Chapter 6 notes

Metaplasia

The transformation of one tissue type into another.

Bronchial metaplasia

A type of metaplasia occurring in smokers, where functional changes in airway epithelial cells are seen.

Vaginal metaplasia

Occurs in young girls, involving changes in the epithelial tissue of the vagina.

Heat (in inflammation)

Increased temperature due to vasodilation in response to chemicals like histamine.

Redness (in inflammation)

Caused by increased blood flow due to vasodilation.

Swelling (in inflammation)

It is a response to histamine that makes the endothelium of blood vessels leaky.

Pain (in inflammation)

Activation of pain neurons by prostaglandin release.

Simple epithelium

A type of epithelial tissue consisting of one layer of cells.

Stratified epithelium

Epithelial tissue made up of two or more layers of cells.

Pseudostratified epithelium

An epithelial tissue that appears to have multiple layers but consists of a single layer of cells.

Endocrine glands

Glands that secrete hormones directly into the bloodstream without ducts. Example: thyroid gland.

Exocrine glands

Glands that secrete products through ducts. Example: sweat gland.

Tight junction

A junction similar to a zipper, fusing plasma membranes of epithelial cells to prevent leaks.

Desmosome

A junction that holds cells together but does not fuse membranes, allowing flexibility.

Gap junction

A junction that allows nutrients and ions to pass between adjacent cells.

Hemidesmosome

Similar to desmosomes but links cells to the basement membrane instead of adjacent cells.

Epithelial membrane

A type of membrane made up of epithelial tissue.

Connective tissue membrane

A type of membrane composed primarily of connective tissue.

Mucous membrane

Membrane that lines the respiratory and digestive tracts and secretes mucus.

Serous membrane

Membrane lining body cavities and organs that secrete serous fluid.

Mesothelium

A simple squamous epithelium that forms the surface layer of serous membranes.

Synovial membrane

Membrane that lines cavities around freely movable joints and secretes synovial fluid.

Epidermis

The outermost layer of skin made up of keratinized stratified squamous epithelium.

Dermis

The layer of skin beneath the epidermis, containing connective tissue and fibers.

Hypodermis

A connective tissue layer beneath the dermis that binds the epidermis and dermis to underlying muscles.

Thick skin

Skin found in palms of hands and soles of feet, has sweat glands, but no hair follicles.

Thin skin

Skin that covers most of the body, has hair follicles and may have sebaceous glands.

ABCD of melanoma detection

A: Asymmetry; B: Border irregularity; C: Color variation; D: Diameter greater than 6mm.

Stratum corneum

The outermost layer of the epidermis composed of dead, keratinized cells.

Stratum lucidum

A layer of the epidermis found only in thick skin.

Stratum granulosum

A layer of the epidermis containing keratohyalin granules.

Stratum spinosum

The thickest layer of the epidermis, containing desmosomes and living keratinocytes.

Stratum basale

The deepest layer of the epidermis that rests on the basement membrane and contains proliferating keratinocytes.

stem cells

Undifferentiated cells which divide by mitosis to produce new keratinocytes

Melanocytes

Cells in the epidermis that synthesize the pigment melanin.

Merkel cells

Specialized cells in the stratum basale involved in light touch sensation.

Dendritic cells

Immune cells located in the stratum spinosum that help fight infection.

Sebaceous gland

Gland located in the dermis that secretes sebum, an oily substance.

Eccrine gland

A type of sweat gland found all over the body, primarily concentrated on palms and soles.

Apocrine gland

A gland that secretes thicker sweat found in areas like the groin and armpits.

Function of eccrine glands

Secretes watery, salty sweat that helps with thermoregulation.

Function of apocrine glands

Secretes thicker sweat that may contain fatty acids, contributing to body odor and hormonal signaling.

Examples of endocrine glands

thyroid gland, adrenal gland, pituitary gland, pancreas

Examples of exocrine gland

sweat gland, tear gland, salivary gland, pancreas

Cardinal signs of inflammation

heat, redness, swelling, pain