Epithelial/Connective Tissues and Integumentary System - Vocabulary

A set of vocabulary flashcards covering key terms related to epithelial and connective tissues, the integumentary system, and their functions, structures, and processes as described in the lecture notes.

Epithelial tissue

A tissue that lines surfaces and forms barriers; primary roles include protection, selective permeability, absorption, and secretion.

Keratin

A tough protein produced by keratinocytes that strengthens the skin and makes it water resistant, reducing water loss.

Keratinocyte

A skin cell that produces keratin and contributes to the epidermal barrier.

Simple columnar epithelium

A single layer of tall, column-shaped cells specialized for absorption and secretion; often with microvilli; common in the digestive tract.

Microvilli

Hair-like projections on epithelial cell surfaces that increase surface area for absorption.

Secretion

The process of releasing substances from a cell or gland into ducts or surfaces.

Exocrine gland

A gland that secretes its products into ducts or onto a surface, exiting the body.

Endocrine gland

A gland that secretes hormones directly into the bloodstream, not into ducts.

Simple squamous epithelium

A single layer of flat cells that allows rapid diffusion; lines blood vessels and air sacs.

Selective permeability

The property of epithelial tissue to choose which substances may pass into or out of the tissue.

Integumentary system

The skin and its derivatives; functions include protection, thermoregulation, sensation, excretion via sweat, and vitamin D synthesis.

Vasodilation

Widening of superficial blood vessels to increase blood flow and dissipate heat.

Vasoconstriction

Narrowing of superficial blood vessels to reduce heat loss and conserve body heat.

Vitamin D synthesis

UV-driven conversion of 7-dehydrocholesterol in the skin to vitamin D3, then to calcidiol in the liver and calcitriol in the kidney to help calcium absorption.

7-dehydrocholesterol

A skin precursor that is converted to vitamin D3 upon UV exposure.

Calcidiol

25-hydroxyvitamin D; liver-produced form that is converted to calcitriol in the kidneys.

Calcitriol

Active form of vitamin D (1,25-dihydroxyvitamin D) that increases calcium absorption.

Adipose tissue

Fat storage tissue that cushions, insulates, and stores energy.

Fibroblast

A connective tissue cell that produces collagen, helping repair and maintain the extracellular matrix.

Collagen

A key structural protein in connective tissue that provides scaffolding and strength.

Blood and lymph

Connective tissues that transport nutrients, immune cells, and waste; essential for protection and transport.

Bone

Rigid connective tissue that protects organs, supports the body, stores minerals, and houses marrow.

Cartilage

A slippery, resilient connective tissue that cushions joints and provides support.

Connective tissue

A diverse tissue class that connects, supports, protects, transports, stores energy, and defends against disease.

Primary function of epithelial tissue

Protection (barrier against external threats and water loss).

Primary function of connective tissue

Protection and support, plus transportation, energy storage, repair, and immune defense.

Receptors

Nerve endings in or around epithelial tissue that detect stimuli such as temperature, pressure, and pain.

Olfactory epithelium

Specialized epithelium involved in the sense of smell; contains receptors for olfactory nerve.

Sweat glands

Glands in the skin that secrete sweat for temperature regulation and excretion of water and salts.

Excretion

Elimination of substances from the body (e.g., via sweat, urine, or feces).