Chapter 3 Human Anatomy Tissues

The Body TissuesThe Body Tissues

Chapter 3

Page 74

Human Anatomy and Physiology

I. Body TissuesI. Body TissuesThe human body starts out as a single cell when

the sperm fertilizes the egg.These cells divide into millions of cells that are

specialized for particular functions. Some become muscle cells, others transparent

lens of the eye, still others into skin cells, etc.This is called division of labor – where certain

groups of specialized cells perform functions that benefit the entire organism.

I. Body TissuesI. Body Tissues

The disadvantage of cell specialization is that if certain groups of cells are disabled or damaged it could damage the entire organism.

Ex – The contractions of the heard depend on a small group of specialized cells. If these are damaged, the heart will either stop or function poorly.

I. Body TissuesI. Body Tissues

Groups of cells that are similar in structure and function are called tissues.

There are 4 primary tissues types LEARN THEM!– Epithelium - covering– Connective - support– Nervous - control– Muscle - movement

II. Epithelial TissueII. Epithelial Tissue

Makes up the lining, covering, and glandular tissue of the body.

Functions of epithelium include:– Protection– Absorption– Filtration– Secretion

II. Epithelial TissueII. Epithelial Tissue

General Characteristics– Fit closely together to form continuous sheets.– The membranes always have one free

(unattached) surface called the apical surface the other side it attached to a basement membrane.

– They have no blood supply of their own. They depend on diffusion from capillaries.

– Can regenerate easily.

III. Classification of III. Classification of EpitheliumEpithelium

Epithelium can be classified in general terms as either:– Simple (one layer of cells) or– Stratified (more than one cell layer.

III.III. Classification of Classification of EpitheliumEpithelium

Types of Simple Epithelia – Since they are thin, they usually are not involved with protection, but rather absorption, secretion, and filtration.

III. III. Classification of EpitheliumClassification of Epithelium Simple Squamous

Epithelium– Single layer of thin

squamous cells resting on a basement membrane.

– Fit together like floor tiles.– Located in air sacs of

lungs, capillary walls, and covers organs in ventral cavity

III. Classification of EpitheliumIII. Classification of EpitheliumSimple Cuboidal

Epithelium– One layer of cuboidal

cells resting on a basement membrane

– Common in glands and ducts

– Walls of kidney tubules and covers the surface of the ovaries

III. Classification of EpitheliumIII. Classification of EpitheliumSimple Columnar

Epithelium– Single layer of tall

cells that fit closely together.

– Goblet cells, which produce lubricating muscus.

– Entire length of digestive tract from stomach to anus.

– Mucous membranes

III. Classification of EpitheliumIII. Classification of EpitheliumPseudostratified Columnar Epithelium

– All cells rest on basement membrane– Some are shorter than others giving the false

impression that it is stratified (made up of more than one layer)

– Lines respiratory tract

III. Classification of EpitheliumIII. Classification of Epithelium

Stratified Epithelia consists of 2 or more cell layers. These are primarily made for protection.

III. Classification of EpitheliumIII. Classification of Epithelium Stratified squamous – most common in body

– Several layers of cells.– Free edge is squamous. Cells close to basement membrane is

either cuboidal or columnar.– Esophagus, mouth, outer part of skin. High use areas.

III. Classification of EpitheliumIII. Classification of EpitheliumStratified cuboidal and

Stratified Columnar– 2 cell layers with surface

being cuboidal in shape– Surface cells of Stratified

columnar are columnar cells, but basal cells vary in size and shape.

– Both are rare in body and only found in the ducts of large glands.

III. Classification of EpitheliumIII. Classification of EpitheliumTransitional

Epithelium – Highly modified

stratified sqamous epithelium

– Forms lining of urinary bladder, ureters, and part of the urethra.

– Aids in stretching

III. Classification of EpitheliumIII. Classification of Epithelium

Glandular Epithelium– Gland consists of one or more cells that make and

secrete a particular product.– Product is called a secretion.– Two types of glands

Endocrine glands – (ductless glands) – Diffuse into the blood to be used in the body – include thyroid, adrenals, and pituitary

Exocrine glands – (retain their ducts) – Empty through ducts to the epithelial surface – include sweat and oil glands, liver, and pancrease.

IV.IV. Connective TissueConnective Tissue

Connects body parts.Found everywhere in the body. Most abundant and widely distributed of all

body tissue types.

IV. Connective TissueIV. Connective Tissue

Common characteristics– Most are well vascularized (good blood supply)

except for tendons and ligaments with poor blood supply and cartilages which are avascular. These heal poorer than the well vascularized tissue.

– Extracellular Matrix – made up of different types of cells plus varying amounts of a nonliving substance outside the cells called extracellular maxtrix.

IV. Connective TissueIV. Connective Tissue

Extracellular matrix is what makes connective tissue different from all other tissue types.

Produced by connective tissue cells and secreted to their exterior.

Matrix may be liquid, semisolid, gel-like or very hard.

Can bear weight, can stretch, can take abuse.

IV. Connective TissueIV. Connective TissueDifferent degrees of strength

– Fat tissue is mostly cells with a soft matrix– Bone and cartilage have few cells and large amounts

of hard matrix which makes them extremely strong.– Fibers that make up the matrix are

Collagen fibers (white) Elastic fibers (yellow) Reticular fibers (fine collagen)

Protecting, support, binding together

V. Types of Connective TissueV. Types of Connective Tissue

Most important thing to remember about the different tissue types is– Fiber type– Number of fibers

From most rigid to the softest are =– Bone, cartilage, dense connective tissue, loose

connective tissue, and blood.


Bone– AKA osseous tissue composed of bone cells

sitting in cavities called lacunae and surrounded by layers of a very hard matrix that contains calcium slats and large numbers of collagen fibers.

– Exceptional protection and support

V. Types of Connective TissueV. Types of Connective TissueCartilage

– Less hard and more flexible than bone.– Few places in the body.– The most common type is hyaline cartilage.

Abundant collagen fibers hidden by a rubbery matrix with a glassy blue-white appearance.

Attaches ribs to breastbone, covers ends of bone, fetus skeleton

– Elastic cartilage – external ear– Fibrocartilage – vertebral disks

V. Types of Connective TissueV. Types of Connective TissueDense Connective Tissue

– AKA dense fibrous tissue– Collagen fibers as main matrix– Crowded between collagen fibers are rows of

fibroblasts (fiber-forming cells) that make fibers.– Make up tendons (attach muscles to bones) and

ligaments (connect bones to bones)– Ligaments are more stretchy and contain more

elastic fibers that tendons.– Makes up lower layers of skin


Loose Connective Tissue– Softer, have more cells and fewer fibers than

the other types

V. Types of Connective TissueV. Types of Connective TissueTypes of Loose Connective Tissue

– Areolar Tissue – soft tissue that cushions and protects body organs.

Universal packing and glue to hold the internal organs together.

When viewed under the microscope it appears to be mostly open space.

– Adipose Tissue – commonly called fat tissue Oil occupies most of the cell compressing nucleus. Cell

looks empty. Subcutaneous tissue beneath skin, insulates body, protects

organs, stored for energy in hips, stomach, and breasts.


Reticular Connective Tissue– Delicate network of interwoven reticular fibers

associate with reticular cells which resemble fibrobasts.

– Located in lymphoid organs such as lymph nodes, spleen, and bone marrow.


Blood– AKA vascular tissue– Blood cells surrounded by a non-living matrix

called blood plasma.– The fibers of blood are soluble protein

molecules that become visible only during blood clotting

– Carries nutrients, waste, respiratory gases and other substances throughout the body.

VI. Types of Muscle TissueVI. Types of Muscle TissueThere are three types of muscle tissue.

– Skeletal muscle is packaged by connective tissue into sheets which are attached to the bones.

These are voluntary muscles (you control them).

Usually called meat or fleshWhen they contract they pull on bones or skin

causing body movements and facial expressions.

They are striated.

VI. Types of Muscle TissueVI. Types of Muscle Tissue

– Cardiac MuscleOnly found in the heart.Acts as a pump and propels blood through

the blood vessels.It has striations, but cells are uninucleate,

branching cells that fit tightly together. (intercalated disks)

Involuntary muscle – we cannot consciously control the activity.

VI. Types of Muscle TissueVI. Types of Muscle Tissue– Smooth Muscle

AKA visceral muscle No striations are visible. Single nucleus and spindle-shaped (pointed at each

end) Found in the walls of hollow organs (stomach,

bladder, uterus, blood vessels) Muscle contraction forces movement through the

organ. Much slower than other types of muscles. Involuntary Peristalsis – wavelike motion that keeps food

moving through the small intestine.

VII. Nervous TissueVII. Nervous Tissue Composed of cells called

neurons– Highly specialized to

receive and transmit nerve impulses and supporting cells.

– Neurons are important in controlling body processes

– Found in brain, spinal cord, and nerves.

VIII. Tissue RepairVIII. Tissue Repair

Two ways of tissue repair:– Regeneration – Tissue is replaced

with the same kind of cells– Fibrosis – Repair by dense (fibrous)

connective tissue (scar tissue)


Which type of repair occurs depends on– The type of tissue damaged– The severity of the injury

Clean cuts (incisions) heal much more successfully than ragged tears (lacerations)


Steps to Tissue Repair– Clotting proteins create a clot which stops the

loss of blood, holds the edges of the wound together and prevents bacteria and other harmful substances from spreading to surrounding tissues

– Clot dries and forms a scab.

VIII. Tissue Repair (con’t)VIII. Tissue Repair (con’t)

– Granulation tissue forms next Pink tissue composed largely of capillaries that

grow into the damaged area from undamaged blood vessels nearby.

Fragile and bleed freely when scab is scraped away. Contains phagocytes and get rid of the blood clot

and connective tissue cells that make collagen fibers that permanently bridge the gap.

– While all this is going on, epithelium grows back together covering the scar tissue.

VIII. Tissue RepairVIII. Tissue RepairThe scar is either invisible or visible

depending on the severity of the woundEpithelial tissues such as skin and mucous

membranes regenerate beautifully as do most of the fibrous connective tissue and bone.

Skeletal muscles regenerate poorly, if at all, and cardiac muscle and nervous tissue are replaced only by scar tissue.


Scar tissue is strong, but lacks flexibility.It cannot perform the normal functions of

the tissue it replaces.If scar tissue forms in the wall of the

bladder, heart, or other muscular organ, it may SEVERELY hamper the functioning of that organ.

IX. Developmental Aspects of IX. Developmental Aspects of TissuesTissues

Know some stages of aging (pg 86)Neoplasm – Then cells multiply wildly an

an abnormal mass of proliferating cells results. Can be either benign or malignant.

Hyperplasia – Normal increase in certain body tissues or organs

Atrophy – decrease in the size of an organ due to non-use.

Chapter 3 Human Anatomy Tissues

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