraotic (antiduaratic hormones mostly and small amounts of oxytocin)- secreted into pars nervosa

``` Which of the following cell types is most characteristic of terminal bronchioles? Basal Brush Ciliated Clara Mucous (goblet) ```

CLARA CELLS Terminal bronchioles are simple layer of epithelial- not pseudostratified so no respiratory epithelium- mucous cells are only in bronchi Brioncioles have clara cells or club cells

``` A 12yr old girl with chronic asthma is coughing up large amounts of mucus. Which of the following respiratory structure are the most likely source of mucus? Alveolar ducts Alveolar sacs Respiratory bronchioles Terminal bronchioles Tertiary bronchi ```

TERTIARY BRONCHI- goblet cells are found in the bronchi- excess mucous are secreted

``` Which of the following staining methods will clearly show abundant secretions of mucus in the bronchial epithelium? Hematoxylin and eosin Osmium tetroxide Periodic acid- Schiff (PAS) Sudan black Wrights stain ```

PERIODIC ACID-SCHIFF (PAS)

Which labeled structure in the photomicrograph of respiratory tissue shows the most proximal regions where respiration occurs?

E REGION- refers to proximal region of respiratory zone- alveolar duct, alveolar s, and alveoli- can identify individual alveoli

``` A genetic defect that renders kinesin incapable of binding to microtubules is most likely to impair? Absorption by the microvilli Fast axonal transport Gap junction communication Muscle contraction Pinocytosis ```

FAST AXONAL TRANSPORT- Kinesin is in cytplasmic dyenin- likely impair transport

``` The structure indicated by the arrow on the diagram of a histological section of the skin is specialized to transduce which of the following stimuli into action potential? chemical irritant Cold Heat Light touch Vibration ```

LIGHT TOUCH - meisner corpuscles small arrow at top middle around light grey region

``` Which of the following cell types forms the barrier that prevents interaction b/w developing sperm & the immune system? Capillary endothelium Interstitial cell Myoid cell Sertoli cell Undifferentiated germ cells ```

SERTOLI CELLS- blood testes barrier- seminiferous tubules

``` Chronic administration of glucocorticoids will result in decreased thickness of which region of the adrenal glands? Medulla Zona fasciculata Zona glomerulosa Zona reticularis ```

ZONA FASICULATA adrenal cortex- ZG-> ZF-> ZR-> M (cathecolamine)

``` After swimming in cool water, a fair skinned woman’s skin becomes pale a& cold b/c the blood is diverted away from the capillary bed in the superficial layers of the dermis. The structures responsible for this diversion are? Arterioles Arteriovenous shunts Capillaries Muscular venules sinusoids ```

Diversion of the blood from arteriol to venule through ATERIOVENOUS SHUNTS

``` The epithelial lining of which of the following organs is most likely to be the site of a primary squamous cell carcinoma? Rectum Trachea Ureter Uterine tube Vagina ```

Columnar to squamous epithelium- RECTUM

``` The ducts of apocrine glands are characteristically lined with which type of epithelium? Pseudostratified columnar Simple columnar Simple cuboidal Simple squamous Stratified columnar Stratified cuboidal Stratified squamous Transitional ```

Sweat glands STRATFIFIED CUBODIAL- in the duct- not secretory region

``` The scanning EM shows a broken surface of a mammalian liver, RBC indicates erythrocytes. The arrow at X point to? Bile canaliculus Hepatocyte cytosol Lumen of an artery Perisinusoidal space (of disse) Vascular space ```

BILE CANALICULUS -Study the picture Portion of the liver- fenestrated endothelial cells- sinusoidal epithelial cells- hepatocyte template (long cells with center line down the middle) Blood flow between them. Center line down middle hepatocyte- where the bile is being discharged

``` A polypeptide with a molecular weight of 500 Daltons is introduced into the circulation through an intravenous drip. In which organ is it most likely to remain in the vascular bed? Brain Liver Plasma membrane Rough endoplasmic reticulum Secretory vesicles ```

BRAIN Movement of substances is prevented by blood barrier Liver -> polypeptides will not make it through because of sinusoids Brain -> has continuous capillary so not everything can diffuse

In the illustration of the alveolar wall, which labeled cell produces a substance that lowers alveolar surface tension

LETTER D ``` C- Type 1 pneumocyte A- endothelial cell of capillary B-blood cell D- Type 2 pneumocyte- cubodial cells- with lameral bodies E- alveolar macrophages ``` Referring to surfactants- secreted in type 2 cells

``` In children who exhibit abnormally rapid growth, administration of somatostatin will depress secretion of which of the following cell types in the pituitary gland? Acidiphils Basophils Chromophobes Folliculostellate cells ```

ACIDOPHILS Somatostratin will stop secretions of growth hormones. They are synthesized in Basophils secrete: FLAT acronym (follicle stimulating, leutinzin, a Acidophils- prolactin and growth hormones

``` Translocation of protein from the ribosome into the lipid bilayer of a membrane occurs most frequently at the level of the Cis Golgi Lamellae Nucleolus Plasma cells Rough endoplasmic reticulum Secretory vesicles ```

Lipid bilayer= plasma membrane -> SECRETORY VESICLES responsible for transporting ribosomes through the lipid bilayer- confined in vesicles

Initial glycosylation of glycoproteins occurs at which of the labeled structures on the electron micrograph of cells of a gastric gland?

Study picture Initial glycosalation happnes in RER. Final glycosilation happnes in golgi coomplex. Look for RER-> LETTER C

``` The scanning electron micrograph shows a portion of normal adult kidney. Which letter indicates the cell layer that is directly continuous with the cells of the proximal tubule? A B C D E ```

Bowmans membrane connects to PCT- bowmans is lined with squamous epithelial cells then into cuboid cells in PCT LETTER B Glomerulous was the C, D, E region

``` A 50 yr old postmenopausal woman reports that the amount and coarseness of her facial hair has increased in recent months. Secretions of cells in which of the following regions of the adrenal gland is most likely responsible? Medulla Zona fasciculata Zona glomerulosa Zona reticularis ```

ZONA RETICULARIS- sex hormone

``` In prepubertal boys, cells within the seminiferous tubules are? Mature spermatozoa Primary spermatocyte Secondary spermatocytes Spermatids Spermatogonia ```

Actively dividing SPERMATOGONIA

Which of the following cell types is the source of new skeletal muscles following injury? Embryonic myotubules remaining from fetal myogenesis Endomysial fibroblasts Satellite cells Schwann cells

SATELLITE CELLS associated with skeletal muscle fibers Said schwann but circled satellite- Double check this*

``` The secretory phase of the endometrium is directly controlled by which of the following hormones? Estrogen Follicle-stimulation hormone Human chronic gonadotropin Luteinizing hormone Progesterone ```

PROGESTOERONE

``` The principal extracellular molecule that promotes adhesion of epithelial cells to the basement membrane are? Chondroitin sulfate proteoglycan Type I collagen Elastin Laminin Thrombospondin ```

LAMININ or fibronectin- cell adhesion molecules for cell to basement membrane through hemidesmosomes

``` The most prominent ultrastructural characteristics of interstitial (Leydig) cells? Centrioles Numerous microtubules Rough endoplasmic reticulum Smooth endoplasmic reticulum Zymogen granules ```

SMOOTH ENDOPLASMIC RETICULUM

``` Which of the following structure is labeled X in the photograph? alveolus Bronchus Respiratory bronchiole Terminal bronchiole Trachea ```

Portion of bronchial tree- epithelial lining- TERMINAL BRONCHIOLES Know how each of these would look in a figure Trachea- resp epithelium and cartilage Bronchus- RE and Cartilage

A 55 yr old woman notes a gradually increasing number of episodes of cramping abdominal pain & diarrhea that occur after ingestion of milk products. A decrease in which of the following best explains her condition? Ability of enterocytes to transport calcium Ability of Paneth cells to secretes secrete lactase Ability of Paneth cells to secrete lysozyme Beta-galactosidase activity within lysosomes of enterocytes Sucrose activity within lysosomes of enterocytes

BETA-GALACTOSIDASE ACTIVITY WITHIN LYSOSOMES OF ENTEROCYTES

Which label on the electron micrograph of a nerve is the myelinated axon?

The whole D, H, A region is myelinated D is a schwann cell

``` A mutation interfering with formation of triple helix of Type II collagen most likely causes abnormalities? Basement membrane Blood vessels Hyaline cartilage Skin Bone ```

Type 2 collagen is found in HYALINE CARTILAGE Bone and skin is Type 1 collagen Basement membrane is type 4

``` A 40 yr old woman has reduced 2-point discrimination on the distal phalanges of her fingers. Which of the following skin cell types is most likely affected in this patient? Keratinocytes Langerhans’cells Lymphocyte Melanocytes Merkel’s cells ```

MERKEL CELLS- associated with epidermis

``` Over the course of 2 weeks, the diameter of a 1-cm puncture wound of the skin noticeably decreases. What cell type in the skin is most likely to be responsible for this contraction phenomenon? Arrector pili muscles Fibroblast Keratinocyte Macrophages Merkel’s cells ```

Wound cuts will come close to each other to close the wound FIBROBLAST- myofibroblast (more correct bc actin and myosin contract to bring injured skin together)

``` The exocrine pancreas releases digestive enzymes primarily in response to hormones produced by? Body of the stomach Cardia of the stomach Duodenum Fundus of the stomach Gallbladder ```

Exocrine pancreas- secretions of pancreatic enzyme-faciliated by cck- facilatate secretory asenous- DUODENUM- secreted from intestinal glands

In the kidney, what normally happens to protein that has passed through the filtration barrier? Reabsorption by the collecting tubules Reabsorption by proximal convoluted tubule cells Reabsorption by the thick ascending limb of the loop of the Henle Removal in voided urine Reutilization intact

Afferent arterioles -> glomeruls -> efferent arterioles -> bowmans capsule surrounds this into PCT REABSORPTION BY THE PROXIMAL CONVOLUTED TUBULES CELLS

``` In the epidermis, certain cells form a product that is transferred to other epidermal cells? This product is a Birbeck granule of Langerhan’s cell Dense core granule of Merkel’s cell Keratohyalin granule Membrane-coating granule Melansome ```

MELANOSOMES- Contain melanin

In the kidney, an apical nucleus, extensive basal interdigitations, and absence of brush border characterizes cells of? Thick ascending limb of the loop of Henle Thick descending limb of the loop of Henle Thin limb of the loop of Henle Proximal convoluted tubule

Absence of brush border in distal convoluted tubule THICK ASCENDING LIMB OF THE LOOP OF HENLE is distal convoluted tubules DCT Pct- thick descending limb of loop of henle

``` A 35-year-old man develops erosive lesions in the cartilaginous nasal septum as a result of inhaling cocaine. What type of collagen makes up the nasal fibers that are liberated during this degradation? I II III IV V X ```

Type 2 Collagen- Hyaline cartilage

``` Renin secreting cells in the kidney are located? Afferent arteriole Arched collecting tubules Glomerular mesangium Loop of Henle Macula densa of the distal tubule ```

Juxtaglomuleral cells are in AFFERENT ARTERIOLES- received signals coming from DCT- macula densa Renin used to angiotensin to angiotensin 1

A 4-month old boy is admitted to the hospital because of bilateral hydronephrosis due to posterior urethral valves. Serums studies shows increased concentration of urea nitrogen and creatinine. Following insertion of a catheter into the bladder, there is a marked increase of urinary volume. Which of the following renal renal structure is first affected by the posterior urethral valves? ``` Afferent arteriole Ascending loop of Henle Collecting duct Distal convoluted tubule Proximal tubule ```

Urinary bladder connected into ureters then into kidney - microscopic structures of kidney has callices, collecting ducts, pct, golmerulus, loop of henle, dct, collecting ducts First region affected by urethral is COLLECTING DUCTS- outside the nephron

``` In the mammalian central nervous system, gap junctions are found most frequently between which of the structures? Astrocytes Microglia Neurons Oligodendrocytes Schwann cells ```

ASTROCYTES- most numerous cells in the nervous tissue- connect with each other and facilitates the transportation of ions from one cell to another

``` After an inflammatory response, transmigration of monocytes are most likely to occur through which of the following component of the muscle’s microvasculature? Arterioles Continuous capillaries Fenestrated capillaries Muscular arterioles Venules ```

Arterioles, capillaries, post capillary venules VENULES (post capillary)

``` Which of the following intestinal cells in an adult are most susceptible to chemotherapeutic agents that target rapidly dividing cells? Duodenal enteroendocrine cells Duodenal paneth cells Gastric chief cells Gastric parietal cells Jejunal absorptive cells ```

Chemotherapeutic agenst- front liner cells JEJUNAL ABSORBATIVE CELLS

``` A 24-year-old man is brought to the emergency department 30 minutes after he was involved in a motor vehicle collision. Abdominal examination shows evidence of severe contusion on the liver from blunt trauma to the right upper quadrant. Exploratory laparotomy shows a lacerated right hepatic lobe with a large intrahepatic hematoma. A partial hepatectomy is done. Within 2 months, the size and weight of the liver have returned to normal. Which of the following reparative or adaptive process best describes this changes? Cellular atrophy Cellular hypertrophy Collagen cross linking Collagen fibrillogenesis Neovascularization Replacement by another cell type Replacement by continuously dividing cells Replacement by stimulated G0 cells. ```

REPLACEMENT OF G0 CELLS- not active in cells division- only divide when stimulation- when stimulated they re-enter the g1 phase

``` A previously healthy 8-month –old boy is brought to the physician by his m mother because of a 24-hour history of poor feeding, weak suck, drooling and constipation. His symtomps began after she introduced homemade canned food into his diet. Physical examination shows loss of head control, decreased gag reflex, weak cry, and hypotonia. Testing of blood and stool samples confirms the diagnosis of botulism. The symptoms most likely arose through enzymatic lysis of which of the following types of proteins within the neuromuscular junctions? Acetylcholine receptors Acetylcholinesterase Actins ATPases Clatrhin Dystrophins Myosin heavy chains Ryanodine receptors SNAP receptors (SNAREs) ```

Botulism example SNAP RECEPTORS (SNAREs) Presynaptic cells cannot bind with proteins to release neurotransmitter

``` Breast-fed newborn have earlier better passive immunity during the first few weeks of life than the newborns that are not breast. This is caused by the secretion of which of the following antibodies in the mother’s breast milk? IgA IgD IgE IgM ```

IgA secreted in breast milk

``` The initial glycosylation of secretory proteins occurs at which of the following location in the secretory pathways? Nuclear pores Ribosomes Rough endoplasmic reticulum Secretory vesicles Trans Golgi complex ```

ROUGH ENDOPLASMIC RETICULUM

An experimental study is conducted to examine the binding of insulin to its receptors. The activation of its receptor initiates intracellular signaling. This activity most likely results from which of the following processes? Phosphorylation of phosphoinositol to inositol 1,4,5-triphosphate Phosphorylation of serine residue Phosphorylation of tyrosyl residue Release of Ca2+ Release of diacylglycerol Release of phophatidylcholine

PHOSPHORYLATION OF TYROSYL RESIDUE

``` Which of the following is the predominant component of the organic matrix of mature bone? Hydroxyapatite Osteocalcin Osteonectin Proteoglycan Type I collagen ```

TYPE 1 COLLAGEN inorganic is hydroxyapatite crystals

The transmission electron micrograph shows the basolateral region of an epithelial cell. Which of the following is most likely function of the plasma membrane modification? Compartmentalization of the nucleus basally Formation of microvilli Increased surface area for membrane transport Prevention of junctions from forming with the extracellular matrix Surface specialization for phagocytosis

There will be a picture attached- with lots of basal interdigitations INCREASED SURFACE AREA FOR MEMBRANE TRANSPORT

``` In the digestive tract, immunologically active lymphoid tissue is concentrated in which of the following? Adventitia Epithelium Lamina propia Serosa ```

LAMINA PROPIA

``` The cell indicated by the arrow in the photomicrograph shown most likely participates in which of the following processes? Adaptive cell-mediated immunity Hemostasis Innate immunity Oxygen transport Protection against parasitic infection ```

INNATE IMMUNITY

Which of the following labeled cells in the photomicrograph shown synthesizes anti Mullerian hormone?

Seminiferous tubule- lined by sertoli cells- antimullerian hormone prevents formation of female reproductive system B-basal compartment- ovoid nucleus- is of a sertoli cell

During a study of the integrity of the blood-brain barrier, labeled tracer molecules of varying molecular sizes are injected into the bloodstream of an experimental animal. Immunohistochemical examination of brain tissue prepared for light microscopy shows tracer in the lumen of the blood vessels, but not in the brain tissue. Interaction between which of the following pairs of membrane a protein has more likely prevented the tracer molecules from entering the tissue spaces? ``` Cahedrins and selectins Claudins and occludins Desmoglein and desmocolin Integrin and connexin Plakoglobins and desmoplakin ```

Components of blood brain barrier- indicated by brain tissue Endothelial cells, continous basement membrane, astrocytic EF CLAUDINS AND OCCLUDINS

Which of the following photomicrograph of tissue from the male reproductive system shows structure that contains cells that synthesizes androgen-binding proteins?

Study the picture- androgen binding proteins- leydic cells secrete testosterone Moves into epididymis SEMINFEROUS TUBULES EPIDYDNUS IS PHOTO F (BOTTOM RIGHT) Seminal vesicles is letter e, prostate is letter c

``` An investigator is using antibodies against microfilament-capping protein to study the cellular locations of those factors. It is found that these antibodies inhibit microfilament function when presented to living cells. Which of the cellular activities is most likely to be decreased as result? Cell motility Dyein function Glycolysis Kinesin function Nuclear transport ```

Microfilament is associated with microvilli= decrease in CELL MOTILITY

An investigator is studying a drug that inhibits the polymerization/depolymerization of actin filaments. Which of the following is most likely to be decreased in cells treated with this drug? Binding of integrin to microtubules Cellular response to chemotactic factor Exporting of mRNA from nucleus Importing of cytochrome c into the mitochondria Translocation of new polypeptide into the rough endoplasmic reticulum

CELLULAR RESPONSE TO CHEOTACTIC FACTOR

``` A 62-year-old man is evaluated in the office because of difficulty initiating a urine stream. A histologic exam of resected tissue is shown in the photomicrograph stromal compartment of this tissue consists of which of the following? Adipose tissue Dense irregular connective tissue Simple columnar epithelium Smooth muscle Stratified squamous epithelium ```

Will have a picture of prostate gland Stromal compartment tissues is made of SMOOTH MUSCLES

``` Quality control to remove misfolding during synthesis of integral membrane proteins is mediated by chaperons located in which of the cellular structures? Endoplasmic reticulum Lysosomes Mitochondria Peroxisomes Proteasomes ```

PROTEASOMES

The process of synthesizing protein F is shown in the diagram. Which of the following primary function of the structure labeled G? Arrest protein translation Bind the signal recognition particle Cleave signal sequence in protein F Initiate synthesis of protein F Translation protein F across the lipid bilayer

Function of G BINDS THE SIGNAL RECOGNITION PARTICLE- facilitates the protein synthesis

``` A 24-year-old woman has a 1-year history of loose, watery stools and epigastric pain refractory to the medical treatment. Upper gastrointestinal endoscopy of the upper gastrointestinal tract shows thickened gastric folds and a duodenal ulcer. Basal hydrochloric acid secretion is increased. Both gastrin concentration is also increased and increases further with administration of secretion. Hyper secretion by which of the following cell a type is most likely to produce these findings? Absorptive Chief Enteroendocrine Goblet Paneth ```

Increase HCL- from parietal cells- stimulated by gastrin What stimulates secretion of gastrin? ENTEROENDOCRINE CELLS

``` An 8-year-old boy is brought to the office by his mother 2 days after he cut his thumb while bating a fishhook. Examination of the thumb shows a 1.5-cm purulent laceration with a surrounding area of redness and swelling. Which of the following proteins has most likely been expressed at the site of injury by the endothelial cells in this patient? Adherins Cahedrins Catenins Connexin Selectin ```

Redness and swelling- inflammation process White blood cells come to area- what facilitates white blood cell movement? SELECTIN

``` After neutrophil engulf a microbe by phagocytosis, it must act to kill its prey. The major way this is done is by exposing the content of the phagosome to which of the following substances? Catalase Immunoglobulin Phosphatase Reactive oxygen species Superoxide dismutase ```

REACTIVE OXYGEN SPECIES

``` Which of the following is the initiating event that controls the entry of cells from G1 stage to the M phase of the cell cycle? DNA replication Duplication of centrosome Formation of mitotic spindle Fragmentation of the nuclear envelope Protein phosphorylation ```

PROTEIN PHOSPHORYLATION (of Rb protein)

``` A 4-month-old boy is admitted to the hospital of bilateral hydronephrosis due to posterior urethral valves. Serum studies show increased concentration of urea nitrogen and creatinine. Following insertion of the catheter into the bladder, there is a marked increase in urinary volume. Which of the renal structures is first affected by the posterior urethral valve? Afferent arteriole Ascending loop of Henle Collecting duct Distal convoluted tubule Proximal tubule ```

COLLECTING DUCT

``` A 6-month-old boy is diagnosed with a mutation in an enzyme required for the synthesis of mannose 6-phospahate. The function of which of the following organelle is most likely to be affected by the mutation in this patient? Endosome Lysosome Mitochondria Rough endoplasmic reticulum Smooth endoplasmic reticulum ```

ROUGH ENDOPLASMIC RETICULUM- protein synthesis- then to golgi

``` A 69-year-old woman dies of lung cancer. A photomicrograph of a histologic section of respiratory tract obtained at autopsy is shown. Which of the following explains the presence of the dark blue stain observed in this section? DNA Elastin Glycosaminoglycans Collagen type I Collagen type IV ```

Study picture Has hyaline cartilage- Type 2 collagen GLYCOSAMINOGLYCANS- secreted in outside surroundings of chondrocytes

``` During the hepatic regeneration in response to damage from physical trauma, some new lobules are reorganized from new hepatic cells and new sinusoids. In order for there to be a normal pathway of blood flow within these new lobule, the new central veins must directly connected to which of the following types of vessels at their distal (efferent) end? Large branch of the vena cava Sinusoid Small branch of the hepatic artery Small branch of the hepatic vein Small branch of the portal vein ```

Central vein at distal end Portal triad-> central vein -> sinusoids SMALL BRANCH OF HEPATIC VEIN Study blood flow in liver

BASAL LAYER KERATINOCYTES

``` A 12-year-old boy with asthma is brought to the physician because of wheezing for 2 hours. Treatment with an inhaled bronchodilator has not completely resolved his symptoms. Which of the following portions of the airways is most susceptible to flow limitation due to smooth muscle contraction in this patient? Alveolar duct Alveolus Bronchiole Nasal passages Trachea ```

BRONCHIOLE

Histology NBME Review Flashcards

(104 cards)