2. pulmonary system: Anatomy of the Cardiovascular and Pulmonary Systems_condensed

Ventilation: inspiration and expiration: inspiratory muscles

• inspiratory muscles increase the volume of the thoracic cavity by contracting

  • the result causes a decrease in intrathoracic pressure

    • homeostasis, air flows into lungs

Inspiration causes an increase in intra pressure (in the chest cavity)

- when you initially expand the volume vis the muscles- it decreases the pressure – as you breathe in you create more space so the molecules have more room to move around – this means atmospheric air rushes into the thoracic cavity

Ventilation: inspiration and expiration: expiration

• expiration is the relaxation of the diaphragm and inspiratory muscles, causing a decrease in thoracic cavity volume

  • the result causes an increase in intrathoracic pressure

    • homeostasis, air flows out of the lungs

When you breathe out – you decrease the volume in the thoracic volume which increases the pressure – so the air going out to make homeostasis

Respiratory system: muscles of inspiration - primary muscles

diaphragm and external intercostals

Respiratory system: muscles of inspiration - accessory muscles

• SCM

• Scalenes

• Upper Trapezius

• Pectorals Major and Minor

• Serratus anterior/serratus posterior superior

• Rhomboids

• Latissimus Dorsi

• Thoracic Erector Spinae muscles

if you see that the SCM/scalene/upper trap are hypertrophies it may indicate that they are having breathing problems (pulmonary issues)

Diaphragm (inspiration) (where does it sit, what does it separate, what are the 3 major openings, what nerve)

• can sit as high as the level of T4 at rest

• separated the thoracic and abdominal cavities

• three major openings in the diaphragm to allow for vessels to transverse

  • venal caval opening: inferior vena cava

  • esophageal opening: esophagus

  • aortic opening: aorta

• phrenic nerve arises from C3-C5 spinal nerves and is involved with the contraction of the diaphragm

“C3,C4,C5 keeps you alive” - if these are injured the patient may have difficulties breathing on their own

External intercostals (inspiration)

• external intercostals

  • 11 external intercostals on each side of the sternum

  • contraction of these muscles pull the lower rib up and out towards the upper rib, thus elevating the ribs and expanding the chest

The lower ribs act like a bucket handle – you should find that the lower ribs have a movement that goes up and out

Upper ribs – go up and down (like a pump handle)

muscles of forceful expiration

• expiration should be a relaxed, passive process, however…

  • abdominal muscles

    • rectus abdominus, internal and external obliques, transverses abdomens

    • work to raise intraabdominal pressure with huffing of coughing

      • pressure generated in the abdominal cavity is transmitted to the thoracic cage to allow for greater expulsion of air

  • internal intercostals

    • 11 internal intercostals are located on each side of the sternum

    • depresses the rib to aid in forceful expiration

If expiration is problematic its obstructive – this cues you to take a stethoscope to auscultate the lungs to find that

Rib movement

• bucket handle movement (lower)

• pump handle movement (upper)

clinical: “milking effect”

• changes in intraabdominal and intrathoracic pressure assist with venous and lymphatic return to the heart

  • manual technique

  • breathing

lymphangions are 6-8x/min for the lymphatic system - this is why we need to belly breathe (creates the internal pressure changes we need to move fluid)

Pulmonary system: pleurae

• two serous membranes, or pleurae, exist that cover each lung

  • outer surface of the lung is visceral pleura

    • inseparable from the tissue of the lung

  • the pleura covering the inner surface of the chest wall, diaphragm, and mediastinum is called the parietal pleura

  • normally, the two pleura are in constant contact with eachother

    • there exists a potential space between the pleura called the pleural space of pleural cavity

    • a constant negative pressure within this space maintains lung inflation

You cannot separate the visceral pleura from the lung they are conjoined

Pleural space with pleural fluid (prevents pleural friction rubbing – this as a certain sound that we can hear with auscultation)

Clinical: Complications effecting pleural integrity: Pleuritis or pleurisy

• an infection with resultant inflammatory response in between the pleura

  • detected via auscultation as an abnormal pleural friction rub

Clinical: Complications effecting pleural integrity: pleural effusion

• refers to buildup of fluid in the pleural space, commonly seen after cardiothoracic surgery

  • detected via auscultation as diminished or absent breath sounds in the area of effusion, often accompanied by reduced lung volumes

Hemothorax vs pneumothorax vs empyema

• hemothorax

  • blood in the pleural space

• pneumothorax

  • air in the pleural space as result of a collapsed lung\

• empyema

  • infection with pus in the pleural space

If that pleural space is irritated its pleuritis – can be from material in that space that shouldn’t belong (air, blood, pus)

*******pleural effusion (fluid in pleural space) vs pulmonary edema (fluid in lungs)

Auscultation shows absent or diminished breath sounds –

when testing – the lung volumes would be off (there is more pressure on the lungs causes less space of ability to expand)

This is an example of restrictive lung disease but the etiology (cause) is pleural effusion

Thoracocentesis – drains it so you can see whats inside (if its yellow its pus, if its red its blood, ect)

treatment for complications effecting pleural integrity such as pleuritic, pleural effusion, hemothorax, pneumothorax, empyema

• treatment: insertion of a chest tube into the pleural space to drain pleural secretions or to restore a negative pressure, to allow for lung inflation

  • thoracocentesis: a needle aspiration of fluid into the pleural space for patients who have large pleural effusions

pulmonary system: lobes, tissues, segments - right lung

• 3 lobes: RUL, RML, RLL

• two issues separate these lobes from one another

  • the RML and RLL are separated by the oblique (major) fissure

  • the RUL and RML are separated by the horizontal (minor) fissure

• each lobe is further divided into segments

Each lobes have segments: the areas of the lungs are important because you asacultate the different areas of the lungs and based on where the fluid is congested you have to position the patient in a certain position

- you don’t have to memorize the different segments but this is why you have them

pulmonary system: lobes, tissues, segments - Left lung

• left lung

  • smaller than the right lung, how two lobes: LUL, LLL

  • an oblique fissure divides the LUL from the LLL

  • the portion of the left lung that resembles the middle lobe of the right ling is called the lingular segment, or lingua

    • part of the LUL

  • each lobe further divides into segments

clinical: seasonal allergies

• individuals with seasonal allergies who are prone to developing sinus infections are also prone to developing bronchitis if the infection leaves the sinus cavities and drops down the trachea to the bronchioles

  • upper respiratory infection may lead to a lower respiratory infection

clinical: ETT

• endotracheal intubation may cause damage to the structures within the larynx, producing an inflammatory response - laryngitis

  • hearsness and pain during speech

Pulmonary: lower respiratory tract - airway diameter

• airway diameter progressively decreases with each succeeding generation of branching

  • starting at approximately one inch in diameter at the trachea and reaching 1mm or less at the terminal bronchioles

Pulmonary: lower respiratory tract - Trachea (bifurcation and where and what is it called)

• the trachea bifurcated into the right and left mainstream bronchi at the level of the 5th thoracic vertebra or sternal notch of the sternum

  • carina

lower segments distal to the trachea

• primary bronchi

  • R/L main stem

• secondary bronchi

  • go to each lobe

• tertiary bronchi

  • go to each segments within the lobes

Carina is an upside down triangle at the first dissection pf primary bronchi

Secondary bronchi go to the lobes (3 on R; 2 on L)

Teriary bronchi go to each segment in the lobes

Bronchiole

Alvioli – most functional unit of gas enchange in the lungs (provide oxygenated blood to the lungs and the circulatory system gives CO2)

Clinical: aspiration (angles and which lung is more likely to experience aspiration)

• aspiration - breathing in air or food - can cause infection if not expelled

• the right mainstream branches off at the trachea at approximately a 25* angle

• the left mainstem branched off the trachea at approximately a 40-60* angle

• which lung is more likely to experience aspiration

  • R lung is more likely to experience because there is less resistance to fall

Pulmonary: terminal respiratory (acinar) units

• The functional unit of the lung is the alveoli, where gas exchange occurs.

• Two major types of cells exist along the alveolar wall

  • Squamous pneumocytes (type I): flat and thin. Cover 93% of alveolar surface

  • Granular pneumocytes (type II): thick and cuboidal. Cover 7% of alveolar surface- produce surfactant

    • Surfactant is a lipoprotein that lowers alveolar surface tension at end expiration and thereby prevents the lung from collapsing

• Capillaries deliver blood in close proximity to the alveoli. The alveolar capillary interface is where gas exchange occurs.

KNOW SURFICANT