TISSUE TYPES IN THE HUMAN BODY

TYPES OF TISSUES Tissues are groups of cells with

a common structure (form) and function (job).

Four Main Tissues in the Body: Epithelium Connective tissue Nervous tissue Muscle tissue

EPITHELIAL TISSUE FUNCTIONS

4 Major functions: Protection from the outside world (skin)

Absorption (stomach and intestinal lining of the gut)

Filtration (kidney) Secretions (gland formations)

CHARACTERISTICS OF EPITHELIUM

Closely attached to each other forming a protective barrier.

Always has one free (apical) surface open to outside the body or inside (cavity) an internal organ.

Always had one fixed (basal) section attached to underlying connective tissue.

CHARACTERISTICS OF EPITHELIUM

Has no blood vessels but can soak up nutrients from blood vessels in connective tissue underneath.

Can have lots of nerves in it (innervated)

Very good at regenerating (fixing itself) i.e. sunburn, skinned knee, etc.

EPITHELIAL CLASSIFICATION

By Shape Squamous – flat and scale-like Cuboidal – as tall as they are wide Columnar – tall, column-shaped

By Cell Arrangement Simple Epithelium – single layer of

cells (usually for absorption and filtration) Stratified Epithelium – stacked in

layers (protection from abrasion (rubbing) – mouth, skin)

EPITHELIAL TISSUES

CONNECTIVE TISSUE FUNCTIONS Wraps around to cushion and

protect organs. Stores nutrients Internal support for organs As tendon and ligaments protects

joints and attached muscles to bone and each other.

Runs through organ capsules and in deep layers of skin providing strength

ELEMENTS OF CONNECTIVE TISSUE

Ground substance – gel around cells and fibers

Fibers – provide strength, elasticity, and support

Cells

KINDS OF CONNECTIVE TISSUE

Loose Connective Tissue

Dense Connective Tissue

Special Connective Tissue

LOOSE CONNECTIVE TISSUE

Areolar Connective Tissue – cushion around organs, loose arrangement of cells and fibers.

Adipose Tissue – Storehouse for nutrients, packed with cells and blood vessels.

Reticular Connective Tissue – internal supporting framework of some organs, delicate network of fibers and cells.

DENSE CONNECTIVE TISSUE Dense Regular Connective

Tissue – tendons and ligaments, regularly arranged bundles packed with fibers running same way for strength in one direction.

Dense Irregular Connective Tissue – skin, organ capsules, irregularly arranged bundles packed with fibers for strength in all directions.

SPECIAL CONNECTIVE TISSUES - CARTILAGE

Functions: Provides strength with flexibility while resisting water, i.e. epiglottis, external ear, larynx.

Cushions and absorbs shock where bones meet i.e. intervertebral discs, joint capsules.

SPECIAL CONNECTIVE TISSUES – BONE

Functions: Provides framework and strength for body.

Allows movement. Stores calcium (Ca) Contains blood-forming cells.

SPECIAL CONNECTIVE TISSUES – BLOOD

Functions: Transports oxygen (O), carbon dioxide (CO2), and nutrients around the body.

Provides medium for immune response.

CONNECTIVE TISSUES

NERVOUS TISSUES Functions:

Conducts impulses to and from body organs via neurons.

Elements of Nervous Tissue: Brain Spinal Cord Nerves

NERVOUS TISSUE

MUSCLE TISSUE FUNCTIONS

Responsible for body movement.

Moves blood, food, waste through body’s organs.

Responsible for mechanical digestion i.e. chewing, tearing of food particles.

TYPES OF MUSCLE TISSUES

Smooth Muscle – organ walls and blood vessel walls, involuntary, spindle-shaped cells for pushing things through organs.

Skeletal Muscle – large body muscles, voluntary, striated muscle packed in bundles and attached to bones for movement.

Cardiac Muscle – heart wall, involuntary, striated muscle with intercalated discs connecting cells for synchronized contractions during heart beat.

MUSCLE TISSUE