CHAPTER 19: RESPIRATORY SYSTEM

CHAPTER 19: RESPIRATORY SYSTEM

OBJECTIVES:

Name the organs and functions of the respiratory system.

Organs

Functions

1. Nose/External Nares

2. Nasal Cavity

3. Pharynx

4. Larynx

5. Trachea

6. Bronchial Tree within Lungs

7. Paranasal Sinuses

8. Diaphragm

1 exchange of gases

2 voice production

3 blood pH homeostasis

1. Name the 5 parts of respiration (You will define these in later questions).

PULMONARY VENTILATION

EXTERNAL RESPIRATION

TRANSPORT OF GASES

INTERNAL RESPIRATION

CELLULAR RESPIRATION

2. Describe the significance of oxygen and carbon dioxide in human cells.

OXYGEN IS REQUIRED BY ANIMAL CELLS TO PERFORM CELLULAR RESPIRATION WHICH RELEASES ENERGY FROM NUTRIENTS. A WASTE-PRODUCT OF CR IS CARBON DIOXIDE.

3. Explain the structure and function of mucous membranes that line most of the respiratory tract. Specifically name the tissue that lines the trachea.

MUCOUS MEMBRANES (MM) ARE MOIST MEMBRANES THAT WARM, MOISTEN, AND FILTER INCOMING AIR. GOBLET CELLS SECRETE MUCUS WHICH PROTECTS. SPECIFICALLY IN THE TRACHEA THE MM IS PSEUDOSTRATIFIED COLUMNAR EPITHELIUM (PSCET), WHERE MUCUS COATED CILIA TRAP DEBRIS AND THE CILIA BEAT THE DEBRIS UP AND OUT OF AIRWAY.

4. Locate the upper respiratory organs on the diagram below, describe their structure and any specific functions they may have (both respiratory and other functions, if applicable).

ALL ARE LINED BY MUCOUS MEMBRANES THAT WARM, FILTER, AND MOISTEN INCOMING AIR. NOSE COMPOSED OF BONE AND CARTILAGE HAS MACROSCOPIC HAIRS TO TRAP DEBRIS; NASAL CAVITY IS DIVIDED INTO TWO BY NASAL SEPTUM AND INTO THREE PASSAGEWAYS ON EACH SIDE BY NASAL CONCHAE; PARANASAL SINUSES ARE CONTINUOUS WITH NASAL CAVITY; PHARYX IS DIVIDED INTO NASOPHARYNX, OROPHARYNX, AND LARYNOPHARYNX; LARYNX IS COMPOSED OF SEVERAL HYALINE CARTILAGE COMPONENTS AND ONE ELASTIC CARTILAGE STRUCTURE CALLED THE EPIGLOTTIS. THE LARYNX ALSO CONTAINS VOCAL CORDS PRODUCING SPEECH

5. Name the four skull bones that contain sinuses and label them below.

FRONTAL, ETHMOID, SPHENOID, AND MAXILLARY

6. Name the three parts of the pharynx and label them in the diagram below.

NASOPHARYNX, OROPHARYNX, AND LARYNGOPHARYNX

7. Explain the significance of the epiglottis and glottis. Label the epiglottis above.

THE EPIGLOTTIS CLOSES THE AIRWAY DURING SWALLOWING AND THE GLOTTIS IS THE SLIT-LIKE SPACE BETWEEN THE VOCAL CORDS THROUGH WHICH AIR PASSES

8. Give the scientific name for the "Adam's Apple", and label it in the diagram below.

THYROID CARTILAGE

9. Describe how and where sound originates and how it is then converted into recognizable speech.

SOUND ORIGINATES WHEN EXPELLED AIR PENETRATES THE VOCAL CORDS CAUSING THEM TO VIBRATE. THE CEREBRAL CORTEX ALLOWS FOR SPEECH INITIATION, AND BROCA’S AREAS STIMULATE THE MUSCLES NECESSARY FOR SPEECH. THE SINUSES ACT AS RESONATING CHAMBERS.

10. Locate the lower respiratory organs on the diagram below, and describe the structure and any specific functions each may have.

TRACHEA’S HYALINE CARTILAGE SUPPORTS AIRWAY AND PSCET WARMS, FILTERS AND MOISTENS WITH ITS CILIA; PRIMARY BRONCHI, SECONDARY BRONCHI AND TERTIARY BRONCHI CONTINUE TO WARM….AND DISTRIBUTE AIR

TERMINAL BRONCHIOLES ARE A REGULATION SITE DETERMINING THE AMOUNT OF AIR ALLOWED INTO THE LUNG LOBULE; ALVEOLI ALLOW FOR GAS EXCHANGE.

11. Define the terms C-ring, trachealis muscle, and carina. Label carina above.

C-RINGS ARE THE RINGS OF HYALINE CARTILAGE OF THE TRACHEA; THE TRACHEALIS MUSCLE COMPLETES THE C-RING ANTERIOR TO THE ESOPHAGUS; CARINA IS THE POINT OF BIFURCATION OF THE TRACHEA IN TO THE LUNGS.

12. Name the type of cartilage that composes the trachea wall. HYALINE CARTILAGE

13. Distinguish between a primary, secondary, and tertiary bronchus, and label in the diagram above.

PRIMARY BRONCHI TO EACH LUNG, SECONDARY BRONCHI TO EACH LOBE AND TERTIARY BRONCHI FURTHER SUBDIVIDE AIR.

14. Explain what happens to the epithelial lining, cartilage and smooth muscle of the bronchi as they branch deep into the lungs to form terminal bronchioles.

EPITHELIUM IS REDUCED TO SIMPLE COLUMNAR ET, CARTILAGE DECREASES AND SMOOTH MUSCLE INCREASES.

15. Explain the effects that histamine and epinephrine have on terminal bronchioles.

HISTAMINE CAUSES BRONCHOCONSTRICTION; EPINEPHRINE CAUSES BRONCHODILATION

16. Discuss the structure and function of the pleural membranes.

THE VISCERAL AND PARIETAL PLEURAL MEMBRANES ARE SEROUS MEMBRANES = SIMPLE SQUAMOUS ET OVER LOOSE AREOLAR CONNECTIVE TISSUE (CT). THE SEROUS FLUID BETWEEN THEM ESSENTIALLY GLUES THE TWO MEMBRANES TOGETHER AND THEY ACT AS ONE WHICH AIDS IN INSPIRATION.

17. Distinguish between a lobe and lobule of the lung and label each on the diagram below.

THERE ARE FIVE LUNG LOBES; THREE ON THE RIGHT AND TWO ON THE LEFT. THERE ARE MANY LUNG LOBULES WHERE EACH RECEIVES A RESPIRATORY BRONCHIOLE, IS SURROUNDED BY ELASTIC CT, AND HOUSES A PULMONARY ARTERY AND A PULMONARY VEIN.

18. Discuss the microscopic anatomy of the lung, and label the tissue components below.

THE ALVEOLAR WALLS ARE COMPOSED OF SIMPLE SQUAMOUS ET PLUS ITS BASEMENT MEMBRANE.

19. Track a breath of air from the nose to an alveolus, noting what happens to the air as it meets each structure (16 steps)

*NOSE*	*SECONDARY BRONCHUS*
*NASAL CAVITY*	*TERTIARY BRONCHUS*
*NASOPHARYNX*	*INTERLOBULAR BRONCHIOLE*
*OROPHARYNX*	*TERMINAL BRONCHIOLE*
*LARYNGOPHARYNX*	*RESPIRATORY BRONCHIOLE*
*LARYNX*	*ALVEOLAR DUCT*
*TRACHEA*	*ALVEOLAR SAC*
*PRIMARY BRONCHUS*	*ALVEOLUS*

20. Distinguish between Type I and Type II Alveolar cells, in terms of structure and function and label each in the diagram below.

TYPE I ALVEOLAR CELLS ARE THE WALL CELLS WHILE TYPE II SECRETE SURFACTANT

21. Define the term surfactant and describe its important function.

SURFACTANT, SECRETED BY TYPE II ALVEOLAR CELLS IS COMPOSED OF PHOSHOLIPIDS (FAT,) AND IT FUNCTIONS TO REDUCE THE SURFACE TENSION DURING EXPIRATION, PREVENTING RECOILING OF THE ALVEOLI UPON THEMSELVES.

22. Draw a typical sketch of the respiratory membrane. Then in essay form, provide the scientific name of the process that occurs through this membrane, describe the structure of this membrane in terms of specific tissue components and thickness, and specifically explain what occurs through this membrane using actual numerical values. Finally, explain the fate of the substances involved.

THE PROCESS THAT OCCURS THROUGH THE RESPIRATORY MEMBRANE (RM) IS EXTERNAL RESPIRATION, WHICH IS DEFINED AS THE EXCHANGE OF GASES BETWEEN THE AIR IN THE ALVEOLI AND THE BLOOD IN THE LUNG CAPILLARIES. THE RM IS COMPOSED OF TWO THIN LAYERS: THE SIMPLE SQUAMOUS ET OF THE ALVEOLUS PLUS ITS BASEMENT MEMBRANE AND THE ENDOTHELIUM OF THE LUNG CAPILLARY PLUS ITS BASEMENT MEMBRANE. THE RM IS VERY THIN, 0.5 MICRONS IN THICKNESS. THE MEMBRANE ALLOWS FOR RAPID DIFFUSION OF GASES FROM WHERE THEY ARE IN HIGH PRESSURE TO WHERE THEY ARE IN LOW PRESSURE (DALTON’S LAW).

AIR IS A MIXTURE OF GASES, WHICH IS 21% OXYGEN AND LESS THAN 1% CARBON DIOXIDE. IN A MIXTURE OF GASES, EACH GAS EXERTS A PARTIAL PRESSURE TOWARD THE TOTAL GAS PRESSURE, AND THE PARTIAL PRESSURE OF A GAS IS DIRECTLY PROPORTIONAL TO ITS CONCENTRATION. THE PARTIAL PRESSURE OF OXYGEN IN THE AIR IN THE ALVEOLUS IS 104mmHg AND THE PARTIAL PRESSURE OF OXYGEN IN THE LUNG CAPILLARY IS 40 mmHg. CONSEQUENTLY, OXYGEN DIFFUSES THROUGH THE RM FROM THE ALVEOLUS INTO THE BLOOD IN THE LUNG CAPILLARY WHERE IT IS TRANSPORTED BACK TO THE HEART FOR DISTRIBUTION TO ALL BODY CELLS. CONVERSELY, THE PARTIAL PRESSURE OF CARBON DIOXIDE IN THE LUNG CAPILLARY IS 45 mmHg AND THE PARTIAL PRESSURE OF CARBON DIOXIDE IN THE AIR IN THE ALVEOLUS IS 40 mmHg. THEREFORE CARBON DIOXIDE DIFFUSES THROUGH THE RM FROM THE BLOOD IN THE LUNG CAPILLARY INTO THE AIR IN THE ALVEOLUS WHERE IT IS THEN EXPELLED.

23. Define the term pulmonary ventilation, and describe its two actions in terms of forces, muscles, and membranes involved.

PULMONARY VENTILATION IS BREATHING. THE TWO ACTIONS IN PULMOMARY VENTILATION INCLUDE INSPIRATION AND EXPIRATION. INSPIRATION IS DUE TO ATMOSPHERIC PRESSURE AND EXPIRATION IS DUE TO ELASTIC RECOIL. THE DIAPHRAGM AND INTERCOSTAL MUSCLES ARE INVLOVED.

24. Starting with the diaphragm muscle in its relaxed position, describe in order, the events that occur during inspiration.

1. THE DIAPHRAGM CONTRACTS AND PUSHES DOWNWARD

3. THE PRESSURE WITHIN THE THORACIC CAVITY DECREASES TO 758mmHg (BOYLE’S LAW)

2. THE SIZE OF THE THORACIC CAVITY INCREASES

4. AIR RUSHES INTO AND INFLATES THE LUNGS (DALTON’S LAW)

25. Explain how Boyle's Law relates to ventilation.

BOYLES LAW STATES THAT THE PRESSURE OF GAS IS INVERSLY PROPORATIONAL TO THE VOLUME OF THE GAS. AS THE SIZE (VOLUME) OF THE THORACIC CAVITY INCREASES, THE PRESSURE WITHIN THE THORACIC CAVITY DECREASES TO FROM 760 TO 758mmHg .

26. Explain why the serous fluid between the pleural membranes has such high surface tension.

SEROUS FLUID IS COMPOSED PRIMARILY OF WATER WHOSE MOLECULES ARE VERY COHESIVE RESULTING IN HIGH SURFACE TENSION.

27. Define the term atelectasis, explain what is usually lacking within the alveoli when it occurs, and name the disease of premature newborns when it occurs.

ATELECTASIS IS COLLAPSED LUNG. PREMATURE INFANTS LACK SURFACTANT WHICH FUNCTIONS TO OVERCOME THE HIGH SURFACE TENSION WITHIN THE ALVEOLI. THIS IS CALLED RESPIRATORY DISTRESS SYNDROME.

28. Name the instrument used to measure lung volumes.

SPIROMETER

29. List, define, give estimate values, and correlate the six different lung volume measurements shown in the graph below.

TIDAL VOLUME (TV) IS THE NORMAL VOLUME INSPIRED AND EXPIRED.

VITAL CAPACITY (VC) IS TV + IRV + ERV.

INSPIRATORY RESERVE VOLUME (IRV) IS THE VOLUME OF AIR ONE CAN FORCIBLY INHALE AFTER A NORMAL TIDAL INSPIRATION.

RESIDUAL VOLUME (RV) IS THE VOLUME OF AIR THAT ALWAYS REMAINS IN THE LUNGS.

EXPIRATORY RESERVE VOLUME (ERV) IS THE VOLUME OF AIR ONE CAN FORCIBLY EXHALE AFTER A NORMAL TIDAL EXPIRATION.

TOTAL LUNG CAPACITY IS VC + RV.

30. Define the term external respiration.

EXTERNAL RESPIRATION, IS DEFINED AS THE EXCHANGE OF GASES BETWEEN THE AIR IN THE ALVEOLI AND THE BLOOD IN THE LUNG CAPILLARIES.

31. State Dalton's Law and explain its significance in respiration.

DALTON’ S LAW STATES THAT GASES DIFFUSE FROM WHERE THEY ARE IN HIGH PRESSURE TO WHERE THEY ARE IN LOW PRESSURE. DURING INSPIRATION, THE PRESSURE OF THE GAS IN THE THORACIC CAVITY FALLS TO 758 mmHg, SO AIR RUSHES FROM THE OUTSIDE WHERE ITS PRESSURE IS 760 INTO THE ALVEOLI.

32. List the percentages of N₂, O_2, and CO₂ in air.

NITROGEN = 78%; OXYGEN IS 21%; AND CARBON DIOXIDE IS LESS THAN 1%.

33. Define what is meant by the partial pressure (pp) of a gas in a mixture and list the pp values of O₂ and CO₂ in air and in the lung capillaries.

34. Discuss the factors that influence the rate at which a gas diffuses.

THE FACTORS THAT INFLUENCE THE RATE AT WHICH A GAS FLOWS INCLUDE: EXCHANGE SURFACE AREA, DIFFUSION DISTANCE, AND BREATHING RATE AND DEPTH.

35. Define the term internal respiration.

INTERNAL RESPIRATION IS THE EXCHANGE OF GASES BETWEEN THE BLOOD IN THE TISSUE CAPILLARIES AND THE TISSUE CELLS.

36. Discuss how oxygen, carbon monoxide and carbon dioxide are transported in the blood.

OXYGEN IS LOOSELY CARRIED BY THE HEMOGLOBIN IN ERYTHROCYTES AS OXYHEMOGLOBIN.

MOST CARBON DIOXIDE (70%) IS CARRIED AS BICARBONATE ION, SOME (23%) IS CARRIED BY HEMOGLOBIN AS CARBAMINOHEMOGLOBIN, AND 7% IS DIFFUSED IN THE BLOOD.

CARBON MONOXIDE IS TRANSPORTED TIGHTLY BY HEMOGLOBIN.

37. Name the three factors that cause oxygen to be released from the hemoglobin of red blood cells.

OXYGEN IS RELEASED BY HEMOGLOBIN UNDER THE FOLLOWING CONDITIONS: INCREASED TEMPERATURE; INCREASED CARBON DIOXIDE CONCENTRATION/PRESSURE; DECRESED BLOOD pH.

38. Define the term hypoxia, and describe how it occurs during carbon monoxide poisoning.

HYPOXIA IS A REDUCTION OF OXYGEN TO CELLS. BECAUSE CARBON MONOXIDE IS TIGHTLY BOUND TO HEMOGLOBIN, THERE ARE FEWER HEMOGLOBIN MOLECULES TO CARRY OXYGEN.

39. Write the chemical equation that involves carbon dioxide, water, carbonic acid, a hydrogen ion, and a bicarbonate ion, and explain its significance.

CO₂ + H₂O <------> H₂CO₃ <-------> H⁺ + HCO₃^-

IN TISSUES, CO₂ IS PRODUCED BY CELLULAR RESPIRATION.

A. THIS CO₂ COMBINES WITH H₂O TO FORM H₂CO₃ (CARBONIC ACID) WHICH THEN

B. DISSOCIATES UNDER THE INFLUENCE OF CARBONIC ANHYDRASE TO RELEASE

C. H⁺ AND BICARBONATE ION(HCO₃^-):

* REACTION IS REVERSED IN LUNGS & CO₂ IS EXPELLED DURING EXPIRATION.

40. Locate the neural respiratory center on the diagram below.

41. Distinguish between the rhythmicity area and pneumotaxic area of the neural respiratory center.

RHYTHMICITY AREA IS LOCATED IN THE MEDULLA. IT IS COMPOSED OF A DORSAL RESPIRATORY GROUP WHICH CONTROLS THE BASIC RHYTHM OF BREATHING AND A VENTRAL RESPIRATORY GROUP WHICH CONTROLS FORCEFUL BREATHING.

PNEUMOTAXIC AREA IS LOCATED IN THE PONS AND CONTROLS RATE OF BREATHING.

42. Explain how respiration is affected by varying chemical (CO₂ and O₂) concentration in the blood.