Animal Tissues - Epithelial and Connective Tissues

Vocabulary practice flashcards covering Epithelial Tissue, Connective Tissues, Cartilage, Bone structure, Bone classification, and Fractures based on lecture notes.

Epithelial Tissue

A living, avascularised tissue (no blood supply) that covers surfaces and lines cavities and ducts. It consists of cells resting on a basal layer and basal membrane.

Squamous Epithelium

Simple epithelial tissue composed of delicate cells without regular boundaries; found in the endothelium of blood vessels, alveoli of lungs, mesothelium, descending limb of Henle, Bowman's capsule, and glomerulus.

Simple Cuboidal Epithelium

Epithelial tissue made of cube-like cells with centrally located nuclei that perform absorption and secretion; found lining ducts, thyroid follicles, gonadial epithelium, and brush bordered PCT.

Simple Columnar Epithelium

Epithelial tissue composed of cells arranged in columns to increase surface area for absorption and secretion; found in sweat glands, stomach, intestine, DCT, CD, and ventricles of the brain and spinal cord.

Pseudostratified Epithelium

Epithelium that appears to be multilayered but is actually unicellular (single layer); examples include the male urethra, olfactory epithelium, and trachea.

Transitional Epithelium (Urothelium)

A stretchable type of compound epithelium that lines the ureter and urinary bladder.

Keratinised Stratified Epithelium

A compound stratified epithelium containing keratin; found in the skin.

Non-Keratinised Stratified Epithelium

A compound stratified epithelium lacking keratin; found in the buccal cavity, pharynx, and upper $\frac{1}{3}\text{rd}$ of the oesophagus.

Connective Tissue Matrix

The ground substance of connective tissue composed of water, mucopolysaccharides, proteins, salts, and fibers.

Areolar Tissue

The most abundant tissue in the body, occupying more than $80\%$ of loose connective tissue.

Mast Cells

Cells in loose connective tissue that secrete histamine (vasodilator), heparin (anticoagulant), bradykinin (vasodilator), and serotonin (vasoconstrictor).

Histiocytes

Tissue-fixed phagocytes present in the matrix of loose connective tissue.

Signs of Inflammation

Manifested by Rubor (redness), Calor (heat), Dolor (pain), and Bump (tumor).

Brown Adipose Tissue

Metabolically active fat containing iron pigment (giving it a brown color) and abundant mitochondria, found in the fetus.

White Adipose Tissue

Stubborn fat tissue found in adults beneath the skin, behind the eyes, above the kidneys, and around the knees; forms blubber in aquatic mammals.

Tendon

Dense regular connective tissue made of more collagen and less elastin; connects bone to muscle and forms chordae tendinae.

Ligaments

Dense regular connective tissue containing more elastin and less collagen; connects bone to bone or organs to the body wall.

Dense Irregular Connective Tissue

Connective tissue in which fibroblasts and their fibers are scattered in the matrix; examples include periosteum, endosteum, perichondrium, pericardium, vocal cords, ear drums, sclera, and perimysium.

Cartilage

Also called gristle; an avascularised tissue (only perichondrium is vascularized) containing organic components (chondrin protein, chondroblasts, chondrocytes) and inorganic chondroitin salts.

Hyaline Cartilage

Translucent cartilage found in the nasal septum, costal cartilage, tracheal rings, epiphyseal cap, and articular cartilage.

Elastic Cartilage

Yellow cartilage found in the Eustachian tube (middle ear to nasopharynx), epiglottis, and ear pinna.

Fibrous Cartilage

White cartilage present in intervertebral discs and the pubic symphysis.

Bone (Osseous Tissue)

A hard, non-pliable tissue of mesodermal origin consisting of organic matrix (ossein, collagen, osteoblasts, osteocytes, osteoclasts) and inorganic salts (calcium and phosphorus).

Osteoclasts

Phagocytic, bone-eating cells responsible for bone resorption.

Dermal Bones

Bones formed directly in the skin/membrane, such as skull bones and the clavicle.

Replacing Bones

Bones formed by replacing cartilage during development, including all long bones.

Sesamoid Bones

Bones formed by the ossification of tendons; examples include the patella and the pisiform bone (smallest carpal).

Visceral Bones

Bones formed within soft visceral organs, such as os cordis (heart of a crocodile) and os rostralis (snout of a pig).

Types of Bone Fractures

Includes green stick (common in children below $10$ years), hairline, complex, and comminuted (the most dangerous type where bone shatters).

Leprosy (Effect on Nerves)

A condition in which the nerve roots are eaten by bacteria, resulting in no pain sensation.