Pulmonary Anatomy and Physiology Flashcards
Vertebrae
Provide stability
Ribs
Protect thoracic organs
Provide dynamic bone lever system for ventilation
Ribs 1-7
True ribs
Most stable
Directly attach to sternum via costocartilage
Ribs 8-10
False ribs
Insert to the sternum through the costal cartilage of rib 7
Ribs 11-12
Floating ribs
Do not articulate with the sternum
Designed for mobility at the expense of stability
Sternum
Provides mobility
Manubrium - articulates with clavicles and ribs 1 and 2
Body - ribs 3-7
Xiphoid - most inferior portion (hyaline cartilage); fully ossifies by age 40
Sternal angle - horizontal ridge at level of 2nd rib, level of the carina (T5)
-Allows pump handle motion
Pump handle
Anterior and superior motion of the sternum and upper rib cage
Bucket handle
Lateral and superior motion of the ribs
Chest mobility increases as you move…
Inferiorly and anteriorly
Chest mobility decreases as you move…
Superiorly and posteriorly
Sequence of normal breathing
- Diaphragm rise
- Lateral costal expansion of lower chest
- Gentle rise of upper chest superiorly and anteriorly
Mm of larynx and pharynx
Act as valves that help regulate airflow
Diaphragm
Primary mm of inspiration
External intercostals
Elevate ribs and increase thoracic volume
Internal intercostals
Lower the ribs and decrease thoracic volume
Simultaneous intercostal contraction
Elevates the ribs
Quiet breathing exhalation
Passive recoil of lungs and ribs
Forceful exhalation
Use abdominal mm to depress lower ribs and compress abdominal contents to push against the diaphragm and help to actively exhale
Diaphragm resting
Supine - rests higher, has a larger excursion
Sitting and standing - rest lower
Side lying - dependent side of diaphragm has larger inspiratory excursion
Breathing INN
Phrenic nerve
C 3 4 5
Abdominal mm
Stabilize rib cage and provide visceral support
Provide positive pressure for diaphragm
Provide increased intrathoracic pressure for effective cough, BM, venous return, etc
INN T6-L1
Paradoxical breathing pattern
Complete opposite of the way the diaphragm is supposed to contract
CONCENTRIC diaphragm cx
Quiet, forceful inhalation
ECCENTRIC diaphragm cx
Controlled exhalation or speech
Intercostal fx
Stabilize rib cage during inhalation and prevent chest wall from moving inward toward the negative pressure
INN T1 - T12
Erector spinae fx
Stabilize thorax posteriorly
Pectoralis fx
Can stabilize the ribs
Used in reverse, can assist with ant and lat chest wall expansion
Forced exhalation when chest moves into flexion
SA fx
Only insp mm paired with trunk flexion
Post expansion with fixed UE
SCM fx
Superior and anterior expansion
Trapezius fx
Superior expansion
LEAST energy efficient accessory mm
Newborn breathing
Triangle shape
Diaphragmatic breathers
No functional accessory mm
No pulmonary reserves
Stability more important than mobility in newborn thorax
Ribs horizontally aligned
Not a lot of neck presentation
Respiration > 40 (high)
Low tidal volume
3-6 mo breathing
Rectangular-shaped chest
Mostly diaphragmatic with some upper chest movement
You will see a bigger breath going in and a slowing down of respiration rate
6-12 mo breathing
MOST SIGNIFICANT STAGE OF NORMAL CHEST DEVELOPMENT
Elliptical and rectangular shape
All mm now available
Intra-abdominal pressure
Always reported as positive
Fluctuates with breathing
Increases with inhalation
Decreases with exhalation
Intrathoracic pressure
Lower to draw air in inhalation and higher with exhalation
As we age…
Decreased lung compliance
Decreased chest wall compliance
Lung volumes and expiratory flow rates decrease
Upper airways
Nasal and oral orifices to the false vocal cords in the larynx
Conducting airways filter warm, conduct air to the respiratory units
Nose Nasal cavity Pharynx Nasopharynx Oropharynx Laryngopharynx Larynx
Pharynx
Shared thoroughfare for digestive and respiratory system
Larynx
Prevents food and other things from entering airways
Lower airways
True vocal folds to the alveoli
Conducting airways function to filter, warm, and conduct the air to the respiratory units
Respiratory units…
where gas exchange occurs
Trachea
12 cm long
Carina - where it divides into R and L main stem bronchi
Cartilaginous rings
R main stem bronchus is more vertical, shorter, and wider than L
***More prone to aspirate to R side than L
Resp unit organs
Trachea
Bronchi
Bronchioles
Terminal bronchioles
Terminal respiratory units
Where gas exchange occurs
Alv ducts and sacs
Alv epithelium
Alv capillary septum (membrane) - where O2 gets from lung to capillary
Coughing only gets us to…
7th generation
Alveolus
Cup-shaped out pouching lined by simple squamous epithelium and supported by a thin elastic membrane
Alveolar sac
2+ alveoli that share a common opening
Type I Alveolar Cells
Simple squamous
Form a continuous lining of the wall
MAIN SITE FOR GAS EXCHANGE
Macrophages - phagocytes that help remove dust particles and other debris
Type II Alveolar Cells
Septal cells
Secrete alveolar fluid, which includes SURFACTANT
Cilia
Helps move secretions
Needs ATP and appropriate ionic conditions of Ca++ and Magnesium
Parenchyma
Spongy, porous material that the lungs are made of
Apex of lung
About 1 in about clavicle
Hilus/hilum
Principal bronchus Pulmonary artery Pulmonary veins Bronchial arteries and veins Pulmonary nerve plexus Lymph vessels
Purposes of thorax
Attachment for mm of ventilation
Houses lungs and mediastinum
Lung blood supply
L and R bronchial arteries and veins
Lung INN
Lungs, trachea, bronchi INN by SNS and PNS
L lung 10% smaller than R lung…
Cardiac notch
Oblique fissures
Upper and middle lobe
from
Lower lobe
Horizontal fissure
R lung only
Separates upper lob and middle lobe
Right lung
3 lobes
RUL
RML
RLL
Left lung
2 lobes
LUL
LLL
Lingula (incorporated into LUL)
Lobules
Contain lymph vessel, arteriole, venule, and branch from a terminal bronchiole
Pleurae
Membranous serous sac covers each lung
Visceral and parietal
Somatosensory nn hit this so if you hit a parietal pleura, you could feel this pain in the thoracic or abdominal walls or neck and shoulders
Pleural space
Potential space
Pleuritis
Inflammation of membranes
Build up of fluid possible
Thoracocentesis
Tx - around 7th IC space and suck the fluid out
SURFACTANT
Week 28
Ventilation
Movement of gas to and from the alveoli
Diffusion
Passage of O2 and CO2 across the alveolar membrane
Perfusion
Transport dissolved and bound gases to/from lungs and cells in blood
Respiration
O2 consumption at cell level and production of CO2 in use of metabolic substrates
O2 transport
Delivery of fully oxygenated blood to peripheral tissues, cellular uptake of O2, use of O2 in tissues, and return of desaturated blood to the lungs
DO2
Oxygen delivery
VO2
Oxygen consumption
OER
Oxygen Extraction Ratio
VO2/DO2
@ rest, we extract 23%
Steps in O2 Transport Pathway
- Inspired O2 and quality of ambient air
- Airways
- Lungs and chest wall
- Diffusion
- Perfusion
Upper respiratory tissue type
More cartilage
Lower respiratory tissue type
More smooth mm and cilia
75% inspiration
Caused by contraction of diaphragm and intercostals
Pulmonary circulation
Delivery of DEoxygenated blood and return of oxygenated blood to the heart
Bronchial circulation
Bronchial arteries from the aorta deliver oxygenated blood to the lungs
Accounts for 1-2% of CO
Pulmonary veins drain from…
Capillaries
Anatomic Dead Space
Does not participate in gas exchange
Respiratory membrane
0.5 micrometers thick
Allows for rapid gas diffusion
Partial pressure
The pressure exerted by each component of a gas mixture
Poor ventilation
Shunt
Poor perfusion
Physiologic dead space
Factors Affecting O2 Concentration in the Blood
Decreased hemoglobin concentration
Inadequate alveolar ventilation
Decreased diffusion across the pulmonary membrane when diffusion distance increases the pulmonary membrane changes
V/Q mismatch occurs when a portion of the alveoli collapses
Medullary rhythmicity
Inhale:exhale 2:3
Inspiratory neurons
Expiratory neurons
Pneumotaxic area in the pons
Maintains normal pattern of respiration
Inhibitory impulse shortens inhalation, increases RR
Apneustic area in the pons
Impulses activate/prolong inspiration
Hering-Breuer reflex
When smooth mm receptors are stretched too much, it sends message to brain to prevent over expansion of lung
Not involved in normal breathing
Labored breathing from exercise
How does baby learn to breathe?
Ventilation is initiated quickly due to hypoxia and hypercapnia
Once placenta is disturbed during delivery, chemoreceptors in baby’s brain make them take a breath
Avg lung can hold…
6 L of air
Surface tension
Surfactant lowers wall tension in relation to size to maintain proper wall tension so alveoli do not collapse
If lung collapses…
Your chest can expand more
CO2 transport
Dissolved in plasma
Bound to proteins
Bicarbonate
