Anatomy Chapter 4

Adipose tissue

Little extracellular matrix surrounding cells, the adipocytes, or fat cells, are so full of lipid that the cytoplasm is pushed to the periphery of the cell. Packing material, thermal insulation, energy storage, and protection of organ against injury from being bumped or jarred.

Skeletal muscle

Skeletal muscle cells or fibers appear striated; cells are large, long, and cylindrical, with many nuclei located at the periphery. Function: Moves the body, is under voluntary control. Location: Attached to bone or other connective tissue.

Tissue

Collection of specialized cells and the extra-cellular substances surrounding them

Connective tissue

o Enclosing and separating other tissues: Sheets of connective tissue form capsules around organs such as liver and kidneys. Connective tissue also forms layers that separate tissues and organs. o Connecting tissues to one another: Strong cables, or bands, of connective tissue called tendons attach muscles to bone, whereas connective tissue bands called ligaments hold bones together. o Supporting and moving parts of the body: Bones of the skeletal system provide rigid support fro the body, and the semirigid cartilage supports structures such as the nose, ears, and joint surfaces. Joints between bones allow one part of the body to move relative to other parts. o Strong compounds: Adipose tissue stores high-energy molecules and bones store minerals, such as calcium and phosphate. o Cushioning and insulting: Adipose tissue cushions and protects the tissue it surrounds and provides an insulating layer beneath the skin that helps conserve heat. o Transporting: Blood transports the nutrients, enzymes. Hormones, and other cells of the immune system throughout the body. o Protecting; Cells of the immune system and blood protect against toxins and tissue injury as well as against micrororganisims. Bones protect underlying structures from injury.

Embryonic tissue

o Endoderm: Inner layer, forms the lining of the digestive tract and its derivatives. o Mesoderm: The middle layer, forms tissues such as muscle, bone and blood vessels. o Ectoderm: The outer layer forms the skin. o Nueroectoderm: Becomes the nervous system. o Nueral crest cells: Gives rise to parts of the peripheral nerves skin pigment, the medulla of the adrenal gland, and many tissues of the face.

Histology

The micorscopic study of tissues.

Microscopy

The way Histology is done.

Cardiac muscle

Cardiac muscle cells are cylindrical and straited and have a single, centrally located nucleus, they are branced and connected to one another by intercalated disks, which contain gap junctions. Function: Pumps the blood, is under involuntary control. Location: In the heart.

Areolar tissue

Cells within a fine network of mostly collagen fibers, often merges with denser connective tissue. Loose packing, support, and nourishment for the structures with which is associated. Widely distrubted throughout the body, substance on which epithelial basement membranes rest, packing between glands, muscles, and nerves attaches the skin to underlying tissue.

Loose connective tissue

Consists of relatively few protein fibers that form a lacy network, with numerous space filled with ground substance and fluid.

Epithelial tissue

Cover and protects surfaces, both outside and inside the body. o Mostly composed of cells: Epithelial tissue consists almost entirely of cells with very little extracellular matrix between them. o Covers body surfaces: Epithelial tissue covers body surfaces and forms glands that are derived developmentally from body surfaces. The body surfaces include the exterior surface, the lining of the digestive and respiratory tracts, the heart and blood vessels, and the lining of the many body cavities. o Distinct cell surfaces: Most epithelial tissues have one free or apical surface not attached to other cells a lateral surface attached to other epithelial cells and a basal surface. The free surface often lines the lumen of ducts, vessels and cavities. The basal surface of most epithelial tissues is attached to a Basement membrane, a specialized type of extracellular material. o Cell and matrix connections: Specialized cell contacts bind adjacent epithelial cells together an to the extracellular matrix of the basement membrane. o Nonvascular: Blood vessels in the underlying connective tissue do not penetrate the basement membrane to reach the epithelium: thus, all gases and nutrients carried in the blood must reach the epithelium by diffusing from blood vessels across the basement membrane. o Capable of regeneration: Epithelial cells retain the ability to undergo mitosis and therefore are able to replace damaged cells with ne epithelial cells.

Extracellular Matrix

Extracellular marix of a connective tissue has three major components: 1. Protein-fibers. 2. Ground substance consisting of nonfiburous protein and other molecules. 3. Fluid.

Reticular tissue

Fine network of reticular fibers irregularly arranged. Provides a super-function for lymphatic and hemopoietic tissues. Located within the lymph nodes, spleen, and bone marrow.

Autopsy

Is an examination of the organs is a dead body to determine the cause of death or to study the changes caused by a diseases.

Biopsy

Process of removing tissue samples from patients surgically or with a needle for diagnostic purposes

Smooth muscle

Smooth muscle cells are tapered at each end, are not striated and have a single nucleus. Function: Regulates the size of organs, forces fluid through tubes, controls the amount of light entering the eye and produces "goose flesh" in the skin; is under involuntary control. Located in hollow organs.

Functions of epithelial tissue

o Protecting underlying Structures: For example, the outer layer of the skin and the epithelium of the oral cavity protect the underlying structures from abrasion. o Acting as a barrier: Epithelium prevents many substances from moving through it. For example, the skin acts as a barrier to water and reduces water loss from the body. The skin also prevents many toxic molecules and microorganisms from entering the body. o Permitting the passage of substances: Eptithelium prevents many substances to move through it. For example, oxygen and carbon dioxide are exchanged between the air and blood by diffusuion through the epithelium in the lungs. o Secreting substances: Mucous glands, sweat glands, and the enzyme secreting protions of the pancreas are all composed of epithelial cells that secrete their products on the surface or into ducts that carry them to other areas of the body. o Absorbing substances: The plasma membranes of certain epithelial tissues contain carrier proteins, which regulate the absorption of marerials.