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2 Biology 20 Unit D: Respiratory and Motor Systems

3 Earth s atmosphere is about: 78 % N2 21 % O2 1 % remaining gases Aerobic organisms require O 2 for cellular respiration

4 Breathing (ventilation). Involves movement of air between external environment and body Uptake of O 2 and release of CO 2 by cells occurs across respiratory membrane.

5 Describes all processes that supply O 2 to cells of body. For breakdown of glucose Describes processes by which CO 2 is transported to lungs for exhalation. a.) Breathing is the process of how air enters and exits the lungs b.) External respiration occurs in the lungs Involves exchange of O 2 and CO 2 molecules between air and blood

6 c.) Internal respiration occurs within body Involves exchange of O 2 and CO 2 molecules between blood and tissue fluids d.) Cellular respiration involves production of ATP in body cells Energy released is used for: Cell processes Growth Movement Synthesis of new molecules

8 Organs involved are: Nasal cavity and sinuses Pharynx Larynx Trachea Bronchi Bronchioles Alveoli Lungs respiratory system

Warms air (contact with blood vessels). Moistens air with secretions of the epithelial tissue. Cleans air by trapping debris in mucus and fine hairs.

9 Warms air (contact with blood vessels). Moistens air with secretions of the epithelial tissue. Cleans air by trapping debris in mucus and fine hairs. Forms a tube common to respiratory and digestive systems. Top portion of pharynx cleans the air. Adenoids and tonsils help in immunity. 2 openings branch from pharynx Trachea (windpipe) and esophagus (carries food to stomach).

10 Epiglottis is a flap like structure Covers opening of trachea when food is being swallowed (reflex action). It seals opening leading into respiratory tract. IV. larynx (voice box) Composed of 2 thin sheets of elastic ligaments called vocal cords. Sounds are made when cords vibrate as air passes by them. Protected by a thick band of cartilage - Adam s apple Voice box

11 Larger voice box in males produces a deeper sound Inflammation Laryngitis may result Lined with ciliated cells that produce mucus. Mucus traps debris that escape hair filters in nasal passage. Wall of trachea is supported by cartilage rings, which keep trachea open.

12 Left and right bronchi also have cartilage rings Bronchi branch out in the lungs to become bronchioles which have no cartilage but smooth muscle. Smooth muscle in bronchioles can decrease in diameter. Any closing of the bronchioles increases resistance of air movement. Wheezing sound Air moves from bronchioles into tiny blind ended sacs called alveoli (singular: alveolus).

13 Small size and great # of alveoli increase surface area greatly Each alveolus is surrounded by capillaries

14 O 2 diffuses into blood and CO 2 diffuses out of blood Due to concentration gradients During inhalation Alveoli are bulb shaped During exhalation Alveoli collapse

15 Breathing animation and asthma: MOV Action of the cilia: General Respiration animation: Lung Attack! Shows normal vs CO gas exchange

16 Membranes are prevented from sticking by a film of lipoprotein Film allows the alveoli to pop during inhalation Respiratory distress syndrome Some babies do not produce enough lipoprotein Difficulty inhaling May result in death

17 Contained within pleural membrane Isolate and lubricate lungs within thoracic cavity Reduces friction between lungs and chest cavity during inhalation Pleurisy Inflammation of pleural membranes and build up of fluids in chest cavity Expiration is easier but inspiration is more difficult Contain alveoli and bronchioles Stretch from clavicle to diaphragm Lung anatomy

18 Determined by action of muscles and size of thoracic cavity Atmospheric pressure remains relatively constant; pressure in chest cavity varies Gases move from an area of high to low pressure Dome shaped sheet of muscles Separates chest cavity from abdominal cavity Regulates pressure in chest cavity

19 Diaphragm is assisted by movement of ribs Ribs are hinged to vertebral column, allowing them to move up and down Bands of muscles, the external intercostals, are found between ribs A second set, internal intercostals, are not used during normal breathing, but during exercise Concentration of gases inhaled: 78 % nitrogen, 21 % oxygen, and 0.04 % carbon dioxide Composition of gases exhaled: 78 % nitrogen, 16 % oxygen, and 5 % carbon dioxide

20 Air enters lungs when pressure of air outside is greater than pressure inside lungs (pleural pressure). Increase size (volume) of chest cavity. Diaphragm moves down. External intercostals (muscles) contract (the muscles flatten). Due to a nerve stimulus Rib cage moves up and out

21 Air leaves lungs when pleural pressure inside is greater than air pressure outside Diaphragm relaxes and pushes up. Volume of chest cavity decreases External intercostals (muscles) relax, i.e, become dome shaped) No nerve stimulation Rib cage moves downward

23 Breathing animation showing rib cage and diaphragm:

24 A hit to the solar plexus (bottom of rib cage) Drives abdominal organs upward Dome shape of diaphragm is exaggerated A large quantity of air is expelled A bullet or a stab wound to ribs creates a hole in pleural cavity During inhalation, pressure inside chest cavity is much less than normal Air flows directly through hole in chest Treatment: Air must be removed so that lung can re expand

25 Diffusion of a gas occurs from an area of high to low pressure Dalton s Law of Partial Pressure Each gas in a mixture exerts its own pressure, which is proportional to total volume O 2 diffuses from air (21.2 kpa) into lungs (13.3 kpa for alveoli) Partial pressure of O 2 depends on location Arteries carry blood away from heart Veins carry blood toward heart

26 Capillaries connect arteries with veins I.e., are in between arteries and veins Are the sites of gas exchange O 2 diffuses into cells CO 2 diffuses out of cells Product of cellular respiration Largest change in partial pressure of O 2 is in capillaries Partial pressure of CO 2 is highest in tissues and venous blood Partial pressure of N 2 remains relatively constant Gases must be dissolved to cross cell membrane Alveoli have a film of moisture

27 O 2 moves from atmosphere to alveoli; moves into blood and dissolves in plasma. O 2 is not very soluble in blood Thus, when O 2 dissolves into plasma, hemoglobin, on a red blood cell, greatly increases O 2 carrying capacity of the blood a. Hemoglobin Consists of 4 polypeptides Composed of: Heme (iron containing) Globin (protein component)

28 Each heme group contains an iron atom Binds to O 2 When O 2 dissolves into plasma, hemoglobin forms a weak bond with O 2 molecule Forms oxyhemoglobin Other O 2 molecules can dissolve in plasma O 2 carrying capacity of the blood is: 20 ml of O 2 per 100 ml of blood (70 fold increase compared to blood without hemoglobin)

29 Partial pressure in lungs = 13.3 kpa Partial pressure in capillaries = 5.3 kpa Partial pressures/ diffusion of oxygen/ carbon dioxide: /student_view0/chapter44/ animations.html# Drop in partial pressure causes dissociation (split) of O 2 from hemoglobin O 2 diffuses into tissues little O 2 is released from hemoglobin until partial pressure of O 2 reaches 5.3 kpa Ensures most O 2 remains bound to hemoglobin until it gets to tissue capillaries Venous blood still carries a rich supply of O 2 70 % of hemoglobin still saturated with O 2 when blood returns to heart Partial pressure

30 CO 2 is 20 X more soluble than O 2 9 % of CO 2 produced by tissues is carried in plasma 27 % of body s CO 2 combines with hemoglobin Forms carbaminohemoglobin 64 % of body s CO 2 combines with H 2 O from plasma. Forms carbonic acid (H 2 CO 3 (aq) ) Enzyme, carbonic anhydrase, increases rate of chemical reaction CO 2 + H 2 O H 2 CO 3 Decreases concentration of CO 2 in plasma Ensuring that CO 2 continues to diffuse into blood

31 H 2 CO 3 dissociates to bicarbonate ions and hydrogen ions H + ions dislodge O 2 from hemoglobin H + combines with hemoglobin to form reduced hemoglobin Hemoglobin acts as a buffer, thus, keeping acidity down Bicarbonate ions are transported to plasma Combines with H + to form H 2 O and CO 2 O 2 is released from its binding site and is free to move into body cells CO2 diffuses from blood into alveoli Eliminated during exhalation

32 During exercise: Cellular respiration increases; Causes CO 2 levels to increase Stimulates chemical receptors in brain stem Brain impulses are carried to muscles--- increase breathing movements, flush CO 2 from body. Other chemical receptors in walls of carotid artery detect low levels of O 2 in blood. A nerve is stimulated Message sent to brain Brain relays message to muscles that control breathing

33 Chemoreceptors Specialized nerve receptors sensitive to specific chemicals Two types of chemoreceptors: 1.Carbon dioxide chemoreceptors 2.Oxygen chemoreceptors Chemoreceptors located in medulla oblongata of brain Detects increased amount of CO 2, in the form of an acid, in blood

34 Nerve cells in medulla oblongata send nerve impulses to diaphragm and intercostals Breathing rate increases and exchange of CO 2 and O 2 is sped up Once the level of CO 2 decreases, chemoreceptors then become inactive

35 Sensitive to low O 2 levels in blood Chemoreceptors are found in carotid and aortic arteries Messages are sent to medulla oblongata Message is then sent to intercostal muscles and diaphragm to increase breathing rate 2 nd function is detection of high levels of CO 2 in blood

36 Oxygen receptors act as a back up system Are only called into action when O 2 levels are low and CO 2 levels high In high altitudes Air is thinner Carotid and aortic chemoreceptors stimulate breathing movement CO competes with O 2 oxygen for active site on hemoglobin molecule

37 Lungs Increased ventilation provides additional O 2 and removes excess CO 2 Kidneys Remove excess H + from blood Muscles Increased activity produces more CO 2 CO 2 and H + increase Increased O 2 demand of muscles lowers O 2 Adrenal gland Epinephrine is released in response to exercise Hormone causes breathing rate to increase

38 Can vary (as will the amount of gas exchanged). Tidal volume = amount of air exchanged at rest. Vital Capacity = amount of air exchanged at maximum conditions.

39 A. Bronchitis Bacterial or viral infections Reactions to environmental chemicals Narrowing of air passages and inflammation of mucus lining in bronchial tubes Mucous cells secrete more mucus Tissues swell in bronchioles As mucous secretions increase, air movement decreases Bronchioles are not supported by bands of cartilage to help keep them open

40 B. Asthma - often associated with allergies C. Emphysema ( over inflated ) Walls of alveoli become inflamed; thin walls stretch and rupture. Greater effort is required to exhale than inhale Respiratory disorders - Allergies - Uncontrolled growth of cells Greatly decreases surface area for diffusion Tumors may actually block bronchioles, thereby reducing airflow to the lungs, potentially causing the lungs to collapse

41 Read Section 9.3 in your textbook Pages Complete Section 9.3 Questions 1-3,5-6, Page 297 Smoking and Lung Cancer Case Study Page 295, Questions 1-6 Lung Capacity Pre-lab Questions in Workbook Lung Capacity Lab

42 Biology 20 Chapter 9 Notes

43 Human body has 600 muscles 3 types of muscles

44 Muscle of the heart Involuntary Makes heart beat Controlled by nerves of autonomic nervous system Is striated Narrow stripes or bands that are visible under a microscope

45 Involuntary Found in the lining of many organs Stomach, esophagus, uterus, walls of blood vessels Unstriated

46 Voluntary Makes the bones of skeleton move Walk, talk Are attached to tendons Band of connective tissue that joins muscle to bone

48 Many skeletal muscles are arranged in pairs Work against each other to make a joint move Antagonistic muscles When biceps contract, triceps relax Bones forming elbow joint are brought closer together When biceps relax, triceps contract Two bones move apart

49 Flexor Muscle that contracts to bend a joint (Bicep). Extensor Muscle that contracts to straighten a joint (Tricep) Joints - ealth/skeletalsystem/joints

50 Origin Place where the muscle attaches to a stationary bone Insertion Place where muscle attaches to moving bone

51 Ensures that biceps and triceps do not attempt to pull against each other Excitatory nerve impulses cause triceps to contract Inhibitory nerve impulses cause biceps to relax I.) Skeletal Muscle Enables movement, smiling, and keeping body warm 80 % of energy used in skeletal muscle contraction is lost as heat

52 Composed of several bundles of cells called fibres Fibres Most cells contain only 1 nucleus However, many nuclei are found in each muscle cell Enclosed within a membrane Sarcolemma Within muscle fibres are tiny myofilaments bundled together Two types of myofilaments 1. Actin thin filaments 2. Myosin thick filaments

54 Each myofilament is composed of different contractile proteins Both types overlap to produce a striated (striped) appearance Muscle fibres appear to have alternating dark and light bands Due to arrangement of myofilaments Muscles - m/health/muscularsyste m/muscles

55 Length of muscle fibre is defined by Z lines that anchor actin fibres Area between Z lines is the sarcomere Thick myosin filaments form darker A band Thin actin filaments allow more light to penetrate Forms lighter I band Muscle fibers - /objects/489/500888/cda43_2/cd A43_2a/CDA43_2a.htm

56 Muscles cause movement by shortening Actin filaments slide over myosin filaments Z lines move closer together when muscle fibres contract As actin and myosin begin to overlap, lighter I band becomes progressively smaller Cause: knoblike projections on myosin forms cross bridges on receptors sites of actin Series of cross bridges attach and detach as actin filaments are drawn inward Contraction -

1 4 2 3 Myosin head hydrolyzes ATP to ADP and P i. Myosin head binds to actin, forming a cross bridge.

57 Myosin head hydrolyzes ATP to ADP and P i. Myosin head binds to actin, forming a cross bridge. Releasing ADP and P i, myosin relaxes to its low E state, sliding the thin filaments. Binding of new ATP releases myosin head

58 Functional Unit of Muscle -Sarcomere by Harvey Project - Sarcomere Shortening McGraw-Hill - Sliding Filament theory animation: Muscle structure, sliding filament theory awesome animations! n_myosin/actin_myosin.swf

59 Energy required for muscle contraction comes from ATP In absence of ATP, cross bridges fail to detach and muscle becomes rigid Rigor mortis Due to contraction of muscles following death Lasts up to 60 hours after death Paralysis Insecticides may cause paralysis by inhibiting cross bridges

60 Very little ATP can be stored in muscle tissue Energy demand is met by aerobic respiration Creatine phosphate Found in muscle cells High energy compound Ensures that ATP supplies remain high Supplies a phosphate to ADP to replenish ATP Should energy demand exceed ATP supply, lactic acid will accumulate Muscle pain and fatigue Oxygen debt Rapid breathing is designed to repay the oxygen debt

61 Occurs when a nerve impulse stimulates several muscle cells Latent period A pause between impulse and muscle contraction Muscle contraction: Actin and myosin fibres slide over one another Muscle shortens Muscle relaxation: Actin and myosin fibres disengage Muscle relaxes (lengthens) Should a muscle cell be stimulated once again, it will contract with equal force

Summation Stimulation before relaxation Overlap of actin and myosin is increased Greater muscle shortening Sum of 1 st and 2 nd twitch creates a greater force of contraction Strength

62 Summation Stimulation before relaxation Overlap of actin and myosin is increased Greater muscle shortening Sum of 1 st and 2 nd twitch creates a greater force of contraction Strength of contraction depends on how close the second stimulus is to the first Repeated muscle stimulation prevents any relaxation phase constant state of muscle contraction results in tetanus

63 Sprinters Born with fast twitch muscle fibre Thick myosin filaments determine speed of muscle contraction 3 different forms of myosin, isomers, refer one s potential Type I, IIa, and IIx Type I Cause slower muscle twitch Distance runners Break down ATP slowly but efficiently Rely predominantly on aerobic respiration

64 Type IIa and IIx Fast twitch myosin fibres Break down ATP faster but less efficiently Rely predominantly on anaerobic respiration

65 Regular exercise and a healthy intake of food are necessary for maintaining muscles Injuries are common among people who perform heavy work or exercise Torn muscles, stretched tendons, torn ligaments, joint sprains, joint dislocations

66 Used to view torn ligaments or cartilage Needle like tube, 2 mm wide Equipped with a fibreoptic light source Needle is inserted through a small puncture in a knee Fibreoptic lens can be linked to a TV screen Can be fitted with thin surgical tools Snip away unhealthy tissue Video - media/acl2.asx

67 Read section 9.4 in Your Textbook pages Complete Section 9.4 Questions Page #1-7 Fast and Slow Twitch Muscle Fibres Lab Muscle tissue microscopic lab Investigation Unit Review for Exam Define Key words on page 307 Text Chapter 9 Review Questions 1-22 on pages

Lesson 9.1: The Importance of an Organ Delivery System

Lesson 9.1: The Importance of an Organ Delivery System Animals require a continuous supply of oxygen (O 2 ) for cellular respiration, and they must expel carbon dioxide (CO 2 ), the waste product of this