Ch. 37-38 Intro to Body Systems, Circulatory, Respiratory Systems

1. Ch. 37-38 Intro to Body Systems, Circulatory, Respiratory Systems By: Brianna Shields June 1, 2006

2. GOAL • Identify four levels of structural organization within the human body • Analyze the four kinds of body tissue • List the body’s major organ systems • Evaluate the importance of endothermy in maintaining homeostasis • Analyze the structure of bone, and summarize the process of bone development • Identify the three main classes of joints • List two ways to prevent osteoporosis • Describe the action of muscle pairs in moving the body and how energy is supplied to the muscles for contraction • Analyze the structure and function of the epidermis • Describe how the dermis helps the body maintain homeostasis • Summarize how hair and nails are formed • Identify various skin disorders • Summarize how the respiratory system functions- what are the roles played by the major organs? • Summarize how the circulatory system functions- what are the roles played by the major organs?

3. Tissues- building blocks of the human body Epithelial Thin flat cells line body surfaces, seal in water, protects other tissues from damage Constantly replaced as cells die Nervous Made of nerve cells (for messaging) Connective Supports, protects, insulates body Fat, cartilage, bone, tendons, blood Body Systems

4. Tissues- building blocks of the human body Muscle Enables movement of body structures by muscle contraction Skeletal Voluntary (conscious control) Ex: muscles in leg Smooth Involuntary (no conscious control) Ex: muscles in walls of blood vessels Cardiac Heart muscle Body Systems

6. Stem Cells Masses of embryonic cells found in middle of developing zygote Undifferentiated (unspecialized) cells that have the potential to develop into all other types of cells Immortal, divide indefinitely Extracting them destroys early embryos May help in repairing damaged tissue Adults have stem cells that only survive 100 or so divisions Body Systems

7. Organ Systems Body organs made of tissues working together to perform a specific function Body Systems

8. Body Cavities Four fluid filled spaces that house and protect major internal organs Thoracic cavity- heart, lungs protected by ribs and sternum Cranial cavity- brain protected by skull Abdominal cavity- digestive organs protected by pelvis and abdominal muscles Spinal cavity- spinal cord protects vertebra Body Systems

10. Endothermy Maintain a constant internal temperature at 98.6 F Allows humans to sustain strenuous activity for a long time Too cold or too hot temps may inactivate critical enzymes Body Systems

11. Maintaining Homeostasis in the Body Temperature regulation Adjusting metabolism Detecting and responding to environmental stimuli Maintaining water and mineral balances Body Systems

12. ASSESSMENT (use notesheet) • Summarize the four levels of structural organization in the body • List the four different kinds of body tissues and give an example of each kind • Describe the relationship between organs and organ systems • How is endothermy advantageous to humans?

13. The Skeleton Shapes and supports body Protects internal organs Enables movement with aid of muscles Axial Skeleton- bones of skulls, spine, ribs, sternum Appendicular Skeleton- appendage and limb bones (shoulders, arms, hips, legs) Body Systems

14. BONES: Structure Hard, outer covering of compact bone Porous inner core of spongy bone Bone marrow- fills cavities of spongy bone (produces blood cells and platelets) Body Systems

15. BONES: Growth Cartilage hardens with minerals (calcium) New bone cells are added in layers to form rings allowing the bones to withstand tremendous stress Osteocytes become embedded in the bone tissue Bones lengthen as cartilage degenerates Body Systems

16. BONES: Osteoporosis Age 35 Less bone replacement Severe bone loss= osteoporosis Bones become brittle and easily fractured Effects women more than men (smaller bones, decrease in sexual hormones after menopause) Increase bone density through regular exercise and a diet rich in veggies, whole grains, legumes and dairy products Body Systems

17. BONES: Joints Two bones meet, cushioned by cartilage pads for withstanding stress Ligaments- strong bands of tissue holding joints together Immovable Joints- tight joints with no movement (skull) Slightly Movable Joints- limited bone movement (ribs, vertebra) Freely Movable Joints- permit free movement Body Systems

18. BONES: Joint Disorders When lubricating fluid around joints is lacking, friction increases Rheumatoid arthritis- painful inflammation of freely movable joints Osteoarthritis- degeneration of cartilage that covers bone surfaces, causes pain when bones rub Body Systems

19. ASSESSMENT (use notesheet) • Distinguish between the axial skeleton and the appendicular skeleton • Differentiate between compact and spongy bone • Describe how bones elongate in development • List the three main types of joints, and give an example of each • Why are women more likely than men to develop osteoporosis?

20. Muscular System Tendons- attach skeletal muscles to bones Muscles attached to skeleton in opposing pairs (one pulls in one direction, one pulls in the opposite direction) Flexor- causes a joint to bend Extensor- muscles causes joint to straighten Body Systems

21. Muscular System: Muscle Structure Actin and myosin are protein filaments that enable muscles to contract Myofibrils- small cylindrical structures in muscles fibers giving it the banded light and dark appearance Sarcomeres- area between two “z” lines where thin and thick protein filaments overlap and interact Body Systems

23. Muscular System Muscle Contraction Sarcomere replaced, myosin and actin filaments partially overlap Muscle fiber stimulated by signal sent by nerve cell Myosin and actin slide along one another and overlap closely Sarcomere shortens (z lines pulled in close) Body Systems

25. Muscular System Interaction of Myosin and Actin Head of Myosin attaches to open binding site on Actin Myosin head rotates causing Actin to slide (overlap occurs) ATP used for myosin head to detach and snap back to original position (myosin “walks” along actin, stepping into each open binding site causing sarcomere to shorten Body Systems

26. Muscular System Aerobic and Anaerobic Energy Pathways Muscle contraction is powered by ATP generated by aerobic respiration During intense workouts, oxygen is consumed too quickly, and anaerobic processes take over (glycolysis generates ATP) Body reverts to glycogen for energy when aerobic and anaerobic processes are insufficient (when glycogen is used up, it switch to fat burning) When ATP consumption exceeds ATP production, resulting in muscle fatigue and soreness Body Systems

27. Muscular System Exercise and Fitness Increasing endurance- aerobic exercise makes heart pump more efficiently and increases muscle efficiency by increasing energy available to muscles Increasing muscle mass- resistance training like weightlifting (doesn’t usually improve oxygen uptake to muscles) Excessive exercise or failure to warm up can tear muscles Body Systems

28. ASSESSMENT (use notesheet) • Describe how muscle pairs work together to move body parts • Compare the roles of thick and thin filaments in muscle contraction • Identify the energy pathway that is primarily involved with exercises that increase muscle size and strength

29. SKIN Protection from injury First line of defense against disease Regulates body temperature Prevents body from drying out Body Systems

30. SKIN Epidermis- outermost layer of skin (outside consists of flat, dead cells) Keratin- tough, waterproofing protein Cells are continuously replaced New cells made at base of epidermis and push up towards surface Melanin- skin coloring pigment Absorbs U.V. light = tanning (darkening of melanin) Too much U.V. light absorption = skin cancer Body Systems

31. SKIN Dermis- layer beneath epidermis Contains : Sensory cells Muscles controlling hair follicles Blood vessels here regulate body temperature by radiating or conserving heat When too hot, vessels dilate bringing blood closer to skin to release heat When too cold, vessels constrict to reduce heat loss Sweat glands Body Systems

32. SKIN Subcutaneous Tissue- under skin (fatty layer) Absorbs shock, insulates body, stores energy Anchors skin to organs Body Systems

34. HAIR AND NAILS Hair- made of dead, keratin filled cells Each hair grows for several years, rests for a few months and is then shed Hair color determined by melanin Nails- produced by epidermal cells at base of each nail Fill with keratin as they push upward Protects tips of fingers and toes Body Systems

35. Skin Disorders Exposed to damaging factors: insect bites, microorganisms, UV radiation Scrapes/blisters- heal quickly Burning- can result in permanent scarring Acne Results when oily sebum that naturally lubricates the skin, traps dirt, oil and bacteria in skin pores The tissue becomes infected and accumulates pus Body Systems

36. Skin Disorders Skin Cancer Caused by overexposure to U.V. radiation Carcinomas- occurs in non pigment producing cells (most treatable) Malignant Melanomas- grow and spread quickly (deadliest) Body Systems

37. ASSESSMENT (use notesheet) • Describe the structure of the epidermis • List two ways that the dermis helps regulate body temperature • Summarize how nails are formed • Identify the most common cause of skin cancer and how it can be avoided.

38. Circulatory System Cardiovascular system Transports materials to different parts of the body Nutrients from digested food to cells Oxygen from lungs cells Metabolic wastes from cells  excretory organs Hormones to specific places in body Distributes heat to conserve or release it Heart pumps blood which carries substances within blood vessels Circulatory System

39. Blood Vessels Arteries- carry blood away from heart Flexible, expand as blood flows through Thick walls to withstand great pressure Capillaries- tiny tubes for exchange of materials One cell thick walls Allows for nutrients, wastes and gases to pass through walls into or out of blood Circulatory System

40. Blood Vessels Veins- carry blood back to heart Thinner than arteries, but larger in diameter Contain valves (flaps of tissue) that ensure blood flows only in one direction Blood pushes through as skeletal muscles contract Malfunctioning valves = varicose veins Circulatory System

42. Lymphatic System Collects and recycles fluids leaked from cardiovascular system and helps fight infection Carries lymph (leaked fluid) back to lymph nodes found in Armpits Neck Groin Lymph nodes contain immune cells that help body fight of bacteria, viruses and cancer Swelling of lymph nodes indicates the body is actively fight infection and is full of white blood cells Circulatory System

43. Components of Blood Plasma= liquid portion (60% of blood) 90% is water 10% is metabolites, wastes, salts, proteins Proteins in plasma defend body from disease, play a role in blood clotting and thicken blood Circulatory System

44. Components of Blood Red Blood Cells Contain hemoglobin for carrying oxygen Known as erythrocytes Short life span (4 months), constantly replaced by stem cells in bone marrow Anemia- low iron levels due to nutrition Circulatory System

45. Components of Blood White Blood Cells Cells that defend the body against disease Platelets Cell fragments Role in clotting blood (form sticky enlarged clumps to plug holes in blood vessels) Stimulate chemical reactions to plug open wounds- fibrin threads trap red blood cells and platelets to form a mass that blocks the wound Hemophilia- genetic blood clotting disorder Circulatory System

47. Blood Type Determined by presence or absence of specific antigen (carbohydrate) on rbc’s surface ABO System A blood- A antigens on surface B blood- B antigens on surface AB blood- both A and B antigens on surface O blood- lacks antigens on surface Circulatory System

49. Blood Type Must receive blood compatible with your own, or your body will produce an immune response to the “foreign” antigen on the new blood given to you AB people- can receive any type of blood O people- universal donors Circulatory System

50. Blood Type Rh factor- antigen on surface of rbc’s Have protein = Rh + Lack protein = Rh – If an Rh- mother has an Rh + infant, the mother’s system will make anti Rh antibodies that can be passed on to an Rh + fetus in the future, resulting in death Circulatory System