RS Anatomy Flashcards
What structures are in the upper respiratory tract?
- Nasal passages (nasal cavity)
- Pharynx
- Larynx (level of glottis)
What structures are in the lower respiratory tract?
- Sub-glottis & trachea
- Bronchi
- Bronchiole
- Alveolus
What do the nasal passages include?
- Nasal vestibule
- Nasal cavities
Nasal cavities have 2 parts: Olfactory region (for smell; FYI) & Respiratory region (area that ‘conditions’ the air)
What does the pharynx include?
- Nasopharynx (opens into nasal cavity)
- Oropharynx (opens into oral cavity)
- Laryngopharynx (opens into larynx)
Pharynx is a fibromuscular tube
What does the larynx include?
- Laryngeal inlet
- Cavity of larynx
- Glottis
What is found in the nasal vestibule?
Aka nostrils
- Skin
- Hair (vibrissae): Trap bigger dust particles
Where are the turbinates found?
In the nasal cavity
What is the function of the turbinates?
- Slow down air flow to enable air conditioning & filtering
- Bony structures
turbinates = rmb ‘turbulence’ so slow down = give more time for the cells of mucous mbn
What lines the lateral walls of the nasal cavity?
Respiratory epithelium
What does the respiratory epithelium consist of?
- Ciliated Pseudostratified columnar epithelium (move mucus/foreign particles)
- Goblet cells : secrete mucin; when mixed with water = mucus
- Sensory cells (sneeze/cough)
What does the respiratory epithelium do?
- Mucus produced by goblet cells trap dust/particles/bacteria
- Cilia moves trapped dust to larynx to be coughed/spat out
Basically, traps and remove bad things from the air that entered your body
What is present beneath the respiratory epithelium and what is the function?
Within the lamina propria (beneath epithelium):
- Seromucous glands = secrete watery secretions to humidify air
- Blood vessels = warm the air
What is the function of the soft palate?
Seals off the nasopharynx from the oropharynx in the presence of food (so food X go up nasopharynx)
What is the epiglottis and what does it do?
- Elastic cartilage
- Epiglottis bends & seals off laryngeal inlet (X aspiration)
What are the 4 mechanisms that prevent aspiration?
- Epiglottis: Bends & seals off laryngeal inlet
- Glottis: Closes off when there is food
- When eating/swallowing, you stop breathing for 1 second
- Larynx and trachea are pulled up = more space for oesophagus
What does the vocal cords/glottis do?
When there is food, the glottis is closed off
Opens when breathing
Structure of larynx
- Cartilaginous assembly connected by ligaments & membranes
- Epiglottis forms the inlet
- Thyroid & Cricoid cartilages bound the cavity
What are the functions of the larynx?
- Prevent. asphyxiation (main function)
- Vocal production (phonation): vocal cords (folds)
What causes the vocal folds to move?
Muscles
- Vocal folds pulled away - abduction
- Vocal folds close together - adduction
What is the structure of the trachea?
- C-shaped cartilage rings - aka Hyaline cartilage
- Two ends of the “C” connected by smooth muscle - trachealis muscle at the back of body
At which vertebrae does the trachea divide?
Bifurcation happens at rib T4 (thoracic rib 4)
At which rib does the trachea start and end?
Starts at C6 (cervical vertebrae 6) and ends at T4 (thoracic vertebrae 4)
What connects the one C-shaped hyaline cartilage to the next?
Fibroelastic tissue
What are the 3 branches from the arch of aorta?
- Brachiocephalic artery
- Left common carotid artery
- Left subclavian artery
What does the brachiocephalic artery split into?
- Right common carotid artery
- Right subclavian artery
Where does the arch of aorta cross the trachea?
Crosses the trachea on the left side of the trachea bifurcation
What does the lamina propria consist of?
- Connective tissue (a bit)
- Seromucous glands
- Blood vessels
- nerve endings
What are the differences between the right and left main bronchus?
Right main bronchus is
- more vertical
- wide in diameter
- shorter in length
Foreign bodies more likely to be aspirated into the right side
Most common side of obstruction
What is the conducting zone?
- Space between the nose to terminal bronchiole
- No gas exchange: anatomical ‘dead’ space
- Primary source of airway resistance (bronchi)
Where is the respiratory zone?
- respiratory bronchiole to alveoli
- gas exchange occurs here (acinus)
Structure of the bronchus
- Respiratory epithelial lining
- Smooth muscle beneath the epithelium
- Broken cartilage in walls - so doesn’t collapse
- Seromucous glands
How is the structure of the bronchus affected in asthma?
There is airway resistance in the medium bronchus (in everyone)
Smooth muscles in bronchus contracts = diameter smaller
Structure of the bronchiole
- Lumen diameter ≤ 1 mm
- No cartilage in walls
- Sparse glands & goblet cells
- Low columnar epithelium (X pseudostratified)
- Club cells in the epithelium: replaces goblet cells in epithelium
- Smooth muscles in the walls (more abundant)
The lung
- Crepitant to touch (feel air bubbles escaping out)
- Sometimes got blackened spots
Each lung provided with: - 1 principal bronchus
- 1 pulmonary artery
- 2 pulmonary veins
- bronchial vessels, nerves & lymphatics
How much pleural fluid is in the pleural cavity?
5-15 mL
pleural fluid is plasma filtered from capillaries
What is the hilum?
Portal to the lung; where air enters
The gap produced where the parietal pleura meets the visceral pleura
What happens when breathing in?
Lung doesn’t want to expand but
- Parietal pleura moves outwards with thoracic wall + moves away from visceral pleura
- Since pleura cavity is a closed space, visceral pleura also moves outwards = lung expands
- Diaphragm also contracts & chest wall expands
- Increases negative pressure in the lung (intrapleural pressure & intra-alveolar pressure)
- Air goes in (inspiration)
What is the intrapleural pressure at rest?
756 mm Hg
What is pleural effusion?
- Excess of pleural fluid > 15 mL
- Positive intrapleural pressure
- Reduced lung expansion
What is the costophrenic angle?
Where the diaphragm meets the chest wall.
Where does pleural effusion show up first?
Costodiaphragmatic recess
recess = space
What prevents lung collapse when not breathing?
Pleura & pleural cavity prevents lung collapse
- Parietal pleura is attached to thoracic wall (which is fixed)
- Creates a vacuum that maintains shape of lung
What is pneumothorax and what is the consequence?
- The presence of air in the pleural cavity
- May result from rib fractures/stab wounds to chest
- Results in +ve intrapleural pressure (supposed to be -ve)
- ^ could cause compression & collapse of the lung
- Shift of trachea and mediastinal structures to opposite side
Consequence: reduced alveolar ventilation
Which lung has 3 lobes and which lung has 2 lobes?
Right: 3 lobes
Left: 2 lobes
Structure of the right lobe
- Superior lobe
- Middle lobe
- Inferior lobe
Horizontal fissure separates Superior lobe and Middle lobe
Oblique fissure separates Superior & Middle from Inferior lobe
Structure of the left lobe
- Superior lobe
- Inferior lobe
- Cardiac notch
- Lingula
Oblique fissure separates Superior and Inferior lobe
Why does the right lung have 3 lobes but the left lung have only 2 lobes?
The heart takes up space on the left side
What does the anterior border of the lung separate?
Separates the costal surface from the mediastinal surface
What does the inferior border of the lung separate?
Separates the diaphragmatic surface from the costal surface
The left ventricle is responsible for the ….
- Cardiac notch
- Lingula
How many bronchopulmonary segments in each lung?
10 bronchopulmonary (BP) segments in each lung
What does each bronchopulmonary segment have?
Each BP segment has its own
- Bronchus (air supply)
- pulmonary artery (blood supply)
An independent structural & functional unit of the lung
E.g. if 1 segment is infected & has to be removed, the rest of the segments continue to work
Each segment is a ‘mini-lung’
Division of airway within the lung
- Bronchi
- bronchioles
- terminal bronchiole
- respiratory bronchiole (resp zone)
- alveolar ducts (resp zone)
- alveolar sacs & alveoli (resp zone)
Size decreases down the airway but the surface area increases
How many secondary bronchi does the right lung have?
3 secondary bronchi; one for each lobe
Changes in the lining epithelium along the:
1. Trachea
2. Bronchi
3. Bronchioles to Terminal bronchioles
4. Respiratory bronchioles
5. Alveolar duct
6. Alveoli
- Trachea: Pseudostratified columnar ciliated
- Bronchi: Pseudostratified columnar ciliated
- Bronchioles to Terminal bronchioles: Simple columnar ciliated
- Respiratory bronchioles: simple cuboidal (some cilia)
- Alveolar duct: Mostly simple squamous
- Alveoli: Simple squamous (Type I and II cells)
Changes in the secreting cell in epithelium along the:
1. Trachea
2. Bronchi
3. Bronchioles to Terminal bronchioles
4. Respiratory bronchioles
5. Alveolar duct
6. Alveoli
- Trachea: Goblet
- Bronchi: Goblet
- Bronchioles to Terminal bronchioles: Club cells
- Respiratory bronchioles: Club cells
- Alveolar duct: No
- Alveoli: Type II cell
Changes in the cartilage and smooth muscle in the wall:
1. Trachea
2. Bronchi
3. Bronchioles to Terminal bronchioles
4. Respiratory bronchioles
5. Alveolar duct
6. Alveoli
- Trachea: C-shaped cartilage, SM at opening of C-shaped cartilage
- Bronchi: Pieces of cartilage, SM enncircles lumen
- Bronchioles to Terminal bronchioles: No cartilage, Yes SM
- Respiratory bronchioles: No cartilage, Yes SM
- Alveolar duct: No cartilage, Yes/No SM
- Alveoli: No cartilage, no SM
Types of cells in the alveolus
- Capillary endothelial cells
- Type I pneumocytes
- Type II pneumocytes
- Interstitial cells (incl. fibroblasts & mast cells)
- Alveolar macrophages (digest debris)
Which pneumocyte cell synthesises surfactant?
Type II pneumocyte
Type I and Type II pneumocyte cell
Type I pneumocyte cell: simple squamous epithelium - gas exchange
Type II pneumocyte: surfactant synthesis (phospholipid)
What does the surfactant synthesised by the type II pneumocyte do?
- Lowers surface tension in alveoli to prevent collapse
- Water film (needed for gaas diffusion in alveoli BUT air bubbles in water are unstable = collapse
- Surfactant on top of water film = bubbles more stable
- Lack of surfactant in premature babies = X keep alveoli open = respiratory distress syndrome
Epithelial cells vs endothelial cells
Epithelial cells
- Line ext. surface of body
- Skin, resp tract that comes in contact w air
Endothelial cells
- Never comes into contact w external things
- Usually lines bld. vessels
Parts of the sternum
- Jugular notch
- Manubrium
- Sternal angle (aka manubriosternal joint)
- Body of sternum
- Xiphoid process
What are the parts of a typical rib?
(6 parts)
All of the following must be present for the rib to be considered ‘typical’
- Head (two facets which joins w two vertebrae)
- Neck
- Tubercle (roughed area; forms another joint w vertebrae)
- Angle (change in direction of rib, most fragile)
- Costal groove
- Costal cartilage
Pump handle motion of chest wall for respiration
Superior & anterior movement of sternum
- Forward movement of sternal body at manubriosternal joint (Straightens off the sternal angle)
- Manubrium & body come to a straight line
- Increases the anteroposterior diameter of thoracic cavity (front to back diameter of chest)
- Involves 2nd to 5th ribs mainly
- First rib X movement (fixed)
Bucket handle motion of chest wall for respiration
- Elevation of 6-10 ribs at the costovertebral and sternocostal joints
- Increases transverse diameter of the cavity
Principal movements for respiration in all 3 dimensions
- Increased anterior-posterior diameter
- Increased vertical diameter
- Increased transverse diameter
Where does the fibrous pericardium (heart) attach to (lung)?
Attaches to the central tendon of the diaphragm
Where does the phrenic nerve originate from?
Cervical spinal segments C3. 4. 5
Where does the diaphragm attach to?
Attached to:
- lower 6 ribs
- costal margins & 11, 12 ribs
- back of sternum
- lumbar vertebrae
Where is the vena caval opening? (vertebrae)
Vena cave = 8 letters
T8 (TVIII)
Thoracic vertebrae 8
Where is the oesophageal opening? (vertebrae)
Oesophagus = 10 letters
T10 (TX)
Thoracic vertebrae 10
Where is the aortic hiatus? (vertebrae)
Aortic hiatus = 12 letters
T12 (TXII)
Thoracic vertebrae 12
How do the external intercostal muscle run?
- Adjacent borders of upper and lower ribs
- Run downwards & forwards (runs externally (outer side) to internal (inner side; closer to midline of body)
- outermost
What do the external intercostal do?
- Elevates ribs in inspiration
- Stiffen chest wall
Attaches lower border of upper rib to the upper border of lower rib = when contract = lift up lower rib towards upper rib
How do the internal intercostal muscles run?
- adjacent borders of upper and lower ribs
- runs downwards & backwards (runs internally (closer to midline) to external (outer part))
- Perpendicular direction to external intercost.
What is the function of the internal intercostal muscle?
- Depress ribs in forced expiration
(When quiet breathing, expiration X need muscle = recoil of lung (diaphragm go back up) is enough [unless asthma] - Stiffen chest wall
What constitutes the innermost layer of intercostal muscles?
- Transversus thoracis (back of sternum to costal cartilages)
- Innermost intercostal (side of upper to lower ribs (shafts) on their inner surfaces
- Subcostalis (posterior part of ribs on their inner surfaces)
Function of the innermost layer of intercostal muscles?
Most active in forced expiration
What are the accessory muscles for inspiration?
(6 muscles)
- Sternocleidomastoid
- Pectoralis major
- Serratus anterior
- Scalene muscles
- Levator Costarum
- Erector Spinae
Help to expand chest more for inspiration (forced inspiration)
*Not active during quiet inspiration
What are the accessory muscles for forced expiration?
- External oblique
- Internal oblique
- Transversus abdominis
- Rectus abdominis
Compresses abdomen = expels air = forced expiration
Which ribs are false, true, typical, atypical?
Rib 1: True rib; atypical rib
Rib 2: True; typical/atypical
Rib 3 to 7: True & typical
Rib 8 to 9: False & typical
Rib 10: False & typical/atypical
Rib 11 to 12: False & atypical
How do inhalers help with asthma?
Relax the smooth muscles
- Dilates the bronchi/bronchioles = reduces obstruction to airflow
Primary bronchus
Secondary bronchus
Tertiary bronchus
Primary bronchus: R & L main bronchus
secondary bronchus: Lobar bronchus (3 in R, 2 in L)
Tertiary bronchus: segmental bronchus
