Tissues Flashcards
What are tissues?
-A group of cells working together
What are the 4 types of tissues?
- Epithelial tissue
- Muscle tissue
- Nervous tissue
- Cardiac tissue
Epithelial tissue
-Covers and lines surfaces
Characteristics of Epithelial Tissue
- Highly cellular
- Polar (apical/basal surface)
- Basement membrane
- Avascular
- Regenerative
- Specialized contacts
What is simple squamous epithelium?
- a single layer of flat cells
- Filtration and diffusion
Where is simple squamous epithelium located?
- Alveolar air sacs of lungs
- Kidney glomerulus
Two special types of simple squamous epithelium
- Endothelium
- Mesothelium
Endothelium
-Lines circulatory system (blood vessels and heart) and lymphatic vessels
Mesothelium
-Lines serous membranes
Simple cuboidal epithelium
-Secretion and absorption
Simple cuboidal epithelium locations
- Kidney tubules
- Glands
Simple columnar epithelium
-Secretion and absorption
Location of simple columnar epithelium
- Digestive tract (stomach, intestines)
- Glands
- Uterine tubes
Pseudostratified columnar epithelium
- Single layer of cells, nuclei at various heights
- Secretion
Pseudostratified columnar epithelium location
- Trachea
- Glands
- Sperm carrying ducts
Stratified squamous epithelium
- Protection
- Found in areas exposed to a lot of friction
- Upper layer replaced by rapidly dividing cells in basal layer
Stratified squamous epithelium location
- Skin
- Mouth
- Esophagus
- Vagina
Stratified Cuboidal epithelium
- Rare
- Found in some sweat and mammary glands
- Typically two cell layers thick
Stratified columnar epithelium
- Rare
- Some parts of pharynx, male urethra and lining some glandular ducts
- Only apical layer columnar
Transitional epithelium location
- Bladder
- Ureters
- Urethra
Glands
-One or more cells that secrete a product (proteins, hormones, steroids)
Endocrine glands
- Ductless
- Secrete products into extracellular space by exocytosis
- Products are hormones
Examples of endocrine glands
- Pituitary gland
- Thyroid gland
- Adrenal gland
Exocrine glands
- Have ducts
- Secrete products onto body surfaces (skin) or into body cavities
Examples of exocrine secretions
-Mucus, sweat, oil, saliva, bile, digestive enzymes (pancreas)
Unicellular exocrine glands
- Single cell
- Ductless
- Ex: goblet cell
Where are unicellular exocrine glands found
- Intestines
- Trachea