Chapter 5

Tissues

PowerPoint Presentation to accompany Hole’s Human Anatomy and Physiology, 10th edition, edited by S.C. Wache for Biol2064.01

Simple Columnar Epithelium

You are responsible for the following figures and tables:

Tab. 5.1 - Tissues.Tab. 5.4 - Epithelial Tissues (ET) including glandular ET.Tab. 5.3 - Types of glandular exocrine secretions.Tab. 5.7 - Connective Tissues (CT). Tab. 5.8 - Muscle Tissues (MT) and Nervous Tissues (NT).Study all corresponding figures.

It is important to correlate structural and functional characteristics of each tissue type.

Characteristics of ETCharacteristics of CTCharacteristics of MTCharacteristics of NT

Tissues

• Cells are organized into sheets or groups called tissues.

• There are four major tissue types found in the body: epithelial tissue (ET), connective tissue (CT), muscle tissue, and nervous tissue (Tab. 5.1).

• These tissues associate and interact to form organs with specialized functions.

Tissues and Cell-to-Cell Communication• Cells are often connected to each other by

intercellular junctions providing a tissue with a mechanism to become specialized (for example: cardiac muscle).

• Tight junctions occur when cell membranes of adjacent cells are tightly fused.

• Desmosomes form small reinforced regions of cell membranes of cells.

• Gap junctions connect the cell membranes of adjacent cells, but have channels to allow ions to move.

Figure 3.8

Epithelial Tissue (ET)

• Epithelia are sheets of cells (Fig. 3.2b) that function in protection, secretion, absorption, and excretion.

• Epithelium is composed of tightly packed cells anchored to a basement membrane.

• It lacks blood vessels and rapidly divides.

• ET are classified by cell shape and number of cell layers.

NAME OF ET STRUCTURE LOCATION FUNCTION

SIMPLESQUAMOUS

single layer of flat cells linings of air sacs, capillaries, lymph vessels, & body cavities

diffusion, cushioning

SIMPLE CUBOIDAL

a single layer of cube-shaped cells with large centrally located nuclei

linings of kidney tubules, ducts of glands

absorption,secretion

SIMPLE COLUMNAR

single layer of tall cells with basally located nuclei, goblet cells

lining of digestive tractprotection,absorption,secretion

PSEUDO-STRATIFIEDCOLUMNAR

a single layer of tall cells with scattered nuclei, cilia, & goblet cells

lining of trachea,lining of fallopian tube

protection, secretion

STRATIFIEDSQUAMOUS

many layers of flattened cells

keratinized = epidermis;non-keratinized = lining of vagina, anus, mouth

protection

TRANSITIONAL several layers of cells; change shape

lining of urinary bladder and ureters

distensibility

GLANDULAR simple cuboidal lining the ducts of glands secretion

Simple Squamous Epithelium (Fig. 5.1)

It consists of a single layer of thin, flat cells that fit tightly.

Simple Squamous Epithelium

• consists of a single layer of thin, flat cells that fit tightly.

• functions in filtration, diffusion, osmosis, and covers surfaces.

• found in air sacs of the lung, walls of capillaries, lines blood vessels, and covers the membranes that line body cavities.

* Since it is only one layer of cells and very thin it allows diffusion of small

molecules unlike stratified squamous epithelium

Simple Cuboidal Epithelium (Fig. 5.2)

It consists of a single layer of cube-shaped cells.

Simple Cuboidal Epithelium

• consists of a single layer of cube-shaped cells.

• functions in secretion and absorption.

• found on the surface of the ovaries, linings of kidney tubules, linings of the ducts of certain glands.

Simple Columnar Epithelium (Fig. 5.3)

It is a single layer of elongated, column-shaped cells.

Simple Columnar Epithelium

• single layer of elongated, column-shaped cells.

• functions in protection, secretion, and absorption and can be ciliated or nonciliated.

• specialized goblet cells secrete mucus.

• found as lining of the uterus, stomach, and intestines.

Pseudostratified Columnar ET (Fig.5.5)

It is a single layer of elongated cells that appears to be more than one layer.

• often ciliated and contains goblet cells.

• functions in protection, secretion, and movement of mucus and cells.

• found lining the respiratory passages, trachea.

Pseudostratified Columnar Epithelium

Stratified Squamous Epithelium (Fig. 5.6)

It consists of many layers of cells with flat cells on the outer layers.

Stratified Squamous Epithelium

• consists of many layers of cells with flat cells on the outer layers.

• functions in protection.

• found in the outer layer of the skin, linings of the oral cavity, throat, vagina, and anal cavity.

* Since it consists of many layers it acts as a barrier which prevents entry of pathogens into the human body through the epithelium

Stratified Cuboidal Epithelium (Fig. 5.7)

It consists of two to three layers of cubed-shaped cells.

Stratified Cuboidal Epithelium

• consists of two to three layers of cubed-shaped cells.

• functions in protection.

• found in the linings of the mammary glands, sweat glands, salivary glands, and pancreas

* see also glandular epithelium, textbook p. 138

Glandular Epithelium

• It is composed of cells that produce and secrete substances.

• Exocrine glands secrete products into ducts.

• Endocrine glands secrete products into tissue fluid or blood.

* A unicellular exocrine gland is the mucous-secreting goblet cell.

Stratified Columnar Epithelium (Fig. 5.8)

It consists of a top layer of elongated cells, and lower layers of cube-shaped cells.

Stratified Columnar Epithelium

• consists of a top layer of elongated cells, and lower layers of cube-shaped cells.

• functions in protection and secretion.

• found in the vas deferens, part of the male urethra, and parts of the pharynx.

Transitional Epithelium (Fig. 5.9a)

It consists

of many layers of cube-shaped and elongated cells.

Transitional Epithelium

• It consists of many layers of cube-shaped and elongated cells.

• functions in distensibility and protection.

• found in the inner lining of the urinary bladder, ureters and part of the urethra.

Glandular Epithelium

• It is composed of cells that produce and secrete substances.

• Exocrine glands secrete products into ducts.

• Endocrine glands secrete products into tissue fluid or blood.

* A unicellular exocrine gland is the mucous-secreting goblet cell.

e

Multicellular Glands (Fig. 5.10)

Simple glands communicatewith the surface through one unbranched duct.

Multicellular Glands

• Simple glands communicate with the surface through one unbranched duct.

• A compound gland communicates with the surface through a branched duct.

• Tubular glands are epithelial-lined tubes.

• Alveolar (acinar) glands have saclike endings.

Glandular Secretion (Fig. 5.11)

Merocrine glands release fluid through exocytosis. Ex: salivary glands.

• Apocrine glands release cellular product by pinching off the free end of the cell. Ex: mammary glands.

Glandular Secretion (Fig. 5.11)

Glandular Secretion (Fig. 5.11)

• Holocrine glands secrete the entire cell full of the secretory product. Ex: sebaceous glands.

Merocrine Secretion

• Most exocrine glands are merocrine.

• There are two types of merocrine cells, serous and mucous:

Serous fluid is watery with a high enzyme concentration.

Mucous cells secrete a mucus, a thick fluid rich in the glycoprotein, mucin.

Connective Tissues (CT)

• Connective tissue is the most abundant tissue in the body.

• Extracellular material, a matrix, makes up the bulk of the tissue.

• Matrix is composed of fibers and ground substance.

• Connective tissue cells usually can divide.

NAME DESCRIPTION LOCATION FUNCTION

MESENCHYME precursor matrix Embryo gives rise to all other CT’s

AREOLAR gel-like matrix with fibroblasts, collagen and elastic fibers

beneath ET (serous membranes around organs & lining cavities)

cushions, diffusion, inflammation

ADIPOSE closely packed adipocytes with nuclei pushed to side

beneath skin, breasts, around kidneys & eyeballs

insulation, energy store, protection

RETICULAR reticular net of fibers in loose matrix; lymphocytes and reticulocytes

basement membrane,lymph organs

support

DENSEREGULAR

dense matrix of collagen fibers

tendons, ligaments attachment (high tensile strength)

DENSEIRREGULAR

loose matrix of collagen fibers

dermis of skin tensile strength

ELASTIC CT matrix of elastic fibers lung tissue, wall of aorta durability with stretch

HYALINECARTILAGE

chondrocytes in lacunae in amorphous matrix

embryo skeleton, costal cartilage, tip of nose, trachea, larynx

support

FIBRO-CARTILAGE

less firm than above intervertebral discs, pubic symphysis

tensile strength, shock absorber

ELASTICCARTILAGE

above plus elastic fibers external ear, epiglottis shape maintenance plus flexibility

BONE concentric circles of calcified matrix

bones support, protection, movement, Ca ++ store, hematopoiesis

BLOOD red and white cells; platelets in plasma

in heart, and blood vessels transport of nutrients, wastes & gases

CT Cell Types

• Fibroblasts secrete protein into the matrix, usually collagen which is a fibrous protein resulting in fibers.

Figure 5.13

CT Cell Types

• Macrophages originate as white blood cells. They can move and phagocytize foreign particles.

Figure 5.14

CT Cell Types

• Mast cells or basophils release heparin, which prevents blood clotting, and histamine, which aids in the inflammatory response.

Figure 5.15

CT Fibers (Fig. 5.16)

• White collagenous fibers, are made of thick threads of collagen. They are strong, flexible, and inelastic.

• Elastic fibers, yellow fibers, are made of bundles of elastin.

• Reticular fibers are thin,collagenous fibers that form branched networks for support.

Loose CT (Fig. 5.18)

• Loose CT or areolar tissue binds organs together and holds tissue fluids.

Loose Connective Tissue

• Loose CT or areolar tissue binds organs together and holds tissue fluids.

• It consists of cells (fibroblasts) in a fluid-gel matrix.

• It forms thin membranes found beneath the skin, between muscles, and beneath epithelial tissue.

Adipose Tissue

• Adipose tissue protects, insulates, and stores fat in droplets inside the cells.

Figure 5.19

Adipose Tissue

• Adipose tissue protects, insulates, and stores fat in droplets inside the cells.

• It consists of cells (adipocytes) in a fluid-gel matrix.

• It is found beneath the skin, around the kidneys, behind the eyes, and on the heart.

Reticular Connective Tissue

• Reticular connective tissue supports organs.

Figure 5.20

Reticular Connective Tissue

• Reticular connective tissue supports organs.

• It is composed of thin, collagenous fibers and cells in a fluid-gel matrix.

• It is found in the walls of the liver, spleen, and lymphatic organs.

Dense Connective Tissue

• Dense connective tissue binds organs together.

Figure 5.21

Dense Connective Tissue

• Dense connective tissue binds organs together.

• It is composed thick collagenous fibers, thin elastic fibers and fibroblasts in a fluid-gel matrix.

• It is found in tendons, ligaments, and the dermis of the skin.

Elastic Connective Tissue

• Elastic connective tissue supports, protects, and provides a flexible framework.

Figure 5.22

Elastic Connective Tissue

• Elastic connective tissue supports, protects, and provides a flexible framework.

• It consists of elastic fibers and fibroblasts in a solid-gel matrix.

• It connects vertebrae and is found in the walls of arteries and airways.

Cartilage, a CT

• Cartilage is a rigid connective tissue.

• The matrix consists of collagenous fibers in a gel-like ground substance.

• Cartilage cells, chondrocytes, are found in small chambers, lacunae.

• Cartilage is covered with a thin layer of CT, the perichondrium.

• Cartilage lacks blood vessels.

Hyaline Cartilage

• It supports, protects, and provides a framework.

• It is the most common type of cartilage.

Figure 5.23

Hyaline Cartilage

• It supports, protects, and provides a framework.

• It is the most common type of cartilage.

• It is found in the ends of bones, nose, and rings in the respiratory passages.

• Hyaline cartilage provides the embryonic model for the skeleton.

Elastic Cartilage

• It supports, protects, and provides a flexible framework.

Figure 5.24

Elastic Cartilage

• It supports, protects, and provides a flexible framework.

• Its matrix contains many elastic fibers.

• It is found in the outer ear and part of the larynx.

Fibrocartilage

• It supports, protects, and absorbs shock during body movement.

Figure 5.25

Fibrocartilage

• It supports, protects, and absorbs shock during body movement.

• It is the toughest type of cartilage.

• It is found between the vertebrae (intervertebral discs), in the knee and parts of the pelvic girdle.

Bone• Bone

supports, protects, provides a framework for muscle attachment.

Figure 5.26

Bone

Bone

• Bone supports, protects, provides a framework for muscle attachment.

• It is composed of cells (osteocytes) in a hard calcified matrix. The osteocytes are located in layers, lamellae, organized into osteons.

• It is found in the skeleton and middle ear.

Blood

• Blood transports gases, nutrients, and wastes, defends against disease, and acts in clotting. Figure 5.27

Blood

• Blood transports gases, nutrients, and wastes, defends against disease, and acts in clotting.

• It is composed of cells and platelets in a fluid matrix, the blood plasma.

• It is found within the blood vessels.

Muscle Tissue (MT)

There are three types of muscle tissue:

skeletal, smooth, and cardiac.

Properties:

• It is contractile (muscle fibers can shorten and thicken).

• It is excitable.

MUSCLETISSUE

DESCRIPTION OFSTRUCTURE

TYPE OFCONTROL

LOCATION FUNCTION

SKELETALMUSCLE

long, thin fibers with many nuclei and striations

voluntary attached to bones

to move bones

SMOOTHMUSCLE

spindle shaped cells with one centrally located nucleus, lacking striations

involuntary walls of visceral hollow organs, irises of eyes, walls of blood vessels

to move substances through passageways (i.e. food, urine, semen),constrict blood vessels, etc

CARDIAC MUSCLE

a network of striated cells with one centrally located nucleus attached by intercalated discs

involuntary heart pump blood to lungs and body

Skeletal Muscle

• It attaches to bones and is controlled by conscious effort.

• It is also called voluntary muscle.

Figure 5.28

Skeletal Muscle

• It attaches to bones and is controlled by conscious effort.

• It is also called voluntary muscle.

• The muscle cells have many nuclei and exhibit light and dark banding patterns called striations.

• Skeletal muscles contract in response to nerve signals.

Smooth Muscle

• It appears smooth because it lacks striations.

• Smooth muscle action is not under conscious control and it is called involuntary. Figure 5.29

Smooth Muscle

• It appears smooth because it lacks striations.

• Smooth muscle action is not under conscious control and it is called involuntary.

• The cells are spindle-shaped with a central nucleus.

• Smooth muscle is found in the stomach, intestines, uterus, and blood vessels.

Cardiac Muscle

• Cardiac muscle tissue is found only in the heart.

Figure 5.30

Cardiac Muscle

• It is found only in the heart.

• The striated cells are joined end to end with a specialized intercellular junction called an intercalated disk.

• Cardiac muscle is under involuntary control.

Nervous Tissue (NT)

• It is excitable, but not contractile.

Figure 5.31

Nervous Tissues• Nervous tissue is excitable like muscle tissue.

• It is found in the brain, spinal cord, and peripheral neurons.

• Nerve cells or neurons sense changes and transmit signals.

• Neuroglia are cells that support and bind nervous tissue. They supply nutrients, carry on phagocytosis, and play a role in cell to cell communication.

Epithelial Membranes

• They consist of two tissues: a thin, sheet like epithelial tissue (ET) that covers body surfaces together with the underlying connective tissue (CT).

• Two or more types of tissues with differing function form an organ. Epithelial membranes are organs.

• There are three types of EM:

Serous / Mucous / Cutaneous

• Serous membranes line body cavities that lack an opening to the outside. They line the thorax and the abdomen.

• Mucous membranes line cavities and tubes that open to the outside, including nose, mouth, digestive, urinary, respiratory, and reproductive systems openings.

• The cutaneous membrane or skin is an organ of the integumentary system (Ch.6).

Epithelial Membranes