9.2 Respiratory System

• Left Lung- 2 lobes due to the heart

• ​Right Lung- 3 lobes

​Some text here about the topic of discussion.

Lungs and Lobes

• Pulmonary (visceral) pleura covers the lung surface

  Parietal pleura lines the walls of the thoracic cavity

  Pleural fluid fills the area between layers of pleura to allow gliding

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​Lung Membranes

Multiple Choice

Match the term

Viscera Pleura

• membrane that covers the lungs

• membranes the line the thoracic cavity

• membrane that lines the alveoli

• membrane that covers the trachea

• Thin squamous epithelial layer lining alveolar walls

  Pulmonary capillaries cover external surfaces of alveoli

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​Air-Blood Barrier

• Gas crosses the respiratory membrane by diffusion

• Oxygen enters the blood

• Carbon dioxide enters the alveoli

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Macrophages add protection

Surfactant coats gas-exposed alveolar surfaces

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​Gas Exchange

Multiple Choice

The air sacs that are covered with capillaries where gas exchange takes place

• bronchi

• lungs

• oxygen

• alveoli

9.2 Respiratory System

By Stacy King

air always moves from a higher pressure area to a lower pressure area

four key tasks involved in respiration

pulmonary ventilation – air moving in and out of lungs

external respiration- fresh O2 from outside fills lungs

respiratory gas transport – O2 and CO2 gas transported in blood

internal respiration- Gas exchange occurs between tissue and capillaries

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​Respiration

Multiple Choice

Air always moves from

• from an area of high pressure to a lower pressure

• From an area of lower pressure to a higher pressure

Boyle’s law – the mechanics of breathing

as the volume of a gas increases, the pressure of the gas decreases

At rest, both atmospheric and intrapulmonary air pressures are 760 mm/Hg

For lungs to take in air, the intrapulmonary air pressure must be less than the atmospheric

For the lungs to expel air, the intrapulmonary air pressure must be greater than atmospheric pressure.

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​Respiration

Multiple Choice

For the lungs to expel air, the intrapulmonary air pressure must be

• greater than atmospheric pressure.

• less than atmospheric pressure.

• 760mm/hg atmospheric pressure.

• equal to the atmospheric pressure.

Inspiration (inhalation)

diaphragm and intercostal muscles contract

thoracic cavity expands decreasing internal pressure

Expiration (exhalation)

diaphragm and intercostal muscles relax

thoracic cavity shrinks increasing internal pressure

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​Respiration

Multiple Choice

Which is passive?

• inhalation

• Exhalation

• Niether

These non-respiratory maneuvers often occur as a reaction, or reflexive response to a stimulus (dust or debris)

• Cough

• Sneeze​

• Hiccup

• Yawn

• ​Airway constriction

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​Respiratory Reflexes

Poll

Does this video make you want to yawn?

• yes

• no

• sort of

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​Average respiratory rate at rest is 12 to 15 breaths per minute

Biological factor

Gender: women have higher rates because of smaller lung capacity

Age: infants take around 40 to 60 breaths per minute

Physical Factor

Posture position (sitting or standing)

Breath rate doubles when you move from reclined to standing

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​Breathing Controls

neural factors that control rate and depth

Located in the pons and medulla oblongata

Medulla Oblongata sets normal breathing pace

Pons appears to smooth out respiratory rate

chemical factors

central chemoreceptors – monitor changes in cerebrospinal fluid pH

peripheral chemoreceptors- monitors changes of oxygen concentrations in the blood (aorta and carotid artery)

Mechanoreceptors- located in muscles and joints, responsible for quick increase in ventilation when exercising.

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Breathing Controls

Multiple Choice

These chemoreceptors monitor changes of oxygen concentrations in the blood (aorta and carotid artery)

• central

• peripheral

• medulla oblongata

• pons

Lung volume- measurements are used to assess whether or not a persons lungs capacity is normal.

static

air volume in lungs

Measured by a spirometer

dynamic

air volume in lungs based on time

Measured using a flow volume meter.

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​Lung Volume

tidal volume –6 normal breaths

vital capacity –deep breaths

residual volume – air left over

In lungs.

Other static lung volume

measurements are

functional residual capacity

inspiratory reserve volume

expiratory reserve volume

total lung capacity- IRV+TV+ERV+RV= 6L of air​

​Static

Multiple Choice

air left over

In lungs

• tidal volume

• residual volume

• vital capacity

Multiple Choice

The amount of air you can force out after a normal breath out

• Expiratory Reserve
• Functional Residual Capacity
• Vital Capacity
• Inspiratory Capacity

Dynamic Lung Volume is a measurement of flow rate during a forced vital capacity maneuver

Use a pulmonary function testing

Can determine if a person has

Asthma, obstructive lung disease, restrictive lung disease

Most important measurements obtained from test:

forced expiratory volume in one second (FEV1)

forced expiratory volume in one second/forced vital capacity (FEV1/FVC)

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Dynamic Lung Volume