Tissues
a group of cells with a common embryonic origin performing a similar function
4 types of tissue
epithelial=skin, covers body surfaces
connective= protects, and supports the body
muscular= produces force
nervous= conducts electrical impulses
epithelial tissue
tightly packed cells, little/no intercellular space, avascular, contains basement membranes
layers of cells (epithelial)
simple, stratified, and pseudostradified
simple epithelium
single layer of cells
absorption and filtration
minimal wear and tear
stratified epithelium
cells stacked in several layers
high degree of abrasion (wear and tear)
pseudostratified epithelium
only one layer of cells, but looks like multiple. not all cells reach the free surface, many have cilia and mucous.
shapes of cells
squamous
cuboidal
columnar
transitional
squamous
flattened or scale like cells
cuboidal
box or cube shaped
columnar
longer than wide
transitional
combination of other shapes, can be found where structures can change shapes, very elastic and extensible
endocrine glands
ductless glands, secretion diffuses into the blood, found in the pituitary, thyroid, and adrenal glands, and the pancreas.
exocrine glands
secretes products into ducts, may enter at the surface or line the covering of the epithelium. found in sweat and salivary glands
mucous membrane
lines structure with opening to the external environment, epithelial layer secretes mucous. lines respiratory, gastrointestinal, urinary, and reproductive tracts.
serous membrane
lines body cavities that don't open to the external environment, consists of 2 layers (visceral and parietal)
cutaneous membrane
the skin
synovial membrane
contains no epithelial tissue, lines cavities of freely moving joints. lubricates and nourishes hyaline cartilage
connective tissue
most abundant in body, tissue that binds and supports
loose connective tissue
also called areolar connective tissue, loosely woven arrangement of fibers. found in mucous membranes, around blood vessels/nerves and body organs
adipose tissue
loose connective tissue that contains adipocytes. fat droplets= triglycerides, major energy reserve
cartilage
avascular, can withstand tremendous force
types of cartilage
hyaline (articular)
fibrocartilage
elastic
hyaline cartilage
most abundant, bluish white in appearance, reduces friction at joints. found at ends of long bones, ribs, embryonic skeleton.
fibrocartilage
main purpose is shock absorbtion, more elastic than hyaline. found in invertebral discs, menisci of knee, epiglottis
elastic cartilage
structural, provides rigidity/strength, maintains shape of some organs. found in the larynx, ear, trachea, Eustachian tubes, nose.
dense fibrous tissue
composed of a close packed matrix of collagen fibers and fibroblasts that are either in regular or irregular arrangement
dense connective tissue (regular)
adapted for tension in one direction, arranged in parallel fashion. found in tendons, aponeuroses, and ligaments.
dense connective tissue (irregular)
found where multi-directional forces are found. located in most fascia, reticular region of skin.
elastic connective tissue
freely branching fibers, provides strength/stretch but snap back to position when stretched. yellowish in color, found in trachea, bronchi, lungs, and vocal chords.
reticular connective tissue
contains a special type of reticular fiber, found in framework of organs, liver, spleen, binds smooth muscle
vascular tissue
blood. made up of plasma, red blood cells, white blood cells, and platelets.
osseus tissue
maintained by special cells, two types (compact and spongy)
muscle tissue
made of muscle cells, highly specialized, converts chemical energy into mechanical energy, 3 types (skeletal, cardiac, and smooth)
nervous tissue
highly specialized and sensitive tissue. capable of converting stimulus to nervous impulses. transmits to other neurons, glands, and muscle fibers
nerve cells (neurons)
made up of the cell body, axons, and dendrites