Untitled Flashcards Set

Types of Tissues

The four basic types of tissues are epithelial, connective, muscle, and nervous tissue.

Epithelial vs Connective Tissue

Epithelial tissue covers body surfaces and lines cavities, whereas connective tissue supports, binds, and protects other tissues.

Organization of Epithelial and Connective Tissue

Epithelial cells are tightly packed with minimal extracellular matrix, while connective tissue has more matrix with more space between cells.

General Characteristics of Epithelial Cells

Epithelial cells are closely packed, have polarity, are anchored to the basement membrane, and have a high rate of regeneration.

Polarity in Epithelial Cells

Polarity refers to the structural and functional differences between the apical (top) and basal (bottom) surfaces of epithelial cells.

Specialized Contacts

Specialized contacts, such as tight junctions and desmosomes, help to bind epithelial cells together.

Apical Surface

The apical surface is the upper free surface of epithelial tissue that faces the body surface or cavity.

Basal Surface

The basal surface is the bottom surface of epithelial tissue that is attached to the basement membrane.

Histology Identification

Based on histology images, epithelial cell shapes include squamous (flat), cuboidal (cube-shaped), and columnar (column-like).

Microvilli

Microvilli are tiny finger-like projections that increase surface area and are commonly found in intestinal epithelial cells; they aid in absorption.

Cilia

Cilia are hair-like structures that move fluid and particles along epithelial surfaces; commonly found in respiratory tract and reproductive tubes.

Glandular Epithelia Purpose

Glandular epithelia are specialized for secretion, producing hormones, enzymes, and other substances.

Endocrine vs Exocrine Glands

Endocrine glands secrete hormones directly into the bloodstream, while exocrine glands secrete substances through ducts; examples include thyroid (endocrine) and sweat glands (exocrine).

Modes of Secretion

Merocrine glands secrete by exocytosis, apocrine glands secrete by pinching off part of the cell, and holocrine glands release entire cells; merocrine is the most common.

Types of Connective Tissue

Connective tissue types include loose connective tissue, dense connective tissue, cartilage, bone, and blood.

General Characteristics of Connective Tissue

Connective tissue generally has a diverse cell population, an abundant extracellular matrix, and varies in degrees of vascularity.

Matrix in Connective Tissue

The matrix refers to the non-cellular material that surrounds the cells in connective tissue, providing support and structure.

Types of Fibers in Connective Tissue

The types of fibers include collagen fibers (strong and flexible), elastic fibers (stretchable), and reticular fibers (supportive network).

Common Cells in Connective Tissue

Common cells include fibroblasts (produce fibers and matrix) and adipocytes (store fat); -blast indicates a cell that forms, while -cyte indicates a mature cell.

Loose vs Dense Connective Tissue

Loose connective tissue has a gel-like matrix with fewer fibers for flexibility, while dense connective tissue has a higher concentration of collagen fibers for strength.

Types of Loose Connective Tissue

The three types of loose connective tissue are areolar (provides cushioning), adipose (stores fat), and reticular (supports organs).

Types of Dense Connective Tissue

The three types of dense connective tissue are dense regular (collagen fibers arranged parallel), dense irregular (fibers arranged randomly), and elastic (contains elastic fibers).

General Characteristics of Cartilage

Cartilage is flexible, resilient, avascular, and consists of chondrocytes within a gel-like matrix.

Types of Cartilage

The three types of cartilage are hyaline (smooth surface for joints), elastic (flexible support), and fibrocartilage (shock absorption in discs).

Function of Epithelial Tissue

Epithelial tissue functions include protection, absorption, secretion, and sensation.

Types of Cell Junctions

The main types of cell junctions include tight junctions (prevent leaks), adherens junctions (hold cells together), desmosomes (anchor cells), and gap junctions (allow communication).

Regeneration of Epithelial Tissue

Epithelial tissue has a high capacity for regeneration due to its rapid cell division, essential for healing.

Definition of Exocrine Glands

Exocrine glands are glandular tissues that secrete their products via ducts to the epithelial surface.

Structure of Connective Tissue

Connective tissue is composed of cells, fibers, and ground substance (matrix), defining its characteristics.

Function of Connective Tissue

Connective tissue supports, binds, and protects other tissues; it also stores energy and helps in transport.

Blood as Connective Tissue

Blood is considered a connective tissue because it contains cells suspended in a liquid matrix (plasma) and connects the body systems.

Hyaline Cartilage Characteristics

Hyaline cartilage is the most common type of cartilage, featuring a smooth surface that reduces friction in joints.

Fibrocartilage Function

Fibrocartilage provides strong support and can withstand tension and pressure, found in intervertebral discs and the pubic symphysis.

Function of Muscle Tissue

Muscle tissue is responsible for movement, both voluntary and involuntary, and is classified into three types: skeletal, cardiac, and smooth.

Characteristics of Skeletal Muscle

Skeletal muscle is striated, voluntary, and composed of long fibers that can contract to produce movement.

Characteristics of Cardiac Muscle

Cardiac muscle is striated, involuntary, and composed of branched fibers that contract rhythmically and are found only in the heart.

Characteristics of Smooth Muscle

Smooth muscle is non-striated, involuntary, and found in the walls of hollow organs, enabling movements such as peristalsis.

Nervous Tissue Function

Nervous tissue is responsible for transmitting electrical signals throughout the body, facilitating communication between different systems.

Neurons vs Neuroglia

Neurons are the primary cells responsible for transmitting signals, while neuroglia support and protect neurons.

Types of Neurons

The main types of neurons include sensory neurons, motor neurons, and interneurons, each serving specific functions in the nervous system.

Properties of Connective Tissue Matrix

The matrix of connective tissue is composed of ground substance and fibers, which provide support, protection, and nourishment.