Animal Life Systems

Animal Science IIUnit 1Animal Life SystemsObjectivesName, locate and describe the functions of the parts of the respiratory systemName, locate and describe the functions of the parts of the circulatory system

Respiratory SystemWhy Animals Need to BreatheUse oxygen to release energy in the cells by oxidation of molecules that contain carbon dioxide

Basic RespirationThe process by which oxygen is brought into the body and carbon dioxide is removed along with water and other gases that the body does not need.

Mammalian Respiratory System StructuresNostrilsNasal CavityPharynxLarynxTracheaBronchiBronchiolesAlveoliSee p. 108-109

Avian Respiratory System see p. 110Physiology of RespirationUtilize muscles to enlarge the chest cavity, forcing air in, and to reduce the chest cavity, forcing air outAir enters the body through the nostrils and/or mouth, passes through the nasal passage to the pharynx, then goes through the trachea to the lungs.In the lungs the air sacs called alveoli oxygen is exchanged for carbon dioxide from the body Also helps control temperature and produce soundhttp://www.youtube.com/watch?v=vu_ONM3Bj9A&feature=related

Circulatory SystemMajor PartsHeartArteriesCapillariesVeinsClosed system in mammals

Heart MuscularPumps blood through the body 4 chambersLeft and right ventricles in the lower partLeft and right atria in the upper partContraction begins with the ventricles and proceeds to the atria. When the ventricles are contracting the atria are relaxing; as the atria contract the ventricles relax.This rhythmic cycle of contraction and relaxation forces the blood to move through the circulatory system

The Path of Blood Flow*When a heart contracts and forces blood into the blood vessels, there is a certain path that the blood follows through the body. The blood moves through pulmonary circulation and then continues on through systemic circulation. Pulmonary and systemic are the two circuits in the two-circuit system of higher animals with closed circulatory systems.Mammals have a two-circuit circulatory systems: one circuit is for pulmonary circulation (circulation to the lungs; pulmo = lungs), and the other circuit is for systemic circulation (the rest of the body). As each atrium and ventricle contract, blood is pumped into certain major blood vessels, and from there, continues through the circulatory system

The Path of Blood Flow

ArteriesConstructed with three layers of tissueOuter wall Made up of connective tissue strong enough to provide protection from cutting or tearingMiddle wallMade of smooth muscle and elastic connective tissueInner wallMade up of a layer of endothelium cells over connective tissueGenerally does not allow blood or other material to pass throughElastic enough to smooth out the pulsation of the blood caused by the pumping action of the heart this helps maintain a steady blood pressure

ArteriolesBranches of the arteriesLess than 0.2 mm in diameterConstructed almost entirely of smooth muscleBranch into capillaries

CapillariesAbout 8 microns in diameterBlood flow and pressure is smooth and steadyThis is important to for the proper exchange of nutrients and waste products to occurWalls are composed of cells that permit the passage of gases and some fluidsHere oxygen and nutrients are exchanged between the blood and tissues and waste picked up from the tissueAll body tissue except hair, cartilage, hooves, horns, nails, part of the teeth and the cornea of the eye contain capillary bedsVenules & VeinsVenulesSmall veins formed when the capillaries come together in the tissueContinue to recombine to form larger vesselsthe VeinVeinsReturn blood to the heartWalls are three layered composed of elastic tissue and smooth muscleWalls are thinner than those of the arteriesGreater capacity than arteries

Blood-FunctionsTransport nutrients, oxygen & carbon dioxide, waste products, & hormonesregulate body temperature by transferring heat from the internal organs to the outside of the body clot to reduce blood loss in the case of injuryMaintain the electrolyte balance and pH level Help protect the body against disease organismsBlood ComponentsPlasma50-60%Red blood cells, white blood cells, platelets40-50%Plasma Fluid portion of the blood50-60% of its total volume90% waterOther 10% made of Proteins Organic nutrients Inorganic ionsHormonesGases Waste productsRed Blood Cells (Erythrocytes)NumerousFormed in the red bone marrow of adult vertebratesNo nuclei- except in birdsThey originate from cells that do have nuclei but as the cell matures it loses its nuclei and aquiers hemoglobinon Hemoglobin consists of iron and globulin- it helps transport oxygen and carbon dioxide and gives blood its red colorHelp maintain a normal pHLive about 120 days and are continually being replaced by new cellsWhite Blood Cells (Leukocytes)Not as numerous as redLargeHave a nuclei but do not contain hemoglobin5 types that all function as part of the immune systemNot confined to the blood, may be found in other tissues of the bodyPlatelets (Thrombocytes)Small particlesOccur in large numbersLive about 10 days and are continuously replaced by the red bone marrowAttach themselves to injuries in blood vessels and release a chemical necessary for blood clottingSticky, allowing the blood to clot Lymphatic SystemAuxiliary to the circulatory systemCarry lymph (a tissue fluid) into the capillaries of the circulatory systemA small amount is carried back to the blood through a system of fine capillaries of the lymphatic system that are located adjacent to the blood capillariesAbsorb nutrients from the digestive system (primarily the small intestine) for transport to the tissues of the bodyNervous SystemTransmits information 2 major partsCentralPeripheralCentral Nervous SystemSkull and vertebral columnMaster control system of the bodyConsists of the brain and spinal cord

Peripheral Nervous SystemNerves that radiate from the central nervous systemSensory nerve fibers carry information to the central nervous system where it is analyzed and appropriate responses are transmitted to the bodyAutonomic nervous system controls those activities of the body that are under automatic controlEndocrine SystemPituitary gland- secretes hormones that regulate hormone production in other endocrine glands, the level of hormone in the bloodActions of the target organs maintain the appropriate level of hormones in the body by utilizing a feedback mechanismGlands do not have ducts to transport hormones-blood passing through the gland absorbs the hormone and transports it to its target organ or tissueSee table 5-2 Major Hormones p. 114-115Urinary SystemKidneys, ureters, bladder, urethraBlood passes through the kidneys where waste and some water is filtered out.The liquid, urine, is passed through the ureters to the bladder where it is stored until the bladder is full before being voided from the body through the urethraPoultry do not have a bladder or urethra; instead the ureters lead to the cloaca where the urine is voided with the feces.AssignmentDiscussion Questions 10-12 14, 16-23For #s 16 ,18, 21 you only need to name the two kinds of blood vessels (16) ,the major components of blood (18), and the major parts of the nervous system (21).