A&P Histology

Tissue, Function, Location

Simple Squamous Epithelium (one layer of flat cells)

Function: thin for diffusion

Location: lungs and blood vessels

Tissue, Function, Location

Simple Cuboidal Epithelium (one layer of boxed shaped cells)

Function: secretion and absorption

Location: walls of glands and in the kidneys

Tissue, Function, Location

Simple Columnar Epithelium (one layer of pillar shaped cells)

Function: absorption and secretion of mucus

Location: lining of the digestive tract

Tissue, Function, Location

Stratified Squamous Epithelium (two ore more layers of flat cells)

Function: protection from abrasion

Location: skin, mouth esophagus, vagina

Tissue, Function, Location

Stratified Cuboidal Epithelium (two or more layers of box shaped cells)

Function: N/A

Location: in the ducts of sweat glands and mammary glands

Tissue, Function, Location

Stratified Columnar Epithelium (two or more layers of pillar shaped cells)

Function: N/A

Location: pharynx and male urethra

Tissue, Function, Location

Pseudostratified Columnar (pillar shaped cells of varying heights with vary nuclei)

Function: propels particles forwards using cilia; secretes mucus

Location: trachea and fallopian tubes

Tissue, Function, Location

Transitional Epithelium (stratified epithelium with a top layer that is sometimes squamous and sometimes dome shaped)

Function: stretches easily

Location: urinary bladder, ureters, and urethra

Merocrine

Cells excrete the products via cytosis

Ex. sweat glands

Apocrine

A portion of the cell pinches off with the secreted products

Ex. mammary glands

Holocrine

Cells rupture and spill products into the ducts

Ex. sebaceous glands

Tissue, Description, Location

Aerolar (connective tissue)

Description: loose CT, mostly open space, holds water and salts for surrounding tissues

Location: under epithelial tissues and around organs

Tissue, Description, Location

Reticular (connective tissue)

Description: loose CT that forms a soft skeleton which supports other cells; has only reticular fibers

Location: lymph nodes, spleen, bone marrow

Tissue, Description, Location

Adipose (connective tissue)

Description: loose CT that is made of tightly packed fat cells; serves as energy reserves, insulation, and cushioning

Location: under the skin, around the kidneys and heart

Tissue, Description, Location

Regular dense (connective tissue)

Description: dense CT that has closely packed, parallel collagen fibers; strong when pulled in one direction

Location: within tendons and ligaments

Tissue, Description, Location

Irregular Dense (connective tissue)

Description: dense CT that has randomly arranged collagen fibers; strong when pulled in many directions

Location: in the dermis, in fibrous coverings that surround organs and joints

Tissue, Description, Location

Elastic dense (connective tissue)

Description: dense CT that has a high number of elastic fibers; allows tissues to bounce back after stretching; provides flexible cushioning

Location: walls of arteries, ligaments connecting vertebrae, lungs

Tissue, Description, Location

Hyaline cartilage (connective tissue)

Description: cartilage that is the most common in the body; few collagen fibers; firm ground substance; appears glassy

Location: larynx, bridge of nose, ribs

Tissue, Description, Location

Elastic cartilage (connective tissue)

Description: cartilage that contains many elastic fibers and is very flexible

Location: external ear, epiglottis

Tissue, Description, Location

Fibrocartilage (connective tissue)

Description: cartilage that contains rows of thick collagen fibers, allowing it to resist compression and tension

Location: intervertebral disks, cartilage of the knee

Tissue, Description, Location

Blood (connective tissue)

Description: only liquid body tissue; has a matrix known as plasma with no fibers within it

Location: within blood vessels

Tissue, Description, Location

Bone (connective tissue)

Description: also known as osseous tissue; rigid matrix due to abundant collagen fibers and calcium salts

Location: compact and spongy bone

Simple epithelium

One layer

Stratified epithelium

Multiple layers and vary in cell shape

Pseudo-stratified epithelium

Appears to have more than one layer

Transitional epithelium

Changes its appearance as it stretches

Epithelial tissue

Lining tissue that forms the boundary between our body and the external environment. Functions include protection, absorption, filtration, secretion.

Apical surface

Free surface (top) of epithelial tissue

Basal surface

Bottom surface of epithelial tissue

Basement membrane

Membrane underneath the basal surface

Avascular

No blood vessels

Gland

A group of cells that secrete a fluid substance. Classified by complexity and how the substances are secreted (exocrine vs. endocrine).

Exocrine glands

Secrete substances outward through a duct

Endocrine glands

Ductless glands that secrete hormones through the bloodstream so they can be delivered over longer distances.

Connective tissue

Provide support and bind other tissues together. Provide insulation and protection for other tissues. Some can transport substances.

Mesenchyme

Stem cell that forms all connective tissues

Osteocytes

Secrete ground substances, fibers, collagen, and fluids. The ground substance eventually becomes calcified and hard.

Mast cells

Detect foreign substances; contain granules that secrete inflammatory chemicals

Macrophages

Blob-like cells that engulf invading substances or organisms

Red blood cells

(Erythrocytes), carry oxygen

White blood cells

(Leukocytes), provide immune response

Smooth muscle tissue

Contracts involuntarily, non-striated. Found in the walls of the uterus, stomach, intestines, bladder, arteries, veins and eyes.

Cardiac muscle tissue

Contracts involuntarily, striated. Found in the heart and activated by the brain or hormones.

Skeletal muscle tissue

Contracted voluntarily, striated. Connected to the bones of the skeleton and controlled by somatic nervous system.

Neurons

Make up 10% of all nerve cells. Convert stimuli into nerve impulses. Pass impulses to other neurons, muscle fibers, or glands. Unable to regenerate.

Neurologia

Make up 90% of all nerve cells. Support and protect neurons. Do not generate nerve impulses. Able to regenerate after injury.

Tissue

A group of cells that work together to perform a specific job. Four major tissues include connective, epithelial, muscular, and nerve.

Loose connective tissues

Aerolar, adipose, reticular

Dense connective tissue

Regular dense, irregular dense, elastic dense

Cartilage

Hyaline, fibrocartilage, elastic cartilage