8 Respiratory System

Respiratory System

Respiratory System

1. Function Division of the Respiratory System

2. Conducting Zone

   1. Upper Airway

      1. External nose

      2. Nasal cavity

      3. Pharynx

      4. Respiratory epithelium

      5. Larynx

   2. Deglutition

   3. Trachea & Bronchial Tree

3. Respiratory Zone

   1. Alveoli

4. Lungs

   1. Pleura of the lungs

5. Mechanism of Breathing

   1. Boyle’s Law

   2. Gas Atmospheric & Alveolar Pressure

6. Mechanism of Respiration

   1. Inspiration & Expiration

   2. Types of Breathing

   3. Ventilation Control Centers

7. Respiratory Volumes & Capacities

8. Mechanism of Gas Exchange

Respiratory System

• responsible for the exchange of oxygen and carbon dioxide between the body and the environment

• lungs, trachea, bronchi, bronchioles, alveoli, and diaphragm

air, filtering, pathogens

Conducting Zone

• conducting ___ to and from the lungs

• _____, humidifying, and warming the air as it passes through the respiratory tract

• kills off invading _______ and protects from foreign particles & irritants

  • Nasal cavity

  • Nostril

  • Oral cavity

  • Pharynx

  • Larynx

  • Trachea

  • Right & left main bronchus

Upper Respiratory Tract

1. External nose

2. Nasal cavity

3. Pharynx

4. Respiratory epithelium

5. Larynx

frontal, nasal, septal

1. External nose

• responsible for filtering, warming, and humidifying the air as it enters the body

  • Root: _____ bone

  • Nose bridge: ____ bone

  • Dorsum nasi: _____ cartilage

  • Ala: major & minor alar cartilage

mucous, cilia, surface, water, beneath, ethmoid, semilunaris, nasolacrimal, pharynx

2. Nasal cavity

• a hollow space behind the nose that is lined with _____ membranes and tiny hair-like structures called ____.

• further filters, humidifies, and warms the air before it enters the lungs

• Nasal conchae

  • AKA nasal turbinates

  • Increase the _____ of the nasal cavity → disrupts flow of air → air bounces to nasal epithelium → air is cleansed

  • also conserve ___ and prevent dehydration of the nasal epithelium by trapping _____ during exhalation

• Nasal meatuses

  • narrow passageways in the nasal cavity located _____ the nasal conchae

  • superior meatus

    • narrowest

    • receives drainage from the posterior _____ air cells

  • middle meatus

    • largest

    • contains the hiatus _______

  • inferior meatus

    • receives drainage from the ________ duct

• Internal nares

  • Air exits the nasal cavity to the _____

mucous, airway, pharyngeal, immune, lymphocytes, food, stratified, palatine, lingual, nasal, middle

3. Pharynx

• is a tube formed by skeletal muscle and lined by _____ membrane that is continuous with that of the nasal cavities

  • nasopharynx

    • flanked by the conchae of the nasal cavity, and it serves only as an ____

    • on top are the _______ tonsils

      • similar to a lymph node (releases _____ cells)

      • contains a rich supply of _______ and is covered with ciliated epithelium that traps and destroys invading pathogens

  • oropharynx

    • passageway for both air and ____

    • As the nasopharynx becomes the oropharynx, the epithelium changes from pseudostratified ciliated columnar epithelium to _______ squamous epithelium

    • contains palatine & lingual tonsils

      • ______ tonsil is one of a pair of structures located laterally

      • ______ tonsil is located at the base of the tongue

    • contains uvula

      • is a small bulbous, teardrop-shaped structure located at the apex of the soft palate

      • swings upward to close off the nasopharynx to prevent ingested materials from entering the ____ cavity.

    • contains Eustachian tubes

      • connect to each _____ ear cavity open into the nasopharynx

      • why colds often lead to ear infections (Niña’s problem!)

• laryngopharynx

  • continues the route for ingested material and air until its inferior end, where the digestive (esophagus) and respiratory (larynx) systems diverge

  • stratified squamous epithelium

pseudostratified, columnar, mucus, beating, lysozyme, defensins, convection

4. Respiratory epithelium

• lines the conchae, meatuses, and paranasal sinuses

• warm and humidify incoming air

• composed of _________ ciliated ______ epithelium

  • Goblet cells

    • one of the specialized, columnar epithelial cells that produce _____ to trap debris

  • Cilia

    • help remove the mucus and debris from the nasal cavity with a constant _______ motion

  • Seromucous gland

    • secrete the _____ enzyme and proteins called ______, which have antimicrobial peptides (AMP)

  • Capillaries

    • located just beneath the nasal epithelium warm the air by _______

trachea, volume, prominence, elastic, vestibular, vocal, arytenoids, corniculates, cuneiforms, ring

5. Larynx

• cartilaginous structure inferior to the laryngopharynx

• connects the pharynx to the _____ and helps regulate the _____ of air that enters and leaves the lungs

  • thyroid cartilage (anterior)

    • largest piece of cartilage

    • consists of the laryngeal _______, or “Adam’s apple,”

  • epiglottis (superior)

    • very flexible piece of _____ cartilage

    • When in the “closed” position, the unattached end of the epiglottis rests on the glottis

      • composed of the _____ folds, the true ___ cords, and the space between these folds

    • Three smaller, paired cartilages—the ______, _____, and ______—attach to the epiglottis and the vocal cords

  • cricoid cartilage (inferior)

    • forms a ___

false, oscillation, pitch

Glottis

• Vestibular fold

  • ____ vocal cord, is one of a pair of folded sections of mucous membrane

• True vocal cord

  • one of the white, membranous folds attached by muscle to the thyroid and arytenoid cartilages of the larynx on their outer edges.

  • inner edges of the true vocal cords are free, allowing ______ to produce sound

• size of the membranous folds of the true vocal cords differs between individuals, producing voices with different ____ ranges

  • thinner in females

Vocal Chords

uplifted, expands

Deglutition

1. Larynx and pharynx are _____

2. Pharynx ______

   • accommodates food balls

Deglutition

• The act of swallowing causes the pharynx and larynx to lift upward, allowing the pharynx to expand and the epiglottis of the larynx to swing downward, closing the opening to the trachea.

• These movements produce a larger area for food to pass through, while preventing food and beverages from entering the trachea.

windpipe, hyaline, fibroelastic, pseudostratified

Trachea

• AKA _____

• extends from the larynx toward the lungs

• formed by 16-20 stacked, C-shaped pieces of _____ cartilage that are connected by dense connective tissue

• ________ muscle

  • trachealis muscle + elastic connective tissue

  • connects the C-shaped cartilages

  • allows the trachea to stretch and expand slightly during inhalation and exhalation

• lined with ___________ ciliated columnar epithelium, which is continuous with the larynx

carina, columnar, goblet, nervous, muscle

Bronchial Tree

• trachea branches into the right and left primary bronchi at the ______

• lined by pseudostratified ciliated ____ epithelium containing mucus-producing ___ cells

• Rings of cartilage, similar to those of the trachea, support the structure of the bronchi and prevent their collapse

• Carina

  • is a raised structure that contains specialized _____ tissue that induces violent coughing if a foreign body

• A bronchial tree (or respiratory tree) is the collective term used for these multiple-branched bronchi

• Bronchi

  • provide a passageway for air to move into and out of each lung

  • mucous membrane traps debris and pathogens

• Bronchiole

  • branches from the tertiary bronchi

  • lead to the structures of gas exchange

  • do not contain cartilage like those of the bronchi (_____ instead)

gas, terminal

Respiratory Zone

• includes structures that are directly involved in __. exchange

• begins where the ______ bronchioles join a respiratory bronchiole

  • respiratory bronchiole

  • alveoli

alveolar

1. Respiratory bronchiole

• smallest type of bronchiole

• which then leads to an ______ duct, opening into a cluster of alveoli

smooth, expand, cluster, connects

2. Alveoli

• Alveolar duct

  • tube composed of _____ muscle and connective tissue, which opens into a cluster of alveoli

• Alveolus

  • small, grape-like sacs that are attached to the alveolar ducts

  • 200 μm in diameter with elastic walls that _____ for gas exchange

• Alveolar sac

  • _____ of many individual alveoli that are responsible for gas exchange

• Alveolar pores

  • ______ each alveoli

  • help maintain equal air pressure throughout the alveoli and lung

squamous, permeable, surfactants, tension, phagocytic

2. Alveoli

• Type 1 alveolar cell

  • ______ epithelial cell

  • constitute up to 97% of the alveolar surface area

  • highly _____ to gases

• Type 2 alveolar cell

  • interspersed among the type I cells and secretes pulmonary _______

    • a substance composed of phospholipids and proteins that reduces the surface ______ of the alveoli

• Alveolar macrophage

  • ______ cell of the immune system that removes debris and pathogens that have reached the alveoli

basement, diffusion

Respiratory membrane

• alveoli + capillary membranes

  • type 1 cells attached to a thin, elastic ______ membrane

    • is extremely thin and borders the endothelial membrane of capillaries

• allows gases to cross by simple _______

  • allowing oxygen to be picked up by the blood for transport and CO2 to be released into the air of the alveoli

edema, bronchospasms

Asthma

• inflammation and ____ of the airway, and _______ (that is, constriction of the bronchioles), which can inhibit air from entering the lungs

  • thickened mucosa, increased mucus-producing goblet cells, and eosinophil infiltrates

• Bronchospasms occur periodically and lead to an “asthma attack.”

• Triggered by dust, pollen, pet hair, or dander, changes in the weather, mold, tobacco smoke, and respiratory infections, or by exercise and stress

right, notch, lobes, Fissures, septum, tertiary, diaphragm

Lungs

• paired organs that are connected to the trachea by the right and left bronchi;

  • ___ lung is shorter and wider than the left lung

  • the left lung occupies a smaller volume than the right

    • cardiac ____

      • allows space for the heart

• Each lung is composed of smaller units called _____.

  • ____ separate these lobes from each other

  • Each lobule receives its own large bronchiole that has multiple branches

  • interlobular _____

    • wall, composed of connective tissue, which separates lobules from one another

• Bronchopulmonary segment

  • a division of a lobe, and each lobe houses multiple bronchopulmonary segments

  • Each segment receives air from its own _____ bronchus and is supplied with blood by its own artery

• bordered by the _____ inferiorly

Diaphragm

• flat, dome-shaped muscle located at the base of the lungs and thoracic cavity

mediastinum, lungs, fissures, thoracic, hilum, lubricate, Intercostal

Pleura of the Lungs

• is a serous membrane that surrounds the lung

  • produce pleural fluid and create cavities that separate the major organs

• right and left pleurae, which enclose the right and left lungs, respectively, are separated by the ______

  • Visceral pleura

    • layer that is superficial to the ___

    • extends into and lines the lung ____

  • Parietal pleura

    • outer layer that connects to the ____ wall, the mediastinum, and the diaphragm

  • visceral and parietal pleurae connect to each other at the ____

• Pleural cavity

  • space between the visceral and parietal layers

• Pleural fluid

  • secreted by mesothelial cells from both pleural layers and acts to _____ their surfaces

• ______ muscles

  • superficial to the pleural of the lungs

difference, confined, constant

Mechanisms of Breathing: Pressure Relationships

• Inspiration and expiration are dependent on the ________ in pressure between the atmosphere and the lungs

• Pressure

  • force created by the movement of gas molecules that are _____

• At a _____ temperature, changing the volume occupied by the gas changes the pressure, as does changing the number of gas molecules.

inversely

Boyle’s Law

• describes the relationship between volume and pressure in a gas at a constant temperature

• pressure of a gas is _____ proportional to its volume (P = k/V)

  • ↑ volume, ↓ pressure

  • the pressure in the 1L container (1/2 the volume of the 2L container) would be 2X the pressure in the 2L container

single, nonreactive

Gas Atmospheric Pressure

• Gaseous mixture exerts a certain pressure referred to as atmospheric pressure

  • Partial pressure (Px)

    • pressure of a ____ type of gas in a mixture of gases

  • Total pressure

    • sum of all the partial pressures of a gaseous mixture

  • Dalton’s Law

    • describes the behavior of ______ gases in a gaseous mixture and states that a specific gas type in a mixture exerts its own pressure

• relative concentration of gases is N > O > H2O (vapor) > CO2.

CO2, greater

Alveolar Air

• relative concentration of gases is N > O > H2O (vapor) > CO2.

• composition of air in the atmosphere and in the alveoli differs

  • contains a greater amount of ___ and less O than atmospheric air.

    • will cause oxygen to enter and carbon dioxide to leave the blood more quickly

• The amount of water vapor present in alveolar air is ______ than that in atmospheric air

gradient, atmospheric, alveolar, pleural

Mechanism of Respiration (Pulmonary Ventilation)

• difference in pressures drives pulmonary ventilation because air flows down a pressure _____ (high → low)

• Air flows into the lungs largely due to a difference in pressure

  • _____ pressure > intra-_____ pressure > intra____ pressure

surrounding, alveoli, equalizes, cavity, lower

Pulmonary Ventilation

• is dependent on three types of pressure:

  • Atmospheric pressure

    • amount of force that is exerted by gases in the air _______ any given surface, such as the body

    • One atm = 760 mm Hg, which is the atmospheric pressure at sea level

  • Intra-alveolar pressure

    • pressure of the air within the _____

    • changes during the different phases of breathing

    • interpulmonary pressure of the alveoli always _______ with the atmospheric pressure

  • Intrapleural pressure

    • pressure within the pleural _____

    • due to the fluid bond between the visceral and parietal pleura and the parietal pleura’s adhesion to the body wall and diaphragm

    • intrapleural pressure is always _____ than, or negative to, the intra-alveolar pressure

Changes in intrapleural pressure during inspiration

Pulmonary Ventilation

Mechanism of Breathing

diaphragm, external, inferiorly, External, upward, fluid, decrease, lower

Pulmonary Ventilation

• Respiratory cycle

  • one sequence of inspiration and expiration

  • ___ and the ____ intercostal muscles

    • Additional muscles can be used if a bigger breath is required

• 2 major steps:

1. Inspiration

• process that causes air to enter the lungs

2. Expiration

• process that causes air to leave the lungs

1. Diaphragm contracts and moves ______

2. Larger thoracic cavity and more space for the lungs is created

3. _____ intercostal muscles contract

4. Ribs move ______ and outward, expanding the rib cage

5. Volume of thoracic cavity increases

6. Adhesive force of pleural ____ causes lungs to stretch and expand

7. Increase in volume leads to a ____ in intra-alveolar pressure (creating a pressure ____ than atmospheric pressure)

8. Pressure gradient created due to decrease in pressure

9. Pressure gradient drives air into the lungs.

internal

Muscles of Forced Expiration

• _______ intercostals pull ribs downward and inward

Pulmonary ventilation

Types of Breathing

• require a slightly different process to allow inspiration and expiration

1. Quiet breathing

   1. Diaphragmatic breathing

   2. Costal breathing

2. Forced breathing

external

Quiet breathing

• AKA eupnea

• occurs at rest and does not require the cognitive thought of the individual.

• diaphragm and ______ intercostals must contract.

deep, passively

Diaphragmatic breathing

• AKA ____ breath

• requires the diaphragm to contract.

• As the diaphragm relaxes, air ______ leaves the lungs

shallow, intercostal

Costal breathing

• AKA ______ breath

• requires contraction of the intercostal muscles.

• As the ______ muscles relax, air passively leaves the lungs.

exercise, obliques, internal, compress

Forced breathing

• AKA hyperpnea

• is a mode of breathing that can occur during _____ or actions that require the active manipulation of breathing, such as singing.

• inspiration and expiration both occur due to muscle contractions.

  • other accessory muscles must also contract (scalenes, _____, _____ intercotals)

    • internal intercostals help to ______ the rib cage, which also reduces the volume of the thoracic cavity

constant, diaphragm, forced, accessory, internal, pons, medulla, stimulate, inhibits

Ventilation Control Centers

• The major brain centers involved in pulmonary ventilation are the medulla oblongata and the pontine respiratory group

• Medulla oblongata

  • Dorsal respiratory group (DRG)

    • maintaining a _____ breathing rhythm by stimulating the _____ and intercostal muscles to contract, resulting in inspiration

  • Ventral respiratory group (VRG)

    • involved in _____ breathing

    • as the neurons in the VRG stimulate the _____ & _____ intercostal muscles involved in forced breathing to contract, resulting in forced inspiration

• Pontine respiratory group

  • located within the ____

  • alter/modify the function of those at the level of the ______ depending on the situations

    • integrates

      • Chemoreceptors- e.g. pH

      • Thermoreceptors

      • Stretch receptors

      • Proprioceptors

      • Ex. signals from stretch receptors and proprioceptors modify breathing patterns

• Apneustic center

  • double cluster of neuronal cell bodies that ______ neurons in the DRG

  • controlling the depth of inspiration, particularly for deep breathing

• Pneumotaxic center

  • network of neurons that ______ the activity of neurons in the DRG

  • allowing relaxation after inspiration, and thus controlling the overall rate.

Ventilation Regulation

quiet, forcefully, deep, left

Respiratory Volumes & Capacities

• Respiratory Volume

  • various volumes of air moved by or associated with the lungs at a given point in the respiratory cycle.

  • 4 types

1. Tidal volume (TV)

   • amount of air that normally enters the lungs during ____ breathing

   • 500 mL

2. Expiratory reserve volume (ERV)

   • amount of air you can _____ exhale past a normal tidal expiration

   • 1200 mL for men

3. Inspiratory reserve volume (IRV)

   • produced by a ____ inhalation, past a tidal inspiration

   • the extra volume that can be brought into the lungs during a forced inspiration

4. Residual volume (RV)

   • air ____ in the lungs if you exhale as much air as possible

   • makes breathing easier by preventing the alveoli from collapsing

volumes, forceful, TV, ERV, IRV, TV, IRV, ERV, RV

Respiratory Volumes & Capacities

• Respiratory Capacity

  • combination of two or more selected _____, which further describes the amount of air in the lungs during a given time

1. Total lung capacity (TLC)

   • sum of all of the lung volumes (TV, ERV, IRV, and RV)

   • total amount of air a person can hold in the lungs after a _____ inhalation

   • about 6000 mL air for men, and about 4200 mL for women

2. Vital capacity (VC)

   • amount of air a person can move into or out of his or her lungs

   • sum of all of the volumes except residual volume (++__)

• 4000-5000 mL

3. Inspiratory capacity (IC)

• maximum amount of air that can be inhaled past a normal tidal expiration

• is the sum of the ____ + ____

4. Functional Residual Capacity (FRC)

• amount of air that remains in the lung after a normal tidal expiration

• it is the sum of ____ + ____

Total lung capacity (TLC)

TV + ERV + IRV + RV

Vital capacity (VC)

TV + ERV + IV

Inspiratory capacity (IC)

TV + IRV

Functional residual capacity (FRC)

ERV + RV

Respiratory Volumes & Capacities

capillaries

Mechanism of Gas Exchange

• External respiration

  • a function of partial pressure differences in oxygen and carbon dioxide between the alveoli and the blood in the pulmonary _______

  • oxygen diffuses across the respiratory membrane from the alveolus to the capillary, whereas carbon dioxide diffuses out of the capillary into the alveolus

body, low, high, hemoglobin, interstitial

Mechanism of Gas Exchange

• Internal respiration

  • occurs at the level of ___ tissue

  • also occurs as simple diffusion due to a partial pressure gradient

    • partial pressure gradients are opposite of those present at the respiratory membrane

      • partial pressure of oxygen in tissues is ___, because oxygen is continuously used for cellular respiration.

      • In contrast, the partial pressure of oxygen in the blood is ___.

    • This creates a pressure gradient that causes oxygen to dissociate from ____, diffuse out of the blood, cross the ___ space, and enter the tissue.

    • Hemoglobin that has little oxygen bound to it loses much of its brightness, so that blood returning to the heart is more burgundy in color.

Internal respiration

Transport of CO2

Gas Exchange

Gas Exchange