1. List the 4 primary tissue types and give the general characteristics and functions of each one.
Epithelium: Covers the body and many of its parts (skin). Because epithelial cells are packed so close together, they form continuous sheets that contain no blood vessels.
Protects from injury, contains receptors which respond to stimuli, and filters and secretes materials and secretes serous fluids.
Connective: Most abundant and widely distributed tissue. Connects, binds, and supports structures, protects and cushions organs and tissues, insulates fat, and transports substances such as blood.
Muscle: Associated with the bones of the skeleton, the heart and in the walls of the hollow organs of the body. Helps with movement, locomotion, maintain posture, producing heat, facial expressions, pumping blood, and peristalsis.
Nervous: The main component of the nervous system. Regulates and controls body functions, generates and transmits nerve impulses, and supports, insulates and protects impulse generating neurons.
1. How are epithelial tissues classified?
Simple (one layer of cells) or stratified (more than one layer).
1. How does the type of epithelial tissue relate to its function? Give at least 1 example of where you would find each type of epithelial tissue.
Squamous: Simple, forms solid layer of cells that line blood vessels, body cavities, & cover organs in the body cavities. Stratified, forms epidermis. Located in the lining of the heart, blood and lymphatic vessels, alveoli of the lungs, and the lining of the serous membranes.
Cuboidal: Simple, roughly cube shaped, lines ducts in kidneys where reabsorption and secretory activities take place. Located in kidney tubules, glands and their ducts, choroid plexus of the brain, and surface of the ovaries.
Columnar: Simple, column shaped, lines the digestive tract where reabsorption and secretion occurs. Located in glands, some ducts, bronchioles of lungs, uterus, uterine tubes, stomach, small and large intestines.
1. Differentiate between exocrine and endocrine glands. Give an example of each.
Exocrine glands are open to the exterior of the body via ducts (sweat, oil). Endocrine glands have no contact with the exterior of the body, are ductless, and produce hormones (pituitary, thyroid, adrenals, pancreas).
1. What is the difference between apocrine, merocrine and holocrine glands? Which is the most common?
Apocrine: Fragments of the gland go into the secretion, apex of cell pinches off. (Mammary glands)
Merocrine: No loss of cytoplasm, secretion leaves by exocytosis. (Sweat glands, pancreas, and salivary glands)
Holocrine: Whole cell becomes part of secretion, secretion accumulates in cell and the cell ruptures and dies. (Sebaceous glands)
The most common of these is merocrine
1. Describe connective tissue’s intercellular material.
The intercellular substance (matrix) consists of fibers (collagenous, elastic, reticular), amorphous ground substance (glycoproteins, proteins, proteoglycans) and tissue fluid.
1. What are the 8 main types of connective tissue? Briefly describe each.
Bone: Tissue composed of bone cells, provides exceptional protection and support.
Cartilage: Less hard and more flexible than bone, found in few places in the body such as the ear.
Dense: Makeup tendons and ligaments as well as the lower layers of skin.
Loose: Softer, have more cells and fewer fibers than the other types.
Areolar: soft tissue that cushions and protects body organs.
Adipos: Often called fat tissue; tissue beneath the skin, insulates body, protects organ, stored for energy in hips, stomach, and breasts.
Reticular: located in lymphoid organs such as lymph nodes, spleen, and bone marrow.
Blood: carries nutrients, waste, respiratory gases and other substances throughout the body.
1. Order the types of connective tissue from most rigid to softest. Be sure that you understand why?
Bone, cartilage, dense, loose, blood.