STUDY GUIDE IN BIO 1 1ST QUARTERLY EXAM: ANIMAL TISSUES

Tissue

A group of structurally similar cells performing the same function; the subject of histology.

Histology

The study of tissues.

Epithelial tissue

Avascular tissue that lines surfaces and cavities; protects, absorbs, secretes, excretes, filters, diffuses, and senses.

Avascular

Lacking blood vessels; epithelia rely on diffusion from underlying tissues.

Basement membrane

Anchors the basal surface of epithelium to the underlying connective tissue.

Fibers (fibrillar proteins)

Proteins such as collagen, alpha-keratin, myosin, and elastin that provide structural support in tissues.

Collagen

Strong, most abundant protein; forms fibers that give tensile strength.

Elastin

Elastic protein that allows tissues to recoil after stretching.

Alpha-keratin

Structural protein in hair, nails, and epidermis; contributes to toughness.

Ground substance

Semifluid matrix in connective tissue where cells and fibers reside.

Connective tissue

Tissue that supports, connects, or separates body parts; cells are embedded in an extracellular matrix.

Areolar

Loose connective tissue with fibroblasts, macrophages, and mast cells in a semifluid ground substance.

Adipose

Fat tissue composed of adipocytes that cushions, insulates, and stores energy.

Reticular

Network of reticular fibers forming the supporting framework in organs like the spleen and lymph nodes.

Dense regular connective tissue

Dense connective tissue with parallel collagen fibers; forms tendons and ligaments.

Dense irregular connective tissue

Dense connective tissue with collagen fibers in multiple directions; resists forces from many directions (e.g., dermis).

Cartilage

Rigid, avascular connective tissue with a gel-like matrix; types include hyaline, elastic, and fibrocartilage.

Hyaline cartilage

Cartilage that covers bone ends and supports bone growth; found at the ends of long bones.

Elastic cartilage

Cartilage with elastic fibers; can recoil after bending (external ear, epiglottis, auditory tubes).

Fibrocartilage

Strong cartilage that resists compression; found in intervertebral discs and joints.

Bone tissue

Rigid connective tissue with a mineralized matrix; two forms: compact and spongy.

Osteocyte

Mature bone cell located in a lacuna; maintains bone tissue.

Osteoblast

Bone-forming cell; responsible for forming new bone.

Osteoclast

Bone-resorbing cell; breaks down old bone tissue.

Diaphysis

Shaft of a long bone; houses the medullary cavity with yellow marrow.

Epiphysis

End of a long bone; articulating surface; site of red marrow and erythropoiesis.

Metaphysis

Region between diaphysis and epiphysis; contains growth region and helps transfer loads.

Epiphyseal plate

Growth plate; cartilaginous region that allows bone lengthening before puberty.

Ligament

Connects bone to bone; dense elastic tissue; example: ACL.

Tendon

Connects muscle to bone; dense fibrous tissue.

Blood

Fluid connective tissue with plasma, red and white blood cells, and platelets; transports gases and nutrients.

Plasma

Liquid component of blood; carries water, salts, enzymes, nutrients, and proteins.

Red blood cells (RBCs) / erythrocytes

Cells that transport oxygen via hemoglobin.

White blood cells (WBCs) / leukocytes

Immune cells that defend against infection; includes lymphocytes, monocytes, and granulocytes.

Platelets (thrombocytes)

Cell fragments that help stop bleeding; originate in bone marrow.

Lymph

Colorless fluid carrying white blood cells; part of the lymphatic system.

Skeletal muscle

Voluntary, striated muscle with multiple nuclei; organized into fascicles.

Smooth muscle

Involuntary, non-striated muscle; single nucleus; lines walls of hollow organs.

Cardiac muscle

Involuntary, striated muscle with intercalated discs; fatigue-resistant.

Intercalated discs

Cell junctions in cardiac muscle that coordinate rapid conduction between cells.