fibroblasts (connects body parts)
the elongated shape of this cell lies along the cable like fibers it secretes. it has abundant ER and a large Golgi apparatus to make and secret protein building blocks of these fibers. most common in connective tissue.
epithelial cells (covers and line body organs)
the hexagonal shape of this cell allows to pack together in thin sheets.
skeletal muscle and smooth muscle cells (move organs and body parts)
these cells are elongated and filled with abundant contractile filaments, so they and shorten forcefully and move the bones or change the size of internal organs.
fat cell (stores nutrients)
the huge spherical shape of a fat cell is produced by a large lipid droplet in its cytoplasm.
macrophage (histiocytes) (fight disease)
this cells extends long pseudopods to crawl through tissue to reach infection sites. the many lysosomes within the cell digest the infectious microorganisms it takes up. originated as white blood cells and are common in connective tissue.
nerve cell (neuron) (gathers information and controls body functions)
this cell has long processes for receiving messages and transmitting them to other structures in the body.
oocyte (female) (reproduction)
the largest cell in the body, this eggs contains several copies of all organelles for distribution to the daughter cells that arise when the fertilized egg divides to become an embryo.
this cell is long and streamed lined built for swimming to the egg for fertilization. its flagellum acts as a motile whip to propel the sperm.
are found throughout the body. cover organs, forms the inner lining of body cavities, and lines hollow organs. lack blood vessels however nutrients diffuse by connective tissue. they divide readily. are tightly packed. functions include secretion, absorption, and excretion.
the underside of this tissue is anchored to connective tissue by a thin nonliving layer.
simple squamous epithelium
A single layer of thin, flat cells. It is often found where diffusion or filtration take place (alveoli in lungs, kidneys). It also covers organs in the pericardial, pleural, and peritoneal cavities. are tightly together and are easily damaged.
simple cuboidal epithelium
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 epithelium
single layer of tall, narrow cells; oval or sausage-shaped nuclei such as in the lining of the digestive tract. this tissue can be ciliated or nonciliated. in female reproductive tubes cilia help move eggs to the uterus. nonciliated lines the uterus and organs in the digestive tract (stomach and large and small intestine). specialize for absorption. have tiny processes extending from their surface called microvilli increase the surface area of the cell membrane when substances being absorbed. goblet cells scattered in this tissue secret a protective fluid called mucus onto the free surface of the tissue.
pseudo stratified columnar epithelium
-Single layer of cells of differing heights, some not reaching the free surface, nuclei at different levels, bear cilia.
-Secretion (mucous) and have goblet cells.
-Line the trachea, respiratory system.
stratified squamous epithelium
thick membrane with several cell layers, surface cells can contain keratin when they become old and then harden and die . this keratinization produces a covering of dry, tough, protective material that prevents water and other substances from leaving the underlying tissues and block chemicals and microorganisms from entering. (skin)
stratified squamous cuboidal
consist of 2 or 3 layers of cuboidal cells lining the lumen. lines larger ducts of the mammary glands, sweat glands, salivary glands, and pancreas. lines ovarian follicles and parts of the female and male reproductive organs.
specialized to change in response to increased tension. lines the urinary bladder and the ureters and superior urethra.
Cancer that originates in the coverings of the body, such as skin or the lining of the intestinal tract up 90% of cancer are carcinomas.
composed of cells that are specialized to produce and secrete substances into ducts or into body fluids. such cells are usually found within columnar or cuboidal epithelium and one or more of these cells constitute a gland.
ductless glands that secrete hormones directly into the bloodstream. ex. pituitary, adrenal glands
secrete their products by exocytosis as they are produced (salivary pancreatic, and sweat glands) most are exocrine.
glands that lose small portions of their glandular cell bodies during secretion. (mammary glands, ceruminous glands lining the external ear canal)
bind structures,provide support and protection, serve as framework, fill spaces, store fat, produce blood cells, protect against infections, help repair tissue damage. are separated and have abundant extracellular matrix. are vascularized, tendons and ligaments have poor and cartilages are avascular. have fixed cells which means they stay there for a long time (fibroblasts and mast cells) and wandering cells (macrophages) that and stay temporarily usually in response to an injury.
nonliving material in connective tissue consisting of ground substance and fibers that separates the living cells. is made of proteins, non fibrous proteins and other molecules and fluids.
are a lot in connective tissue are found near blood vessels. release heparin prevents blood clotting and histamine which produces some reactions associated with inflammation and allergies.
They are made of collagen that are nonelastic and do not tear easily when pulled lengthwise are flexible. are important in tendons and ligaments. sometimes are called white fibers.
dense connective tissue
Type of connective tissue containing many collagen fibers packed together; found in tendons and ligaments, for examples. also found in the protective white layer of the eyeball and in the deeper skin.
long, thin fibers that form branching networks in the extracellular matrix. Contain rubber like protien, elastin, that allows them to stretch and recoil like rubberbands. ex vocal cords. weaker than collagen fibers. they appear yellow so they are sometimes called yellow fibers.
thin, collagenous fibers whose networks surround and support the soft tissue of organs such as the spleen. when the skin is exposed to a lot of sun it looses elasticity and becomes wrinkly and collagen injections may temporarily smooth them but does not combat because collagen molecules are to big to penetrate the skin.
most plentiful connective tissue. binds skin to the underlying organs and fills spaces between muscles. lies beneath epithelium where it blood vessels nourish epithelial cells.
adipose or fat
develops when certain cells adipocytes store fat in droplets in their cytoplasm. found beneath the skin, in spaces between muscles, around kidneys, behind the eyeballs, around heart and around certain joints. function to cushions joints and some organs, and insulates beneath the skin and stores energy in fat molecules .
reticular connective tissue
consists of many closely packed, thick, collagenous fibers and a fine network of elastic fibers.
strong connective tissue. provides support, framework, and attachements, protects underlying tissues, and forms structural models for many developing bones. extracellular is abundant and it is composed of collagenous fibers embedded in a gel like substance.
Dense irregular connective tissue membrane covering cartilage which contain blood vessels that provide cartilage cells with nutrients by diffusion.
Most common type of cartilage; it is found on the ends of long bones, supporting rings of the respiratory system, and nose. important in the development and growth of bones.
much more flexible than hyaline cartilage and tolerates repeated bending better w/ more elastic fibers (cartilages of external ear and of the larynx)
has a matrix containing strong collagen fibers. found in structures that withstand tension and pressure, such as the pads between the vertebrae in the backbone and the wedges in the knee joint.
most strong connective tissue. its strong due to mineral salts such as phosphate and calcium carbonate between cells. this extracellular matrix also has collagenous fibers which are flexible and reinforce the mineral components of the bones. supports body structure. protects vitals parts in the cranial and thoracic cavities and is an attachement to muscles.
osteon (haversian system)
The unit of combact bone, also called a Haversian system. Osteons are essentially long cylinders of bone; the hollow center is called the central canal, and is where blood vessels, nervs, and lymphatic vessels are found. Compact bone is laid down around the central canal in rings (lamellae).
transport materials between interior body cells and exchange substances with external environments. blood helps maintain homeostasis. blood is composed of elements suspended in a fluid extracellular matrix called blood plasma. the formed elements include red blood cells, white blood cells, and cell fragments called platelets.
are found in the brain, spinal cord, and peripheral nerves. in addition to neurons, nervous tissue.
divide, carry phagocytes and supply nutrients to neurons by connecting them to blood vessels.
repair by dense fibrous connective tissue (scar tissue) depends on the type of tissue and severity of the injury. the capillaries become more permeable and allows the construction of a clot preventing bacteria from getting to the tissue. when the clot is exposed to air it dries and forms a scab. granulation tissue pink tissue composed of capillaries grow into the area from undamaged blood vessels. contains phagocytes that dispose of the blood clot and connective tissue (fibroblasts) that synthesize the building blocks of collagen fibers (scar tissue) to permanently bridge the gap.
the increased production and growth of normal cells in a tissue or organ, resulting in an abnormal increase in size of the tissue or organ (breast enlargement in pregnancy)
a localized tumor that has a fibrous capsule, limited potential for growth, a regular shape, and cells that are well differentiated; does not invade surrounding tissue or metastasize to distant sites.
Tumor that invades surrounding tissue and is usually capable of metastasizing; can be located in any organ or tissue in the body
substances known to produce or promote the development of cancer. causes mutations in DNA alter the expression of certain genes.
lysosomal enzymes (peroxisomal)
Enzymes with destructive properties toward cell walls and certain bacteria. (like cancer cells)