Animal Life Systems

1. Animal Life Systems Animal Science I Unit 1

2. Objectives • Name, locate and describe the functions of the parts of the respiratory system • Name, locate and describe the functions of the parts of the circulatory system

3. Respiratory System

4. Basic Respiration • Oxygen is brought into the body • Carbon dioxide is removed along with water and other gases that the body does not need.

5. Mammalian Respiratory System Structures • Nostrils • Nasal Cavity • Pharynx • Larynx • Trachea • Bronchi • Bronchioles • Alveoli

6. Avian Respiratory System see p. 110

7. Physiology of Respiration • Utilize muscles to enlarge the chest cavity, forcing air in, and to reduce the chest cavity, forcing air out • Air 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 sound

8. Circulatory System

9. Major Parts • Heart • Arteries • Capillaries • Veins • Closed system in mammals

10. Heart • Muscular • Pumps blood through the body • 4 chambers • Left and right ventricles in the lower part • Left and right atria in the upper part • Contraction 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 is the force that moves blood through the circulatory system

11. 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 closed circulatory system. • 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

12. The Path of Blood Flow

13. Arteries • Constructed with three layers of tissue • Outer wall • Made up of connective tissue strong enough to provide protection from cutting or tearing • Middle wall • Made of smooth muscle and elastic connective tissue • Inner wall • Made up of a layer of endothelium cells over connective tissue • Generally does not allow blood or other material to pass through • Elastic enough to smooth out the pulsation of the blood caused by the pumping action of the heart –this helps maintain a steady blood pressure

14. Arterioles • Branches of the arteries • Less than 0.2 mm in diameter • Constructed almost entirely of smooth muscle • Branch into capillaries

15. Capillaries • About 8 microns in diameter • Blood flow and pressure is smooth and steady • This is important to for the proper exchange of nutrients and waste products to occur • Walls are composed of cells that permit the passage of gases and some fluids • Here oxygen and nutrients are exchanged between the blood and tissues and waste picked up from the tissue • All body tissue except hair, cartilage, hooves, horns, nails, part of the teeth and the cornea of the eye contain capillary beds

16. Venules & Veins • Venules • Small veins formed when the capillaries come together in the tissue • Continue to recombine to form larger vessels—the Vein • Veins • Return blood to the heart • Walls are three layered composed of elastic tissue and smooth muscle • Walls are thinner than those of the arteries • Greater capacity than arteries

18. Blood-Functions • Transport nutrients, oxygen & carbon dioxide, waste products, & hormones • regulate body temperature by transferring heat from the internal organs to the outside of the body • clot to reduce blood loss in the case of injury • Maintain the electrolyte balance and pH level • Help protect the body against disease organisms

19. Blood Components • Plasma • 50-60% • Red blood cells, white blood cells, platelets • 40-50%

20. Plasma • Fluid portion of the blood • 50-60% of its total volume • 90% water • Other 10% made of • Proteins • Organic nutrients • Inorganic ions • Hormones • Gases • Waste products

21. Red Blood Cells (Erythrocytes) • Numerous • Formed in the red bone marrow of adult vertebrates • No nuclei- except in birds • Originate from cells with 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 color • Help maintain a normal pH • Live about 120 days and are continually being replaced by new cells

22. White Blood Cells (Leukocytes) • Not as numerous as red • Large • Have a nuclei but do not contain hemoglobin • 5 types that all function as part of the immune system • Not confined to the blood, may be found in other tissues of the body

23. Platelets (Thrombocytes) • Small particles • Occur in large numbers • Live about 10 days and are continuously replaced by the red bone marrow • Attach themselves to injuries in blood vessels and release a chemical necessary for blood clotting • Sticky

24. Lymphatic System • Auxiliary to the circulatory system • Carry lymph (a tissue fluid) into the capillaries of the circulatory system • Absorb nutrients from the digestive system (primarily the small intestine) for transport to the tissues of the body

25. Nervous System • Transmits information • 2 major parts • Central • Peripheral

26. Central Nervous System • Skull and vertebral column • Master control system of the body • Consists of the brain and spinal cord

27. Peripheral Nervous System • Nerves that radiate from the central nervous system • Sensory nerve fibers carry information to the central nervous system where it is analyzed and appropriate responses are transmitted to the body • Autonomic nervous system controls those activities of the body that are under automatic control

28. Endocrine System • Pituitary gland- secretes hormones that regulate hormone production in other endocrine glands, the level of hormone in the blood • Actions of the target organs maintain the appropriate level of hormones in the body by utilizing a feedback mechanism • Glands do not have ducts to transport hormones-blood passing through the gland absorbs the hormone and transports it to its target organ or tissue • See table 5-2 Major Hormones p. 118-119

29. Urinary System • Kidneys, ureters, bladder, urethra • Blood 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 urethra • Poultry do not have a bladder or urethra; instead the ureters lead to the cloaca where the urine is voided with the feces.

30. Assignment • Discussion Questions 10-12, 14, 16-23 • For #’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). Due— Monday Aug 26 end of period.