Histology Mid Year 2

The surface modification seen on the cells of the epididymis is stereocilia. Stereocilia are long, non-motile microvilli-like structures that increase the surface area of the epididymal epithelium. They are involved in the absorption and secretion of fluid, as well as the movement and maturation of sperm cells. Unlike true cilia, stereocilia do not have the ability to move independently.

The proximal tubules of the kidney exhibit numerous microvilli at the cell surface. Microvilli are tiny, finger-like projections that increase the surface area of the cell, allowing for more efficient absorption and reabsorption of substances such as water, ions, and nutrients. This characteristic is important for the proximal tubules as they play a crucial role in the reabsorption of filtered substances from the glomerular filtrate back into the bloodstream. The presence of numerous microvilli enhances the tubules' ability to perform this function effectively.

The correct answer is Cowper's gland. Cowper's gland is another term for the bulbourethral gland. This gland is located below the prostate gland and produces a clear fluid that helps to lubricate and neutralize the acidity of the urethra before ejaculation. It plays an important role in the reproductive system of males.

Lacis cells, also known as extraglomerular mesangial cells, are located outside the glomerulus in the kidney. They are specialized cells that provide structural support to the glomerulus and help regulate blood flow within the kidney. These cells are not secretory cells, intra-glomerular mesangial cells, or neuroepithelial cells.

Large lipid droplets are typical of the zona fasiculata of the adrenal cortex. The zona fasiculata is responsible for producing glucocorticoids, such as cortisol, which are steroid hormones. These hormones are derived from cholesterol, and the presence of large lipid droplets indicates the storage and synthesis of these hormones. The other options, such as the pineal body, catecholamines producing cells of the medulla, and somatotropin cells of the pituitary, do not typically contain large lipid droplets.

The correct answer is "all of the above features." Podocytes are specialized cells found in the glomerulus of the kidney. They have secondary processes that come into direct contact with the basal lamina, which helps in filtration. These cells also form the visceral layer of Bowman's capsule, which surrounds the glomerulus. Additionally, podocytes contain actin microfilaments, which are important for maintaining the structure and function of these cells. Therefore, all of these features are true for podocytes.

Leydig cells are responsible for producing testosterone, which is a male sex hormone. Testosterone plays a crucial role in the development and maintenance of male reproductive tissues and secondary sexual characteristics. Inhibin, on the other hand, is produced by the Sertoli cells in the testes and helps regulate the production of sperm. Androgen binding protein is also produced by the Sertoli cells and aids in the transport and regulation of testosterone within the testes. Therefore, the correct answer is testosterone, as it is the only hormone produced by the Leydig cells.

The correct answer is acidophils of pars distalis. Acidophils are a type of cell found in the anterior pituitary gland, specifically in the pars distalis region. These cells secrete hormones such as growth hormone (GH) and prolactin. Orange G is a stain commonly used in histology to differentiate between different types of cells. In this case, it specifically stains the acidophils in the pars distalis, allowing for their identification and study.

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Parafollicular cells often reside inside the basal lamina of the thyroid epithelium. This means that these cells are located within the layer of cells that surrounds and supports the thyroid follicles. The basal lamina provides structural support and helps in the regulation of substances that enter and leave the thyroid gland. The statement suggests that parafollicular cells are found in close proximity to the thyroid follicles and are involved in the functioning of the thyroid gland.

The distal convoluted tubules of the kidney are composed of simple cuboidal epithelium. This type of epithelium is made up of a single layer of cube-shaped cells. It is well-suited for absorption and secretion functions, which are important for the reabsorption of water and electrolytes in the distal convoluted tubules. This arrangement allows for efficient transport of substances in and out of the tubules.

The correct answer is MSH. MSH stands for Melanocyte-Stimulating Hormone, which is secreted by the pars intermedia of the pituitary gland. It plays a role in regulating skin pigmentation and has been implicated in various physiological processes such as appetite regulation and sexual behavior. FSH (Follicle-Stimulating Hormone) is secreted by the anterior pituitary and is involved in the development of ovarian follicles and sperm production. TSH (Thyroid-Stimulating Hormone) is also secreted by the anterior pituitary and regulates the release of thyroid hormones. ACTH (Adrenocorticotropic Hormone) is another hormone secreted by the anterior pituitary, which stimulates the release of cortisol from the adrenal glands.

The cells of the adrenal medulla are both chromaffin cells and ganglion cells. Chromaffin cells are responsible for producing and releasing hormones like adrenaline and noradrenaline, while ganglion cells are involved in transmitting signals within the nervous system. Both types of cells are found in the adrenal medulla.

The correct answer is "contains pituicytes, herring bodies, and axons." The posterior pituitary gland is made up of specialized nerve cells called pituicytes, which store and release hormones produced by the hypothalamus. Herring bodies are neurosecretory granules found within the pituicytes, which contain the hormones oxytocin and vasopressin. Additionally, the posterior pituitary contains axons that extend from the hypothalamus, allowing for the transport and release of hormones into the bloodstream. Therefore, the statement that the posterior pituitary contains pituicytes, herring bodies, and axons is accurate.

Parathyroid hormone (PTH) is responsible for increasing the activity of osteoclasts, which are cells that break down bone tissue. PTH also increases calcium levels in the blood by stimulating the release of calcium from bone and reducing calcium excretion by the kidneys. Additionally, PTH indirectly increases the absorption of calcium from the gastrointestinal tract (GIT) by promoting the production of active vitamin D, which enhances calcium absorption. However, PTH does not reduce calcitonin secretion by para-follicular cells. Calcitonin is a hormone that opposes the actions of PTH by decreasing blood calcium levels. Therefore, the correct answer is that PTH does not reduce calcitonin secretion.

The epididymis is a long, coiled tube that is responsible for the storage and maturation of sperm. Pseudostratified epithelium is the correct answer because it is the type of epithelium that lines the epididymis. Pseudostratified epithelium appears to be stratified, but all of the cells are in contact with the basement membrane. This type of epithelium is found in areas where secretion and absorption take place, which is important for the function of the epididymis in sperm maturation and storage.

Renin is an enzyme that plays a crucial role in regulating blood pressure and fluid balance. It is primarily secreted by specialized cells called juxtaglomerular cells, which are located in the walls of the afferent arterioles of the kidney. These cells are sensitive to changes in blood pressure and can release renin into the bloodstream in response to low blood pressure or decreased blood flow. Therefore, the correct answer is afferent arterioles.

The correct answer is "a medullary ray and all nephrons that empty into it." A renal lobule is a functional unit of the kidney, and it consists of a medullary ray and the nephrons that empty into it. The medullary ray is a structure that extends from the renal cortex into the renal medulla, and it contains collecting ducts and blood vessels. The nephrons are the microscopic units responsible for filtering blood and producing urine. Therefore, the correct answer accurately describes the components of a renal lobule.

The most commonly seen type of epithelium in the prostate is simple columnar. This type of epithelium is characterized by tall, narrow cells that are closely packed together. It lines the ducts and glands of the prostate and helps in the secretion and absorption of substances. The simple columnar epithelium provides a protective barrier and helps in the smooth functioning of the prostate gland.

The stroma of the prostate refers to the supportive tissue that surrounds and provides structure to the glandular tissue of the prostate. It is composed of fibromuscular tissue, which means it contains both fibrous tissue and smooth muscle. This fibromuscular stroma helps to maintain the shape and integrity of the prostate gland.

Sertoli cells and pale type A cells are directly involved in spermatogenesis. Sertoli cells provide structural and nutritional support to developing sperm cells, while pale type A cells are responsible for the division and differentiation of germ cells. Both of these cell types play crucial roles in the process of spermatogenesis.