Histology Practice Questions

Q: T cells in lymph node are present in:

Paracortical area. ***Paracortical area*** - The **paracortical area** contains a high concentration of **T cells**, particularly activated T cells in response to antigenic stimulation [1]. - It plays a crucial role in **immune responses**, bridging the cortex and medulla of the lymph node [1]. *Mantle layer* - The **mantle layer** surrounds the follicles and primarily consists of **B cells**, not T cells. - It is involved in the initial immune response but does not contain a significant number of T lymphocytes. *Medullary cords* - **Medullary cords** mainly contain **plasma cells** and macrophages, with very few T cells present. - Their primary function is the secretion of antibodies rather than T cell activation or response. *Cortical follicles* - **Cortical follicles** are primarily sites for **B cell activation and proliferation**. - While they may have some T cells at their periphery, the majority of T cells are located in the paracortical area.

Q: All are true regarding the development of T-cells, except?

T-cells are located in mantle layer of spleen. ***T-cells are located in mantle layer of spleen*** - The **mantle layer** (or marginal zone) of the spleen is primarily associated with **B-lymphocytes**, which are involved in antibody production. - While T-cells are present in the spleen, they are predominantly found in the **periarteriolar lymphoid sheath (PALS)**, which is part of the white pulp, rather than the mantle layer. *T-cells are formed in bone marrow* - **Hematopoietic stem cells** in the **bone marrow** are the progenitors of all blood cells, including lymphocytes. - These stem cells differentiate into **lymphoid stem cells**, which then travel to the thymus to become T-cells. *Maturation of T-cells take place in thymus* - **T-cell precursors** migrate from the bone marrow to the **thymus**, where they undergo a complex process of differentiation and selection. - In the thymus, T-cells acquire their **T-cell receptors (TCRs)** and undergo positive and negative selection to ensure they are self-MHC restricted and tolerant to self-antigens. *In lymph nodes, T-cells are found in paracortical area* - The **paracortical area** (or paracortex) of the lymph node is the **T-cell zone**, rich in T-lymphocytes and dendritic cells. - This region is crucial for the interaction between T-cells and antigen-presenting cells, initiating adaptive immune responses.

Q: What is the approximate ratio of connective tissue to smooth muscle in the cervix?

Approximately 8:1. ***Approximately 8:1*** - The **cervix** is predominantly composed of **fibrous connective tissue**, which provides its structural integrity and rigidity [1]. - This high ratio of **collagenous connective tissue** to smooth muscle is crucial for maintaining pregnancy and undergoing significant remodeling during parturition [1]. - The approximate ratio is **8:1 to 10:1**, with connective tissue forming about 85-90% of cervical tissue [1]. *2:1* - This ratio would imply a significantly higher proportion of **smooth muscle** (33%), making the cervix much more muscular and less fibrous than it actually is. - Such a composition would compromise the cervical function of maintaining a **closed uterine orifice** during pregnancy. *5:1* - While higher than 2:1, this ratio still underestimates the true dominance of **connective tissue** in the cervical structure. - The **cervix's mechanical properties**, including its ability to resist stretching, are primarily due to its abundant collagen content. *15:1* - This ratio overestimates the proportion of connective tissue, suggesting less than 7% smooth muscle. - While the cervix is indeed fibrous, it does contain a modest amount of **smooth muscle** (10-15%) particularly in the internal os region, making this ratio too extreme [1].

Q: Type of collagen found in space of Disse in liver is -

Collagen III & IV. ***Collagen III & IV*** - The **space of Disse** in the liver contains a delicate extracellular matrix predominantly composed of **collagen type III (reticular fibers)**, which provides structural support, and **collagen type IV**, a major component of basement membranes. - This specific collagen composition is crucial for regulating the exchange of solutes between **sinusoidal blood** and **hepatocytes**, as well as for the functional integrity of the liver [1]. *Collagen I & II* - **Collagen type I** is the most abundant collagen in the human body, found in connective tissues like **bone, skin, tendons, and ligaments**, but is not primary in the space of Disse. - **Collagen type II** is characteristic of **hyaline cartilage** and vitreous humor, and is not a significant component of the liver's extracellular matrix in the space of Disse. *Collagen II* - As mentioned, **collagen type II** is primarily found in **cartilage** and vitreous humor, which are distinct from the architectural requirements of the liver sinusoidal space. - Its presence in the space of Disse would not provide the necessary structural flexibility and support for the metabolic functions of the liver. *Collagen II & V* - While **collagen type V** is a minor fibrillar collagen that associates with collagen type I in many tissues, it is not a primary component of the space of Disse. - **Collagen type II** is, again, largely confined to cartilaginous structures, making this an unlikely combination for the liver microenvironment.

Q: Which type of collagen is primarily responsible for forming the basement membrane sheets?

Type IV. ***Type IV*** - **Type IV collagen** is unique as it forms a **two-dimensional network** that constitutes the structural foundation of **basement membranes**. - Its structure, with **non-fibrillar domains**, allows for assembly into sheets rather than fibrils, providing essential support and filtration properties. *Type I* - **Type I collagen** is the most abundant type in the human body, providing **tensile strength** to tissues like **skin, bone, tendons**, and ligaments. - It forms **thick, striated fibrils** and does not primarily associate with basement membranes [1]. *Type II* - **Type II collagen** is the main collagen found in **cartilage**, providing **resilience and shock absorption**. - It forms thin fibrils within the cartilage matrix and is not a component of basement membranes. *Type VI* - **Type VI collagen** is a minor fibrillar collagen that associates with **interstitial connective tissues**, often forming a **microfibrillar network**. - It links cells to the surrounding matrix and is not a primary component of basement membrane sheets.

Q: What is the approximate number of cones in the human retina?

Approximately 3-5 million cones. Approximately 3-5 million cones - The human retina contains roughly **4.5 million cones**, concentrated in the **fovea**, which is responsible for **high-acuity vision** and color perception [1]. - Cones are light-sensitive cells that detect **fine details** and are essential for vision in **bright light conditions** [1]. *Approximately 10-20 million cones* - This range is significantly higher than the actual number of cones found in the human retina. - While there are millions of photoreceptors, the *majority are rods*, not cones [1]. *Approximately 25-50 million cones* - This figure vastly *overestimates* the number of cones in the human eye. - The total number of photoreceptor cells (rods and cones combined) in the retina typically ranges from **100-125 million** [1]. *Approximately 50-100 million cones* - This range is incorrect as it refers more closely to the *total number of rods* in the human retina, which is about **90-120 million** [1]. - Cones constitute a much smaller proportion of the total photoreceptor population [1].

Q: Which of the following statements about cardiac muscle is true?

Cardiac muscle cells have centrally located nuclei.. ***Cardiac muscle cells have centrally located nuclei.*** - Unlike **skeletal muscle** cells which have multiple, peripherally located nuclei, cardiac muscle cells typically have one or two **centrally located nuclei**. - This is a key distinguishing histological feature when observing cardiac muscle tissue under a microscope. *Cardiac muscle fibers are arranged in sheets.* - While cardiac muscle forms the walls of the heart, its individual fibers (cells) are **branched** and interconnected, not typically described as being arranged in discrete sheets. - The arrangement allows for a **syncytium-like functionality**, enabling coordinated contraction. *Cardiac muscle fibers are spindle-shaped.* - **Spindle-shaped cells** with a single central nucleus are characteristic of **smooth muscle**, not cardiac muscle. - Cardiac muscle cells are branched and generally cylindrical with blunt ends. *Cardiac muscle lacks gap junctions.* - Cardiac muscle cells are abundant in **gap junctions**, which are critical for electrical coupling and synchronous contraction. - These gap junctions are located within **intercalated discs** and allow for rapid propagation of action potentials between cells.

Q: Billroth's cords are present in which part of the spleen?

Red pulp. ***Red pulp*** - **Billroth's cords**, also known as **splenic cords**, are a prominent histological feature found exclusively within the **red pulp** of the spleen [1]. - They are composed of a meshwork of reticular cells and fibers, with large numbers of **macrophages**, red blood cells, and other leukocytes, which are critical for **blood filtration** and old red blood cell destruction [1]. *White pulp* - The white pulp is primarily composed of lymphoid tissue, including **lymphocytes** clustered around central arteries, forming the periarteriolar lymphoid sheaths (PALS) and lymphoid nodules (follicles). - Its main function is immunological, involving **lymphocyte proliferation** and immune responses, rather than blood filtration via Billroth's cords [1]. *Both* - This option is incorrect because Billroth's cords are specifically located in the red pulp and are not a feature of the white pulp. - The architectural and functional roles of the white and red pulp are distinct, with specialized structures allocated to each region. *Capsule* - The **capsule** is the outermost connective tissue layer that encloses and protects the entire spleen. - It contains smooth muscle cells and fibroblasts but does not house the splenic parenchyma, including Billroth's cords.

Q: Identify the type of connective tissue present in the image.

Dense irregular. ***Dense irregular*** - The image shows **densely packed collagen fibers** arranged in an **irregular, haphazard fashion**, characteristic of dense irregular connective tissue. - This type of tissue provides **strength** and resistance to stress from multiple directions, found in the **dermis of the skin** and organ capsules. *Loose and irregular* - **Loose connective tissue** would show more ground substance and fewer, loosely arranged fibers, whereas this image displays high fiber density. - While it is "irregular" in fiber arrangement, the density of fibers rules out the "loose" classification. *Specialized* - **Specialized connective tissues** include cartilage, bone, blood, and adipose tissue, which have distinct cellular and extracellular matrix components not seen here. - This tissue lacks the specific cellular and matrix characteristics that would classify it as specialized (e.g., chondrocytes in lacunae, osteocytes, blood cells). *Dense regular* - **Dense regular connective tissue** features collagen fibers arranged in parallel bundles, providing strength in one direction. - Examples include **tendons and ligaments**, which are structurally organized in an orderly, aligned manner, unlike the displayed irregular arrangement.

Q: Which of the following hormones is secreted by acidophils in the anterior pituitary gland?

GH. ***GH*** - **Growth Hormone (GH)** is secreted by **somatotrophs**, which are a type of acidophil cell in the anterior pituitary. - GH plays a crucial role in **growth**, **metabolism**, and cell reproduction. - **Note**: Prolactin is also secreted by acidophils (lactotrophs), but among the given options, only GH is an acidophil hormone. *TSH* - **Thyroid-stimulating hormone (TSH)** is secreted by **thyrotrophs**, which are **basophil** cells in the anterior pituitary. - TSH stimulates the **thyroid gland** to produce thyroid hormones. *ACTH* - **Adrenocorticotropic hormone (ACTH)** is secreted by **corticotrophs**, which are another type of **basophil** cell. - ACTH stimulates the **adrenal cortex** to secrete glucocorticoids. *FSH* - **Follicle-stimulating hormone (FSH)** is secreted by **gonadotrophs**, which are also **basophil** cells. - FSH is involved in the **development of follicles** in the ovaries and **spermatogenesis** in the testes.

Question 1

T cells in lymph node are present in:

Accepted Answer

Paracortical area

Answer

Mantle layer

Answer

Medullary cords

Answer

Cortical follicles

Question 2

All are true regarding the development of T-cells, except?

Accepted Answer

T-cells are located in mantle layer of spleen

Answer

T-cells are formed in bone marrow

Answer

In lymph nodes, T-cells are found in paracortical area

Answer

Maturation of T-cells take place in thymus

Question 3

What is the approximate ratio of connective tissue to smooth muscle in the cervix?

Accepted Answer

Approximately 8:1

Answer

2:1

Answer

5:1

Answer

15:1

Question 4

Type of collagen found in space of Disse in liver is -

Accepted Answer

Collagen III & IV

Answer

Collagen I & II

Answer

Collagen II

Answer

Collagen II & V

Question 5

Which type of collagen is primarily responsible for forming the basement membrane sheets?

Accepted Answer

Type IV

Answer

Type I

Answer

Type II

Answer

Type VI

Question 6

What is the approximate number of cones in the human retina?

Accepted Answer

Approximately 3-5 million cones

Answer

Approximately 25-50 million cones

Answer

Approximately 50-100 million cones

Answer

Approximately 10-20 million cones

Question 7

Which of the following statements about cardiac muscle is true?

Accepted Answer

Cardiac muscle cells have centrally located nuclei.

Answer

Cardiac muscle fibers are arranged in sheets.

Answer

Cardiac muscle fibers are spindle-shaped.

Answer

Cardiac muscle lacks gap junctions.

Question 8

Billroth's cords are present in which part of the spleen?

Accepted Answer

Red pulp

Answer

White pulp

Answer

Both

Answer

Capsule

Question 9

Identify the type of connective tissue present in the image.

Accepted Answer

Dense irregular

Answer

Loose and irregular

Answer

Specialized

Answer

Dense regular

Question 10

Which of the following hormones is secreted by acidophils in the anterior pituitary gland?

Accepted Answer

GH

Answer

TSH

Answer

ACTH

Answer

FSH

Histology — MCQs

Histology — MCQs

On this page

Practice by Chapter

Want unlimited practice?