Chapter 23: The Animal Body and How It Moves Lecture Outline PDF

Because learning changes everything. ® Chapter 23 The Animal Body and How It Moves Lecture Outline Essentials of the Living World Seventh Edition George Johnson, Joel Bergh © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGr...

Because learning changes everything. ® Chapter 23 The Animal Body and How It Moves Lecture Outline Essentials of the Living World Seventh Edition George Johnson, Joel Bergh © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  23.1 Organization of the Vertebrate Body 1 All vertebrates have the same general architecture: a long internal tube that extends from mouth to anus, which is suspended within an internal body cavity called the coelom. The coelom of many terrestrial vertebrates is divided into two parts. Thoracic cavity contains the heart and lungs. Abdominal cavity contains the stomach, intestines, and liver. © McGraw Hill, LLC 2  23.1 Organization of the Vertebrate Body 2 A tissue is a group of cells of the same type that performs a particular function. There are four general classes of tissues. Epithelial. Connective. Muscle. Nerve. © McGraw Hill, LLC 3  Figure 23.1: Vertebrate tissue types Access the text alternative for slide images. © McGraw Hill, LLC 4  23.1 Organization of the Vertebrate Body 3 Organs are body structures comprised of several different tissues grouped together into a larger structural and functional unit. An organ system is a group of organs that work together to carry out an important function. © McGraw Hill, LLC 5  Figure 23.2: Levels of organization within the vertebrate body Access the text alternative for slide images. © McGraw Hill, LLC 6  There Are 11 Principal Organ Systems in the Vertebrate Body Skeletal. Digestive. Circulatory. Urinary. Endocrine. Muscular. Nervous. Reproductive. Respiratory. Integumentary. Immune. © McGraw Hill, LLC 7  23.2 Epithelium Is Protective Tissue 1 The epithelium functions in three ways. To protect the tissues beneath them from dehydration. To provide sensory surfaces. Many of a vertebrate’s sense organs are modified epithelial cells. To secrete materials. Most secretory glands are derived from pockets of epithelial cells. © McGraw Hill, LLC 8  Figure 23.3: The epithelium prevents dehydration Tim Flach/Getty Images © McGraw Hill, LLC 9  23.2 Epithelium Is Protective Tissue 2 Epithelial cells are classified into three types according to their shapes: squamous, cuboidal, columnar. Layers of epithelial tissue are usually one or two cells thick but the sheets of cells are tightly bound together. Epithelium possesses remarkable regenerative abilities. © McGraw Hill, LLC 10  23.2 Epithelium Is Protective Tissue 3 There are two general kinds of epithelial tissue. Simple epithelium is only one cell layer thick and is important for exchanging materials across it. Stratified epithelium is multiple cell layers in thickness and provides for cushioning and protection. Found in the skin, it is continuously replaced. © McGraw Hill, LLC 11  23.2 Epithelium Is Protective Tissue 4 Cuboidal epithelium has a secretory function and often forms glands. Endocrine glands secrete hormones into the blood. Exocrine glands have ducts that open to the body’s outside. Secrete sweat, milk, saliva, and digestive enzymes. © McGraw Hill, LLC 12  23.3 Connective Tissue Carries Out Various Functions 1 Connective tissue cells fall into three functional categories. Defense (cells of the immune system). Support (cells of the skeletal system). Transport and storage (blood and fat cells). All connective tissues share a common structural feature. They have an abundant extracellular material, called the matrix, between widely spaced cells. © McGraw Hill, LLC 13  23.3 Connective Tissue Carries Out Various Functions 2 Immune cells roam the body within the bloodstream and hunt invading microorganisms and cancer cells. There are two kinds of immune cells. Macrophages that engulf and digest invaders. Lymphocytes that attack virus-infected cells or make antibodies. These cells are collectively known as “white blood cells.” © McGraw Hill, LLC 14  23.3 Connective Tissue Carries Out Various Functions 3 There are three kinds of skeletal connective tissue. Fibrous connective tissue: Made of cells called fibroblasts that secrete structural proteins in the spaces between the cells. Collagen protein is an example. Cartilage: Cartilage is firm but flexible due to its configuration of collagen. Bone: Bone is stronger than cartilage because the collagen is coated with calcium phosphate salt, making the tissue rigid. © McGraw Hill, LLC 15  Figure 23.4: Cartilage—Skeletal connective tissue Richard Carey/Alamy Stock Photo © McGraw Hill, LLC 16  23.3 Connective Tissue Carries Out Various Functions 4 Some connective tissue cells are specialized to accumulate and transport particular molecules. Adipose tissue is made up of fat-accumulating cells. Erythrocytes are red blood cells that transport and store. © McGraw Hill, LLC 17  23.3 Connective Tissue Carries Out Various Functions 5 The vertebrate endoskeleton is strong because of the structural nature of bone. Bone is a dynamic tissue that is constantly being reconstructed. The outer layer of bone is very dense and compact and called compact bone. The interior of bone has a more open lattice structure and is called spongy bone. Red blood cells form in the marrow of spongy bone. © McGraw Hill, LLC 18  23.3 Connective Tissue Carries Out Various Functions 6 New bone is formed in two stages. First, osteoblasts lay down collagen fibers along lines of stress. Then calcium minerals impregnate the fibers. Bone is laid down in thin, concentric layers. The layers form as a series of tubes around a narrow central channel called a central canal (Haversian canal). © McGraw Hill, LLC 19  Figure 23.5: The structure of bone Access the text alternative for slide images. © McGraw Hill, LLC 20  23.3 Connective Tissue Carries Out Various Functions 7 There is dynamic bone “remodeling” going on all the time. Osteoblasts deposit bone while osteoclasts break down bone and release calcium. As a person ages, the backbone and other bones tend to decline in mass. Excessive bone loss is a condition called osteoporosis. © McGraw Hill, LLC 21  Figure 23.6: Osteoporosis (a) Science Photo Library/Alamy Stock Photo; (b) Pasieka/Science Source © McGraw Hill, LLC 22  23.4 Muscle Tissue Lets the Body Move 1 Muscle cells are the motors of the vertebrate body. They have many contractible proteins fibers, called myofilaments, inside of them. The proteins actin and myosin make up the myofilaments. There are three different kinds of muscle in vertebrates. Smooth muscle. Skeletal muscle. Cardiac muscle. © McGraw Hill, LLC 23  23.4 Muscle Tissue Lets the Body Move 2 Smooth muscle cells are long and spindle-shaped. Each cell contains a single nucleus. Smooth muscle is organized into sheets of cells. Smooth muscle is found in areas such as the walls of blood vessels and the gut. © McGraw Hill, LLC 24  23.4 Muscle Tissue Lets the Body Move 3 Skeletal muscle moves the bones of the skeleton. Skeletal muscle cells form by the fusion of several cells to form one very long fiber with the nuclei pushed out to the periphery of the cytoplasm. Each muscle fiber consists of many elongated myofibrils composed of actin and myosin. © McGraw Hill, LLC 25  Figure 23.8: A skeletal muscle fiber, or muscle cell Access the text alternative for slide images. © McGraw Hill, LLC 26  23.4 Muscle Tissue Lets the Body Move 4 Cardiac muscle is comprised of chains of cells. These chains are organized into fibers that branch and interconnect to form a network. Electrical impulses can pass from cell to cell across small openings called gap junctions. This causes the heart to contract in an orderly fashion. © McGraw Hill, LLC 27  23.5 Nerve Tissue Conducts Signals Rapidly 1 Nerve cells carry information rapidly throughout the body. Nerve tissue is comprised of two types of cells. Neurons are specialized for transmitting nerve impulses. Glial cells are supporting cells that supply neurons with nutrition, support, and insulation. © McGraw Hill, LLC 28  23.5 Nerve Tissue Conducts Signals Rapidly 2 Each neuron is comprised of three parts. A cell body that contains the nucleus. Dendrites that extend from the cell body and act as antennae to receive nerve impulses. An axon that is a single, long extension which carries nerve impulses away from the body. Some axons can be quite long. © McGraw Hill, LLC 29  Figure 23.9: Neurons carry nerve impulses Access the text alternative for slide images. © McGraw Hill, LLC 30  23.5 Nerve Tissue Conducts Signals Rapidly 3 There are three general types of neurons. Sensory neurons: Carry electrical impulses from the body to the central nervous system. Motor neurons: Carry electrical impulses from the central nervous system to the muscles. Association neurons: Occur within the central nervous system and act as connectors between sensory and motor neurons. © McGraw Hill, LLC 31  Table 23.1: Types of Neurons Access the text alternative for slide images. © McGraw Hill, LLC 32  23.5 Nerve Tissue Conducts Signals Rapidly 4 Neurons are separated by a tiny gap, called a synapse. Communication occurs between neurons when chemical signals, neurotransmitters, are passed across the synapse. © McGraw Hill, LLC 33  23.6 Types of Skeletons 1 Animals are able to move because the opposite ends of their muscles are attached to a rigid scaffold, or skeleton. There are three types of skeletons in animals. Hydraulic skeletons are fluid-filled cavities encircled by muscles that raise the pressure of the fluid when they constrict. Exoskeletons surround the body as a rigid hard case to which muscles attach internally. Endoskeletons are rigid internal skeletons to which muscles are attached. © McGraw Hill, LLC 34  23.6 Types of Skeletons 2 Figure 23.10: Earthworms have a hydraulic skeleton. Maskot/Image Source Figure 23.11: Crustaceans have an exoskeleton. Figure 23.12: Snakes have an endoskeleton. Garry Gay/Getty Images Access the text alternative for slide images. © McGraw Hill, LLC 35  23.6 Types of Skeletons 3 The human skeleton is made up of 206 bones. Axial skeleton: Made up of the skull, backbone, and rib cage. Appendicular skeleton: Made up of the bones of the arms and legs and the girdles where they attach to the axial skeleton. Pectoral girdle forms the shoulder joints. Pelvic girdle forms the hip joints. Bones pivot about flexible connections called joints. © McGraw Hill, LLC 36  Figure 23.13: Axial and appendicular skeletons Access the text alternative for slide images. © McGraw Hill, LLC 37  23.7 Muscles and How They Work 1 Skeletal muscles move the bones of the skeleton. Tendons are straps of dense connective tissue that attach muscles to bone. The origin of the muscle is the end of the muscle attached to a bone that remains stationary during a contraction. The insertion of the muscle is attached to a bone that moves if the muscle contracts. © McGraw Hill, LLC 38  Figure 23.14: The muscular system Access the text alternative for slide images. © McGraw Hill, LLC 39  23.7 Muscles and How They Work 3 The sliding filament model of muscular contraction describes how actin and myosin filaments cause muscles to contract. The head of a myosin filament binds to an actin filament. The myosin filament pulls against the actin filament, causing it to slide inward. Energy from ATP drives the process. © McGraw Hill, LLC 40  Figure 23.16: How myofilament contraction works Access the text alternative for slide images. © McGraw Hill, LLC 41  Figure 23.17: The sliding filament model of muscle contraction The heads on the two ends of the myosin filament are oriented in opposite directions. Thus, as the right-hand end of the myosin filament "walks" along the actin filaments, pulling them and their attached Z line leftward toward the center, the left-hand end of the same myosin filament "walks" along the actin filaments, pulling them and their attached Z line rightward toward the center. The result is that both Z lines move toward the center and contraction occurs. Access the text alternative for slide images. © McGraw Hill, LLC 42