Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies The Animal Body...

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

The Animal Body and How It Moves

Chapter 22

Copyright © McGraw-Hill Companies Permission required for reproduction or display


Outline

• Animal Body Plan• Vertebrate Body Organization• Vertebrate Organ Systems• Epithelium• Connective Tissue• Muscle Tissue• Nerve Tissue• Skeletal System

Bones and Muscles


Radial Versus Bilateral Symmetry

• Radial Symmetry - body parts are arranged around a central axis.

• Bilateral Symmetry - body has a right and left half that are mirror images of each other. Allows different organs to be located in

different parts of the body. Allows for more efficient movement. Allows for cephalization - evolution of

definite head and brain area.


Body Cavity Versus No Cavity

• Presence of body cavity allows dramatic expansion of portions of digestive tract. Allows for more storage and time for

enzymatic activity for enhanced digestion.- Allows animals to eat more during safe

periods. Allows space for gonad expansion.

- Diverse breeding strategies.


Body Cavity Versus No Cavity

• Kinds of Body Cavities Acoleomates - No body cavity. Pseudocoelomate - Body cavity located

between endoderm and mesoderm. Coelomates - Body cavity forms entirely

within mesoderm.


Nonsegmented Versus Segmented Bodies

• Advantages of early embryonic segmentation: Each segment may develop a more or less

complete set of adult organ systems. Locomotion is more effective because of

increased flexibility.


Protostomes Versus Deuterstomes

• Deuterstomes evolved from protostomes more than 630 mya. Differ fundamentally in three aspects of embryonic growth. Cleavage Blastophore determination of body axis Developmental fate of embryo


Vertebrate Body Organization

• General Architecture Food flows from in tube from mouth to anus.

- Suspended in coelom, divided into: Thoracic cavity (heart and lungs) Abdominal cavity (stomach intestines)

- Supported by skeleton made up of jointed bones.

- Skull protects brain.- Vertebral column protects spinal cord.



• Tissues Cells of same type organized into tissues. Three fundamental layers

- Endoderm- Mesoderm- Ectoderm



• Adult tissues grouped into four general classes: Epithelial Connective Muscle Nerve



• Organs Body structures composed of several

different tissues grouped together into a larger structural and functional unit.

• Organ Systems Group of organs that work together to carry

out important function.


Vertebrate Organ Systems

• Skeletal Bones, Skull, Cartilage, Ligaments

• Circulatory Heart, Blood Vessels, Blood

• Endocrine Pituitary, Adrenal, Thyroid Glands

• Nervous Nerves, Brain, Spinal Cord



• Respiratory Lungs, Trachea

• Immune Lymphocytes, Macrophages, Antibodies

• Digestive Mouth, Esophagus, Stomach, Intestines,

Liver, Pancreas• Urinary

Kidneys, Bladder



• Muscular Skeletal, Cardiac, and Smooth Muscle

• Reproductive Testes, Ovaries

• Integumentary Skin, Hair, Nails, Sweat Glands


Epithelium

• Outside of body covered with cells developed from embryonic ectoderm tissue.

• Body cavity lined with cells developed from embryonic mesoderm tissue.

• Hollow inner core of digestive tract lined with cells developed from embryonic endoderm tissue.

• Collectively termed epithelium.


Epithelium

• Epithelium Functions: Protect tissues from dehydration and

mechanical damage. Provide sensory surfaces. Secrete materials.

• Types of Epithelial Cells: Squamous Cubodial Columnar


Epithelium

• Three general kinds of Epithelial Tissue: Simple Epithelium

- Single cell layer thick - lining lungs and major body cavities.

Stratified Epithelium- Complex layer of cells - skin.

Glands- Secretion


Connective Tissue

• Connective tissue cells fall into three functional categories: Immune System - Defense Skeletal System - Support Blood and Fat - Storage and Distribution

• Immune System Macrophages - Engulf and digest invaders. Lymphocytes - Produce antibodies and

attack virus-infected cells.


Connective Tissue

• Skeletal Connective Tissue Fibroblasts - Secrete structurally strong

proteins into spaces between cells. Cartilage - Collagen matrix forms long

parallel arrays along lines of stress. Bone - Collagen fibers coated with calcium

phosphate.


Connective Tissue

• Storage and Transport Connective Tissues Adipose Tissue - Fat accumulating cells. Erthrocytes - Red blood cells that transport

oxygen and carbon dioxide in blood.- Move in plasma.


Muscle Tissue

• Distinguishing characteristics of muscle cells is abundance of contractible protein fibers (Microfilaments). Shortening of fibers produces considerable

force.• Kinds of Muscle Cells

Smooth - Microfilament loosely organized. Skeletal and Cardiac - Microfilaments

bunched into myofibrils (Striated Muscle).


Nerve Tissue

• Composed of two types of cells: Neurons - Specialized for transmission of

nerve impulses. Glial Cells - Supply neurons with nutrients,

support, and insulation.• Neuron plasma membranes are rich in ion-

selective channels that maintain voltage difference between cell interior and exterior.


Nerve Tissue

• Each neuron composed of: Cell Body - Contains nucleus. Dendrites - Bring nerve impulses to cell. Axon - Carries nerve impulses away.

- Nerve is made of axons of many neurons.• Gaps (synapses) separate neurons.• Neurons communicate by passing

neurotransmitters across the gap.



Types of Skeletons

• Hydraulic - Fluid-filled cavity encircled by muscle fibers.

• Exoskeletons - Rigid hard case surrounding body.

• Endoskeletons - Rigid internal skeleton.


Types of Skeletons

• Human Skeleton Made up of 206 individual bones.

- Axial Skeleton (80 bones) support main body axis.

Skull, Backbone, and Rib Cage.- Appendicular Skeleton (126 bones)

support arms and legs. Pectoral girdle Pelvic girdle



Structure of Bone

• Bone is produced when needle-shaped crystals surround and impregnate collagen fiber. Outer bone layer is dense and compact

(compact bone). Interior of bone is open lattice structure

(spongy bone).


Structure of Bone

• New Bone Formed in Two Stages: Collagen secreted by osteoblasts which

lay down matrix of fibrils. Calcium minerals impregnate fibrils.

- Layers form as series of tubes around narrow central channel (Haversian Channel) running parallel to length of bone.


Structure of Bone

• Two cell types responsible for bone remodeling during growth: Osteoblasts - Deposit bone. Osteoclasts - Secrete enzymes that digest

organic matrix of bone, liberating calcium for reabsorption.

• Osteoporosis - Excessive bone loss usually associated with aging.


Bone Structure


Kinds of Muscle

• Skeletal Muscle - Move bones of the skeleton. Each muscle fiber consists of many

elongated myofibrils, in turn composed of many myofilaments.

- Contains protein filaments actin and myosin.

• Cardiac Muscle - Composed of chains of single cells organized into fibers that branch and interconnect. Coupled by gap junctions.


Kinds of Muscle

• Smooth Muscle - Contain long, spindle-shaped cells. Individual myofilaments are not aligned into orderly assemblies, but into sheets. Some contract only when stimulated by a

nerve or hormone.


Kinds of Muscle

• Tendons Straps of densely connective tissue

attaching muscles to bones. Bones pivot about flexible joints, pulled back

and forth by muscles.- Origin attached by tendon to stationary

bone.- Insertion attached to bone that moves

during muscle contraction.


Skeletal Muscle Organization


Skeletal Muscle Organization

• Muscles in movable joints of vertebrates are attached in opposing pairs: Flexors and Extensors


How Muscles Work

• When myosin filaments contract heads of myosin filaments move first, moving them closer in the direction of the flex.


How Muscles Work

• Nerve fibers embedded in surface of muscle fiber forming neuromuscular junction. When signal reaches end of neuron,

neuron releases acetylcholine into gap separating neuron from muscle.

- Depolarization



How Muscles Work

• Role of Calcium Ions in Contraction When muscle is relaxed, attachment sites

for myosin heads are physically blocked by tropomyosin.

- In order to contract a muscle, troponin must move tropomyosin.

Complex regulated calcium ion concentration.

Muscle fibers store Ca++ in sarcoplasmic reticulum.


Calcium Controls Muscle Contraction


Review

• Animal Body Plan• Vertebrate Body Organization• Vertebrate Organ Systems• Epithelium• Connective Tissue• Muscle Tissue• Nerve Tissue• Skeletal System

Bones and Muscles


Copyright © McGraw-Hill Companies Permission required for reproduction or

display

Date post:	27-Mar-2015
Category:	Documents
Upload:	madeline-stanley
View:	213 times
Download:	1 times

Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies The Animal Body...

Documents