Lecture Exam One

Question 1

define external respiration

Answer 1

movement of oxygen from the lungs to the blood and of carbon dioxide from the blood to the lungs

Question 2

define internal respiration

Answer 2

movement of oxygen from the blood to the tissue cells and of carbon dioxide from tissue cells to blood

Question 3

define cellular respiration

Answer 3

the actual use of oxygen and production of carbon dioxide by tissue cells

Question 4

list four functions of the respiratory mucosa

Answer 4

moistens air, warms air, cilia filter air, enzyme lysozyme destroys bacteria

Question 5

list three divisions of the pharynx

Answer 5

nasopharynx, oropharynx, and laryngopharynx

Question 6

which division of the pharynx do the eustachian tubes drain into?

Answer 6

the eustachian tubes drain into the lateral walls of the nasopharynx

Question 7

which division of the pharynx assists in swallowing

Answer 7

the laryngopharynx assists in swallowing

Question 8

where do the respiratory and digestive systems become distinct

Answer 8

in the laryngopharynx the respiratory and digestive pathways diverge and the larynogophraynx is continuous with the esophagus posteriorly

Question 9

define and describe the larynx

Answer 9

larynx is also known as voice box. attaches to the hyoid bone and opens into the laryngopharynx. Inferiorly it is continuous with trachea.

Question 10

what are the functions of the larynx

Answer 10

1. to provide a patent (open) airway 2. to act as a switching mechanism to route air and food into the proper channels. 3. voice production

Question 11

describe the structure of the vocal chords

Answer 11

are under the laryngeal mucosa on each side. attach the arytenoid cartilages to the thyroid cartilage. composed largely of elastic fibers, form the core of mucosal folds called true vocal chords. Appear pearly white because they lack blood vessels. function is voice production

Question 12

describe the structure of the glottis

Answer 12

it is the vocal folds (chords) and the medial opening that goes between them.

Question 13

describe the structure of the epiglottis

Answer 13

composed of elastic cartilage and is almost entirely covered in taste bud-containing mucosa. is flexible and spoon shaped. extends from the posterior aspect of the tongue to its anchoring point on the anterior rim of the thyroid cartilage

Question 14

discuss the trachea

Answer 14

descends from the larynx through the neck and into the mediastinum. it ends by dividing the two main bronchi at mid thorax. trachea wall consists of several layers that are common to many tubular body organs–the mucosa, submucosa, and adventitia–plus a layer of hyaline cartilage.

Question 15

discuss the mucosa layer of the trachea

Answer 15

the mucosa has the same goblet cell containing psuedostratified epithelium that occurs throughout most of the respiratory tract. its cilia continually propel debris-ladden mucus toward the pharynx.

Question 16

discuss the submucosa layer of the trachea

Answer 16

the submucosa layer of the trachea is a connective tissue layer deep to the mucosa that contains seromucous glands that help produce the mucus “sheets” within the trachea. The submucosa is supported by 16-0 c shaped rings of hyaline catilage encased by the adventitia, the outermost layer of connective tissue.

Question 17

trachea continued

Answer 17

the trachea’s elastic elements make it flexible enough to stretch and move inferiorly during inspiration and recoil during expiration, but the cartilage rings prevent it from collapsing and keep the airway patent (open) despite the pressure changes that occur during breathing. The open posterior parts of the cartilage rings, which abut the esophagus, are connected by smooth muscle fibers of the trachealis muscle and by soft connective tissue.

Question 18

define carina

Answer 18

the carina is the last trachea cartilage. it is expanded and projects posteriorly from its inner face, marking the point where the trachea branches into the two main bronchi. The mucosa of the carina is highly sensitive and violent coughing is triggered when a foreign object makes contact with it.

Question 19

define the bronchial or respiratory tree

Answer 19

the branching pattern of the airwaves. the site where conducting zone structures give way to respiratory zone structures.

Question 20

describe bronchi

Answer 20

the trachea divides to form the righ and left main (primary) bronchi approximately at the level of T7 in an erect person. Each bronchus runs obliquely in the mediastinum before plunging into the medial depression of the lung on its own side. The right main bronchus is wider, shorter, and more vertical than the left. Therefore, it is the more common site for an inhaled foreign object to become lodged.

once inside the lungs, each main bronchi subdivides into lobar (secondary) bronchi–three on the right and two on the left–each supplying one lung lobe.

the lobar bronchi branch into third-order segmental (tertiary) bronchi, which divide repeatedly into smaller and smaller bronchi.

Question 21

describe bronchioles

Answer 21

passages smaller than 1 mm in diameter are called bronchioles, and the tiniest of these, the terminal bronchioles are less than 0.5 mm in diameter.

Question 22

more about bronchi and bronchioles

Answer 22

the tissues of the walls of the main bronchi mimics that of the trachea, but as the conducting tubes become smaller, the following structural changes occure:

1. the cartilage rings are replaced by irregular plates of cartilage, and by the time teh bronchioles are reached, supportive cartilage is no longer present in the tube walls. However, elastic fibers are found in the tube walls throughout the bronchial tree.
2. the mucosal epithelium thins as it changes from pseudostratified columnar to columnar and then to cuboidal in the terminal bronchioles. Cilia are sparse, and mucus-producing cells are absent in the bronchioles.
3. the relative amount of smooth muscle in the tube walls increases as the pasageways become smaller. A complete layer of circular smooth muscle in the bronchioles and the lack of supporting cartilage allows the bronchioles to provide substantial resistance to air pasage under certain conditions.

Question 23

function and structure of conducting zone of the lungs

Answer 23

the conducting zone of the lungs is made up of the trachea, windpipe, which branches off into the main (primary) bronchi. The bronchi further subdivides into the lobar bronchi which splits further into segmental (tertiary) bronchi. These tertiary divide repeatedly into smaller and smaller bronchi until they are small enough to be called bronchioles…(if smaller than 1 mm in diameter)

The purpose of the trachea as an air passageway is to clean, warm, and moisten incoming air.

the bronchial tree is also an airpasage connecting the trachea with alevoli; cleans warms, and moistens incoming air.

Question 24

function and structure of the respiratory zone of the lungs

Answer 24

the respiratory zone begins as the terminal bronchioles feed into respiratory bronchioles within the lung. Present are thin-walled air sacs called alveoli. These air sacs are where gas exchange occurs.

the respiratory bronchioles have scattered alveoli in their walls which lead into alveolar ducts, which are completely lined by alveoli. These ducts end in clusters of alveoli called alveolar sacs. The alveolar sacs look much like a bunch of grapes with the alveoli being a single grape.

gas exchange occurs in the alveoli across the respiratory membrane. this occurs through simple diffusion—O2 passes from the alveolus into the blood, and CO2 leaves the blood to enter the gas-filled alveolus.

Question 25

list and define the three types of cells present in the alveoli

Answer 25

1. the walls of the alveoli are composed primarily of a single layer of **squamous** **epithelial** cells, called **type 1 cells**, surrounded by a flimsy basement membrane. The external surfaces of the alveoli are densely covered with a "cobweb" of pulmonary capillaries. Together the alveolar and capillary walls and their fused basement membranes form the respiratory membrane. 2. **cuboidal** **type** **2** cells are spread amongst the type 1. These cells secrete a fluid containing a detergent-like substance called **surfactant** that coats the gas exposed alveolar surfaces. 3. the alveoli also contain aleolar macrophages that crawls freely along the internal surfaces.

Question 26

define parietal pleura

Answer 26

the parietal pleura covers the thoracic wall and superior face of the diaphragm. It continues around the heart and between the lungs, forming the lateral walls of the mediastinal enclosure and snugly enclosing the lung root.

Question 27

define visceral pleura

Answer 27

the layer of the pleura that covers the external lung surface, dipping into and linning its fissures.

Question 28

define pleural cavity

Answer 28

the slit-like cavity between the parietal and visceral pleurae. this cavity is filled with pleural fluid and the lubricating secretion allows the lungs to glide easily over the thorax wall during breathing movements. the pleura also help divide the thoracic cavity into three chambers--the central medistinum and the two lateral pleural compartments, each containing a lung.

Question 29

define pleurisy

Answer 29

inflammation of the pleurae, often results from pneumonia. Inflamed pleurae become rough, resulting in friction and stabbing pain with each breath. disease progression involves an excessive amount of liquid production. the increased fluid relieves pain caused from the pleural surfaces rubbing together, but may exert pressure on the lungs and hinder breathing movements.

Question 30

define pleural effusion

Answer 30

fluid accumulation in the pleural cavity

Question 31

define Boyles law

Answer 31

describes the relationship between the volume and pressure of gases. It says that at constant temperature, the pressure of a gas varies inversely with its volume. volume changes lead to pressure changes, and pressure changes lead to the flow of gases to equalize the pressure. for example: in a large container, the molecules in a given amount of gas will be far apart and the pressure will be low. But if the volume of the container is reduced, the gas molecules will be forced closer together and the pressure will rise.

Question 32

which muscles are involved in breathing? and which one is most important?

Answer 32

the diaphragm and intercostal muscles the most important is the diaphragm

Question 33

name the nerve that controls the diaphragm

Answer 33

the phrenic nerve controls the diaphragm

Question 34

define the term compliance as it relates to the respiratory system

Answer 34

lung compliance is a measure of the change in lung volume that occurs with a given change in the transpulmonary pressure. the more a lung expands for a given rise in transpulmonary pressure, the greater its compliance. or the higher the lung compliance, the easier it is to expand the lungs at any given transpulmonary pressure lung compliance is determined largely by two factors: 1. distensibility of the lung tissue 2. alveolar surface tension because lung distensibility is generally high and alveolar surface tension is kept low by surfactant, the lungs of healthy people tend to have high compliance lung compliance is diminished by a decrease in the natural resilience of the lungs. Chronic inflammation, or infections such as tuberculosis, can cause nonelastic scar tissue to replace normal lung tissue (fibrosis)

Question 35

define tidal volume

Answer 35

tidal volume is the amount of air that moves into and then out of the lungs during normal quite breathing--500 ml

Question 36

define inspiratory reserve volume

Answer 36

inspiratory reserve volume is the amount of air that can be inspired (breathed in) forcibly beyond the tidal volume (2100-3200 ml)

Question 37

define expiratory reserve volume

Answer 37

expiratory volume is the amount of air--normally 1000 to 1200 ml---that can be evacuated from the lungs after a tidal expiration.

Question 38

define resdiual volume

Answer 38

residual volume is the amount of air that remains in the lungs even after the most strenuous expiration, about 1200 ml. This helps to keep the alveoli patent and to prevent lung collapse

Question 39

define inspiratory capacity

Answer 39

inspiratory capacity is the total amount of air that can be inspired after a tidal expiration...it is the sum of tidal volume and inspiratory reserve volume

Question 40

define functional residual capacity

Answer 40

functional residual capacity is the amount of air remaining in the lungs after a tidal expiration and is the combined residual volume and expiratory reserve volume

Question 41

define vital capacity

Answer 41

vital capacity is the total amount of exchangeable air. it is the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume.

Question 42

define total lung capacity

Answer 42

total lung capacity is the sum of all lung volumes and is normally around 6000 ml

Question 43

define anatomical dead space

Answer 43

inspired air that fills the conducting respiratory passageways and never contributes to gas exchange in the alveoli.

Question 44

define minute respiratory volume

Answer 44

total amount of gas that flows into or out of the respiratory tract in 1 minute. During normal quite breathing, the minute ventilation in healthy people is about 6 L/min

Question 45

define Dalton's law

Answer 45

Dalton's law of partial pressures states that the total pressure exerted by a **mixture** of gases is the **sum** of the pressures exerted **independently** by each gas in the mixture also, the pressure exerted by each gas--the **partial pressure, is directly proportional to the percentage of gas in the gas mixture**

Question 46

list the three factors that determine the solubility of gases

Answer 46

the solubility of gases is influenced by these three factors: 1. temperature - increasing the liquids temperature decreases the gas' solubiity. 2. partial pressure - the partial pressure of the gas compared to the partial pressure of the liquid 3. the nature of a solvent and solute - whether the solute and solvent is polar or non-polar

Question 47

define Henry's law

Answer 47

says that gas will dissolve in a liquid in proportion to its partial pressure. therefore, the greater the concentration of a particular gas in the gas phase, the more and the faster that gas will go into solutin in the liquid. at equilibrium, the gas partial pressures in the two phases are the same. If, however, the partial pressure of the gas later becomes greater in the liquid than in the adjacent gas phase, some of the dissolved gas molecules will reenter the gaseous phase. So the direction and amount of movement of a gas is determined by its partial pressure in the two phases. Carbon dioxide is very soluble in blood, allowing many molecules to diffuse along this small partial pressure gradient. oxygen is less soluble, requiring a larger concentration gradient.

Question 48

list four factors that determine the rate of exchange of oxygen and carbon dioxide across the alveolar-capillary membrane (respiratory membrane)

Answer 48

1. thickness of the membrane - any factor that increases respiratory membrane thickness will interfere with normal respiratory exchange of gases in edema - increased fluid in the interstitial space - because gas must diffuse through the fluid fibrosis - an increase in respiratory membrane thickness 2. surface area of the membrane - the greater the surface area of the respiratory membrane, the more gas can diffuse across it in a given time period. in certain pulmonary diseases, the alveolar surface area actually functioning in gas exchange is drastically reduced. This occurs in **emphysema**, when the walls of adjacent alveoli break down and the alveolar chambers become larger. 3. the solubility of the gas - carbon dioxide is much more soluble than oxygen 4. partial pressure gradients - there is a steep partial pressure gradient across the respiratory membrane because the partial pressure of O2 of the deoxygenated blood in the pulmonary arteries is only 40 mm Hg, as opposed to a Po2 of approximately 104 mm Hg in the alveoli. This means O2 diffuses rapidly from the alveoli into the pulmonary capillary blood. Equilibrium--that is a Po2 of 104 mm Hg on both sides of the respiratory membrane---usually occurs in .25 second, about 1/3 the time a RBC is in a pumonary capillary

Question 49

explain the method by which oxygen and carbon dioxide are carried by the blood

Answer 49

oxygen is carried in the blood by two ways: 1. bound to hemoglobin within red blood cells 2. dissolved in plasma

Question 50

explain why carbon monoxide is so dangerous

Answer 50

carbon monoxide is dangerous because it competes with oxygen and wins. it is also an odorless and colorless gas that is hard to detect

Question 51

how does carbon monoxide interact with hemoglobin What is formed when carbon monoxide and Hb bind

Answer 51

carbon monoxide binds with the heme sites on hemoglobin which has an affinity for CO more than 200 times the affinity for oxygen when Hb and CO bond carboxyhemoglobin is formed

Question 52

what are the three parts of the respiratory center of the brainstem

Answer 52

Dorsal respiratory group ventral respiratory group pontine respiratory centers

Question 53

where are the respiratory centers located?

Answer 53

they are located in the pons (pontine centers) and the medulla oblongata

Question 54

explain what happens if the carbon dioxide concentration in the blood rises above normal.

Answer 54

if the carbon dioxide concentration in the blood rises above normal, called **hypercapnia**, CO2 accumulates in the brain. As it accumulates it forms carbonic acid. The acid dissociates, H+ is liberated, and the pH drops. The increase in H+ excites the central chemoreceptors, which make abundant synapses with the respiratory regulatory centers. As a result, the depth and rate of breathing are increased. This enhanced breathing (aveolar ventilation) quickly flushes CO2 out of the blood, increasing blood pH.

Question 55

define hypercapnia

Answer 55

high carbon dioxide levels in blood

Question 56

which receptors sense the increase of carbon dioxide in the blood?

Answer 56

the central chemoreceptors

Question 57

list two factors affected by exercise which results in an increase in the depth and rate of breathing

Answer 57

working muscles consume large amounts of O2 and produce large amounts of CO2 so ventilation increases

Question 58

which "other activity" of the respiratory system persists even during deep coma?

Answer 58

coughing

Question 59

explain the stages of development of the respiratory tree at :

Answer 59

week 4: trechea and bronchial buds appear around 4 weeks week 8: bronchi are in mature form about 8 weeks then broncholies branch by week 24 alveoli form and surfactant is secreted

Question 60

list the 8 major functions of blood

Answer 60

1. transport respiratory gases 2. helps regulate acid-base balance 3. aids in the transport of nutrients, hormones, and enzymes 4. helps transport wastes 5. regulates body temperature 6. aides in stoppage of bleeding 7. helps regulate body fluids 8. helps defend against microorganisms and toxins

Question 61

explain how blood gets its red color

Answer 61

the amount of oxygen determines the red color. oxygen rich blood is scarlet oxygen poor blood is deep red

Question 62

define blood viscosity

Answer 62

the measure of the thickness of blood. having a higher number of RBS accounts for a higher viscosity. higher viscosity translates to slower blood flow

Question 63

define blood

Answer 63

specialized connective tissue, in which living blood cells, called the formed elements, are suspended in a nonliving fluid matrix called plasma.

Question 64

how much of blood is "formed elements" what are they?

Answer 64

about 45% of blood is the formed elements they are a buffy coat - consisting of leukocytes and platelets \<1% of whole blood and erythrocytes which are 45% of whole blood, most dense component

Question 65

how much of blood is plasma?

Answer 65

plasma makes up 55% of blood

Question 66

list the components of plasma and what each does

Answer 66

water - 90% of plasma volume; dissolving and suspending medium for solutes of blood; absorbs heat plasma proteins: Albumin - 60% of plasma proteins; produced by liver; main contributor to osmotic pressure Globulins - 36% of plasma proteins - alpha, beta--produced by liver; most are transport proteins that bind to lipids, metal ions, and fat-soluble vitamins gamma- antibodies released by plasma cells during immune response fibrinogen - 4% of plasma proteins; produced by liver; forms fibrin threads of blood clot nonprotein nitrogenous substances----by products of cellular metabolism, such as urea, uric acid, creatinine, and ammonium salts

Question 67

describe the general structure and chemical make up of an erythrocyte (RBC)

Answer 67

small cells; shaped like biconcave disks---flattened discs with depressed centers---they appear lighter in color at their thin centers than at their edeges...mature erythrocytes are bound by a plasma membrane, but lack a nucleus they are basically bags of hemoglobin, the RBC protein that functions in gas transport

Question 68

what is the benefit of the RBCs shape?

Answer 68

the biconcave shape of RBCs, erythrocytes, is to increase surface area.

Question 69

describe the components of hemoglobin

Answer 69

hemoglobin is made up of the protein globin bound to the red heme pigment (heme contains iron) a hemoglobin molecule can transport four molecules of oxygen because each iron atom can combine reversibly with one molecule of oxygen

Question 70

list three properties of the cell membrane of the RBC