Ch. 3 - Tissues Flashcards
Epithelial Tissue
Body surfaces
- Cells are attached by cell junctions
- Epithelial tissue is avascular (lacks circulatory system)
- Nerves only send projections into tissue
Connective Tissue
Connects, supports
Nervous Tissue
Communication
Muscle Tissue
Contraction
Apical Surface
Toward the lumen (open space)
Basal Surface
Toward the basement membrane
Lateral Surface
Toward other epithelial cells
Tight Junctions
Zip-lock seal (i.e. intestines)
Gap Junctions
Tunnels for large molecules
Adherence Junctions
Velcro seal, holds cells together
Desmosomes
Dots of velcro (adherence junctions)
Hemidesmosomes
Velcro to basement membrane (half of a desmosome)
Lining epithelium
Covers the surfaces of the body (internal and external)
Single layer of Epithelium
Simple
More than one layer of Epithelium
Stratified
Squamous
The cells are much wider than they are tall
Cuboidal
The cells are about as wide as they are tall (most common)
Columnar
The cells are much taller than they are wide
Simple squamous
One layer of squamous cells (i.e. lungs)
Function: Exchange, more permeable
Simple Cuboidal
Basic cell shape (i.e. in the tubules of kidneys, the pancreas, and the thyroid)
Simple Columnar
i.e. in the small intestine.
Functions: Tight junctions seal spaces between cells, and the absorption of nutrients
Stratified squamous
Multiple layers and outer layer is squamous (i.e. skin, esophagus, mouth)
Function: Protection against mechanical stress
Stratified cuboidal
i.e. sweat glands and salivary glands. Very rare
Stratified columnar
Multiple layers of columnar, i.e. in male urethra, epididymis, mammary glands. Very rare
Pseudostratified
A single layer that looks like multiple layers, i.e. in the trachea.
Function: Mucous cells and cilia remove particles
Transitional
Multiple layers, and cells change shape, i.e. in the urinary bladder
Function: Can change shape and stretch
Glandular epithelium
Epithelium… With glands
Endocrine glands
Release substances into the body, i.e. hormones
Exocrine Glands
Release substances into the surface, i.e. Sweat glands, mucous cells
Merocrine glands
The final production of the product is in the golgi complex
Transported through vesicles and secreted through exocytosis
i.e. Sweat glands, Pancreatic digestive enzymes
Apocrine glands
After production, the product accumulates in apical end of cell
This end pinches off and bursts to release the product
i.e. Mammary glands
Holocrine glands
The product accumulates in the cell
The cell lyses to release the product
i.e. Sebaceous glands
Connective tissue
Includes tendons, dermis of the skin, bones, blood, fat, and white blood cells
Connective Tissue Functions
Binds tissues together (tendons) Supports and strengthens other tissues (dermis of skin, membranes) Protection of vital organs (skeleton) Transport (blood) Insulation (fat) Energy storage (fat) Immune response (white blood cells)
The matrix
Consists of fibers and ground substance
Collagen Fibers
Strong, resist stretching
Elastic Fibers
Form a network, stretch (150%) and recoil
Reticular Fibers
Form a network to support cells, support and strength
Ground Substance
The molecules between the cells and the fibers. Can be fluid, semi-fluid, gelatinous, or calcified
Loose connective tissue
Areolar, adipose, and loose reticular connective tissue
Areolar Connective Tissue
Fibroblasts, macrophages, mast cells
All three types of fiber (collagen, elastic, and reticular), random distribution
Location: Widely distributed, under skin, digestive tract, etc.
Functions: Weak, flexible, binding
Adipose Tissue
Some reticular fibers, adipocytes store fat
Location: Widely distributed in the body
Function: Store energy
Reticular Connective Tissue
Reticular cells
Reticular fibers form a mesh to support cells
Location: Liver, spleen, kidneys, lymph nodes
Function: Framework
Dense connective tissue
Regular, irregular, regular elastic, and irregular elastic
Dense regular connective tissue
- Fibroblasts secrete collagen
- All fibers parallel
- i.e. Tendons, ligaments
- Function: Hold structures together
Dense irregular connective tissue
- Fibroblasts secrete collagen
- Random distribution
- i.e. Dermis of skin, fascia around muscles
- Function: Strength
Dense regular elastic connective tissue
- Fibroblasts secrete elastic fibers
- All fibers parallel
- i.e. Vocal cords
- Function: Strength and stretch
Dense irregular elastic connective tissue
- Fibroblasts secrete elastic fibers
- Random distribution
- i.e. Aorta, lungs
- Function: Strength and stretch
Cartilage
All cells are in “lacuna”
Consists of hyalin, elastic, and fibrocartilage
Hyalin Cartilage (Jello with grapes)
- Thin, pale collagen fibers (not visible)
- Location: Ends of long bones, trachea, larynx, joints (facilitates growth of skeleton)
- Function: Protection and cushioning
Elastic Cartilage (Jello with hair and grapes)
- Elastic fibers
- Location: Ear and nose
- Function: Support and flexibility
Fibrocartilage (Jello with grapes in tendons…)
- Thick visible collagen fibers giving extra strength, stronger than hyalin but less elastic
- Location: Pubic symphysis, intervertebral discs, miniscus in knee
- Function: Limit compression
Bone
- Osteocytes in lacuna, calcified matrix, collagen fibers
- Location: Skeleton
- Function: Strength and support
Blood
- Plasma and formed elements (cells and platelets)
- Location: Circulatory system, Liquid matrix in blood vessels
- Function: Transport
Lymph
- Clear liquid flows through lymphatic system
Skeletal muscle
Striated, voluntary, long cells, multinucleated
Location: Muscles that move the skeleton
Smooth muscle
No striations, involuntary, influenced by hormones and the autonomic nervous system
Location: Blood vessels, intestine, etc.
Cardiac muscle
Striated, involuntary, branching fibers, influenced by hormones and autonomic nervous system. Intercalated discs.
Location and Function: Heart muscle, pumps blood
Nervous Tissue
Axon (Long), dendrite (branches), soma/cell body
Location: Everywhere
Function: Transmit signals and process information
