bell jar and spirometry

Bell jar

____ ___ in the Thoracic cavity

Balloon(s) inside

_______ ______ represents the Lungs

Y-shaped glass or plastic tube

_______ ________ ___ ________ ________ represents the trachea and main bronchi

Rubber sheet at the bottom

________ ______ __ ___ _______ diaphragm

Space inside the jar surrounding the balloon:

________ _____ __ ______ ___________ ___ ____________ pleural cavity/intrapleural space

how the model is different from human anatomy

• Rigid vs. Movable Chest Wall: The bell jar is made of hard, rigid plastic/glass that cannot change its shape or volume, whereas the human chest wall consists of movable ribs and intercostal muscles that expand and contract.

• Diaphragm Action: In the model, the diaphragm is a rubber sheet that you manually pull down or push up. In a human, the diaphragm is a dome-shaped skeletal muscle that actively contracts (flattening downward) and relaxes.

• Pleural Space Contents: The space inside the bell jar contains air, whereas the human intrapleural space is a microscopic, fluid-filled potential space containing just a thin film of serous fluid.

• Lung Recoil: While balloons provide some elastic recoil, they do not fully replicate the complex micro-elastic tissue structure and surfactant lining found in real human alveoli.

inside the balloon

Ppul (Intrapulmonary pressure): Point _______ __ _____ (representing the pressure inside the alveoli and airways).

empty space inside the bell jar surrounding the outside of the balloon

Pip (Intrapleural pressure): Point to _____________________________________________________________________ the (representing the pressure in the intrapleural space between the lung and the chest wall).

respiratory membrane layers

• 1. Alveolar epithelium: A single layer of thin, simple squamous epithelial cells (primarily Type I alveolar cells / pneumocytes) that line the inner surface of the alveolus.

• 2. Epithelial basement membrane: A thin basal lamina underlying the alveolar epithelial cells.

• 3. Capillary basement membrane: A basal lamina surrounding the capillary endothelial cells. (Note: The epithelial and capillary basement membranes are often fused together into a single shared basement membrane).

• 4. Capillary endothelium: A single layer of endothelial cells forming the wall of the pulmonary capillary.

spirometry

measures the amount (volume) and/or

speed (flow) of air when performing various pulmonary function tests

spriometer

a device used to mea-sure exhaled air volumes

Tidal volume

Volume of air exchanged with normal, quiet breathing

Inspiratory reserve volume

Maximum volume of air that can be forcibly inspired after a tidal inspiration

Expiratory reserve volume

Maximum volume of air that can be forcibly expired after a tidal expiration

Expiratory reserve volume (ERV)

The maximum extra volume of air that can be forcefully exhaled after a normal exhalation.

Residual volume (RV)

The volume of air left in the lungs even after pushing out as much air as possible.

Inspiratory capacity

The total amount of air you can inhale following a normal exhalation; calculated as tidal volume plus inspiratory reserve volume.

Functional residual capacity

The volume of air remaining in the lungs after a normal exhalation; calculated as residual volume plus expiratory reserve volume.

Vital capacity

The maximum volume of air that can be moved into and out of the lungs; calculated as the sum of tidal volume, expiratory reserve volume, and inspiratory reserve volume.

Total lung capacity

The total volume of air the lungs can hold, including both exchangeable and non-exchangeable air; calculated as the sum of all four pulmonary volumes.

tidal volume

Breathe normally, exhale 3 times through the mouthpiece, and divide the total by 3.

vital capacity

prep: Reset to zero and look up expected VC in Table 21.4 (male) or 21.5 (female).

Stand, inhale fully, exhale forcibly as much as possible, record in Table 21.6, and reset to zero.

Expiratory reserve volume

Breathe normally, then after a normal exhale, force out all remaining air into the mouthpiece and record in Table 21.6.

Tidal Volume

• Inhale: Take a normal, relaxed, unforced breath in through your mouth.

• Exhale: Place the mouthpiece between your lips and exhale normally into the spirometer (repeat for 3 normal expirations, then divide the total reading by 3).

Vital Capacity (VC)

• Inhale: Take the deepest, maximum breath you possibly can.

• Exhale: Place the mouthpiece between your lips and forcibly blow all the air out of your lungs into the spirometer as hard and completely as you can.

Tidal Volume + Inspiratory Reserve Volume

inspiratory capacity equation

Tidal Volume + Inspiratory Reserve Volume + Expiratory Reserve Volume

Vital Capacity equation

Expiratory Reserve Volume + Residual Volume

Functional Residual Capacity equation

Vital Capacity + Residual Volume

Total Lung Capacity equation

Carbonic acid

Name the acid in our blood plasma that functions as a buffer

The pH should decrease

How should blowing bubbles into distilled water change the pH?

blowing bubbles

_________ ________ introduces carbon dioxide, which dissolves in the water and reacts to form carbonic acid, increasing the concentration of hydrogen ions

The pH should drop significantly

How should the pH of distilled water change after adding HCl?

hydrochloric acid

_____________________ is a strong acid that dissociates completely to release a large amount of H+, and distilled water contains no buffer systems to neutralize them.

The pH should change very little (resist a drastic drop)

How should the pH of animal plasma change after adding HCl?

animal plasma

__________ _______ contains chemical buffer systems (such as the bicarbonate buffer system) that bind excess hydrogen ions and minimize changes in pH.