Tissues,%20Glands%20

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Chapter 4

• Tissues, Glands Membranes

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Histology

• Is the study of body tissues
• There are 4 ways body tissue is classified
• Epithelial Tissue covers the surfaces of the
  body, lines cavities forms glands
• Connective Tissue supports and forms the
  framework of all parts of the body
• Muscle Tissue contracts and produces movement
• Nervous Tissue conducts nerve impulses

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Epithelial Tissue

• Forms a protective covering for the body all
  the organs
• Example
• It is the main tissue of the outer layer of skin
  it forms the lining of the intestinal tract,
  respiratory urinary passages, blood vessels,
  the uterus other body cavities

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Structure of Epithelial Tissue

• Epithelial tissue is classified according to its
  shape
• Squamous epithelial tissue is flat and irregular
• Cuboidal epithelial tissue is square
• Columnar epithelial tissue is long narrow
• Simple arrangement of cells is a single layer
• Stratified arrangement of cells is many layered

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Squamous Cells

• Simple Squamous is a single layer of flat,
  irregular cells
• Stratified squamous are many layered, flat,
  irregular cells

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Cuboidal Cells

• Simple cuboidal single layer of square shaped
  cells

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Columnar Cells

• Simple columnar single layer of long, narrow
  cells

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What is Transitional Epithelium?

• Because certain organs must vary a great deal in
  size during the course of their activities, they
  are composed of a specialized tissue called
  transitional epithelium
• This specialized tissue is capable of expanding
  and returning to its original form
• Examples of epithelial tissue are
• Urinary bladder gt
• Uterus

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Functions of Epithelial Tissue

• To produce secretions - Ex mucous, perspiration
  digestive juices
• Absorption of digested food done by special
  epithelium in the digestive tract
• Trapping of dust and foreign particles in the
  passages of the respiratory system
• Certain areas of the epithelium are capable of
  modifying themselves for greater strength Ex
  calluses
• Reproduce frequently Ex skin, lining of the
  mouth lining of the intestinal tract

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Glands are organs specialized to produce a
substance that is sent out to other parts of
the body

• Have many active cells made up of epithelial
  cells
• Glands are divided into 2 categories
• Exocrine Glands
• Endocrine Glands

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Exocrine Glands

• Have DUCTS to carry secretions away from the
  gland either to a body cavity or another organ
• Ex digestive juices, oil glands of the skin
  called SEBACEOUS glands tears from the LACRIMAL
  glands

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Endocrine Glands

• Depend on the blood that flows through a gland to
  carry the secretion to another organ these
  glands are DUCTLESS
• These secretions are called HORMONES and have
  specific effects on tissues
• Because they secrete directly into the
  bloodstream, they have an extensive blood vessel
  network Ex Adrenal Glands (near the kidneys)
  secrete epinephrine adrenaline

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Connective Tissue

• Is the supporting fabric for all parts of the
  body
• Has large amounts of non-living material between
  the cells called MATRIX
• Matrix contains water, fibers hard minerals
• There are 4 types of connective tissue classified
  by the degree of hardness
• 1. Soft 2. Liquid 3. Fibrous 4. Hard

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Soft Connective Tissue

• Loosely held together with a semi-liquid material
  between cells
• Adipose (Fat) Tissue contains cells capable of
  storing large amounts of fat which are used as a
  reserve energy supply, serve as a heat insulator
  a protective padding for organs and joints
• Areolar (Loose) Tissue the most common type in
  the body which contains cells fibers in a
  loose, jelly-like material found in membranes
  around vessels organs, between muscles under
  skin

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Liquid Connective Tissue

• Suspended in a fluid environment
• Ex
• Blood
• Lymph (fluid that circulates the lymphatic
  system)

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Fibrous Connective Tissue

• Densely packed tissue with fiber cells called
  FIBROBLASTS
• Examples
• Collagen flexible, white protein that is the
  main type of fiber found in connective tissue
• Capsules a particularly strong form that makes
  up the covering around certain organs kidneys,
  liver glands
• Tendons connect muscle to bone and the fibers
  all run in the same direction
• Ligaments connect bone to bone and the fibers
  all run in the same direction

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Repair of Fibrous Tissue

• Can repair itself easily
• Example
• Blood clots to form scabs to protect underlying
  tissue
• From damaged capillaries, new vessels branch
  grow to the injured tissue
• Fibroblasts produce collagen extensive growth
  of new tissue will form a scar
• Excessive production of collagen may cause
  development of a KELOID

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What is Keloid Scarring?

• Keloid scarring is a sharply raised area on the
  surface of the skin
• Parts of the body susceptible to keloids are the
  deltoid region of the upper arm, the upper back,
  and the sternum. The earlobes and the back of the
  neck are common sites as well.

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Hard Connective Tissue

• Made up of a firm consistency or actually
  hardened by minerals
• Examples
• Cartilage used as a shock absorber and a
  bearing surface because of its strength and
  flexibility
• Bone made up of OSSEOUS tissue, it is much like
  cartilage in its cellular structure but becomes
  solid and hard with the addition of calcium
  phosphorus

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Muscle Tissue

• Designed to produce movement by contraction of
  its cells which are called MUSCLE FIBERS
• Muscle tissue is not repaired easily, if at all,
  once an injury has been sustained
• Muscle tissue is classified a follows
• Skeletal
• Cardiac
• Smooth

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Skeletal Muscle

• Works with tendons bones to move the body
• Known as voluntary muscle
• Moves or contracts by conscious thought

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Cardiac Muscle

• Forms the bulk of the cardiac wall called the
  MYOCARDIUM
• Produces the regular contractions of the heart
• Known as involuntary muscle
• Moves or contracts independently of conscious
  thought

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Smooth Muscle

• Also known as VISCERAL muscle
• Forms the walls of the VISCERA, which are the
  organs of the ventral body cavity except the
  heart includes muscles of the digestive
  tract, walls of the blood vessels tubes that
  carry urine from the kidneys
• Also attached to the base of each body hair
  contraction of these muscles cause the condition
  called goose bumps

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Nervous Tissue

• Makes up the entire communication system of the
  brain, nerves and spinal cord

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Neurons

• Basic unit of nervous tissue
• Consists of a nerve cell body and fibers
• Dendrites carry impulses TO the cell body
• Axons carry impulses AWAY from the cell body
• Axons are insulated protected by the MYELIN
  SHEATH

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Membranes

• Thin sheets of tissue that can be fragile, tough,
  transparent or opaque
• Cover surfaces, serve as dividing partitions,
  line organs or anchor organs
• May contain cells that secrete lubricants, such
  as in the joints

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Membranes Disease

• A number of diseases directly affect membranes
• The Common Cold Inflammation of the nasal
  passages
• Peritonitis Infection of the peritoneum
  commonly follows the rupture of the appendix
  which can be fatal if not treated in time

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• - Rheumatoid Arthritis where the synovial
  membrane becomes inflamed and swollen affecting
  the cartilage in the joints
• - Lupus the serous membranes (pleura
  pericardium) become inflamed, damaged and
  destroyed leading to a number of physical problems

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• Membranes usually protect against the spread of
  infection, but in some cases, can also act as a
  pathway to spread disease
• In general, when a persons resistance is
  lowered, infection can spread
• For example, a pregnant female can develop an
  infection in the tubes of the reproductive system
  which could travel into the placenta and affect
  the unborn child

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Benign Malignant Tumors

• Any abnormal cell growth is called a TUMOR or
  NEOPLASM
• Benign tumors are typically confined to an area
  and do not spread
• Malignant tumors spread to neighboring tissues or
  distant parts of the body
• METASTASIS is the process of tumor cell spread

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Benign Tumors

• Although typically not life-threatening, they can
  be harmful in certain cases, such as growing
  within an organ, increasing in size and causing
  damage to the organ
• Types of benign tumors include
• Papilloma grows in epithelium, such as a wart
• Osteoma originates in the bones
• Myoma originates in muscle tissue common
  mostly in involuntary muscle, particularly in the
  uterus (Fibroid Tumors)
• Angioma composed of small blood vessels more
  commonly known as a birthmark
• Nevus skin tumors better known as moles which
  are ordinarily harmless, but can become malignant

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• Papilloma a common wart
• Mastoid Osteoma tumor of the bone behind the ear

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• Fibroid Tumor (Myoma)
• Birthmark (Angioma)

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• Mole (Nevus)

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Malignant Tumors

• Can cause death, no matter where they occur
• Send out claw-like extensions into neighboring
  tissue
• Cancer cells travel to other body parts fairly
  easy
• Secondary tumors form or METASTASIZE
• Grow more rapidly than benign tumors

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Carcinoma

• Most common form of cancer
• Originates in the epithelium which includes
• Skin
• Mouth
• Lung
• Breast
• Stomach
• Colon
• Prostate
• Uterus
• Usually spreads by the lymphatic system

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Sarcoma

• Cancer of the connective tissue
• Can be found anywhere in the body
• Usually spreads by the bloodstream

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• Gastric LymphomaA lymphoma is a malignant tumor
  that arises from the lymphoid cells in the body.
  They can occur almost anywhere in the body,
  including the stomach. In this instance, the
  tumor is present in the upper portion of the
  stomach and appears as an irregular ball.
  (Carcinoma)
• Kaposis Sarcoma

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Cancer Symptoms

• Unusual bleeding or discharge
• Persistent indigestion
• Chronic cough
• Change in a mole
• Sore that doesnt heal
• Presence of a lump
• Unexplained loss of weight

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Cancer Diagnosis

• Biopsy removal of living tissue to examine
  cells
• Ultrasound high frequency sound waves to
  differentiate tissue
• Computed Tomography (CT Scan) cross sectional
  x-rays
• Magnetic Resonance Imaging (MRI) use of
  magnetic fields radio waves to show changes in
  soft tissue
• Blood Tests screen the blood for key
  information Example Prostate Specific Antigen
  (PSA) test that screens for proteins produced in
  large quantities by prostate tumors

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Cancer Treatment

• Surgery benign tumors are removed more easily.
  Malignant tumor surgery could leave cancerous
  tissue behind. Laser surgery can destroy the
  tumor or cut the tumor in order to remove it.
• Radiation destroys rapidly dividing cells with
  small doses of radioactivity
• Chemotherapy drugs called ANTINEOPLASTIC AGENTS
  act selectively on cancer cells