There are nerve supplies to the epithelia, but they are already supplied with oxygen and nutrients. The epithelia’s growth and repair capacity is greater than that of the other tissues. Connective The connective tissues are largely distributed around the body, and they lie beneath the epithelial tissues, connecting different parts of the internal structure. Different types of cells lie in a different material, which would be known to us as a ‘matrix’. This could be in the form of a liquid, like blood.
Epithelial Tissue: Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial tissue that occurs on surfaces on the interior of the body is known as endothelium. Epithelial cells are packed tightly together, with almost no intercellular spaces and only a small amount of intercellular substance.
It is anchored to a basement membrane, made of tightly packed cells, lacks blood vessels, and contains minimal extracellular matrix material. The epithelial tissue is replaced frequently. The function of epithelial tissue is determined by the cell type and number of cell layers. There are two types of epithelial tissue: covering/lining epithelia and glandular epithelia. Functions of epithelial tissue are protection, secretion, absorption, excretion, and sensory reception.
The muscle fibers contain many myofibrils, which are the parts of the fiber that actually contracts | Part B: Epithelial Histology Based on shape, identify the three types of epithelial tissues and provide a description of each: Epithelial Tissue Type | Description | Squamous | single layer of flat cells; scale like | Cuboidal | single layer of cubed shaped cells | Columnar | tall, column-shaped | Identify where each of the following types of epithelial tissues are found: Epithelial Tissue Type | Location | Simple squamous | found in lungs and kidneys | Simple cuboidal | Is found covering the kidneys, lining the kidneys tubule, and lining some glandular ducts. | Simple columnar | lines most of the gastrointestinal tract | Stratified squamous | lining of mouth, esophagus, anus, and vagina | Stratified cuboidal | is found in the larger ducts of the mammary glands, sweat glands, salivary glands, and pancreas | Stratified columnar | is found in the vas deferens, part of the male urethra, and
| | Components and function of Blood Blood is used to transport materials around the body, and protect against disease. Blood contains plasma, a liquid that contains dissolved substance, cells and cell fragments. These include the following: Red blood cells | Transport oxygen – this cell in the blood of vertebrates that transports oxygen and carbon dioxide to and from the tissues. The red blood cell is disk; it contains hemogbin and lacks nucleus, | | White blood cells | Protect against disease - any of various blood cells that have a nucleus and cytoplasm, separate into a thin white layer when blood cells are separate from plasma cells, and help protect the body from infection and disease. White blood cells include – neutrophils, eosinophils, basophils, lymphocytes and monocytes.
Clearly, such delicate thin cells cannot offer much protection and their chief function is to allow materials to pass through via diffusion and osmosis. Simple squamous epithelium is found in the walls of; lung alveoli, blood capillaries and Bowman’s capsule of nephrons. As their names propose, cuboidal cells are cube-shaped, with spherical nuclei. They often line ducts and tubes and can allow materials
It is actually one continuous sheet. The cutaneous membrane, also known as the skin, is epithelium on connective tissue and is the largest membrane. (Sloan Thompson, 2013) If there is damage to the cutaneous membrane, such as a cut or injury to the skin, the blood would clot. Then there would be regrowth of epithelial cells, formation of scar tissue and a scab. Eventually the scab would fall off.
Since the epithelial cells act as lining cells, they are very prone to damage and need constant replacement (see Indge (2003) p.99), especially the epidermic epithelial cells of the skin which will be explained in detail later. Epithelial cells are classified primarily according to the number of cell layers and the shape of the superficial cells. There are two major types of epithelium based on the number of cell layers in each type; simple epithelium (a single layer of cells) and stratified epithelium (more than one layer) (see Diagram 1 and Seeley, Stephens & Tate (2006) p.107). There are three types of epithelium based on the shape of the epithelial cells; squamous cells (flat or scale-like), cubiodal cells (cube shaped), and columnar cells (that are taller than they are wide) (see Diagram 1 & Seeley,
Cell Analogy Assignment Glossary Cell Membrane: The cell membrane is a thin membrane that surrounds the cytoplasm and holds the content of a cell. Its job is to protect the substances within a cell by allowing some substances in and keeping others out. It maintains the shape and helps support the cell. The Cell membrane has Phospholipids components that have polar heads and hydrophobic tail that face opposite of each other it allows some types of molecules to diffuse on the cell membrane. Cytoplasm: The cytoplasm consists of all the components outside of the nucleus and within the cell membrane of the cell.
There are not blood vessels or nerve endings in the epidermis, but its deeper layers are bathed in interstitial fluid from the dermis, which provides oxygen and nutrients, and rained away as lymph. 2. The dermis lies directly underneath the epidermis, is tough and elastic. Dermis is formed from connective tissue and the matrix (collagen and elastic fibres).The collagen and elastin give skin strength and flexibility. A decrease in those proteins with age is common and contributes to the more fragile skin of elderly people.