Tissues Major Functions of Epithelia:
1. Protecting underlying structures
Created by: its_nikkii
(e.g., skin, oral cavity epithelium).
Tissues are groups of similar cells with a 2. Acting as a barrier (e.g., skin
common origin, functioning together to epithelium preventing water loss).
perform specialized activities. The structure 3. Permitting the passage of substances
of each tissue type is related to its function, (e.g., gas exchange in lungs).
and the structure of tissues in an organ is 4. Secreting substances (e.g., sweat
related to the organ's function. There are glands, mucous glands).
four main types of tissue: 5. Absorbing substances (e.g., intestinal
epithelium absorbing nutrients).
• Epithelial Tissue
• Connective Tissue Classifications of Epithelial Tissue:
• Muscular Tissue Epithelia are named based on the number of
• Nervous Tissue cell layers and the shape of the cells.
Epithelial Tissue Layers:
Epithelial tissue covers external and internal • Simple: One layer of cells.
surfaces throughout the body and forms • Stratified: More than one cell layer.
most glands. Its functions include
Shapes:
protection, absorption, filtration, and
secretion. • Squamous: Flattened cells.
Functions of Epithelial Tissue: • Cuboidal: Cube-shaped cells.
• Columnar: Column-shaped cells.
• Cells fit closely together to form
continuous sheets (except for Types of Epithelial Tissue:
glandular epithelium). Simple Squamous:
• Has a free or apical surface exposed
to the body's exterior or to the cavity • Function: Filtration or rapid
of an internal organ. diffusion.
• Can regenerate easily if well- • Location: Lining of blood vessels,
nourished. heart, lymphatic vessels, alveoli of
• The basal surface rests on a lungs, kidney tubules, serous
basement membrane (composed of membranes.
proteins and carbohydrates). Simple Cuboidal:
• Avascular (no blood supply of its
own), relying on diffusion from • Function: Secretion and absorption.
underlying connective tissue. The • Location: Glands and ducts, kidney
basement membrane acts as a filter tubules, choroid plexuses of the
and barrier. brain, terminal bronchioles of lungs,
surfaces of ovaries.
1. Protecting underlying structures
Created by: its_nikkii
(e.g., skin, oral cavity epithelium).
Tissues are groups of similar cells with a 2. Acting as a barrier (e.g., skin
common origin, functioning together to epithelium preventing water loss).
perform specialized activities. The structure 3. Permitting the passage of substances
of each tissue type is related to its function, (e.g., gas exchange in lungs).
and the structure of tissues in an organ is 4. Secreting substances (e.g., sweat
related to the organ's function. There are glands, mucous glands).
four main types of tissue: 5. Absorbing substances (e.g., intestinal
epithelium absorbing nutrients).
• Epithelial Tissue
• Connective Tissue Classifications of Epithelial Tissue:
• Muscular Tissue Epithelia are named based on the number of
• Nervous Tissue cell layers and the shape of the cells.
Epithelial Tissue Layers:
Epithelial tissue covers external and internal • Simple: One layer of cells.
surfaces throughout the body and forms • Stratified: More than one cell layer.
most glands. Its functions include
Shapes:
protection, absorption, filtration, and
secretion. • Squamous: Flattened cells.
Functions of Epithelial Tissue: • Cuboidal: Cube-shaped cells.
• Columnar: Column-shaped cells.
• Cells fit closely together to form
continuous sheets (except for Types of Epithelial Tissue:
glandular epithelium). Simple Squamous:
• Has a free or apical surface exposed
to the body's exterior or to the cavity • Function: Filtration or rapid
of an internal organ. diffusion.
• Can regenerate easily if well- • Location: Lining of blood vessels,
nourished. heart, lymphatic vessels, alveoli of
• The basal surface rests on a lungs, kidney tubules, serous
basement membrane (composed of membranes.
proteins and carbohydrates). Simple Cuboidal:
• Avascular (no blood supply of its
own), relying on diffusion from • Function: Secretion and absorption.
underlying connective tissue. The • Location: Glands and ducts, kidney
basement membrane acts as a filter tubules, choroid plexuses of the
and barrier. brain, terminal bronchioles of lungs,
surfaces of ovaries.
