How Animals work

1. How Animals work • Theme is Biology: Form and function • What a structure can do is influenced by it’s form • The form of a structure is uniquely suited to what that structure does • Both the form and function evolve together • Areas of Biological study: • Anatomy: the structures of an organism (form) • Physiology: how the structures work (function)

2. We are a tube within a tube • We are a thick walled tube • Running through the center of the tube is a digestive system, another tube. http://biology.kenyon.edu/courses/biol112/Biol112WebPage/Syllabus/Topics/Week%207/Resources/coelom.GIF http://www.mscd.edu/~biology/231course/cavity.jpg

3. Which way is which? http://anthro.palomar.edu/animal/images/dorsal.gif

4. Tissues • A tissue is a group of similar cells that usually have a similar embryological origin and are specialized for a particular function. • Tissue cells are often separated by non-living, intercellular materials that cells produce. This substance is called the matrix. • Histology – the study of tissues

5. Four Principal Types of Tissues: • Epithelial –covering and lining; and glands • Connective – protects and supports, binds organs together, stores energy, and provides immunity • Muscle – movement • Nervous –transmits impulses that coordinate body activities

6. Feature of Epithelial Tissue • Closely packed cells with little extracellular material • Epithelial cells are arranged in continuous sheets, in single or multiple layers • Epithelial cells have two surfaces • One side is up against other tissues • The other side faces an open space http://www.cnas.missouristate.edu/labimages/biology/bio122/images/Week%208%20Images/trachea.jpg

7. Connective Tissue • Connective tissue is the most abundant and widely distributed tissue in the body . • The functions of connective tissue: • Binding, attachment and support (bones, tendons and ligaments, organs) • Protection- bones and adipose tissue • Insulation - adipose tissue • Storage - of energy and fat soluble substances • Transportation - blood

8. Muscle Tissue Skeletal Smooth Cardiac voluntary involuntary involuntary cells are long short, spindle-shaped branched many nuclei single nucleus single nucleus striated nonstriated striated intercalated disks Diagram of skeletal muscle

9. Nervous tissue Sends signals to other parts of body neurons : Dendrites - (one or many) receive incoming signals Cell body Axon - (one) transmits outgoing signals neuroglia : protective and supporting cells

10. Axon dendrites

11. Organs are two or more tissues which together perform a specialized function. • Epithelial membranes are thin structures that usually contain both epithelial and connective tissue.

12. Integumentary system is the skin and the organs derived from it (hair, glands, nails) • One of the largest organs • 2 square meters; 10-11 lbs. • Largest sense organ in the body • The study of the skin is Dermatology

13. Three types of epithelial membranes • Serous Membranes • Line cavities and cover organs • Mucous membranes • Line cavities that open to the exterior • Layer of epithelium over connective tissue; • Cutaneous membrane is the skin • the major organ of the integumentary system

14. Functions: 1. Regulation of body temperature • Cellular metabolism produces heat as a waste product . • High temperature • Dilate surface blood vessels • Sweating • Low temperature • Surface vessels constrict • shivering

16. 2. Protection physical abrasion dehydration ultraviolet radiation 3. Sensation touch vibration pain temperature

17. 4. Excretion • Sweat, rid excess salt for example • 5. Immunity/ Resistance • Keeps microbes out, fights infections • 6. Blood Reservoir • 8-10 % of blood in a resting adult • 7. Synthesis of vitamin D • Produced by exposure to UV light • aids absorption of calcium

18. Anatomy • Epidermis Skin • Dermis • Subcutaneous layer or hypodermis See next two slides

21. The Skeletal System • comprised mostly of connective tissue • In the case of most vertebrates, a skeletal system is comprised of bone • Various bone types

22. Functions of Bone • Support • For soft tissues • For attachment of skeletal muscles • Protection • Movement • Storage : minerals, fat • Blood cell production – hematopoiesis • Erythrocytes, leukocytes, platelets

23. Matrix • As a connective tissue, bone is living cells embedded in a matrix consisting of • Secreted substances (proteins) • Proteoglycans and glycoproteins • Collagen – reinforces, gives tensile strength • Mineral salts • Tricalcium phosphate (hydroxyapatite) and calcium carbonate • Calcium is thus needed for bone. • Bone is an active, living material!

24. Remodeling • Bone is continually being broken down and reformed • 3-5 % of bone calcium exchanged each year • In response to stress on bones • Balance between actions of osteoclasts and osteoblasts • Osteo means bone • Osteoblasts MAKE bone, osteoclasts dismantle it. • Vitamins needed for maintenance, esp. D

25. 3 related organ systems • Two important things that animals do: feed and breed • We’ll skip “breed”, but explore 3 organ systems by looking at “feed” • Part of “survival of the fittest” is being able to procure nutrients to survive and live long enough to breed. • Digestive system: processes nutrients • Respiratory exchanges nutrients and wastes • Cardiovascular system transports these

26. Needed to function (but not discussed) • Urinary system: without kidneys to filter waste products from the blood for excretion, we’d be in trouble. • Muscles: movement required for animals. • Nervous system and endocrine system: • nerve cells allow communication by electrochemical signals • Coordinated with chemical signal: hormones

27. Digestive system • Food is needed • Organic materials to break down for energy • Organic molecules as building blocks for cellular material • Specific organic molecules (amino acids, vitamins) we are unable to make ourselves • Certain minerals needed to assist enzymes • How much? • We need enough energy (measured in calories) to power our activities. • Over and under nutrition can occur.

28. A digestive system needed • A large organism has a system for extracting nutrients from food for distributing to the rest of the body. • Food must be physically broken down • Food must be chemically broken down • Nutrients must be absorbed • Excess water used in digestion must be recovered • Waste must be excreted

29. Parts of a digestive system • Mouth • Teeth for breaking up food • Saliva for wetting, breakdown of starch • Esophagus: muscular tube for transferring food to the stomach • Stomach • Physical digestion; muscular stomach churns • Chemical: low pH (high stomach acid) dissolves food; enzymes also breakdown food

30. Food passes into small intestine • Bile salts and enzymes from liver (via gallbladder) act as detergents, break up fats. • Pancreas neutralizes stomach acid, adds enzymes that break down food more. • Small intestine: site of nutrient absorption • Possesses a high surface area • Cells are arranged in villi • Each cell is covered with microvilli • Each villus contains lots of blood capillaries for transporting nutrients away

31. Form and function in the small intestine villi High surface area for lots of absorption. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/V/villi.gifhttp://distance.stcc.edu/AandP/AP/imagesAP2/digestion/microvilli.jpg

32. The end of the line • Large intestine = colon • Most of the water is absorbed here • In an irritated colon, material is moved through quickly before all the water is absorbed: diarrhea • Home to billions of bacteria • Most are anaerobic • Responsible for bad odors, production of gas from fermentation • Feces are mostly bacterial bodies; undigested food a smaller proportion

33. Respiratory system • During metabolism, cells “burn” organic molecules. • E.g. glucose ultimately gets converted to CO2, energy is released. • Process needs oxygen, releases CO2 • Respiratory system must efficiently get O2 into the body • Yet protect from microbes, dirt and dust, drying out, etc.

34. Respiratory anatomy • Nose, sinuses • Trachea = windpipe, tube that leads from oral cavity (mouth) to lungs • Bronchi: the trachea branches • Bronchioles: the bronchi branch into smaller tubes that lead to the lobes of the lung • Alveoli = air sacs: small compartments in which gasses are transferred between air and bloodstream

35. Lungs http://www.aduk.org.uk/gfx/lungs.jpg

36. Respiratory protections • Ciliated epithelium • Surfaces lined with cells that secrete mucus, push mucus along with cilia • Mucus with entrapped bacteria, dust, pushed towards mouth for coughing out or swallowing • Swallowing leads to stomach, acid • Things that kill epithelium interfere with these protections • Influenza virus • smoking

37. Single ciliated cell Cilia http://n2.bioeng5.bioeng.auckland.ac.nz/ontology/images/RespiratoryEpitheliumCiliatedEpithelialCell.png

38. Where does Oxygen go? http://training.seer.cancer.gov/module_anatomy/images/quiz_dd_pulmonary_circulation.jpg

39. Cardiovascular terms to know • Cardio means heart; vascular means tubes • From big to small • Arteries, arterioles, capillaries: • Take blood AWAY from the heart • Veins, venules, capillaries • Bring blood TO the heart • Capillaries are where exchange of materials between blood stream and cells occurs.

40. Status of blood • Pulmonary circulation • Blood traveling AWAY from heart to lungs has little O2 content (in blue): pulmonary artery • Blood traveling from lungs TO heart has lots of O2 (in red): pulmonary vein.

41. The rest of the circulation • Heart has 4 chambers in a mammal • 2 atria and 2 ventricles • Pulmonary and systemic circulation • Blood returns from body into right atrium • Flows into right ventricle, pumped to lungs • Returns from lungs to left atrium • Flows into left ventricle, pumped to the rest of the body • Main artery leading to rest of body: aorta

42. Heart structure Ao = aortaLA = left atriumLV = left ventriclePA = pulmonary arteryRA = right atriumRV = right ventricle Match up with description on previous slide. http://www.rch.org.au/cardiology/media2/Fontan_pic1.gif