Pathophysiology Exam #1
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,Cellular Functions Movement
Conductivity
Metabolic absorption
Secretion
Excretion
Respiration
Reproduction
Communication
Cellular Components Plasma Membrane
Cytoplasm
Intracellular Organelles
Movement Muscle cells can generate forces that produce motion. Muscles that attach to
bones produce limb movements, whereas muscles that enclose hollow tubes
or cavities move or empty contents when they contract (colon)
Conductivity Conduction as a response to a stimulus is manifested by a wave of excitation,
an electrical potential that passes along the surface of the cell to reach its
other parts. Conductivity is the chief function of nerve cells (brain & heart)
Metabolic Absorption All cells can take in and use nutrients and other substances from their
surroundings (cells of intestines or kidneys)
Secretion Certain cells, such as mucous gland cells, can synthesize new substances from
substances they absorb and then secrete the new substances to serve
elsewhere as needed.
Excretion All cells can rid themselves of waste products resulting from the metabolic
breakdown of nutrients. Membrane bound sacs (lysosomes) within cells contain
enzymes that break down, or digest, large molecules, turning them into waste
products that are released from the cell (urine)
Respiration Cells absorb oxygen, which is used to transform nutrients into energy in the
form of adenosine triphosphate (ATP). Carbohydrates, fats, and proteins can be
used as fuels. Cellular respiration, or oxidation, occurs in organelles called
mitochondria (glucose)
Reproduction Tissue growth occurs as cells enlarge and reproduce themselves. Even without
growth, tissue maintenance requires that new cells be produced to replace
cells that are lost normally through cellular death. Not all cells are capable on
continuous division (mitosis & meiosis)
, Communication Communication is vital for cells to survive as a society of cells. Appropriate
communication allows the maintenance of a dynamic steady state.
Plasma Membrane Define the cell's boundaries; surround the cell or enclose an intracellular
organelle. Exceedingly important to normal physiologic function because they
control the space, or compartment, they enclose. Can allow or exclude various
molecules, and because of selective transport systems, they can move
molecules in or out of the space. By controlling movement from one
compartment to the other, membranes exert a powerful influence on
metabolic pathways. Directional transport is facilitated by polarized domains,
distinct apical and basolateral domains. Important role in cell-to-cell
recognition, cellular mobility, and the maintenance of cellular shape.
Cytoplasm Is an aqueous solution (cytosol) that fills the cytoplasmic matrix- the space
between the nuclear envelope and the plasma membrane. Represents
approximately half the volume of a eukaryotic cell. Contains thousands of
enzymes involved in intermediate metabolism and is crowded with ribosomes
making proteins. The cytosol is a storage unit for fat, carbohydrates, and
secretory vesicles
Intracellular Organelles Organelles suspended in the cytoplasm are enclosed in biologic membranes
so they can simultaneously carry out functions requiring different biochemical
environments. Many functions are directed by coded messages carried from
the nucleus by RNA. Functions of organelles can be divided into four main
categories: Genetic control; manufacturing, distributing, and breaking down
molecules; energy processing; structural support, movement, and
communication between cells.
Nucleus Cell division and control of genetic information. Located in the center of the
cell, is the largest membrane bound organelle.
Nucleus Structures Nuclear envelope(Is pocketed with pits, called nuclear pores, which allow
chemical messages to exit and enter the nucleus); Nuclear pore complexes;
Nucleolus (small dense structure composed of DNA, RNA, and ribosomal
proteins); RNA; DNA; Histone proteins
Cytoplasm Fills the space between the nuclear envelope and the plasma membrane.
Functions- synthesis and transport, isolates and eliminates wastes; metabolic
processes; maintenance of cellular motility; storage. Cytoplasm Structures-
Cytoplasmic matrix; cytosol; cytoplasmic organelles
Ribosomes Synthesize proteins. Structure- RNA protein complexes; free vs attached
ribosomes. Are synthesized in the mitochondria and secreted into the cytosol.
Endoplasmic Reticulum Site of protein synthesis; senses cellular stress. Structure- Network of tubular or
saclike channels; smooth vs rough endoplasmic reticulum