A&P - 4.1 Types of Tissues

histology

microscopic study of tissues

tissue

group of cells that are similar in form and perform related functions

• cells make up tissues, tissues make up organs

types of tissues

1) epithelial tissues

2) connective tissues

3) muscle tissues 

4) nervous tissue

epithelial tissue

cover exterior surfaces of the body, line internal cavities and passageways, and form certain glands

• lining of GI tract organs and other hollow organs

• skin surface (epidermis)

connective tissue

binds the cells and organs of the body together and functions in the protection, support, and integration of all parts of the body

• fat and other soft padding tissue

• bone

• tendon

muscle tissue

contracts to produce active movements

• cardiac muscle

• smooth muscle

• skeletal muscle

nervous tissue

conducts electrical impulses; detects, interprets, and responds to stimuli

• brain

• spinal cord

• nerves

embryonic origin of tissues

• a fertilized egg becomes an embryo with layers

• there are 3 layer to the embryonic tissues from which all adult tissues are derived

• embryo; has primitive structures that will later differentiate into other stuff

totipotent cells

• embryonic cells that have the ability to differentiate into any type of cell and organ in the body

• in embryonic stage totipotent cells haven’t differentiated yet

germ layers

• primitive structures we have as an embryo

• as the differentiation of totipotent cells progress they develop into 3 main types of germ layers

  • ectoderm

  • mesoderm

  • endoderm

ectoderm

• gives rise to the epidermis of skin and all of the components of the nervous system

  • skin cells, neurons, and pigment cells

• ecto; outer

mesoderm

• wispy collagen fibers and fibroblasts in gel matrix

• gives rise to muscle, bone, blood, ***CARTILAGE

  • cardiac muscle, skeletal muscle, tubule cell of kidney, red blood cells, and smooth muscle

• becomes gelatinous tissue called mesenchyme; jelly-like substance (middle stage before fully formed structures)

• meso; middle

mesenchyme

embryonic tissue from which connective tissue cells derive

endoderm

• gives rise to mucous membrane lining digestive and respiratory tracts, digestive glands, and associated accessory organs

  • lung cell, thyroid cell, pancreatic cell

tissue membranes

thin layer or sheet of cells that covers the outside of the body, organs, and internal cavities

broad categories of tissue membranes

1) connective tissue membranes; connective tissue that encapsulates organs and lines movable joints

• synovial membranes

2) epithelial membranes; epithelium attached to a layer of connective tissue

• mucous membranes

• serous membranes

• cutaneous membranes (skin)

synovial membrane

line joint cavities and produce the synovial fluid within the joint

mucous membrane

• lines tissue and body cavities exposed to exterior environment such as the digestive, respiratory, urinary, and reproductive tracts

• they are coated with the secretions of mucous glands

mucous gland

groups of cells that secrete mucous, a thick, slippery substance that keeps tissues moist and acts as a lubricant

cutaneous membrane

skin; epithelial tissue made up of a stratified squamous epithelial cells that cover the outside of the body

serous membrane

line body cavities closed to the exterior of the body and lubricates then with serous fluid

• peritoneum; lines the peritoneal cavity and lines the surface of the visceral organs

• pleura; lines the chest cavity and surrounds the lungs

• pericardium; lines the pericardial cavity and surround the heart