Albia Dugger Miami Dade College Cecie Starr Christine Evers Lisa Starr Chapter 28 Animal Tissues and Organ Systems (Sections )

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 tissue Fibroblasts 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 bulging with fat droplet 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 Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERECLICK HERE

ANIMATION: Specialized connective tissues To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERECLICK 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 Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERECLICK 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 , 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 Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERECLICK HERE