Ch. 4-Organization of Body Flashcards
Chemical element
Substance that cannot be broken down any further; made up of atoms
Atom
Smallest basic chemical unit of an element. Contains nucleus, protons, neutrons, electrons
6 Elements in the Body
Oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus
Molecules
Combination of two or more atoms that form a compound
Cells
Basic building blocks; perform specific functions
Cell membrane
Outside layer of cell; has selective permeability
Cytoplasm
Substance between nucleus and cell membrane, composed mostly of water, it’s where all the work happens that is not happening in the nucleus
Nucleus
Responsible for cell’s metabolism, growth, and reproduction. The cell’s “brain”. Also contains the chromosomes
Genome
Complete set of genes and chromosomes inside each cell
How many pairs of chromosomes does the body have?
23
Stem cells
Originate primarily from embryo; they can divide and renew themselves and basically form any type of tissue
Tissue
Group of similar cells that perform a specialized function
Four types of I tissue
Epithelial, connective, muscle, nerve
Epithelial tissue
Outer surfaces of body; lines body cavities, organs, and passageways; forms secreting portions of glands (sweat gland for example)
Connective tissue
Most widespread and abundant tissue, supporting network for organs, connects muscle to bone and bone to joint, bone is a dense form of this