Chapter 43

1. Max Ammendolea Greg Raube Chapter 43 The Animal Body and Principles of Regulation

2. Organization of the Vertebrate Body • There are levels of organization in the vertebrate body -cells -tissues -organs -organ systems

3. Tissues are groups of cells of a single type and function • Early in development, the cells of the growing embryo differentiate into the three fundamental embryonic tissues called germ layers -endoderm -mesoderm -ectoderm • Four principal kinds of tissues in adult vertebrates -epithelial, connective, muscle, and nerve tissue

4. Organs and organ systems provide specialized functions -organs are body structures composed of several different types of tissues that form a structural and functional unit -organ system is a group of organs that cooperate to perform the major activities of the body • The general body plan of vertebrates is a tube within a tube, with internal support • Vertebrates have both dorsal and ventral body cavities -dorsal cavity is cranium and vertebrae -ventral: thoracic (pericardial, pleural) cavity and abdominopelvic (peritoneal) cavity

5. EpithelialTissue • Rows of cells exposed to open area and anchored down by a basement membrane to connective tissue • Three types of epithelial cell structures -squamous, cuboidal, and columnar • Classified as simple or stratified • Function in protection, transport, and secretion -examples?

6. Connective Tissue • All CT are widely spaced apart cells in a matrix of extracellular material • CT function in protecting (bone), support (cartilage), food storage (fat or adipose tissue) • CT can be either proper or special

7. CT Proper May Be Either Loose or Dense • Fibroblast cells produce and secrete the extracellular matrix (collagen and elastin fibers) • Loose CT consists of cells scattered within a matrix that contains a large amount of fluid material and fibers. They provide support, insulation, food storage, and nourishment for epithelium -Adipose tissue is fat tissue • Dense CT has a lot more collagen than Loose CT making it structurally stronger. They provide flexible, strong connections -tendons of muscles

8. Special CT have unique characteristics • Cartilage provides flexible support and is a shock absorber (intervertebral disks) • Bone protects internal organs and provides rigid support for muscle attachment • Blood functions as highway of immune system and primary means of communication between organs

9. Muscle Tissue • Muscles are the motors of the vertebrate body • Three types -skeletal: voluntary, moves the body -smooth: involuntary, control most actions of organs -cardiac: involuntary, controls the heart

10. Nerve Tissue • Composed of nerve cells (neurons) and their supporting cells (neuroglia) that are specialized to produce and conduct electrochemical events (impulses) • Two divisions of the nervous system coordinate activity -central nervous system (CNS): the brain and spinal cord -peripheral nervous system (PNS): nerves and ganglia, collections of neuron cell bodies

11. Overview of the Vertebrate Organ Systems • Organ systems are approached by placing them in the following functional groupings: communication and integration, support and movement, regulation and maintenance, defense, and reproduction and development -Communication and integration sense and respond to the environment (nervous, sensory, and endocrine system) -Skeletal support and movement are vital to all animals (musculoskeletal system) -Regulation and maintenance of the body’s chemistry ensures continued life (digestive, circulatory, respiratory, and urinary) -The body can defend itself from attackers and invaders (integumentary and immune system) -Reproduction and development ensure the continuity of species (reproductive system)

12. Homeostasis • The dynamic constancy of the internal environment • Negative feedback mechanisms keep values within range -hypothalamus is the body’s thermostat • Antagonistic effectors act in opposite directions • Positive feedback mechanisms enhance a change -less common and have specialized functions in body

13. The Evolution of Organ Systems • The digestive system -Sponges flipped their stomachs inside out and ate stuff -earth worms obtained a one way digestive tract -vertebrates developed specialized organs for their digestive tracts

14. The Respiratory System • The respiratory system -fishes have gills and let O2 diffuse in -amphibians breathe in cutaneously and have lungs -reptiles have straight up lungs -birds are weird and have a bunch of air sacs -mammals have well developed lungs

15. The Heart • Fish have a 2 chambered heart • Amphibians have a 3 chambered heart • Reptiles have a 3 and a half chambered heart • Mammals have a 4 chambered heart

16. The Brain • Cephalization and the development of a brain were important steps in animal evolution -the concentration of the nervous system toward the anterior end of the organism • the flat worms were the first to cephalize • efficient response to a stimulus (during movement sensory organs encounter the environment first • Ectoderm gives rise to the nervous system -development of notochord -neural tube develops into brain -spinal column/vertebrae/cranium protect the CNS -notochord signals or directs the development of neural tube

17. THE END