USMLE Step 1 Histology Practice Questions

Which type of epithelium lines the lumen of the trachea and large bronchi, characterized by ciliated columnar cells, goblet cells, and basal cells resting on a basement membrane?

• (A) Pseudostratified ciliated columnar epithelium
• (B) Simple squamous epithelium
• (C) Stratified squamous epithelium
• (D) Simple cuboidal epithelium

Which specific cell type within connective tissue is responsible for synthesizing and secreting the components of the extracellular matrix, including collagen fibers and ground substance?

• (A) Fibroblast
• (B) Macrophage
• (C) Mast cell
• (D) Plasma cell

What type of muscle tissue is characterized by striated, branched cells connected by intercalated discs, and is found exclusively in the wall of the heart?

• (A) Cardiac muscle
• (B) Skeletal muscle
• (C) Smooth muscle
• (D) Myoepithelial cells

Which layer of the epidermis is the outermost layer, composed of multiple layers of dead, flattened, anucleated keratinocytes filled with keratin, providing a protective barrier?

• (A) Stratum corneum
• (B) Stratum basale
• (C) Stratum spinosum
• (D) Stratum granulosum

Goblet cells, commonly found interspersed within the epithelium of the respiratory tract and intestines, are specialized for what function?

• (A) Secretion of mucus
• (B) Absorption of nutrients
• (C) Phagocytosis
• (D) Sensory reception

Which type of cartilage is the most common type in the body, characterized by a glassy, homogenous matrix rich in type II collagen fibers, and is found in articular surfaces of joints, respiratory passages (trachea, bronchi), and the fetal skeleton?

• (A) Hyaline cartilage
• (B) Elastic cartilage
• (C) Fibrocartilage
• (D) Bone

Neurons are the primary functional cells of the nervous system. Which part of a typical neuron contains the nucleus and most of the organelles, and serves as the metabolic center of the cell?

• (A) Cell body (soma or perikaryon)
• (B) Axon
• (C) Dendrite
• (D) Synaptic terminal

What type of glandular secretion involves the release of the product via exocytosis from vesicles without loss of cytoplasm (e.g., salivary glands, pancreatic acinar cells)?

• (A) Merocrine secretion
• (B) Apocrine secretion
• (C) Holocrine secretion
• (D) Endocrine secretion

Which specialized cell junction forms a seal between adjacent epithelial cells, preventing the passage of molecules through the intercellular space (paracellular pathway) and helping to maintain cell polarity?

• (A) Tight junction (Zonula occludens)
• (B) Desmosome (Macula adherens)
• (C) Gap junction (Nexus)
• (D) Adherens junction (Zonula adherens)

Which cell type lines the ventricles of the brain and the central canal of the spinal cord, and is involved in the production and circulation of cerebrospinal fluid (CSF)?

• (A) Ependymal cells
• (B) Astrocytes
• (C) Microglia
• (D) Oligodendrocytes

What type of connective tissue is characterized by loosely arranged fibers (collagen, elastin) and abundant ground substance, containing various cell types (fibroblasts, macrophages, mast cells, etc.), and serves to cushion organs and allow diffusion?

• (A) Loose areolar connective tissue
• (B) Dense regular connective tissue
• (C) Dense irregular connective tissue
• (D) Reticular connective tissue

Which histological feature distinguishes skeletal muscle from cardiac and smooth muscle?

• (A) Multinucleated cells with peripheral nuclei
• (B) Presence of intercalated discs
• (C) Spindle-shaped cells with central nuclei
• (D) Lack of striations

Which layer of the small intestine wall contains Brunner's glands, which secrete alkaline mucus to neutralize acidic chyme entering from the stomach?

• (A) Submucosa (specifically in the duodenum)
• (B) Mucosa (lamina propria)
• (C) Muscularis externa
• (D) Serosa

What type of capillary is characterized by numerous small pores or fenestrations (covered by thin diaphragms) in the endothelial cells, allowing for rapid exchange of fluids and small solutes, and is commonly found in endocrine glands, kidney glomeruli, and intestinal villi?

• (A) Fenestrated capillary
• (B) Continuous capillary
• (C) Sinusoidal capillary (Discontinuous capillary)
• (D) Lymphatic capillary

Which cell type in the liver is a specialized macrophage belonging to the mononuclear phagocyte system, located within the liver sinusoids, and responsible for removing aged red blood cells, debris, and pathogens from the blood?

• (A) Kupffer cell
• (B) Hepatocyte
• (C) Stellate (Ito) cell
• (D) Endothelial cell

Which structure in a lymph node primarily contains B lymphocytes, follicular dendritic cells, and macrophages, and is the site of B cell proliferation and differentiation during an immune response?

• (A) Lymphoid follicle (nodule) within the cortex
• (B) Medulla (medullary cords and sinuses)
• (C) Paracortex
• (D) Afferent lymphatic vessel

What type of bone formation involves the direct differentiation of mesenchymal cells into osteoblasts, which then secrete bone matrix, without a preceding cartilage model (e.g., formation of flat bones of the skull)?

• (A) Intramembranous ossification
• (B) Endochondral ossification
• (C) Appositional growth
• (D) Interstitial growth

Which glial cell type is responsible for myelinating axons within the Peripheral Nervous System (PNS)?

• (A) Schwann cell
• (B) Oligodendrocyte
• (C) Astrocyte
• (D) Microglia

The epithelial lining of the urinary bladder, ureters, and renal pelvis is specialized to withstand stretching and resist the toxicity of urine. What is this type of stratified epithelium called?

• (A) Transitional epithelium (Urothelium)
• (B) Stratified squamous epithelium (non-keratinized)
• (C) Stratified cuboidal epithelium
• (D) Pseudostratified columnar epithelium

Which endocrine gland is composed of follicles filled with colloid (stored thyroglobulin) and follicular cells that produce thyroid hormones (T3, T4), as well as parafollicular (C) cells that produce calcitonin?

• (A) Thyroid gland
• (B) Parathyroid gland
• (C) Adrenal cortex
• (D) Anterior pituitary

What is the term for the invaginations of the sarcolemma (plasma membrane) that penetrate deep into a skeletal or cardiac muscle fiber, allowing action potentials to rapidly reach the interior of the cell near the sarcoplasmic reticulum?

• (A) Transverse tubules (T-tubules)
• (B) Sarcoplasmic reticulum
• (C) Sarcomere
• (D) Myofibril

Which region of the adrenal gland cortex is primarily responsible for producing glucocorticoids, such as cortisol, under the stimulation of ACTH from the anterior pituitary?

• (A) Zona fasciculata
• (B) Zona glomerulosa
• (C) Zona reticularis
• (D) Adrenal medulla

Which type of sensory receptor, found in the dermis and hypodermis, is encapsulated, onion-shaped, and specialized for detecting deep pressure and high-frequency vibration?

• (A) Pacinian corpuscle (Lamellated corpuscle)
• (B) Meissner's corpuscle
• (C) Merkel cell
• (D) Free nerve ending

What is the histological term for the functional unit of compact bone, consisting of concentric layers (lamellae) of bone matrix surrounding a central canal (Haversian canal) containing blood vessels and nerves?

• (A) Osteon (Haversian system)
• (B) Trabecula
• (C) Periosteum
• (D) Endosteum

Which cell type is responsible for producing surfactant in the alveoli of the lungs, reducing surface tension and preventing alveolar collapse?

• (A) Type II pneumocyte (Alveolar type II cell)
• (B) Type I pneumocyte (Alveolar type I cell)
• (C) Alveolar macrophage (Dust cell)
• (D) Clara cell (Club cell)

Which layer of an artery wall is typically the thickest and consists primarily of smooth muscle cells and elastic fibers, responsible for regulating vessel diameter and maintaining blood pressure?

• (A) Tunica media
• (B) Tunica intima
• (C) Tunica adventitia
• (D) Endothelium

What is the name of the simple columnar epithelium lining the stomach, characterized by surface mucous cells that secrete a protective alkaline mucus?

• (A) Surface mucous epithelium
• (B) Gastric glands (fundic or pyloric)
• (C) Intestinal villi
• (D) Stratified squamous epithelium

Which organelle is particularly abundant in plasma cells, reflecting their primary function of synthesizing and secreting large amounts of antibodies (proteins)?

• (A) Rough Endoplasmic Reticulum (RER)
• (B) Smooth Endoplasmic Reticulum (SER)
• (C) Mitochondria
• (D) Lysosomes

What type of tissue forms tendons and ligaments, characterized by densely packed, parallel collagen fibers and elongated fibroblasts aligned between the fibers?

• (A) Dense regular connective tissue
• (B) Dense irregular connective tissue
• (C) Elastic connective tissue
• (D) Loose areolar connective tissue

Which cell found in bone tissue is responsible for resorbing (breaking down) bone matrix, playing a crucial role in bone remodeling and calcium homeostasis?

• (A) Osteoclast
• (B) Osteoblast
• (C) Osteocyte
• (D) Chondrocyte

The Islets of Langerhans, clusters of endocrine cells within the pancreas, contain several cell types. Which cell type is most abundant and responsible for producing insulin?

• (A) Beta cells
• (B) Alpha cells
• (C) Delta cells
• (D) PP (F) cells

Which type of cartilage contains abundant elastic fibers in addition to type II collagen, providing flexibility and resilience, and is found in the external ear, epiglottis, and Eustachian tube?

• (A) Elastic cartilage
• (B) Hyaline cartilage
• (C) Fibrocartilage
• (D) Articular cartilage

What is the term for the loose connective tissue layer found immediately deep to the basement membrane of most epithelia, particularly in mucous membranes (mucosae)?

• (A) Lamina propria
• (B) Submucosa
• (C) Adventitia
• (D) Stroma

Which cell type in the central nervous system (CNS) acts as a resident macrophage, mediating immune responses and phagocytosing debris or pathogens?

• (A) Microglia
• (B) Astrocyte
• (C) Oligodendrocyte
• (D) Ependymal cell

What type of epithelium consists of a single layer of flattened, scale-like cells, specialized for facilitating diffusion and filtration, and lines blood vessels (endothelium), lymphatic vessels, and body cavities (mesothelium)?

• (A) Simple squamous epithelium
• (B) Simple cuboidal epithelium
• (C) Simple columnar epithelium
• (D) Stratified squamous epithelium

Which component gives fibrocartilage its great tensile strength and ability to resist compression, making it suitable for structures like intervertebral discs and pubic symphysis?

• (A) Abundant Type I collagen fibers
• (B) Abundant elastic fibers
• (C) High concentration of proteoglycans
• (D) Presence of perichondrium

Which organelle contains hydrolytic enzymes (acid hydrolases) that function optimally at acidic pH and is responsible for degrading cellular waste, debris, endocytosed material, and pathogens?

• (A) Lysosome
• (B) Peroxisome
• (C) Endoplasmic Reticulum
• (D) Golgi apparatus

What is the name for the supporting connective tissue framework of an organ, typically composed of reticular fibers and cells, as distinct from the functional cells (parenchyma)?

• (A) Stroma
• (B) Parenchyma
• (C) Capsule
• (D) Medulla

Which type of intercellular junction directly connects the cytoplasm of adjacent cells, allowing for the passage of ions and small molecules, thereby facilitating electrical and metabolic coupling?

• (A) Gap junction (Nexus)
• (B) Tight junction (Zonula occludens)
• (C) Desmosome (Macula adherens)
• (D) Hemidesmosome