Chapter 4 - Tissue Level of Oganization Flashcards
Epithelial Tissue Location
Every exposed body surface
Epithelial Function
Provides physical protection, controls permeability and absorption, secretion and filtration
Cellularity of epithelial tissue
composed of closely packed cells with very little intracellular material
Specialized contacts of epithelial tissue
cells that fit close together by means of tight junctions
Polarity of epithelial tissue
Always have an exposed surface and a basal surface attached to another tissue. cytoplasmic components are unevenly distributed.
Avascularity of epithelial tissue
No blood vessels nutrients are obtained by diffusion or absorption. there is also a large nerve supply.
Basal Lamina of epithelial tissue
Layer found next to the connective tissue
Regeneration of epithelial tissue
Continuous cell division
Basement Membrane of epithelial tissue
Consists of a layer closer to the epithelium, a basal lamina and reticular lamina, the deepest layer.
Squamous epithelial cells
usually, thin, flat, irregular, and nucleus is newar the surface
Cuboidal epithelial cells
Look like cubes, hexagonal shaped. Nucleus is in the center
Columnar epithelial cells
Tall with the nucleus near the basement membrane
Simple Squamous Epithelia
Flat and scale-like. Absorption, secretion, and filtration by diffusion. Large nucleus and little cytoplasm. Found in airsacs of lungs, kidney, heart, and blood vessels.
Simple Cuboidal Epithelia
Single later, tall and wide. Function in secretion and absorption. Found in kidney microvilli, glands, and ovules.
Simple Columnar Epithelia
Tall, closely-packed, oval nucleus towards the bottom. Used for absorption and secretion. If secretion, elaborate golgi apparatus and ER. Found in digestive tract, where there’s dense microvilli, goblet cells. Found ciliated in oviducts and respiratory tract.
Stratified Squamous Epithelia
External skin surface. Several layers, squamous on surface, basal cuboidal or columnar (can be mixed). Covers the tongue, mouth, and vagina.
Stratified Cuboidal Epithelia
Mostly in glands. Very rare
Stratified Columnar Epithelia
Rare, used for protection and secretion. in stomach junction, pharynx, and male urethra.
Pseudostratified Epithelia
One layer, but looks like more
Transitional Epithelia
Lining of the urinary organs. It stretches.
Mucus membrane
Lines body cavities, open to the exterior. There for absorption and secretion. Have a lamina propria, connective tissue lying under the epithelial sheet
Cutaneous Membrane
Found in the skin
Serous membrane
Found in ventral body cavities. Most have a visceral and a parietal layer. They protect and lubricate.
Gland
one or more cells that produce and secrete a product
Endocrine
ductless glands that secrete hormones
Exocrine
More numerous than endocrine glands. Secrete into ducts. Unicellular produce mucin and don’t have ducts. Multicellular are either simple, single or branched, or compound, have branched/divided ducts.
Tubular Glands
have secreion cells in the form of a tube
Alveolar Glands
cells are in small sacks
Tubuloalveolar Glands
cells are shaped like both tubes and sacks
Merocrine Glands
Mostly exocrine, secrete by exocytosis
Holocrine Glands
Cell fills up, then bursts
Apocrine Glands
Apex fills, pinches off, then secretion is released.
Serous Gland
Secretes watery substance
Mucous Gland
Secretes mucin
Connective Tissue
Most abundant type. Arises from the mesenchyme. Has various degrees of vascularity from none to abundant. It’s matrix is composed for non-living material.
Connective Tissue Functions
Binding, support, protection, insulation, and transportation.
Ground Substance of connective tissue
Fluid that fills the space between the cells and contains fibers. It functions as a filter.
Fibers of connective tissue
Extracellular protein. Collagen, reticular, and elastic fibers. Also known as adhesive proteins.
4 Types of Connective Tissue
1) Connective Tissue Proper ( Fibroblasts)
2) Cartilage (Chondroblasts)
3) Bone (Osteoblasts)
4) Blood (Hemocytoblasts
Areaolar Connective Tissue (Loose)
Semifluid ground substance. Has all 3 fiber types. Serves as a packing around organs, provides cushioning, supports epithelium, surrounds blod vessels, and stores fat.
Adipose Connective Tissue (Loose)
Large number of adipocytes. Mostly cellular, very little matrix. Protects and insulates, slows heat loss. Primarily for nutrient storage.
Reticular Connective Tissue (Loose)
Has fibers in its loose ground. Found in the spleen, lymph nodes, and bone marrow.
Dense Regular Connective Tissue
Usually collagen, very loosely packed. They form tendons and ligaments.
Dense Irregular Connective Tissue
Irregular arrangement of collagen. Found in the dermis of the skin
Dense Elastic Connective Tissue
Has elastic fibers, can stretch more than the others. Found in the aorta.
Hyaline Cartilage
Most abundant type of cartilage. Provides firm support. Has collagen fibers, and is the base structure of the fetal skeleton.
Cartilage
Gel matrix with mineral deposits. It lacks nerve fibers and is avascular.
Fibrocartilage
Thick collagen. Found in the intervertebral discs and knee cartilage. Gives strong support and withstands heavy pressure.
Elastic Cartilage
Has elastic fibers in its matrix. Found in the ear and epiglottis.
Blood
a fluid connective tissue. Cells are suspended in a water matrix with dissolved proteins. Ex: RBCs and WBCs in a fluid matrix called plasma.
Bone
a calcified matrix there to support and protect
Mesenchyme
embryonic connective tissue
Muscle tissue
Elongated and highly cellular
3 types of Muscle tissue
Skeletal muscle, cardiac muscle, smooth muscle
Nervous tissue
Found in the nervous system, brain and spinal cord. Regulates and controls body functions.
2 major cell types of nervous tissue
Neurons - generate and conduct impulses
Neuroglial cells - non conducting, but support and protect the neurons.
Tissue Repair
Inflammatory response, when tissue is injured. It is non specific
Regeneration
Regenerate the same type of cell
Fibrosis
Damaged tissue is replaced by fibrous connective tissue
3 Develeopmental Germ Layers
1) Ectoderm
2) Mesoderm
3) Endoderm
