Albia Dugger • Miami Dade College

Cecie StarrChristine EversLisa Starr

www.cengage.com/biology/starr

Chapter 28Animal Tissues and

Organ Systems(Sections 28.4 - 28.6)

28.4 Connective Tissues

• Connective tissues “connect” tissues to one another, both functionally and structurally

• Different types bind, organize, support, strengthen, protect, and insulate other tissues

• connective tissue • Animal tissue contain cells scattered within an extracellular

matrix of their own secretions• Provides structural and functional support

Connective Tissues

• Connective tissues are described by the types of cells that they include and the composition of their extracellular matrix

• There are two types of soft connective tissues: loose and dense, which have the same components but differ in the proportions

• Cartilage, bone tissue, adipose tissue, and blood are classified as specialized connective tissues

Soft Connective Tissues

• In soft connective tissues, the most abundant cells are fibroblasts, cells that secrete complex carbohydrates and fibers of the structural proteins collagen and elastin

• The most common type of connective tissue in the vertebrate body is loose connective tissue

• loose connective tissue • Relatively few fibroblasts and fibers in its matrix• Holds organs and epithelia in place

Loose Connective Tissue

• Fibroblasts and other cells scattered in a soft matrix with relatively few fibers

• Common Locations: Beneath skin and most epithelia

• Functions: Elasticity, diffusion

Fig. 28.8a, p. 454

collagen fiber

elastic fiber

fibroblast

Loose Connective Tissue

A Loose connective tissueFibroblasts and other cells scattered in a squishy matrix with relatively few fibers

Common Locations Beneath skin and most epithelia

Functions Elasticity, diffusion

Soft Connective Tissues (cont.)

• Dense connective tissues include dense, irregular connective tissue, and dense, regular connective tissue

• dense, irregular connective tissue • Asymmetrically arranged fibers and fibroblasts• Forms deep skin layers, capsules around organs

• dense, regular connective tissue • Fibroblasts in rows between parallel fibers • Tendons and ligaments

Dense, Irregular Connective Tissue

• Fibroblasts in semisolid matrix with many loosely interwoven collagen fibers

• Common Locations: In skin and in capsules around some organs

• Function: Structural support

Fig. 28.8b, p. 454

collagen fibers

Dense, Irregular Connective Tissue

B Dense, irregular connective tissue Fibroblasts in a semisolid matrix with many loosely interwoven collagen fibers

Common Locations In skin and in capsules around some organs

Function Structural support

Dense, Regular Connective Tissue

• Fibroblasts in rows between tight parallel bundles of many collagen Fibers

• Common Locations: Tendons, ligaments

• Functions: Strength, elasticity

Fig. 28.8c, p. 454

collagen fibers

fibroblast

Dense, Regular Connective Tissue

C Dense, regular connective tissue Fibroblasts in rows between tight parallel bundles of many collagen fibers

Common Locations Tendons, ligaments

Functions Strength, elasticity

Specialized Connective Tissues

• Cartilage is found in shark skeletons, human embryos (forms a model for the developing skeleton) , and in adults (in joints, between vertebrae, and in support structures)

• cartilage • Cells surrounded by a rubbery matrix of collagen fibers

and rubbery, compression-resistant glycoproteins• Blood vessels do not extend through cartilage

Cartilage• Chondrocytes and

collagen fibers in a rubbery matrix

• Common Locations: Nose, ends of long bones, airways, vertebrate embryo

• Functions Support, protection, low-friction joint surfaces

Fig. 28.8d, p. 454

glycoprotein-rich matrix with fine collagen fibers

cartilage cell (chondrocyte)

Cartilage

D Cartilage Chondrocytes and collagen fibers in a rubbery matrix

Common Locations Nose, ends of long bones, airways, skeleton of carti-laginous fish, vertebrate embryo

Functions Support, protection, low-friction surface for joint movements

Specialized Connective Tissues (cont.)

• Adipose tissue is the body’s main energy reservoir, cushions and protects body parts, and a layer under the skin insulates the body to keep internal temperature within an optimal range

• adipose tissue • Connective tissue specializing in fat storage • Small blood vessels carry fats to and from cells

Adipose Tissue• Large, tightly packed fat

cells with little extracellular matrix

• Common Locations: Under skin, around the heart and the kidneys

• Functions: Energy storage, insulation, padding

Fig. 28.8e, p. 455

cell bulgingwith fatdroplet

nucleus

Adipose Tissue

E Adipose tissue Large, tightly packed fat cells with little extra-cellular matrix

Common Locations Under skin, around the heart and the kidneys

Functions Energy storage, insu-lation, padding

Specialized Connective Tissues (cont.)

• Bone tissue is the main tissue of bones, which support and protect the body, and allow movement

• Blood cells form in the spongy interior of some bones

• bone tissue • Living cells surrounded by a mineral-hardened matrix of

their own calcium-hardened secretions

Bone Tissue• Collagen fibers,

osteocytes in chambers inside an extensive, calcium-hardened extracellular matrix

• Location: All bony vertebrate skeletons

• Functions: Movement, support, protection

Fig. 28.8f, p. 455

bone cell (osteocyte)

compact bone tissue

blood vessel

Bone Tissue

F Bone tissue Collagen fibers, osteocytes in chambers inside an extensive, calcium-hardened extracellular matrix

Location All bony vertebrate skeletons

Functions Movement, support, protection

Specialized Connective Tissues (cont.)

• Blood consists plasma and cellular components that form inside bones

• blood fluid • Red blood cells transport oxygen• White blood cells defend the body against pathogens• Platelets function in clot formation• Plasma is a fluid extracellular matrix consisting mostly of

water, with dissolved proteins, nutrients, gases, and other substances

Blood• Protein-rich fluid

plasma with cellular components

• Location: Inside blood vessels

• Functions: Distributes essential gases, nutrients; removes waste

Fig. 28.8g, p. 455

white blood cell

platelet

red blood cell

Plasma

Blood

G Blood Protein-rich fluid plasma with cellular components

Location Inside blood vessels

Functions Distributes essential gases, nutrients; removes waste

ANIMATION: Soft connective tissues

To play movie you must be in Slide Show ModePC Users: Please wait for content to load, then click to play

Mac Users: CLICK HERE

ANIMATION: Specialized connective tissues

To play movie you must be in Slide Show ModePC Users: Please wait for content to load, then click to play

Mac Users: CLICK HERE

28.5 Muscle Tissues

• Muscle tissues contract (shorten) when stimulated – they help move the body and its component parts

• Vertebrates have three types of muscle tissue: skeletal, cardiac, and smooth muscle tissues

• Each type has unique properties that reflect its functions

Key Terms

• skeletal muscle tissue • Muscle that interacts with bone to move body parts; under

voluntary control

• cardiac muscle tissue • Muscle of the heart wall

• smooth muscle tissue • Muscle that lines blood vessels and forms the wall of

hollow organs

Skeletal Muscle• Long, multinucleated,

cylindrical cells with conspicuous striping (striations)

• Interacts with bone to bring about movement, maintain posture

• Reflex activated, but also under voluntary control

Fig. 28.9a, p. 456

nucleus

A Skeletal muscle • Long, multinucleated, cylindrical

cells with conspicuous striping (striations)

• Interacts with bone to bring about movement, maintain posture

• Reflex activated, but also under voluntary control

Skeletal Muscle

Cardiac Muscle

• Striated cells attached end to end, each with a single nucleus

• Found only in the heart wall

• Contraction is not under voluntary control

Fig. 28.9b, p. 456

B Cardiac muscle • Striated cells attached end to

end, each with a single nucleus • Found only in the heart wall • Contraction is not under

voluntary control

nucleus

adjoining ends of abutting cells

Cardiac Muscle

Smooth Muscle• Cells with a single

nucleus, tapered ends, and no striations

• Found in walls of some blood vessels, digestive tract, reproductive tract, bladder, and other hollow organs

• Contraction is not under voluntary control

Fig. 28.9c, p. 456

nucleus

C Smooth muscle • Cells with a single nucleus,

tapered ends, and no striations • Found in the walls of some blood

vessels, the digestive tract, the reproductive tract, the bladder, and other hollow organs

• Contraction is not under voluntary control

Smooth Muscle

ANIMATION: Muscle tissues

To play movie you must be in Slide Show ModePC Users: Please wait for content to load, then click to play

Mac Users: CLICK HERE

28.6 Nervous Tissue

• Nervous tissue consists of specialized signaling cells (neurons) and the cells that support them (neuroglia)

• nervous tissue • Animal tissue composed of neurons and supporting cells• Detects stimuli and controls responses to them

• neuron • One of the cells that make up communication lines of

nervous systems

Neuron Structure

• A neuron has a cell body with a nucleus and other organelles

• Projecting from the cell body are long cytoplasmic extensions that allow the cell to receive and send electrochemical signals

• Neuroglial cells wrap around the signal-sending cytoplasmic extensions of most motor neurons – they act as insulation and speed the rate at which signals travel

A Motor Neuron

Fig. 28.10, p. 457

neuroglial cell wrapped around a signal-sending cytoplasmic extension of the neuron

signal-sending extension

cell body of neuron

signal receiving extensions

A Motor Neuron

Neuron Function

• Neurons in nervous tissue make up communication lines through the body

• Different kinds detect, integrate, and assess information about internal and external conditions, and deliver commands to muscles and glands that carry out responses

• A neuron transmits electrical signals along its plasma membrane, and communicates with other cells through chemical messages

Three Types of Neurons

• Sensory neurons are excited by specific stimuli, such as light or pressure

• Interneurons receive and integrate sensory information• Store information and coordinate responses to stimuli• In vertebrates, interneurons occur mainly in the brain and

spinal cord

• Motor neurons relay commands from the brain and spinal cord to glands and muscle cells

Interaction Between Nerves and Muscle

• Interneurons in the lizard’s brain are stimulated by the sight of a tasty fly – signals flow from the interneurons along motor neurons to tongue muscles

Key Concepts

• Animal Tissues • Epithelial tissues cover external surfaces and line cavities

and tubes • Connective tissues bind, support, strengthen, protect, and

insulate other tissues • Contraction of muscle tissue moves body parts • Nervous tissue provides local and long-distance lines of

communication

ANIMATION: Functional zones of a motor neuron

To play movie you must be in Slide Show ModePC Users: Please wait for content to load, then click to play

Mac Users: CLICK HERE