Exam 3 - Respiratory System Flashcards

Question

Vocal folds

Answer 1

True vocal cords Contain inferior ligaments At junction of vocal cords is an opening called the glottis When vocal cords are inflamed, laryngitis occurs Structure that ligaments are found within in larynx

Answer 2

Forceful attempt of exhalation against a closed airway

Answer 3

Windpipe Allows air to flow into lungs Membranous tube attached to larynx Found behind the esophagus Consists of dense regular connective tissue and smooth muscle Reinforced with hyaline cartilage called tracheal rings by preventing collapse Smooth muscle, trachealis, can narrow diameter of trachea by contracting, which aids in coughing Mucous membrane lines trachea Membrane's goblet cells produce mucus, which traps dust and bacteria Ciliated epithelium moves mucus into larynx, which enters pharynx, which is then swallowed Constant, long-term irritation to trachea can cause tracheal epithelium to become moist stratified epithelium that lacks cilia and goblet cells

Answer 4

Trachea divides into two smaller tubes called main bronchi, or primary bronchi, each of which extends to lung Location where trachea divides into the two main bronchi is a ridge of cartilage called carina Primary bronchi split into two secondary (lobal) bronchi in the left lung and three secondary bronchi in the right lung, one for each lung lobe Secondary bronchi split into eight tertiary (segmental) bronchi on the left and ten tertiary bronchi on the right As gets smaller, less cartilage present and more smooth muscle found in walls

Answer 5

Result from continued branching of segmental bronchi Have less cartilage and more smooth muscle Larger bronchioles are lined with ciliated simple columnar epithelium Terminal bronchioles arise from bronchioles Have completed layer of smooth muscle and no cartilage Lined with simple cuboidal epithelium

Answer 6

Where gas exchange occurs Sites of pulmonary gas exchange Small, air-filled chambers where the air and blood come into close contact with each other Alveolar ducts and alveoli consist of simple squamous epithelium

Answer 7

Part of lung where gas exchange occurs, specifically where oxygen is taken up by blood and carbon dioxide is released into air to be exhaled Macrophages do not accumulate because they move into nearby lymphatic vessels or enter terminal bronchioles, thereby becoming entrapped in mucus that is swept to the pharynx Order of flow: Terminal bronchiole Respiratory bronchioles Alveolar ducts Alveolar sacs Alveoli

Answer 8

Two types of cells form alveolar wall: 1) Type I Alveolar Cells/Type I Pneumocytes: thin simple squamous epithelial cells that form 90% of alveolar cells. Most gas exchange takes place through these cells 2) Type II Alveolar Cells/Type II Pneumocytes: Round or cube-shaped secretory cells that produce surfactant, which makes it easier for alveoli to expand during inspiration. Keeps alveoli open

Answer 9

Formed by alveolar walls and surrounding pulmonary capillaries Location of pulmonary gas exchange Extremely thin Components include: 1) Alveolar cell layer 2) Capillary endothelial layer 3) An interstitial space between alveolar layer and capillary layer

Answer 10

Thoracic wall composed of 1) Thoracic vertebrae 2) Ribs 3) Costal cartilages 4) Sternum 5) Associated muscles Thoracic cavity is space enclosed by thoracic wall and diaphragm Diaphragm and other skeletal muscles associated with thoracic wall change thoracic volume during pulmonary ventilation Provides structure necessary for expansion and contraction of thoracic cavity

Answer 11

Each lung is conical in shape and extends from the diaphragm to a point approximately 2.5xm superior to the clavicle The portion of the lungs in contact with the diaphragm is the base Portion of the lungs that extends above the clavicle is the apex Right lung is larger than left lung Right lung has three lobes, and left lung has two lobes

Answer 12

Blood that has passed through lungs and picked up O2 is oxygenated blood Blood that has passed through tissues and released some of its O2 is called deoxygenated blood Two blood flow routes to lungs: 1) Blood flow to alveoli: Deoxygenated blood flows through pulmonary arteries to pulmonary capillaries, where it becomes oxygenated and returns to heart through pulmonary veins 2) Blood flow to tissues of bronchial tree: Oxygenated blood flows through bronchial arteries to capillaries, where O2 is released

Answer 13

Lungs have two lymphatic supplies: 1) Superficial lymphatic vessels: Deep to connective tissue that surrounds each lung, called visceral pleura. These vessels drain lymph from superficial lung tissue and the visceral pleura 2) Deep lymphatic vessels: Follow bronchi. Vessels drain lymph from bronchi and associated connective tissues No lymphatic vessels located in walls of the alveoli Both superficial and deep lymphatic vessels exit lung at hilum

Answer 14

Two pleural cavities within thoracic cavity Each houses one lung Pleural cavities lined with serous membrane Mediastinum separates the two pleural cavities in the central region Parietal pleura: Serous membrane that covers inner thoracic wall, the superior surface of the diaphragm, and the mediastinum At hilum, parietal pleura is continuous with visceral pleura, which covers surface of lung Pleurisy: Inflammation of pleurae; Result in sharp chest pain when breathing

Answer 15

Facilitates the expansion and contraction of lungs during breathing During inhalation, pressure within pleural cavity decreases Pleural fluid within pleural cavity maintains adhesion between pleural layers, ensuring that the lungs expand and contract with the chest wall during breathing movements

Answer 16

Muscles of inspiration act to increase the volume of the thoracic cavity and include: 1) Diaphragm: Contraction causes central tendon to move downward. Downward movement facilitated by relaxation of abdominal muscles, which moves abdominal organs out of way. Continued contraction of diaphragm causes it to flatten as lower ribs are elevated 2) External intercostals: Increase thoracic volume by elevating ribs. As ribs are elevated, costal cartilages allow lateral rib movement and lateral expansion of thoracic cavity 3) Pectoralis minor 4) Scalenes 5) Sternocleidomastoid Quiet breathing: External intercostal muscles contract, elevating ribs and moving sternum

Answer 17

Muscles of expiration act to decrease thoracic volume by depressing ribs and sternum and include: 1) Internal intercostals 2) Abdominal muscles Expiration is passive, so thorax wall and lungs spring back into smaller relaxed state, due to removed tension. External intercostals relax and ribs move downward. Contractions of abdominal muscles cause thoracic cavity volume to decrease and push abdominal organs upward into diaphragm, which moves it superiorly

Answer 18

Higher partial pressure of oxygen in lungs = more oxygen dissolved into blood Higher partial pressure of carbon dioxide than air in alveoli = higher partial pressure of blood than alveoli Henry's Law: Concentration of gas in a liquid is proportional to the partial pressure of that gas; As partial pressure of oxygen or carbon dioxide increases, the concentration of that gas in the blood will increase Dalton's Law: Total pressure of a gas is the sum of the individual pressures of each gas Partial pressure: Individual pressure of each gas

Answer 19

Tidal volume: Normal volume of air inspired and expired with each breath. At rest, the quiet pulmonary ventilation results in a tidal volume of approximately 500mL Inspiratory reserve volume: The amount of air that can be inspired forcefully after a normal inspiration Expiratory reserve volume: Amount of air that can be forcefully expired after a normal expiration Residual volume: The volume of air still remaining in the respiratory passages and lungs after the most forceful expiration

Answer 20

The sum of two or more pulmonary volumes 1) Inspiratory capacity: Tidal volume plus the inspiratory reserve volume. Amount of air a person can inspire maximally after a normal expiration 2) Functional residual capacity: Expiratory reserve volume plus the residual volume. Amount of air remaining in the lungs at the end of a normal expiration 3) Vital capacity: Sum of inspiratory reserve volume, the tidal volume, and the expiratory reserve volume. Maximum volume of air a person can expel from the respiratory tract after a maximum inspiration 4) Total lung capacity: Sum of inspiratory and expiratory reserve volumes plus the tidal volume and residual volume

Answer 21

Air pressure in alveoli is intrapulmonary pressure When person inspires, the intrapulmonary pressure decreases because the alveolar volume has increased When a person expires, the intrapulmonary pressure increases because the alveolar volume has decreased Pressure difference between atmospheric pressure and intrapulmonary pressure that results in air movement during one respiratory cycle 760mmHg at sea level Intrapulmonary pressure fluctuates with breathing and always eventually equalizes with atmospheric pressure

Answer 22

Pneumothorax or hemothorax or collapsed lung Surfactant: Mixture of lipoprotein molecules produced by type II pneumocytes of alveolar epithelium. Reduces surface tension in alveoli. Reduces tendency of lungs to collapse Pleural pressure: Pressure within pleural cavity. When thoracic wall expands during inspiration, the parietal pleura exerts an outward force on the visceral pleura covering the lungs, and the lungs expand. Pleural pressure pulls the lungs outward and is lower than intra-alveolar pressure. Maintains slightly negative pressure between lungs and chest wall. Keeps lungs expanded by counteracting their tendency to recoil and collapse. Similar to a vacuum seal holding lungs open

Answer 23

Partial pressure gradient for O2 is into blood from alveoli. Once in blood, the partial pressure gradient for O2 is into the body's cells into the blood Carbon dioxide moves out of the body's cells and into the blood. Once in the blood, the partial pressure gradient for CO2 is out of the blood into the alveoli CO2 is opposite of that for O2

Answer 24

Membrane thickness: Increasing the thickness of respiratory membrane decreases the rate of gas diffusion; Diseases increase its thickness, therefore decreasing rate of gas diffusion; Most common cause of increased respiratory membrane thickness is an accumulation of fluid in the alveoli, known as pulmonary edema Diffusion coefficient of gas: Measure of how easily a gas diffuses through a liquid or tissue Surface area: More surface area means more gas movement

Answer 25

As fetal blood circulates through the placenta, O2 is released from mother's blood into the fetal blood, and CO2 is released from fetal blood into the mother's blood. These forms of hemoglobin are particularly effective for O2 transport because: 1) The concentration of fetal hemoglobin is approximately 50% greater than the concentration of maternal hemoglobin 2) For a given O2 partial pressure, fetal hemoglobin has a higher affinity for O2 than maternal hemoglobin does

Answer 26

O2 transportation: Once O2 diffuses through the respiratory membrane into the blood, it is transported to all cells of the body. Approximately 98.5% of O2 is transported reversibly bound to hemoglobin within red blood cells, and the remaining 1.5% is dissolved in the plasma. Cells use O2 in aerobic cellular respiration to synthesize ATP Factors affecting hemoglobin's affinity for O2: 1) Partial pressure of O2: 25% of the O2 bound to hemoglobin is released 2) Temperature: Increased blood temperature decreases affinity for hemoglobin for O2 3) Blood pH: Decreased pH decreases affinity for hemoglobin for O2 4) Partial pressure of CO2: Increased CO2 partial pressure decreases affinity for hemoglobin for O2 5) BPG concentration: Increase in BPG decreases affinity for hemoglobin for O2 6) Cigarette smoking: Increased cigarette smoking increases affinity for hemoglobin for O2

Answer 27

CO2 transportation: CO2 is formed as a by-product of the breakdown of glucose when cells use O2 to produce ATP. CO2 diffuses out of individual cells into the blood. Blood concentration of CO2 needs to be tightly regulated because too much CO2 in the blood causes blood to become acidic. There are three ways CO2 is transported in the blood: 1) Dissolved in plasma: 7% of CO2 dissolves directly in plasma 2) Bound to hemoglobin: 23% of CO2 is transported bound to hemoglobin. CO2 ability to bind to hemoglobin depends on amount of O2 bound; Smaller amount of O2 bound means greater amount of CO2 able to bind 3) Converted to bicarbonate ion (HCO3): 70% of blood is transported in form of HCO3, dissolved in either cytoplasm of red blood cells or plasma of blood In lungs: 1) Bicarbonate ions move into red blood cells and bind with hydrogen ions to form carbonic acid 2) Carbonic acid is split by carbonic anhydrase to release carbon dioxide and water 3) CO2 diffuses from blood to alveoli

Answer 28

1) Decreased elasticity of lungs 2) Decreased surface tension of alveolar surfactant; Disrupts surface tension

Answer 29

CO2 + H2O leads to carbonic acid, or H2CO3 H2CO3 leads to H+ + HCO3 Pathway goes back and forth CO2 starts in tissues and is removed from lungs CO2 is diffused to alveoli

Answer 30

O2: When levels of O2 partial pressure are low, hemoglobin affinity for O2 stays stable. An increase in blood pH results in an increased affinity of hemoglobin for O2. An increase of temperature decreases O2 tendency to remain bound to hemoglobin CO2: When levels of O2 partial pressure are low, hemoglobin binds to more CO2. In turn, as more CO2 binds to hemoglobin, the affinity of hemoglobin for O2 decreases. A decrease in blood pH results in a decreased affinity of hemoglobin for CO2. When body temperature increases, more CO2 enters the blood, lowering the pH, which removes excess CO2 from the body

Answer 31

Alveolar ventilation: Relationship between ventilation of alveoli and blood flow to the alveoli; Delivery of air to alveoli Pulmonary capillary perfusion: Flow of blood to alveoli through pulmonary capillaries Relationship: If perfusion is impaired, the effectiveness of ventilation is reduced, and vice versa

Answer 32

Brainstem is site of automatic regulation of pulmonary ventilation Medullary respiratory center in the medulla oblongata consists of two sets of neurons: 1) Ventral respiratory group: Responsible for generating the normal, involuntary rhythm of breathing, called eupnea. Pre-Botzinger complex establishes basic rhythm of pulmonary ventilation. Stimulates the intercostal and abdominal muscles 2) Dorsal respiratory group: Stimulate the diaphragm Pontine respiratory group found within the pons is involved with switching between inspiration and expiration

Answer 33

O2 partial pressure levels: Small changes in O2 partial pressure levels do not cause changes in respiratory rate or pulmonary ventilation. If partial pressure levels of O2 decrease below 80mmHg, oxygen-carrying capacity of blood is significantly reduced CO2 partial pressure levels: Small increase in CO2 in bloodstream triggers a large increase in the rate and depth of pulmonary ventilation Blood pH: Lower pH stimulates respiratory center, resulting in a greater rate and depth of pulmonary ventilation reducing CO2 levels, and blood pH increases to normal levels

Answer 34

Limits the depth of inspiration and prevents overinflation of lungs. This reflex depends on stretch receptors in the walls of bronchi and bronchioles of the lungs. Reflex is only important in adults when tidal volume is large, such as during exercise. In infants, it plays a role in regulating basic rhythm of pulmonary ventilation and in preventing overinflation of the lungs

Answer 35

Cerebral cortex: Pulmonary ventilation is controlled both voluntarily and involuntarily. For example, during talking or singing, air movement is controlled to produce sounds, as well as to facilitate gas exchange Limbic system: Emotions acting through limbic system of the brain can affect respiratory center. For example, strong emotions can cause hyperventilation or produce the sobs and gasps of crying Voluntarily controlled and modified by emotions

Answer 36

During exercise, respiratory rate changes are controlled through various inputs to the respiratory center. Initially, there is a very rapid increase that occurs too quickly to be accounted for by changes in metabolism. After initial immediate increase in respiratory rate, there is a gradual increase that levels off within 4-6 minutes. If exercise intensity is high enough to exceed anaerobic threshold, blood pH drops, which increases pulmonary ventilation. In response to training, athletic performance increases because cardiovascular and respiratory systems become more efficient at delivering O2 and picking up CO2 Vital capacity increases slightly; residual volume decreases slightly At maximal exercise, tidal volume and minute ventilation increases Gas exchange between alveoli and blood increases at maximal exercise Alveolar ventilation increases Increased cardiovascular efficiency leads to greater blood flow through the lungs

Answer 37

Fetus: Autonomous respiration at 28 weeks of gestation Lungs filled with fluid Gas exchange takes place through placenta At birth: Respiratory centers activated Respiratory rate increases Old age: Respiratory efficiency decreases with old age

Answer 38

Hypercapnia: Too much CO2 Hypocapnia: Lower than normal CO2

Answer 39

1) Deformities of thorax 2) Ossification of costal cartilage 3) Paralysis of intercostal muscles

Answer 40

Vital capacity and maximum minute ventilation decrease Residual volume and dead space increase Ability to remove mucus from respiratory passageways decreases Gas exchange across respiratory membrane is reduced

Exam 3 - Respiratory System Flashcards

(64 cards)