The process that involves air entering and exiting the lungs is called VENTILATION

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Bio 067: Review sections 10-12 Respiration, skeletal, muscular Functions of the respiratory system: The process that involves air entering and exiting the lungs is called VENTILATION Involves:

1 Bio 067: Review sections Respiration, skeletal, muscular Functions of the respiratory system: The process that involves air entering and exiting the lungs is called VENTILATION Involves: Inhalation (oxygen in) and exhalation (carbon dioxide out) 1) During inhalation Air is cleaned course hairs act as trap, cilia, mucus in nose Cilia and mucus, beat upward to move mucus and dust to pharynx for swallowing or expectoration Air is warmed heat from blood vessels Air moistened by wet surfaces of passages 2) During exhalation Air is cooled due to condensation and loses its moisture, depositing it on lining in trachea and nose Parts of the respiratory system: Nasal cavity Pharynx Glottis Trachea Primary bronchi Bronchioles alveoli Upper Respiratory Tract: Nose Pharynx - Larynx Lower respiratory tract Trachea o Tube connecting larynx to primary bronchi o C shaped cartilaginous rings which prevent the trachea from collapsing o Mucus membrane lines trachea has simple ciliated epithelium o Traps debris and moves mucus and debris to pharynx away from lungs

2 Bronchial tree o Trachea divided into left and right primary bronchi o Then branch to secondary bronchi o Then branch into bronchioles o Terminates in elongated space enclosed by many alveoli (air sacs) Lungs Lungs are enclosed by 2 pleura (=double layer of serous membranes that secretes serous fluid to keep lungs moist) One pleura adheres to thoracic wall (parietal pleura)- One adheres to surface of lungs (visceral pleura) Alveoli Each sac of alveoli are surrounded by capillaries Walls of capillaries and sac are 1 cell layer thick therefore gas exchange occurs between them Oxygen diffuses from alveoli into bloodstream CO2 diffuses from bloodstream into interior space of alveoli Alveoli are lined with surfactant that prevents them from closing surfactant is a film of lipoprotein that lowers the surface tension of water and prevents the alveoli from closing Mechanism of breathing Ventilation (another word for breathing) = 2 phases 1) Inhalation (aka inspiration) moves air into lungs 2) Exhalation (aka expiration) moves air out of lungs Inspiration Expiration Phase active passive Intercostal muscles and contract relax diaphragm Ribcage Up and out Down and in Volume increases decreases Pressure decreases increases Airflow in Out aided by elastic recoil of lungs Definitions Tidal volume = normal amount of air inhalated and exhalated Inspiratory and expiratory reserve volume is forced inspiration to maximum amount of air going in or out Vital capacity = maximum amount of air that can be moved in and out of lungs during a single breath of deep breathing tidal volume + inspiratory and expiratory reserve volume Residual volume = amount of air that cannot be exhaled from lungs

3 Gas exchange in the body Internal and External Respiration External respiration = gas exchange between continuous column of air in alveoli (external environment) and blood in capillaries surrounding alveoli Internal respiration = gas exchange between bloodstream and tissue fluid surrounding cells. 1. Exchange of oxygen Deoxyhemoglobin + Oxygen oxyhemoglobin Hb + O2 HbO External respiration whats happening in lungs Internal respiration whats happening at cells external resp Blood in pulmonary capillaries has low oxygen concentration or pressure and alveolar oxygen pressure is high therefore it diffuses into plasma and red blood cells and is held by haemoglobin internal resp: Oxygen diffuses out of blood into tissues because partial pressure of O2 in cells is low due to oxygen demand from aerobic cellular respiration 2. Exchange of CO2 Carbon dioxide + water carbonic acid hydrogen ion and bicarbonate ion CO2 (g) + H2O(l) H2CO3 H + + HCO internal respiration External respiration Internal respiration: CO2 constantly produced as waste by product of aerobic cellular respiration form high concentration in cells. CO2 diffuses out of cells into tissue fluid, diffuses into blood at capillaries combines with water to make acid which is broken down to H+ and HCO3- External respiration: Blood reaches pulmonary capillaries and has a higher partial pressure of CO2 than the air inside the alveoli. Bicarbonate reaction goes back and carbon dioxide is produced and diffuses from bloodstream into alveoli where it can be exhaled

4 Cellular respiration a) 3 processes of cell respiration: 1) Glycolysis anaerobic (does not need oxygen) glucose 2 molecules of pyruvate C6H12O6 + O2 2 x 3C molecules **pyruvate is required in order to move into the citric acid cycle NAD NADH Transfers e- and H + to electron transport chain 2 ATP are produced Occurs in the cytoplasm of the cell Is anaerobic because oxygen is not used in glycolysis 2) Citric acid cycle Pyruvate (3 c molecule) bonds broken down Occurs in matrix of mitochondria Hydrogen + e- transfer by NADH to electron transport chain 2 ATP are produced 3) Electron transport chain Located on cristae in mitochondria NADH deliver electrons and H + from glycolysis and citric acid cycle to the electron transport chain Carrier proteins are grouped into complexes and e- are passed from 1 complex to a lower energy complex -so each carrier of the electron transport chain accept 2 electrons and passes them on to the next carrier - Complexes are embedded in cristae e- lose energy as passed down the chain and forms high energy phosphate bond for ATP production oxygen is final receiver of e-, after O2 receives e-, combines with H and forms water. Forms net 32 ATP/glucose molecule 4) Fermentation Anaerobic respiration Does not require O2 Pyruvate is converted to another compound called lactate Cannot enter citric acid cycle therefore builds up in muscles and forms lactic acid causes muscles to cramp and fatigue If oxygen becomes present again...can be converted back to pyruvate by presence of O2 Makes 2 ATP

5 Control of breathing: 1) Nervous control Rhythm of breathing is controlled by respiratory control centre in medulla oblongata of the brain The respiratory control centre automatically sends out nerve signal via the phrenic nerve to the diaphragm and intercostal muscles of the rib cage which contract and inhalation occurs When the signal stops, the muscles relax and exhalation occurs 3) Chemical control Cells use up O2 and produce CO2, this CO2 enters the blood where it combines with water to form an acid which breaks down and releases hydrogen ions and bicarbonate ions which changes the ph of the blood CO 2 (g) + H2O(l) H2CO3 H + + HCO3 - the H and HCO3 Changes ph of blood Carbonic acid There are 2 sets of chemoreceptors in your body which are sensitive to changes in ph 1 set of Chemoreceptors in the medulla oblongata of the brain as well as a set of chemoreceptors in the circulatory system called carotid bodies in carotid arteries and aortic bodies in the aorta both sets of chemoreceptors detect falling ph (more acid) this causes rate and depth of breathing to increase to get the concentration of CO2 to decrease.

6 Skeletal system Functions of the skeletal system: Support body Protect soft body parts Produce blood cells Store minerals and fat Types: 1. A) Bone - Compact: Organized Made up of tube units =osteon Lacunae in concentric circles around central canals B) Bone - Spongy: Unorganized, Lighter Trabeculae thin plates separated by spaces Filled with red bone marrow

7 2. Cartilage: 3 types hyaline (I.e., end of long bones, nose, ribs), fibrocartilage (i.e., vertebral discs, knee), Elastic (i.e, ears, epiglottis) 3. Fibrous connective tissue ligaments and tendons Structure of long bone (refer to notes): Axial Skeleton: Skull/facial bones: Hyoid: Anchors tongue and muscles for swallowing Vertebral column: Cervical 7 in neck Thoracic 12 ribs attach Lumbar have a thick body and thick processes Sacral 5 fused Coccyx - ~4 fused Ribs: 12 pairs of ribs 7 true attached directly to sternum via costal cartilage False indirectly to front by common cartilage 2 floating ribs Sternum breastbone

8 Appendicular skeleton: Pectoral girdle: clavicle (collar bone) and scapula (shoulder blade) - and tendons and ligaments that stabilize this joint. Bones of the arm a. Humerus b. Radius c. Ulna d. Carpals e. Metacarpals f. Phalanges II Pelvic Girdle and bones of the leg Pelvic Girdle Coxal bones: 1. Ilium largest, upper region 2. Ischium sit bones 3. Pubis 2 bones joined at front of pelvic girdle by fibrocartilage makes pelvic cavity Bones of leg a. Femur b. Tibia c. Fibula d. Patella e. Tarsals f. Calcaneus g. Talus h. Metatarsals i. Phalanges Articulations (AKA Joints) I) Fibrous joints II) Cartilaginous joints III) Synovial joints Examples of Types of synovial joints: Ball and socket joints -At hips and shoulders Hinge joints- At elbows and knees Synovial Joint movement Flexion decrease btwn joint and ankle (close) Extension increase btwn joint and ankle (open) Adduction move body towards midline Abduction move body away from midline Rotation move around own axis Circumduction move body part in a circle at one end fixed at other (make cone shape)

Muscular system Functions of the skeletal muscles 1. Supports the body 2. Movement of bones and other body structures 3. Maintains constant internal body temperature 4.

9 Muscular system Functions of the skeletal muscles 1. Supports the body 2. Movement of bones and other body structures 3. Maintains constant internal body temperature 4. Assist movement in veins and lymphatic vessels 5. Protect internal organs in abdominal region 6. Stabilizes joints Skeletal fiber components: 1. Sarcolemma plasma membrane of muscle fiber, forms T-tubules 2. T-Tubules Extension of plasma membrane into muscle fiber Conveys electrical impulse that causes release of calcium ions (Ca 2+ ) from sarcoplasmic reticulum 3. Sarcoplasmic reticulum Smooth ER of skeletal muscle fiber 4. Sarcoplasm 5. Cytoplasm 6. Sarcomere Contractile unit of skeletal muscle fiber 7. Myofibril Organelles that have contractile elements grouped inside them (myofilaments) 8. Myofilament actin and myosin

10 Basic structure of skeletal muscles Whole muscle (surrounded by connective tissue, terminates in tendon that is across joint) Bundles of muscle fibers = fascicle Muscle fiber (AKA skeletal muscle cells) Bundles of myofibrils Myofilaments Sliding filament Model: myosin (thick filament) -actin (thin filament) a) An electrical impulse is delivered to T-tubule system and travels to calcium ion (Ca 2+ ) storage sites in the sarcoplasmic reticulum b) Ca 2+ is released and floods thru the myofibril and occupies molecule on actin filament c) Causes a change in shape and exposes myosin binding sites on actin filament d) Globular heads of myosin contain ATP -ATP hydrolyzes and energy from this cocks the myosin head e) Myosin head then attaches to actin filament at the binding sites forming a cross bridge f) ADP and P is released, energy causes a power stroke to occur g) Actin filaments slide past myosin filaments. Since actin is attached to the Z lines, the sarcomere shortens and contraction occurs h) ATP bind to myosin heads, myosin head detaches and ATP hydrolyzes to ADP and P and isthen ready to undergo another contraction Whole Muscle Contraction Motor unit = nerve fiber with all the muscle fibers it innervates All or none law = all muscle fibers in a motor unit are stimulated at once therefore all contract or none contract Muscle twitch single contraction occurs Single Muscle contraction A single stimulus causes 1 muscle twitch Latent period Contraction Relaxation Sustained Muscle contraction Motor unit given a series of stimuli rapidly Fiber cannot relax before it starts contacting again Summation = a muscle contracting with greater force until max tension is reached is undergoing summation

11 Tetanus = is when many muscle impulses stimulate muscle before it has time to relax producing sustained contraction.

2) During exhalation Air is cooled due to condensation and loses its moisture, depositing it on lining in trachea and nose

2) During exhalation Air is cooled due to condensation and loses its moisture, depositing it on lining in trachea and nose Section 10: The Respiratory System A. Functions of the respiratory system: The organs of the respiratory system make sure oxygen enters the body and carbon dioxide leaves the body. 2 stages: Inhalation