Anatomy & Physiology Chapter 3: Tissue, The Living Fabric

Tissue

a group of cells that are similar in structure and perform a similar or related function

Four Primary Tissues

1) Epithelial tissues

2) Connective tissue

3) Muscle tissue

4) Nervous tissue

Epithelial Tissue

the sheets of cells that cover the body surfaces or line the body cavities

Epithelia are described using two names

1) First name—describes the number of cells (simple & stratified)

2) Second name—describes the shapes of cells

Simple

single-layered cells

Stratified

several layers of cells

Polarity

consists of two surface

Apical surface

the surface which opens to the exterior or the internal body cavity

Basal surface

the surface that attaches to the basal lamina

Reticular lamina

made up of the extracellular material and a fine network of collagen fibers

Basal membrane

the reticular lamina and the basal lamina together

Avascular

not supplied with blood vessels (without vessels) → nutrients and oxygen are supplied by diffusion across cells

Innervated

supplied by nerve fibers

Simple Squamous Epithelium - Structure

• Single layer of flattened cells

• Disc-shaped nucleus

• Sparse cytoplasm

Simple Squamous Epithelium - Function

• Allows passage of material by means of diffusion and filtration

• Secrets lubricating substances in serosae

Simple Squamous Epithelium - Location

Glomeruli, alveoli, lining of the heat, blood vessels, lining of serosae

Simple Cuboidal Epithelium - Structure

• Single layer of cube-like cells

• Central spherical nucleus

Simple Cuboidal Epithelium - Function

• Secretion

• Absorption

Simple Cuboidal Epithelium - Location

Kidney tubules, ducts and secretory portion of small glands, ovarian surface

Simple Columnar Epithelium - Structure

• Single layer of tall cells

• Oval nucleus

• Some cells bear cilia

• Mucus-secreting goblet cells are found

Simple Columnar Epithelium - Function

• Secretion of mucus and certain enzymes

• Absorption

• Propulsion of mucus trapped with harmful organism by cillary action

Simple Columnar Epithelium - Location

• Non-ciliated type—digestive tract, gallbladder, ducts of some glands

• Ciliated type—small bronchi uterine tubes

Pseudostratified Columnar Epithelium - Structure

Single layer of cells of different heights (appears stratified but is really single layer)

Pseudostratified Columnar Epithelium - Function

Secretion of mucus and propulsion of mucus by ciliary action

Pseudostratified Columnar Epithelium - Location

• Non-ciliated type—ducts of large glands

• Ciliated type—trachea and upper respiratory tract

Stratified Squamous Epithelium - Structure

• Contains several layers

• Has two types; keratinized and non-keratinized

Stratified Squamous Epithelium - Function

Protects underlying tissues from friction and injury

Stratified Squamous Epithelium - Location

• Non-kertainized type—mouth, esophagus, vagina

• Keratinized type—epidermis

Transitional Epithelium - Function

Able to stretch and therefor permit distention

Transitional Epithelium - Location

Urter, urinary bladder, part of the urethra

Types of Connective Tissue

• Connective tissue proper; loose connective and dense connective tissue

• Cartilage

• Bone

• Blood

3 Types of Loose Connective Tissue

1) Areolar

2) Adipose

3) Reticular

Areolar connective tissue: Function

• Cushions organs

• Macrophages perform phagocytosis and aid in inflammation

Areolar connective tissue: Location

Located under epithelium

Adipose tissue: Function

• Provides support and protection to organs

• Storage of fat

• Insulation against heat

Adipose tissue: Location

• Hypodermis, around kidneys and eyeballs, within abdomen

• In breast

Reticular tissue: Function

Provide support to cells

Reticular tissue: Location

Lymph node, bone marrow, spleen

Three Types of Deep Connective Tissue

1) Dense regular

2) Dense irregular

3) Elastin connective tissue

Dense regular connective tissue: Function

Withstand tensile stress

Dense Regular connective tissue: Location

Tendon, ligaments, aponeuroses

Dense Irregular: Function

Withstand tension

Dense Irregular: Location

Fibrous capsule of organs and joints

Elastic connective tissue: Function

• Allows recoil of tissues following stretching

• Aids in pulsatile flow of blood in vessels

• Aids in elastic recoil of lungs

Elastic connective tissue: Location

Walls of large arteries, walls of bronchial tubes, in certain ligaments associated with the vertebral column

Three Types of Cartilage

1) Hyaline

2) Elastic

3) Fibro

Hyaline cartilage: Function

Provides support and has a cushioning effect

Hyaline cartilage: Location

Ends of long bones, costal cartilage, trachea, cartilage of nose and larynx

Elastic cartilage: Function

Provide flexibility

Elastic cartilage: Location

External ear, epiglottis

Fibro cartilage: Function

• Provide strength

• Absorb compressive shock

Fibro cartilage: Location

Intervertebral discs, pubic symphysis, discs of knee joint

Bone tissue: Structure

• Hard, calcified matrix containing collagen fibers

• Highly vascular (dense network of blood vessels)

Bone tissue: Function

• Provide support

• Provide levers for the muscle to act

• Storage of calcium, other minerals, and fat

• Site of hematopoiesis

Blood: Structure

• Plasma makes up the matrix of blood.

• No fibers are found.

• Fluid in nature

Blood: Function

Transportation of oxygen, carbon dioxide, nutrients, waste, hormones, and many other substances

Three Types of Cells found in Blood

1) White blood cells

2) Red blood cells

3) Platelets

Three Types of Neurons:

1) Sensory neurons

2) Motor neurons

3) Intermediate neurons

Astrocytes

provide support, nutrition and storage function

Oligodendryocytes

formation of myelin

Microglial cells

perform phagocytosis

Ependymal cells

produce cerebrospinal fluid

Muscle Tissue

designed for locomotion, maintenance of posture, and movement of internal organs

Three Types of Muscle Tissue:

1) Skeletal muscles

2) Cardiac muscles

3) Smooth muscles