Respiratory System Structures Flashcards
2 Major Functions of Respiratory System
1) Pulmonary Ventilation (aka breathing) flow of air into & out of lungs
2) Allow gas exchange (O2 & CO2)
How does carbon dioxide get into the blood?
What happens when there is too much carbon dioxide in the blood?
1) When oxygen enters the body it synthesizes ATP and the byproduct of ATP if carbon dioxide which needs to be removed by the blood
2) pH levels rise and body falls out of homeostasis
2 Types of Gas Exchange
1) Internal or Tissue Gas Exchange- exchange of O2 & CO2 between blood & body tissue
2) External or Pulmonary Gas Exchange- exchange of O2 & CO2 between blood and air in the lungs
What controls the Respiratory System?
Centers in the Medulla Oblongata & Pons
Average number of breaths per day
How much air is processed each day by our lungs?
- 20,000 breaths per day
- 15,000 liters (4,000 gallons) per day
7 Structures of the Respiratory System
1) External Nose
2) Nasal Cavity
3) Pharynx
4) Larynx
5) Trachea
6) Bronchi
7) Lungs
Upper Respiratory Tract Structures
Lower Respiratory Tract Structures
- Upper= External nose, Nasal Cavity, Pharynx, Larynx, Trachea
- Lower= Bronchi, Lungs
Functions of Upper Respiratory Tract Structures (5)
1) External Nose- encloses the chamber for air inspiration (mouth is part of the digestive system)
2) Nasal Cavity- cleaning, warming, and humidifying chamber for inspired air.
3) Pharynx (throat) - common passageway for food & air
4) Larynx (voice box)- rigid structure that helps keep airway constantly open, or patent.
5) Trachea (windpipe)- air-cleaning tube to funnel inspired air to each lung.
Functions of Lower Respiratory Tract Structures (2)
1) Bronchi- tubes that direct air into the lungs
2) Lungs- labyrinth of air tubes & a network of air sacs (alveoli) & capillaries. –> Alveoli= site of gas exchange
What makes up the Bronchial Tree? (4)
1) Trachea
2) Bronchi
3) Bronchioles
4) Alveoli
What are the subdivisions of the respiratory system base on function? (as opposed to location) (2)
1) Conducting Zone- all parts that conduct air but do not engage in gas exchange
2) Respiratory Zone- all structures that participate in gas exchange (Respiratory bronchioles, alveolar ducts, & alveoli)
4 Steps of Gas Exchange
1) Pulmonary ventilation (breathing)
2) Pulmonary gas exchange- movement of O2 out of air into alveoli & CO2 out of blood into the alveoli with air
3) Gas transport- CO2 & O2 travel into blood
4) Tissue gas exchange- within tissues, O2 leaves blood & enters cells while CO2 exits cells & into blood
Other Functions of Respiratory System (aside from gas exchange) (5)
1) Regulation of blood pH
2) Production of chemical mediators- lungs produce ACE enzyme which is important in BP regulation
3) Voice production
4) Olfaction
5) Protection- against microorganisms from entering the body & removing them from respiratory surfaces
Upper Respiratory Structures from top to Bottom (9)
1) Nasal Cavity
2) Nasopharynx
3) Soft Palate
4) Oropharynx
5) Epiglottis
6) Laryngopharynx
7) Larynx
8) Esophagus
9) Trachea
External Nose (4)
1) Supported by bone & hyaline cartilage
2) Covered with muscle, & skin
3) Lined with mucous membrane & nasal hairs (which help filter incoming hair)
4) External Nares- Nostrils
Internal Nose aka Nasal Cavity (3)
1) Bony enclosure within the skull formed by the Ethmoid, Maxilla, Palatine, Lacrimal, & Inferior Nasal Conchae Bones
2) Lined by mucous membrane & blood capillaries
3) Contains Internal Nares (2 posterior openings to Pharynx) & the openings from the 4 Paranasal Sinuses & from Nasolacrimal Ducts
Where is the mucous membrane that helps warm & humidify inspired air?
Lining of the hard plate that’s formed by the Palatine Process of the Maxillae and the Palatine Bone within the Nasal Cavity
5 Functions of Nasal Cavity
1) Passageway for air
2) Cleans the air- via hairs to trap large particles & secretions from goblet cells in the mucous membrane lining the nasal cavity which trap debris in the air (cilia then sweep mucous back to pharynx where it’s swallowed and eliminated by acid in stomach)
3) Humidifies and warms air
4) Contains olfactory epithelium
5) Helps determine voice sound aka Phonation (resonation/modification of speech sounds)
Function of Nasal Vestibule, Respiratory Mucosa, & Paranasal Sinuses
1) Vestibules- removes coarse particles (such as dust) from inspired air, preventing entry to lungs
2) Mucosa- Pseudo-stratified ciliated columnar epithelium with goblet cells that secrete mucus with antibacterial lysozome. Cilia moves mucus towards throat.
3) Sinuses- Spaces that lighten the weight of the skull & warm & moisten air
Pharynx (function, location, & regions)
1) Receives air from nasal cavity & air, food, & drink from oral cavity
2) Connected to Respiratory system at the Larynx & Digestive system at the Esophagus
3) Nasopharynx, Oropharynx, & Laryngopharynx
Nasopharynx (3)
1) Superior portion of Pharynx
2) Superior to the Soft Palate (partition that separates Nasopharynx & Oropharynx
3) Mucous membrane traps debris & microbes inside mucous which is swallowed & killed in stomach
Structures of Nasopharynx (3)
1) Soft Palate (most inferior flap)- prevents swallowed material from entering Nasopharynx & Nasal Cavity
2) Uvula (extension of Soft Palate)
3) Pharyngeal Tonsil (Adenoids)- posterior wall of Nasopharynx
Oropharynx (4)
1) Middle portion of Pharynx
2) Immediately posterior to mouth & begins at the Soft Palate
3) Fauces- region that joins mouth & Oropharynx
4) Palatine tonsils & Lingual Tonsils located near Fauces
Laryngopharynx (2)
1) Lower portion of Phayrnx
2) Spans posterior length of Larynx (from superior Larynx to Epiglottis to Esophagus
Larynx (3)
1) aka Voice box
2) Connects Pharynx to the Trachea
3) Located between C4 & C6 vertebrae
Functions of Larynx (4)
1) Maintains open passageway for air movements
2) Prevents swallowed materials from entering the larynx & lower respiratory tract
3) Produces sound for speech
4) Protects lower respiratory tract from foreign materials
Cartilages of the Larynx (4)
1) Thyroid Cartilage- aka Adam’s apple- hyaline cartilage that form front of Larynx (bigger in men)
2) Epiglottis- single, spoon-shaped, elastic cartilage that acts as a trap door to cover Glottis (opening to tranchea)
3) Arytenoid Cartilage- pair of hyaline structures that connect vocal folds to muscles
4) Cricoid Cartilage- ring of hyaline that attaches larynx to trachea- used as a landmark during a tracheostomy
What are the 3 single cartilages of the Larynx & function
1) Epiglottis- covers opening to tranchea (glottis)
2) Thyroid- largest, aka Adam’s Apple
3) Cricoid- base of larynx where other cartilages rest
Vocal Cords (structure, location, function,)
1) Paired folds of mucous membrane
2) Located on either side of Rima Glottidis in the Glottis
3) When air is forced through the Rima Glottidis, vocal folds vibrate resulting in sound waves heard as speech sounds
Low vs High Pitch voice & structure of Vocal Chords in Men vs. Women
1) Higher pitch voice= vocal folds held tightly together
2) Lower pitch voice= vocal folds held further apart
1) Men= thick & long vocal folds create lower pitch
2) Women= thin & short vocal folds create higher pitch
How does the position of the Arytenoid Cartilages change when a person is simply breathing versus making low-pitched or high-pitched sounds?
- LATERAL rotation of the arytenoid cartilages during routine breathing opens folds and allows greater air movement
-MEDIAL rotation closes folds & allows them to change tension and produce sound
Laryngitis
Inflammation of the larynx due to infection or irritation. If vocal folds are inflamed the voice itself could be affected.
Trachea (2)
1) Windpipe
2) Kept open at all times by C-shaped “tracheal rings” of hyaline cartilage & prevent it from collapsing
3) Ends with the Carina (leads to the 2 primary Bronchi)
Tracheobronchial Tree (6)
1) Right main bronchus larger and more directly in line with trachea (where objects more likely to become lodged)
2) Have cartilage rings like trachea
3) 4 Main classes of air passageways in the lungs
4) 16 generations of branching to smallest tubes
5) Carries air to & from alveoli
6) Conducting & Respiratory Division
What are the 4 main classes of air passageways in the lungs?
1) Lobar Bronchi (Secondary Bronchi)
2) Segmental Bronchi (Tertiary Bronchi)
3) Bronchioles
4) Terminal Bronchioles
What is the difference between the Conducting Division & the Respiratory Division of the Bronchial Tree?
The Conducting Division includes the air passages in which gas exchange does NOT occur. Respiratory Division includes sites of gas exchange.
What makes up the Conducting Division of the Bronchial Tree?
1) Trachea
2) Primary Bronchi
3) Secondary (Lobular) Bronchi
4) Tertiary (Segmental) Bronchi
5) Bronchioles
6) Terminal Bronchioles
Primary Bronchi (4)
1) One per lung
2) Walls composed of hyaline cartilage RINGS & smooth muscle
3) Interiorly lines with ciliated pseudostratisfied columnar epithelial tissue
4) Carry air from Trachea to Secondary Bronchi
Secondary (Lobar) Bronchi (3)
1) Branches of the Primary Bronchi
2) One per lobe
3) Same wall structure as Primary Bronchi but hyaline cartilage is in PLATES, not rings.
Tertiary (Segmental) Bronchi (3)
1) Branches of the Secondary (Lobar) Bronchi
2) Approx 10 per lobe
3) Same wall structure as Secondary Bronchi but with more smooth muscle
Bronchioles (3)
1) Branches of the Tertiary Bronchi
2) Contain no cartilage, large amount of smooth muscle
3) Diameters vary due to smooth muscle contractions
Terminal Bronchioles (2)
1) Branches of Brionchioles
2) Walls have no cartilage but do have large amount of smooth muscle
What makes up the Respiratory Division?
1) Respiratory Bronchioles
2) Alveolar Ducts
3) Alveolar Sacs
What are the 2 types of cells in the alveolar wall & their functions
1)Type 1 pneumocytes- thin squamous epithelial cells that form 90% of alveolar surface. Most of the gas exchange takes place in these cells.
2) Type 2 pneumocytes- round, secretory cells that produce surfactant, which makes it easier for the alveoli to expand during inspiration.
Alveolar Macrophages
Phagocytic cells that wander across the inner surface of alveolus & consume dust, bacteria, & other foreign bodies.
Why is pulmonary ventilation more difficult during an asthma attack?
-Bronchi and Bronchioles capable of changing their diameter to decrease resistance to airflow or increase their resistance.
-Asthma attacks occur when inflammatory chemicals cause severe bronchocronstriction which decreases diameter of airways and increases resistance to airflow (greatly reducing air movement).
-Albuterol promotes smooth muscle relaxation to counteract this.
Respiratory Membrane (4)
1) Formed by alveolar walls & surround pulmonary capillaries.
2) Location of pulmonary gas exchange
3) Extremely thin (thinner than a piece of paper)
4) Large surface area which allows large amounts of gases to diffuse at one time.
3 Layers of Respiratory Membrane
1) Alveolar cell layer
2) Capillary endothelial layer
3) Interstitial space between the 2 layers
What makes up the Thoracic Wall? (5)
1) Thoracic Vertebrae
2) Ribs
3) Costal Cartilages
4) Sternum
5) Associated muscles
Lungs (Apex, Base, Hilum, & sides)
1) Base- bottom that touches diaphragm
2) Apex- top that extends above clavicle
3) Hilum- indent on medial surface of lung where bronchus, blood vessels, nerves, & lymphatic vessels enter or exit.
4) Right lung is larger with 3 lobes, left has 2 lobes & the Cardiac notch (arrangement provides room for heart in between lungs)
Name the structures of the lungs (8)
1) Apex
2) Base
3) Superior lobe (both)
4) Horizontal fissure (right)
5) Middle lobe (right)
6) Oblique fissure (both)
7) Inferior lobe (both)
8) Cardiac Notch (left)
Oxygenated blood vs. deoxygenated blood flow
pg. 874
Lymphatic Supply to the Lungs (?)
pg. 874
What are the 2 Pleural Cavities within the Thoracic Cavity? What lies between the 2?
1) Parietal Pleura- serous membrane that covers inner thoracic wall, superior surface of diaphragm (outer most layer)
2) Visceral Pleura- connective tissue surrounding each lung
3) Pleural Cavity- contains serous fluid which allows free movement of lungs during breathing
What muscles are involved in inspiration? (4)
1) External intercostals
2) Pectoralis minor
3) Scalenes
4) Diaphragm
What muscles are involved in expiration? (2)
1) Internal intercostals
2) Transverse thoracic (with assistance from abdominal muscles)
What is the order of events with inspiration? (3)
1) Diaphragm and external intercostals contract
2) Volume of thoracic cavity increases and pressure decreases
3) Air flows into lungs and alveoli
