Biology Histology Lab Practical

Simple Columnar Epithelial

-Function: Absorbs nutrients, secretes mucus and digestive enzymes, and protects underlying tissue

-Found: Stomach, intestines, reproductive tract

-Description: One layer of tall, column-shaped cells with nuclei usually located near the bottom of the cells. Often contains goblet cells that secrete mucus.

Simple Cuboidal Epithelial

-Function: Absorbs water, ions, nutrients and secretes hormones/enzymes; helps transport materials through ducts and tubules

-Found: Kidney tubules, glands, ovaries

-Description: One layer of cube-shaped cells with round nuclei

Simple Squamos Epithelial

-Function: Allows rapid diffusion and filtration; provides a smooth surface for fluid movement

-Found: Blood vessels, Alveoli, kidney glomeruli

-Description: One thin layer of flat cells

Stratified Squamos Epithelial

-Function: Protects against abrasion, pathogens, and water loss

-Found: Skin, mouth, throat, esophagus

-Description: Multiple layers of cells; surface cells are flat

Ciliated Columnar Epithelial

-Function: Moves mucus and trapped particles using cilia; helps protect and clear passageways

-Found: Respiratory tract, fallopian tubes

-Description: One layer of tall cells with cilia on the surface

Pseudostratified Ciliated Columnar Epithelial

-Function: Secretes mucus (by Goblet Cells) and uses cilia to move mucus, dust, and pathogens out of airways

-Found: Trachea and upper respiratory tract

-Description: One layer of tall cells that looks multilayered, with cilia on the surface

Skeletal Muscle

-Function: Produces voluntary movement, maintains posture, and stabilizes joints

-Found: Attached to bones throughout the body

-Description: Long, cylindrical, striated cells with multiple nuclei

Cardiac Muscle

-Function: Contracts involuntarily to pump blood throughout the body

-Found: Walls of the heart (myocardium)

-Description: Branched, striated cells with 1–2 nuclei and intercalated discs **look for intercalated disk to distinguish b/w skeletal**

Smooth Muscle

-Function: Involuntarily moves substances through organs and controls the diameter of passageways

-Found: Walls of the stomach, intestines, blood vessels, bladder, and airways

-Description: Non-striated, spindle-shaped cells with one central nucleus

Motor Nueron

-Function: Sends signals from the brain/spinal cord to muscles, causing them to contract

-Found: Brain and spinal cord; axons extend to skeletal muscles

-Description: Long cell with branching dendrites and a long axon

Glial

-Function: Support, protect, nourish, and insulate neurons

-Found: Brain, spinal cord, and peripheral nerves

-Description: Smaller cells surrounding and supporting neurons

Adipose

-Function: Stores energy, insulates the body, and cushions/protects organs

-Found: Under the skin, around kidneys and other organs, and in bone marrow

-Description: Large cells filled with fat (~fat droplets), with nuclei pushed to the side

Cartilage

-Function: Supports and cushions joints; reduces friction between bones

-Found: Joints, nose, ears, trachea, between vertebrae

-Description: Firm, flexible tissue with chondrocytes in lacunae; chondrocytes produce and maintain the cartilage matrix

Fibrous (Dense) Connective

-Function: Provides strong support and resists stretching and pulling

-Found: Tendons, ligaments, and dermis of the skin

-Description: Densely packed collagen fibers with few cells (fibroblasts)

Loose Connective

-Function: Supports and connects tissues; cushions organs and allows movement between structures

-Found: Under epithelia, around organs, blood vessels, and nerves

-Description: Contains collagenous fibers (strength), elastic fibers (flexibility), reticular fibers (support), and fibroblasts (produce fibers and matrix)

Bone

-Function: Supports the body, protects organs, enables movement, and stores minerals

-Found: Skeleton — skull, ribs, spine, arms, legs, pelvis

-Description: Hard connective tissue with osteocytes that maintain bone and osteoblasts that build new bone; cells are found in lacunae.

Blood

-Function: Transports oxygen, nutrients, hormones, and wastes; helps regulate temperature and fight infection

-Found: Blood vessels and heart

-Description: Fluid connective tissue made of plasma, red blood cells, white blood cells, and platelets.