Transcript CH 3 and CH 4 BS

Anatomy & Physiology
Cells, Tissues, and
Membranes
CELLS
A cell is microscopic in size.
The cell is the basic unit of a structure
and function of all living things.
Special units are used when describing
the size of cells, μm = micrometer and μ
= micron.
Cells are classified by size and shape.
They contain a cytoplasm which is a living
matter.
Each cell is surrounded by a thin
membrane called the plasma membrane.
Organelles are specialized structures and
are found in the cytoplasm of each cell.
Cell Membrane
Every cell is surrounded by a cell
membrane, aka: plasma membrane.
Cell membrane separates the cell from it’s
external environment.
Regulates the passage or transport of
molecules in and out of the cell. Like a
door watchman who allows people to
enter or leave a private building.
It has a selective semi-permeable
membrane, only lets certain things in or
out of the cell.
Composed of lipids (steroids)
Arranged in a double layer, like a double
set of entry doors.
Nucleus
It is the most important organelle within
the cell.
It contains both DNA and RNA.
Nucleus controls the cell function (like an
operator or director).
Facilitates cell division, (46 chromosomes)
in order for the cells to reproduce.
Nuclear Membrane
Is a double-layered membrane that has
openings at regular intervals.
Through these ports, materials can pass
from either the nucleus to the cytoplasm
or from the cytoplasm to the nucleus. It
works similar to valves by opening one
section at time.
Cytoplasm
Sticky-semifluid material located between
the nucleus and cell membrane.
Has proteins, lipids, carbohydrates, minerals,
salts, and water.
Background area for all chemical reactions
taking place in each cell.
Organelles are within the cytoplasm and
they help the cell function.
Centrosome and Centrioles
Centrioles are 2 cylindrical organelles
found near the nucleus in a small round,
ribbed body called a centrosome.(looks
like a pasta noodle)
During mitosis (cell reproduction), the
centrioles separate to make 2 identical
cells.
Endoplasmic Reticulum
Is a thin network of tubes that are inside
the cell connecting the nuclear membrane
to the cell membrane.
The network acts as a passageway or
road for materials to travel in and out of
the cell.
It can also store large amounts of protein
for the cell.
Rough Endoplasmic
Reticulum
Has ribosomes on it’s outer surface and
this is where protein synthesis takes
place.
Smooth Endoplasmic
Reticulum
Is the site of cholesterol synthesis, fat
metabolism, and detoxification of drugs.
Mitochondria
Supply energy to the cell.
“Powerhouse” or PGE of the cell.
Golgi Apparatus
Synthesizes (breakdown) carbohydrates
and combines them with the protein
molecules as they are passing through the
Golgi Apparatus.
The Golgi stores this products and
packages it up to be discharged from the
cell.(stores the trash or waste of the cell).
Lysosomes
Are oval shaped and found in the
cytoplasm of the cell.
Help to digest protein molecules, old and
worn out cells, bacteria, and foreign
matter.
AKA as the suicide bags, if they rupture,
they will cause the cell to die.
Perioxisomes
Sac that contains oxidase enzymes and
they help to digest (breakdown) fats and
neutralize harmful substances.
Cytoskeleton
Helps support
the cell and aids
in movement.
Cell Division: Mitosis
Mitosis is the act of the cell reproducing
itself.
It makes an exact duplicate of the first
cell.
Our body does this to maintain a healthy
system or environment.
Cells die or are destroyed by bacteria or
tumors so we need to be able to make
new ones to keep us alive.
Diagram of cell mitosis
or cell reproduction.
Protein Synthesis
Cells produce proteins which are essential
to life.
Depending on the type of cell it is, the
amount and kind of protein may be
different.
The DNA determines what kind of
proteins the cell will produce.
Movement of Materials
Across the Cell Membrane
The membrane controls what goes into
and out of the cell. Much like a
gatekeeper.
Active transport means that the action
requires energy in order for it to take place.
Passive transport means that no energy is
needed to move substances in and out of the
cells.
Permeable Membrane
This is a membrane that only allows
certain material to pass in and out based
on it’s size.
Think of it like a strainer that you use
when draining noodles. Only the water is
released, not the noodles. Or a screen on
a door. It lets the air through but keeps
bugs out.
Phagocytosis
Act of cell eating.
Here in this picture you can
see the cell change shape as it
surrounds the green bacteria.
Once it has surrounded the
invader, the cell eats the
bacteria away.
Regeneration
Cells regenerate at different times.
Constant production:
Blood, Skin, and cells of the intestinal tract.
Every few years:
Muscles
NEVER:
Neurons or nerve cells or cells that have received
heavy damage such as heart cells during a heart
attack. The cells turn black and die and do not
regrow so the damage is permanent.
Disorders of Cells
Increase in size = hypertrophy
Decrease in size = atrophy
Increase in number = hyperplasia
Change into another type of cell =
metaplasia
Change size, shape, and organization =
dysplasia
Basal cell carcinoma
Breast ca cell
Sickle-cell
Cell injury
lymphoma
Abnormal
Prostate cell
Dysplasia can lead to neoplasia which is
an abnormal growth and cell structure
change.
Neoplasia can change to cancerous cells.
mouth
kidney
Left lung
Trauma or injury to cells
Hypoxia = not enough blood flow to the
cell structures
Anoxia = not enough or no oxygen to the
cell will cause death
Bacterial or viral infections can also cause
death to the cells
Tumors
Commonly known as neoplasms
2 groups
Benign
Cells are confined to a local area
Most can be surgically removed
Malignant
Cancerous
Continues to grow, interferes with other body functions
• If it spreads to another area in the body, it has metastasized.
TISSUES and MEMBRANES
Cells that are grouped together are called
tissues.
There are 4 main types of tissues.
Epithelial
Connective
Muscle
Nervous
Epithelial tissue
Protects the body by covering internal and
external surfaces.
Can also produce secretions.
Regulate passage of materials across
themselves.
Form a continuous layer to cover
surfaces.
Epithelial
Can be stratified ( layered)
ciliated (hair-like)
keratinized (hard, nonliving)
Squamous epithelial cells
Flat, irregular shaped cells.
Line the heart, blood & lymph vessels, body cavities, and the air
sacs (alveoli) in the lungs.
Cuboidal epithelial cells
Cube-shaped cells that line the kidney tubules, cover the ovaries,
And secretory parts of certain glands.
Columnar epithelial cells
Elongated cells that usually have the nucleus towards the bottom
and are often called ciliated on the surface. They line the ducts,
digestive tract, parts of the respiratory tract, and glands.
Epithelial
Glandular or secretory tissue
Specialized cells that secrete materials like digestive juices, milk,
hormones, perspiration, and wax.
Endocrine – form ductless glands that secrete hormones.
Exocrine – cells secrete substances into ducts like sweat glands.
Connective Tissue
These are cells that support and connect
organs and tissues of the body (matrix).
Found in bones, cartilage, mucous
membranes, muscles, nerves, skin, and all
internal organs.
6 classifications of connective tissue
Connective Tissue
1: Adipose tissue
It stores lipid (fat), acts as a filler tissue, cushions, supports, and
insulates the body.
Loose type of connective tissue that has saclike cells for fat
storage. Found throughout the body, subcutaneous layer of the
skin, around the kidneys, within padding around the joints, and
In the marrow of long bones.
2: Areolar tissue
Surrounds various organs, temporarily stores glucose, salts, and
water. Supports nerve cells and blood vessels.
Large semi-fluid matrix with cells and fibers embedded in it.
The fibers are white fibrous protein called elastin and collagen.
Found in the epidermis of the skin and subcutaneous layer with
the adipose cells.
3:Dense fibrous tissue
Forms ligaments, tendons, and aponeurosis.
Ligaments hold bones together firmly at the joints.
Tendons attach skeletal muscles to the bones.
Aponeurosis holds one muscle to another or to the periosteum.
Fascia wraps around muscles to hold them in place.
Tissue is flexible, but not elastic and heals slowly.
4: Supportive tissue
Osseous (bone) tissue
This type of tissue comprises the skeleton of the body and supports
and protects the soft tissue organs. It also helps with the attachment
of skeletal muscles.
Osseous tissue’s matrix is calcified which gives the bones strength.
Cartilage, provides firm but flexible support
for the embryonic and part of the adult
skeleton.
Hyaline cartilage forms the skeleton of the
growing embryo.
Fibrocartilage is found between bones and
wherever great strength is needed. It is a strong,
flexible and supportive substance.
Elastic cartilage has elastic fibers embedded
throughout it’s matrix and this makes it firm but
flexible.
• Found in the auditory ear tube, external ear, epiglottis,
and larynx
Vascular (liquid blood tissue) tissue
Blood transports food and oxygen to the cells and
carries waste products away from the cells.
Contains specialized cells that aid in the body’s
defense against invaders and also has a clotting
factor in it.
Lymph system aids in the transportation of
proteins, fats, tissue fluid, and other materials
from the circulatory system through the
lymphatic vessels.
5: Muscle
3 types
Cardiac Muscle helps the heart contract to pump
blood through it. Found only in the heart. These
muscles are involuntary.
Skeletal muscles are attached to the moveable
parts of the skeleton and aid in movement. They
are considered voluntary as we have conscious
control over them.
Smooth muscles provide involuntary movement
and aid in the movement of materials throughout
the body. Such as walking contracts our muscles
and helps move the lymph fluid through our body.
It lines the walls of the digestive tract, blood
vessels, genitourinary tract, and lymphatic system.
6: Nerve tissue
Has the ability to react to stimuli.
Irritability = ability of a nerve tissue to respond to
environmental changes.
Conductivity = the ability of the nerve tissue to
carry the message (impulse) away.
MEMBRANES
Are 2 thin layers of tissue that are
together and can secrete fluids.
Classified as epithelial or connective
membranes.
Epithelial Membrane
Can be mucous or serous
Mucous membranes line the interior surfaces
that lead to the outside environment.
It produces mucus to protect and lubricate
the lining.
Respiratory, Gastric, and Intestinal Mucosa
Serous membrane
Double-walled membrane
Produces a watery fluid called serous fluid
• Allows the organ to move without friction
Outer part that lines the cavity = parietal
membrane
Cover the organ within = visceral membrane
• Pleural, Pericardial, and Peritoneal membrane
Connective membranes
Consist of 2 layers of tissue
Synovial membrane
• Prevents friction in a joint cavity