Transcript Chapter Three Notes-

Chapter 3—Cells and Tissues
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.
3. In general, all cells have 3
main regions or parts, a
nucleus, cytoplasm, and a
plasma membrane.
Name Structure Function
Erythrocyte
Concave disk
shape, no
organelles
Epithelial cell
Hexagonal
shape; like a
honeycomb;
packed
together in
sheets
Skeletal and
Elongated and
smooth muscle filled with
filaments
To carry
oxygen in the
bloodstream
To cover and
line body
organs
To move
organs and
body parts
Name Structure Function
Fat cell
Huge spherical
To Store
shape, filled with nutrients
a lipid droplet
Macrophage
Has long
psuedopods to
crawl through
tissue
To digest
infectious microorganisms
Neuron
Long processes
covered with
plasma
membrane
To gather
information and
control body
functions
Name Structure Function
Oocyte
Largest cell in To reproduce
the body,
contains many
copies of all
organelles
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.
9. Tissue Roles
-epithelium: covering
-connective: support
-muscle: movement
-nervous: control
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
Protect and
sitting in
support other
cavities
body organs
surrounded by
a hard matrix
Cartilage
Less hard and
more flexible
than bone
Cushion and
protect bones
Tissue
Description
Function
Dense
connective
tissue
Collagen
Connect bones
fibers; tendons and muscles to
and ligaments one another
Loose
connective
tissue
Softer, more
Areolar tissue
cells and fewer cushions and
fibers
protects
organs
Blood cells
Transports
surrounded by oxygen and
fluid plasma
nutrients to
body cells
Blood
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.
24. All neurons receive and
conduct electrochemical
impulses from one part of
the body to another.
Tissue Repair
 REGENERATION
 FIBROSIS—SCAR TISSUE