A&P Review (Epithelial Tissue, Connective Tissue, Nervous Tissue, Muscle Tissue)
Hyaline Cartilage
- Most common type of cartilage - Composed of abundant collagen fibers and rubbery matrix - Locations: Larynx, entire fetal skeleton prior to birth - Functions as a more flexible skeletal element than bone
Loose Connective Tissue/ Areolar
- Most widely distributed connective tissue - soft, pliable tissue like "cobwebs" - Functions as a packing tissue - Contains all fiber types - Can soak up excess fluid
Elastic Cartilage
- Provides elasticity - Forms cushions - Highly compressible - Location is in external ear
Tissue Repair (Wound Healing)
- Regeneration: replaces the destroyed tissue by the same kind of cells - Fibrosis: repair by dense (fibrose) connective tissue (scar tissue) - Whether regeneration or fibrosis occurs depends on: the type of tissue damaged, or the severity of the injury
Regeneration of Surface Epithelium
- Scab detaches
Tissues that regenerate poorly
- Skeletal Muscle
Cardiac Muscle
- Under involuntary control - Found only in heart - Function: Pump blood - Characteristics: Striated, One nucleus per cell, Cells are attached to other cardiac muscle cells at intercalated disks
Skeletal Muscle
- Under voluntary control - Contracts to pull on bones and skin - Produces gross body movements or facial expressions - Characteristics of skeletal muscle cells: Striated, Multinucleate (More than nucleus), Long,cylinder cells
Smooth Tissues
-Under involuntary muscle -Found in walls of hallow organs such as stomach, uterus, and blood vessels -No visible striations -One nucleus per cell -Spindle-shaped cells
Simple Squamous
1 layer thick; flattened in shape; used in diffusion and filtration; found in air sacs in lungs, lining of blood vessels (exchange takes place in capillaries)
Connective Tissues
Connects body parts
Adipose Tissue
- Also known as fat tissue - Matrix is an areolar tissue in which fat globules predominate - Many cells contain large lipid deposits - Functions: insulates the body, protects organs, serves as a site of fuel storage
Blood (Vascular Tissue)
- Blood cells surrounded by fluid matrix called plasma - Fibers are visible during clotting - Functions as the transport vehicle for materials
Inflammation
- Capillaries become very permeable - Clotting proteins migrate into the area from the blood stream - a clot walls off the injured area
Tissues that are replaced largely with Scar Tissue
- Cardiac Muscle - Nervous Tissue within the brain and spinal cord
Bone (osseous tissue)
- Composed of bone cells in lacunae, hard matrix of calcium salts, large numbers of collagen fibers - Functions in protection and support
Nervous Tissue
- Composed of neurons and nerve support cells - Function is to send impulses to other areas of the body - Irritability - Conductivity
Reticular Connective Tissue
- Delicate network of interwoven fibers - Locations: forms stroma of lymphoid organs, lymph nodes, spleen, bone marrow
Tissues that repair easily
- Epithelial Tissue (skin and mucous membranes) - Fibrous Connective Tissues and bone
Developmental Aspects of Tissue
- Epithelial Tissue arises from all three primary germ layers - Muscle and Connective Tissue arise from mesoderm - Nervous Tissue arises from the ectoderm - With old age, there is a decrease in mass and viability in most tissues
Muscle Tissue
- Function: produces movement
Granulation Tissue Forms
- Growth of new capillaries - Rebuild collagen fibers
Fibrocartilage
- Highly compressible - Location: cushion like disks between vertebrae
Dense Connective Tissue
- Main matrix element is collagen fiber - Fibroblasts are cells that make fibers - Located in Tendons, Ligaments, and Dermis
Functions of Connective Tissue
Binds body tissues together, supports the body, and provides protection
Three Types of Fibers
Collagen, Elastic, Reticular
Endocrine Gland
Ductless since secretions diffuse into blood vessels; all secretions and hormones; secretions empty through ducts to the epithemic; include oil and sweat
Four Primary Types:
Epithelial tissue, connective tissue, muscular tissue, nervous tissue
Connective Tissue
Found everywhere in the body, includes the most abundant and widely distributed tissues
Glandular Epithelium
Glands with one or more cells responsible for secreting a particular product
Two Main Elements of Extracellular Matrix
Ground surface and fibers
Tissues
Groups of cells with similar structure and function
Pseudostratified Columnar
Looks stratified or looks like in layers, but really just odd shaped columnar cells with nuclei located in different parts of each cell. Found in the cells of the respiratory system.
Stratified Squamous
Layers of flattened cells; used in protection (covers areas of high abrasion); found in skin and upper digestive tract (mouth, esophagus)
Transitional Epithelium
Multiple layers of cells which appear cuboidal when not stretched, but squamous when stretched; found in the urinary organs
Extrocellular Matrix
Nonliving materials that surrounds living cells
Shape of cells:
Squamous, flattened, cuboidal, columnar
Fibers
Produced by the cells
Functions of tissues
Protection, absorption, filtration, secretion
Three Functions of Connective Tissues
Protection, support, binding together other body tissues
Simple Cuboidal
Single layer of cube shaped cells, usually with spherical nuclei. Covers ovaries and lines most of the kidney tubules and the ducts of certain glands.
Simple Columnar
Single layer of elongated, rectangular shaped cells. Secretion and absorption. Surface lining of stomach and intestines.
3 Types of Muscle Tissue
Skeletal, Cardiac, and Smooth
Neuroglia insulate
Support cells that protect and support neurons
Tissue Characteristics
Variations in the blood supply, some tissue types are well vascularized, some have poor blood supply (avascular)