animal tissue

Vocabulary flashcards covering key terms and definitions related to epithelial, connective and muscle tissues from the lecture notes.

Tissue

A group of similar cells (with intercellular substance) that perform a specific function in multicellular organisms.

Epithelial Tissue (Epithelium)

Compactly packed cells with a free surface that covers or lines body surfaces, cavities, ducts or tubes.

Simple Epithelium

Single-layered epithelium functioning mainly in lining, secretion and absorption.

Compound Epithelium

Multi-layered epithelium whose primary role is protection against mechanical and chemical stress.

Squamous Epithelium

Single thin layer of flattened cells forming diffusion boundaries (e.g., blood vessel walls, air sacs).

Cuboidal Epithelium

Single layer of cube-like cells specialized for secretion and absorption (e.g., kidney tubules, gland ducts).

Columnar Epithelium

Single layer of tall, slender cells found in stomach and intestine; aids secretion and absorption.

Ciliated Epithelium

Columnar or cuboidal cells bearing cilia that move particles or mucus along internal passages (e.g., bronchioles, fallopian tubes).

Glandular Epithelium

Columnar or cuboidal cells specialized for secretion; may be unicellular (goblet cell) or multicellular (salivary gland).

Exocrine Glands

Glands that release products like mucus, saliva or enzymes through ducts or tubes to an external or internal surface.

Endocrine Glands

Ductless glands that secrete hormones directly into the surrounding fluid or blood.

Cell Junctions

Specialized contacts between epithelial cells; include tight, adhering and gap junctions.

Tight Junctions

Intercellular seals that prevent leakage of substances across a tissue.

Adhering Junctions

‘Cementing’ contacts that firmly anchor neighboring cells together.

Gap Junctions

Cytoplasmic bridges allowing rapid passage of ions and small molecules between adjacent cells.

Connective Tissue

Tissue that links, supports or binds other tissues; contains cells, fibres (collagen/elastin) and ground substance (matrix).

Loose Connective Tissue

Connective tissue with loosely arranged fibres in semifluid matrix; supports epithelia (e.g., areolar tissue).

Areolar Tissue

Loose connective tissue beneath skin containing fibroblasts, macrophages and mast cells.

Adipose Tissue

Loose connective tissue whose cells store fat beneath the skin and around organs.

Dense Regular Connective Tissue

Parallel bundles of collagen fibres with fibroblasts in rows; forms tendons and ligaments.

Dense Irregular Connective Tissue

Collagen fibres oriented in many directions; provides strength to skin and organ capsules.

Cartilage

Solid yet pliable connective tissue with chondrocytes in lacunae; present in nose tip, ear, joints, vertebral discs.

Chondrocyte

Cartilage cell residing in a lacuna and secreting cartilaginous matrix.

Bone

Hard connective tissue rich in calcium salts and collagen, forming the body’s supporting framework.

Osteocyte

Mature bone cell occupying a lacuna within bone matrix.

Blood

Fluid connective tissue composed of plasma, RBCs, WBCs and platelets; main transport medium in the body.

Plasma

Liquid component of blood that carries cells, nutrients, hormones and waste products.

Red Blood Cell (RBC)

Erythrocyte; oxygen-transporting cell of blood.

White Blood Cell (WBC)

Leukocyte; defensive cell of blood involved in immunity.

Platelet

Cell fragment in blood essential for clotting.

Muscle Tissue

Tissue composed of contractile fibres (myofibrils) that enable movement and posture.

Skeletal Muscle

Striated, voluntary muscle attached to bones; fibres bundled and enclosed in connective tissue (e.g., biceps).

Smooth Muscle

Non-striated, involuntary muscle found in walls of hollow organs (e.g., bronchioles, intestines).

Cardiac Muscle

Striated, involuntary muscle forming the heart wall; contracts rhythmically and continuously.

Myofibril

Fine contractile filament inside a muscle fibre responsible for muscle contraction.

Fibroblast

Connective-tissue cell that secretes collagen and other extracellular matrix components.

Collagen

Strong structural protein fibre providing tensile strength to connective tissues.

Elastin

Stretchable protein fibre imparting elasticity to connective tissues.

Matrix (Ground Substance)

Amorphous material of connective tissue in which cells and fibres are embedded.

Tendon

Dense regular connective tissue that connects skeletal muscle to bone.

Ligament

Dense regular connective tissue that connects one bone to another, permitting limited movement