[3.0] HISTO - Integ, Connective Tissue, Adipose, Clinical Corre

Major structural proteins of the epidermis.

Anagen, Catagen, and Telogen.

Keratinized stratified squamous epithelium.

Approximately 8 to 10 days.

Spinous layer or prickle cell layer.

Hard keratin.

The skin, covering approximately 1.7 m².

Separation of the organism from the external environment.

To protect the hair from damage and determine its porosity.

To act as a barrier against physical, chemical, and biological agents.

They provide sensory information.

Finely ordered.

Soft keratin is formed in the epidermis, while hard keratin is found in hair and nails.

Stratified cuboidal epithelium.

In the axilla, areola, nipple of mammary gland, skin around anus, and external genitalia.

The expression of the Pax3 gene.

Keratinization.

KLKs degrade desmosomes and cause keratinocyte release as pH decreases.

Keratinocytes, Melanocytes, Langerhans’ cells, and Merkel’s cells.

Single layer of small cuboidal to low columnar cells, basophilic cytoplasm, closely spaced nuclei, and contains mitotically active stem cells.

Variable amounts of adipose tissue.

Tyrosine -> DOPA -> melanin.

The crescent-shaped white area near the root of the nail, derived from partially keratinized matrix cells.

KLK5, KLK7, and KLK14.

Clear cells, dark cells, and myoepithelial cells.

To produce the watery component of sweat.

Short, fine hairs that may be visible only with a magnifying glass.

It consists of dividing matrix cells that migrate from the follicular bulge and are responsible for hair growth.

It varies from 1 mm to 5 mm.

Proteolytic degradation of the cells’ desmosomes.

Decreased skin barrier function, erythroderma, and scaling.

A group of immune diseases characterized by an abnormal increase and spread of Langerhans' cells.

Rete ridges.

Stratified squamous epithelium.

Stratum Basale (also known as Stratum germinativum).

A secretion containing protein, carbohydrate, ammonia, lipid, and certain organic compounds.

To protect against the damaging effects of ultraviolet irradiation.

It is the horny layer, varies in thickness, and is the thickest in thick skin.

They often have a refractile appearance and may stain poorly.

Through pigment donation involving phagocytosis.

Eumelanin (brownish-black) and pheomelanin (reddish-yellow).

An adrenal hormone imbalance that causes increased pigmentation of the skin.

Merkel cell carcinoma (MCC).

Essential fatty acid deficiency.

47 days.

Isthmus, extending from the infundibulum to the level of insertion of the arrector pili muscle.

They aid in the aggregation of keratin filaments.

Tyrosine.

They lose cytoplasmic organelles and are filled with keratin filaments, becoming anucleate.

The fate of melanin, not the number of melanocytes.

The epidermal-dermal junction, which is an uneven boundary.

Touch receptors, particularly responsive to low-frequency stimuli.

They have an elongated fusiform shape and a thin connective tissue capsule.

In the stratum spinosum.

Epidermis and Dermis.

85%.

Eccrine glands are stimulated by cholinergic transmitters, while apocrine glands are stimulated by adrenergic transmitters.

Henle’s Layer, Huxley’s Layer, and Internal Root Sheath Cuticle.

Skin stretch and torque.

Eosinophilic cells.

In the keratogenous zone, which is the lower third of the follicle.

They function in cutaneous sensation.

A hereditary condition involving lack of pigmentation in hair and skin due to absence of tyrosinase.

They serve multiple sensory modalities including fine touch, heat, cold, and pain.

Cuticle.

Thick skin has a thicker epidermal layer and is hairless, found on the palms of hands and soles of feet.

They provide immunologic information during antigen processing.

To produce sebum, which coats the hair and skin surface.

Keratinocytes in this layer contain keratohyaline granules, which are precursors for filaggrin that aggregates keratin filaments.

It becomes obscured until mature melanin granules (melanosomes) are formed.

A subdivision of the Stratum Corneum, only well seen in thick skin.

They contribute to the formation of the intercellular epidermal water barrier.

Exposure to ultraviolet radiation, which increases melanocyte numbers and accelerates melanin production.

A sensitive mechanoreceptor formed by the combination of a neuron and a Merkel's cell.

Melanocyte depletion occurs with age, leading to lighter skin and increased skin cancer incidence.

They are responsible for sensitivity to light touch.

The monomolecular layer of acylglucosylceramide.

Keratinocytes.

Long and coarse hairs produced by large-diameter follicles.

A protrusion from the hair follicle near the insertion of the arrector pili muscle that contains a niche of epidermal stem cells.

Hair follicles, sweat glands, sebaceous glands, nails, and mammary glands.

Tennis racquet-shaped.

Near the Golgi apparatus.

In light skin, melanosomes are concentrated near the basal layer; in dark skin, they are found throughout the epidermis.

Projections from the dermis into the epidermis.

They create a distinctive pattern unique to each individual, forming the basis of dermatoglyphics.

Type I and Type III collagen.

Infundibulum, isthmus, follicular bulge, and inferior segment.

It is the period of hair growth where new hair develops.

The follicle atrophies, and the hair is eventually lost.

1:36.

Cells shrink, creating expanded intercellular spaces between the spines.

Contains stem cells that regularly divide and produce keratin for the nail.

It regulates body temperature and water loss.

They are Antigen Presenting Cells (APCs) involved in delayed-type hypersensitivity reactions.

Composed of a myelinated nerve ending surrounded by a capsule structure.

Age, ethnicity, gender differences, hormone levels, genetic defects, UV radiation, climate, and chemical exposure.

5 nm.

Melanin content.

It is attached near the follicular bulge and causes hair to stand up.

To regulate temperature through the evaporation of sweat.

Medulla, Cortex, and Cuticle.

Langerhans' cells.

In the deeper dermis and hypodermis, especially in the fingertips.

In darker skin, melanin is degraded slowly; in lighter skin, it is degraded more rapidly.

Antigen-presenting cells in the epidermis.

Ceramides, cholesterol, and free fatty acids.

Their nucleus is characteristically indented and uneven.

By melanocyte-stimulating hormone (MSH) binding to the melanocortin 1 receptor (MC1R).

The gene encoding LEKTI, specifically SPINK5.

They become disrupted and disappear as the cell fills with keratin.

It contains a column of large, loosely connected keratinized cells with soft keratin, present only in thick hairs.

Loricrin, accounting for almost 80% of the total cell envelope protein mass.

Displacement of adjacent collagen fibers induced by sustained mechanical stress.

Regular lines of tension in the skin that affect healing and scarring.

The process where hair cells differentiate, extrude organelles, and become tightly packed with keratin intermediate filaments shortly after leaving the matrix.

The cortex, which is the largest layer of hair and contains melanocytes responsible for melanin pigment.

Deposition of insoluble proteins and a lipid layer on the plasma membrane.

In areas of skin where sensory perception is acute, such as the fingertips.

They are responsible for the maintenance of melanocyte stem cells, and their deficiency can lead to hair graying.

Pressure changes and vibrations applied on the skin surface.

Deep pressure receptors for mechanical and vibratory pressure.

HIV.

Through the displacement of the capsule lamellae, causing depolarization of the axon.

In the dermal papillae just beneath the epidermal basal lamina.

1:53.

Macroautophagy.

Keratohyalin granules and membrane-bound lamellar bodies.

From common lymphoid progenitor (CLP) cells in bone marrow.

They play an important role in cell signaling and inducing cell differentiation.

A layer of adipose tissue beneath the reticular layer that serves as a major energy storage site.

Loose connective tissue.

Thick, irregular bundles of mostly Type I collagen and coarser elastic fibers.

They connect hair follicles to the dermis and cause hair erection and skin puckering.

It represents an invagination of the epidermis responsible for the production and growth of hair.