TISSUES

TISSUESDEFINITION: A GROUP OF SIMILAR CELLS THAT ARE

SPECIALIZED TO PERFORM A SPECIFIC FUNCTION.

4 PRIMARY TISSUE TYPES:

1. EPITHELIAL(covers and lines organs)2. CONNECTIVE (connects parts of the body)3. MUSCLE (movement)4. NERVOUS

Tissue Outline• 1. Epithelial

– Simple squamous epithelium– Simple cuboidal epithelium– Simple columnar epithelium– Pseudostratified columnar epithelium– Stratified squamous epithelium– Stratified cuboidal epithelium– Stratified columnar epithelium– Transitional epithelium– Glandular epithelium

2. Connective Tissue– Connective Tissue Proper (loose/areolar CT,

adipose, reticular CT, Dense CT, Elastic CT)– Cartilage– Bone– Blood– Lymph (book doesn’t classify)

3. Muscle– Striated– Smooth– Cardiac

4. Nervous– (no sub tissue just lots of cells like neurons,

neuroglial etc).

1. Epithelium

Covers or lines organs.

2 WAYS TO CLASSIFY EPITHELIA

BY NUMBER OF LAYERS:

STRATIFIED HAS 2 OR MORE LAYERS

SIMPLE HAS ONE LAYER

Skin is an example

BY THE SHAPE OF THE CELL:

SQUAMOUS - FLATTENED

CUBOIDAL- CUBE SHAPED

COLUMNAR - BRICK SHAPED

Identify the tissue type. (See next slide for answer)

?

Stratified cuboidal epithelium.

2. Connective Tissue

Connects the parts of the body.

CONNECTIVE TISSUE

• THE MOST ABUNDANT OF THE PRIMARY TISSUES

FUNCTIONS:

• BINDING & SUPPORT, PROTECTION, INSULATION, TRANSPORTATION

CONNECTIVE TISSUE SUBCLASSES

a. CONNECTIVE TISSUE PROPER (Binding, Supporting, Protection, Insulation and

Transportation CT)b. CARTILAGE (Supporting CT)

c. BONE (Supporting CT)d. BLOOD (Fluid CT)e. LYMPH (Fluid CT)

CONNECTIVE TISSUE PROPER

Types - Review• Loose CT (aerolar)

• Dense CT

• Adipose

• Reticular CT

• Elastic Ct

CONNECTIVE TISSUE PROPER

Loose – Fibers create loose, open framework between organs,

beneath the skin and between muscles.

• Dense – Fibers densely packed, found in tendons and ligaments

• Adipose – Cells called Adipocytes. They store lipids which are a reserve of energy. Collectively they assist in thermoregulation (body temperature) and in some places like around the kidney/behind the eyeball provide some cushioning.

adipose

tissue

nucleus

stored fat

• Reticular CT – Consists of thin, branched collagenous fibers. This tissue supports the walls of the liver, spleen, and lymphatic organs.

• Elastic CT – composed of elastic fibers. It gives an elastic property to hollow internal organs (ex. Blood vessels and lungs)

Connective Tissue Proper – The Cells

– Fibroblasts – – Macrophages-– Adipocytes-– Mesenchymal cells-– Melanocytes-

• Melanin-

– Mast cells-– Lymphocytes-– Microphages-

Connective Tissue Proper – The Tissue Fibers

• Collagen fibers-

• Reticular Fibers-

• Elastic Fibers-

• Ground Substance-

CARTILAGE (supporting CT)

Not quite as strong as bone

LOCATIONS: external ear and epiglottis, fetal skeleton, growth plates, larynx,

trachea, rib cage.

CARTILAGE

Types of Cartilage

• Hyaline cartilage-

• Elastic Cartilage-

• Fibrocartilage-

BONE (supporting CT)

provides support for soft tissues of the body

LOCATION: BONES

HAVERSIAN SYSTEM

HAVERSIAN CANAL

LAMELLAE

OSTEOCYTE

BLOOD (Fluid Connective tissue)

Transports oxygen, carbon dioxide, nutrients, wastes, antibodies, and hormonesThere are 3 types of blood cells:

RBC- carries oxygenWBC- functions in immunity

Platelet- important in blood clotting

LOCATION: BLOOD VESSELS

WBC

White blood cell

RBC

red blood cell

PLATELET

Lymph (Fluid Connective tissue)

• Lymph

Muscle

• Striated Muscle- Also called skeletal muscle – attached to bone – for movement -usually voluntary

• Smooth Muscle- in the walls of hollow organs ex. Intestine - involuntary

• Cardiac Muscle-only in the heart. It is striated also but connected by intercalated discs. Involuntary also.

Nervous

• Complete text questions pg.143-162 Wed.

• Complete text questions for pg. 163-165 for Friday.

• http://www.siumed.edu/~dking2/intro/ct.htm#adipocytes

• http://www.meddean.luc.edu/lumen/meded/histo/frames/h_frame3.html

• http://www.austincc.edu/histologyhelp/tissues/tn_elas_ct.html