Post on 02-Jan-2016
1. In the cell, calcium is needed for blood clotting, iron is necessary to make hemoglobin, iodine is required to make the thyroid hormone that controls metabolism, and sodium and potassium ions are essential if nerve impulses are to be transmitted.
2. In addition to containing large amounts of water, all the cells of the body are constantly bathed in a dilute saltwater solution called interstitial fluid.
Name Structure FunctionErythrocyte Concave disk
shape, no organelles
To carry oxygen in the bloodstream
Epithelial cell Hexagonal shape; like a honeycomb; packed together in sheets
To cover and line body organs
Skeletal and smooth muscle
Elongated and filled with filaments
To move organs and body parts
Name Structure FunctionFat cell Huge spherical
shape, filled with a lipid droplet
To Store nutrients
Macrophage Has long psuedopods to crawl through tissue
To digest infectious micro-organisms
Neuron Long processes covered with plasma membrane
To gather information and control body functions
Name Structure Function
Oocyte Largest cell in the body, contains many copies of all organelles
To reproduce
Sperm Long and stream-lined, with a flagellum
Introduces DNA into the egg
5. In passive transport processes, substances are transported across the membrane without energy input from the cell.
6. Exocytosis is the means by which cells actively secrete hormones, mucus, or other cell products, or eject cellular wastes.
7. Endocytosis includes those ATP-requiring processes that take up, or engulf, extracellular substances by enclosing them in a vesicle.
8. The 4 primary tissue types, epithelium, connective, nervous, and muscle tissue interweave to form the fabric of the body.
10. Since epithelium forms the boundaries that separate us from the outside world, nearly all substances given off or received by the body must pass through the epithelium.
Describe the 4 functions of epithelium:
Protection: protects against bacterial and chemical damage
Absorption: absorb food substances into the body
Filtration: in the kidneys, it filters impurities out of the blood
Secretion: perspiration, oil, mucus, digestive enzymes are secreted through epithelia
12. Epithelial cells fit closely together to form continuous sheets. The membranes always have one free surface or edge. Epithelial cells have no blood supply of their own, but they regenerate themselves easily if well nourished.
13. Each epithelium is given 2 names. The first indicates the relative number of cell layers it has. The second describes the shape of its cells.
Difference between simple and stratified epithelium
Simple epithelium has 1 layer of cells.Stratified epithelium has more than 1
layer.
3 Basic Shapes of Epithelial Cells
Squamous: flattened like fish scales
Cuboidal: cube-shaped, like dice
Columnar: shaped like columns
16. Transitional epithelium is a highly modified, stratified squamous epithelium that form the lining of urinary organs. The ability of transitional cells to slide past one another and change their shape allows the ureter wall to stretch as urine flows through.
17. The secretions of endrocrine glands diffuse directly into the blood vessels that weave through the glands.
18. Connective tissue is the most abundant and widely distributed type of tissue in the body. Connective tissues are primarily involved in protecting, supporting and binding together other body tissues.
Tissue Description Function
Bone Bone cells sitting in cavities surrounded by a hard matrix
Protect and support other body organs
Cartilage Less hard and more flexible than bone
Cushion and protect bones
Tissue Description FunctionDense connective tissue
Collagen fibers; tendons and ligaments
Connect bones and muscles to one another
Loose connective tissue
Softer, more cells and fewer fibers
Areolar tissue cushions and protects organs
Blood Blood cells surrounded by fluid plasma
Transports oxygen and nutrients to body cells
20. Muscle tissues are highly specialized to contract to produce movement. Because they are elongated, muscle cells are called muscle fibers.
21. Skeletal muscle is packaged by connective tissue sheets into organs called skeletal muscles, which are attached to the skeleton. These muscles can be controlled voluntarily.
22. Cardiac muscle is found only in the heart. Cardiac muscle is under involuntary control, which means that we cannot consciously control the activity of the heart.
23. Smooth muscle is found in the walls of hollow organs. When it contracts, the cavity of an organ alternately becomes smaller or enlarges so that substances are propelled through the organ.