Download Connective tissue

Chapter 4
TISSUES AND
MEMBRANES
TISSUES
• 4 Main types of tissues:
– Epithelial tissue
• protects the body by covering internal and
external surfaces
– Connective tissue
• supports and connects organs and tissue
– Muscle tissue
• contains cell material which has the ability to
move the body
– Nervous tissue
• contains cells that react to stimuli and conduct
an impulse
Epithelial tissue
• Func – cells form a continuous layer
covering internal and external body
surfaces, provide protection,
produce secretions (digestive
juices, hormones, perspiration), and
regulate the passage of materials
across them.
Epithelial tissue – char. and
location
• A – Covering and lining tissue – cells
can be stratified (layered), ciliated or
keratinized (hard, nonliving substance.)
– 1. Squamous epithelial cells
• Are flat, irregularly shaped cells.
• Line the heart, blood and lymphatic
vessels, body cavities, and alveoli of the
lungs.
• Outer layer of skin consists of stratified
squamous epithelia cells. These protect
the body against microbial invasion.
Epithelial tissue – char. and
location
– 2. Cuboidal epithelial cells
• Cube-shaped cells line the kidney tubules
and cover ovaries and secretory parts of
certain glands.
– 3. Columnar epithelial cells
• Are elongated, w/the nucleus generally
near the bottom and often ciliated on
the outer surface.
• Line ducts, digestive tract, parts of the
respiratory tract, and glands.
Epithelial tissue – char. and
location
• B. Glandular or secretory tissue –
cells are specialized to secrete matl’s such as
digestive juices, hormones, milk, perspiration,
and wax. They are columnar or cuboidal
shape.
1. Endocrine gland cells
– Form ductless glands which secrete
their substances (hormones) directly
into the bloodstream.
Epithelial tissue – char. and
location
– 2. Exocrine gland cells
• Cells secrete their substances into
ducts. Ex. Mammary glands, sweat
glands, and salivary glands.
Connective tissue
• Function – cells whose intercellular
secretions (matrix) support and
connect the organs and tissues of
the body.
• Found almost everywhere w/i the
body: bones, cartilage, mucous
membranes, muscles, nerves, skin,
and all internal organs.
Connective tissue – function
• A. Adipose tissue
– Stores lipid, acts as filler tissue,
cushions, and insulates the body.
- Type of loose connective tissue
composed of saclike adipose cells;
specialized for storage of fat.
- Found t/o the body; skin, around the
kidneys, w/i padding of joints, and
marrow of long bones.
Connective tissue – char and
location
• B. Areolar (loose) tissue
– Tissue surrounds various organs and
supports both nerve cells and blood
vessels which transport nutrient
matl’s to cells and wastes from cells.
– Also temporarily stores glucose, salts,
and water.
– Composed of large, semifluid matrix,
w/many different types of cells and
fibers.
– Cells – fibroblasts, plasma cells,
macrophages, mast cells, WBC.
– Fibers – collagen, elastin
– Found in epidermis of skin and
subcutaneous layer with adipose cells.
Connective tissue – function
• C. Dense fibrous tissue
– Forms ligaments, tendons, and
apoenuroses.
• Ligaments – strong, flexible bands or
cords which hold bones firmly together
at the joints.
• Tendons – white, glistening bands
attaching skeletal muscles to the bones.
• Aponeuroses – flat, wide bands of
tendons holding one muscle to another or
to the periosteum (bone covering.)
• Fasciae – fibrous connective tissue
sheets that wrap around muscle bundles
to hold them in place.
Connective tissue – char and
location
• Dense fibrous tissue is also called
white fibrous tissue b/c it is made
from closely packed white collagen
fibers.
Fibrous tissue is flexible, but not
elastic.
• Has poor blood supply and heals
slowly.
Connective tissue – function
• D. Supportive tissue
– 1. Osseous (bone) tissue
• Comprises the skeletons of the body,
which supports and protects underlying
soft tissue parts and organs, and also
serves as attachments for skeletal
muscles.
• Char and location – the matrix is
calcified by the deposition of mineral
salts like CaCO3 and Ca3(PO4)2.
Connective tissue – function
– 2. Cartilage
• Provides firm but flexible support for
the embryonic skeleton and part of the
adult skeleton.
• A. Hyaline – forms the skeleton of the
embryo.
– Char. and location – found on articular bone
surfaces and nose tip, bronchi, and bronchial
tubes. Ribs are joined to the sternum by the
costal cartilage. Also found in the larynx and
rings of the trachea.
Connective tissue – function
• B. Fibrocartilage – strong, flexible,
supportive substance, found b/w bones
and wherever great strength is needed.
• Char and location – located w/i the
intervertebral discs and pubic symphysis
b/w the pubic bones.
• C. Elastic cartilage – intercellular matrix
is embedded w/a network of elastic
fibers and is firm but not flexible.
• Char and location – inside the auditory
ear tube, external ear, and larynx.
Connective tissue – function
– E. Vascular (liquid blood tissue)
• 1. Blood – transports nutrient and
oxygen molecules to cells and metabolic
wastes from cells. Contains cells that
function in the body’s defense and in
blood clotting.
– Char and location – 2 parts: liquid called
plasma and solid called blood cells.
– Plasma suspends the cells. RBC’s , WBC’s,
and platelets (blood clotting, thrombocytes).
– Blood circulates w/I the blood vessels
(arteries, veins, and capillaries) and t/the
heart.
Connective tissue – function
– 2. Lymph – transports tissue fluid,
proteins, fats, and other matl’s from
the tissues to the circulatory system.
• Char and location – consists of water,
glucose, protein, fats, and salts.
• Cellular components are lymphocytes and
granulocytes.
• Flow in tubes called lymphatic vessels
which closely parallel the veins and bathe
the tissue spaces b/w cells.
Muscle tissue
• A. Cardiac muscle
– Function – cells help the heart
contract in order to pump blood t/
and out of the heart.
– Char and location – a striated (having
cross-banding pattern), involuntary
(not under conscious control) muscle.
Makes up the walls of the heart
Muscle tissue
– B. Skeletal muscle
• Function - are attached to the movable
parts of the skeleton. Are capable of
rapid, powerful contractions and long
states of partially sustained
contractions, allowing for voluntary
movement.
• Char and location – striated, voluntary
and skeletal.
Muscle tissue
– C. Smooth muscle
• Function – provide involuntary movement.
• Char and location – nonstriated,
involuntary. Makes up walls of digestive
tract, genitourinary tract, blood vessels,
and lymphatic vessels.
Nervous tissue
• Neurons
– Function – react to stimuli
• 1. Irritability – ability of nerve tissue to
respond to environmental changes.
• 2. Conductivity – ability to carry a nerve
impulse (message).
– Char and location – have branches t/which
various parts of the body are connected
and their activities coordinated. They are
found in the brain, spinal cord, and nerves.
MEMBRANES
• A membrane is formed by putting two
thin layers of tissue together. The cells
in the membrane may secrete a fluid.
• Types:
– Epithelial membranes are classified
according to secretions produced:
• Mucous membranes
• Serous membranes
– Connective tissues support and connect the
organs and tissues
Mucous membranes
– Line surfaces and spaces that lead to the
outside of the body
– Line the respiratory, digestive,
reproductive, and urinary systems.
– Produce mucus, which lubricates and
protects the lining.
• Mucosae
– Respiratory mucosa – lines respiratory
tract.
– Gastric mucosa – lines the stomach.
– Intestinal mucosa – lines the small and large
intestines.
Serous membrane
• Double-walled membrane that produces
a watery fluid and lines closed body
cavities.
• Fluid – serous fluid.
• Outer part of the memb that lines the
cavity is the parietal memb.
• The part that covers the organs w/i is
the visceral membrane.
• The fluid produced allows organs w/i to
move freely and prevents friction.
Serous membrane
• The serosa is given to the specific
serous membranes.
– Pleural memb – lines the thoracic or chest
cavity and protects the lungs. The fluid is
called pleural fluid.
– Pericardial memb – lines the heart cavity
and protects the heart. The fluid is called
pericardial fluid.
– Peritoneal memb – lines the abdominal
cavity and protects the abdominal organs.
The fluid is called peritoneal fluid.
Cutaneous membrane
• Skin
• A specialized type of epithelial
membrane.
Connective membrane
– Synovial membrane – lines joints
cavities.
• Secrete synovial fluid which prevents
friction inside the joint cavity.
ORGANS AND SYSTEMS
• Organs are groups of tissues joined
together to perform a single
function
• An organ system is a group of
organs that together perform a
specific function
DEGREE OF TISSUE REPAIR
• Damaged tissues are repaired
continually
• Depending on the type and location
of injury, some tissues are repaired
quickly
PROCESS OF EPITHELIAL
TISSUE REPAIR
• There are two types of epithelial
tissue repair:
– Primary repair involves skin where
there is no infection present
– Secondary repair occurs in large, open
wounds with tissue loss