Chapter 5 The Human Tissues Flashcards
Tissue
Collection of cells that function together to carry out specialized activities
Tissues can be:
Solid -bone
Semi solid -adipose tissue
Liquid -blood
Histology
Science of the study of tissues
Pathologist
Specialize in studies of cells and tissues
Epithelial tissue
Covers body surfaces, lines hollow organs and forms glands
Connective tissue
Protects and supports the body and organs
Muscle tissue
Generates physical force to make the body move, maintain posture, move substances and produce heat
Nervous tissue
Detects change in conditions inside and outside the body and responds by generated nerve signals to maintain homeostasis
Cellularity
Epithelia are composed of cells closely bound together with cell junctions, cells are tightly packed with extracellular material
How are epithelial cells arranged?
In sheets, in either single or multiple layers
Apical surface
Exposed surface that faces the body surface, a body cavity, a duct receiving secretions or an internal organ
Basal surface
Attached surface attached to underlying tissue
Basement membrane
Base of an epithelium, a thin extracellular layer
Avascularity
Without blood.
The exchange of materials between epithelium and adjacent connective tissue is by diffusion
Functions of epithelial tissues
-protect deeper tissues from injury and infection
-produce and release chemical secretions
-excrete waste
-absorb chemicals and nutrients
-sense stimuli
-filter substances
Epithelial tissues are categorized based on two features:
Number of cells
Shape of cells in the uppermost layer
Simple=
One layer of cells
Stratified=
More than one layer of cells
Pseudostratified=
Looks multilayered but all cells touch the basement membrane
Simple squamous
-permits rapid diffusion or transport of substances
Located: alveoli, glomeruli, endothelium, serosa
Simple cuboidal
-absorption and secretion, mucus production and movement
Located: liver, thyroid, mammary and salivary glands, bronchioles, kidney
Simple columnar
-absorption and secretion
-secretion of mucus
Located: uterus, GI tract, kidney, uterine tubes
Stratified kerantized squamous
Resists absorption
Located: epidermis, palms and soles
Non kerantized stratified squamous
Resists absorption
Located: tongue, oracl mucosa, vagina, esophagus
Stratified cuboidal
Secretes sweat, produces sperm, produces hormones
Located: sweat gland ducts, ovarian follicles, seminiferous tubules