Respiratory System

Functions of the Respiratory System

Functions of the Respiratory System

1. Respiration

2. Regulation of pH

3. Voice production

4. Olfaction

5. Protection

Respiration

intake of O2 and output of CO2

Regulation of pH

through the regulation of CO2 levels

Voice production

air moving through the vocal cords

Olfaction

drawing air through the nose

Protection

inhibit and eliminate foreign bodies from the tract

Air Pathway

Nose - Sinuses - Pharynx - Larynx - Trachea - Tracheobronchial tube - Bronchus tubes - Bronchioles Alveoli

Air pathway through the lungs

Bronchus tubes - Bronchioles - Alveoli

The nose

1. cleans the air - 2. humidifies the air - 3. houses olfactory receptors - 4. affects how the voice sounds

The sinuses open structures within

the skull

The sinuses can become filled with

mucus and microorganisms that can cause infection

Pharynx

1. nasopharynx - 2. oropharynx - 3. laryngopharynx

Nasopharynx

soft palate and uvula

Oropharynx

commonly called the throat

Laryngopharynx

just above the epiglottis

Larynx

1. epiglottis - 2. vocal cords

Epiglottis

prevent the inhalation of food and drink

Vocal Cords

move back and forth to produce sound and pitch

Glottis

the opening between the vocal cords

Trachea & Tracheobronchial Tube

connects the larynx to the bronchial tubes

Cartilage rings help maintain the

tracheal shape

Cilia is found

from this point on to help keep the airways clear of debris and mucus

The tracheobronchial tube

carries air from the cervical region into the thoracic cavity

Right & Left Bronchial Tubes

the main divide that shunts air to either the right or left lung

Due the right bronchus being straighter

solid objects are more likely to lodge on this side

Bronchioles

smaller divisions

Terminal Bronchioles

bronchioles divide up to 16 times before this point

Bronchioles divide up to

16 times

How many alveoli are housed within the right and left lungs?

300 million

Alveoli measuring only

250 μm in diameter

Gas exchanged between the

alveoli and the bloodstream capillaries

The bases of the lungs rest on the

diaphragm

The apex of the lungs are

2.5 cm ABOVE the clavicles

The hilum is the

middle of the lungs

The hilum is where

the structures attach

The right lung is divided into

three lobes

The left has only

two lobes

Ventilation occurs due to

pressure difference

↑ volume

↓ pressure

↓ volume

↑ pressure

Barometric pressure stays

constant at the same altitude

As the diaphragm moves

it changes the pressure within the thoracic cavity

The diaphragm moves

drawing air in or pushing air out of the lungs

As pressure changes within the thoracic cavity

air movement occurs to equalize the pressure both inside the lungs and in the atmosphere

End of Expiration

Pressures are equal; no air movement occurs

Inspiration

Contraction of respiratory muscles ⇨ increase in thoracic volume ⇨ decrease in pressure ⇨ air rushes in

End of Inspiration

Pressures are equal; no air movement occurs!

Expiration

Relaxation of respiration muscles ⇨ decrease in thoracic volume ⇨ increase in pressure ⇨ air rushes out

Lung Recoil (elasticity) and Surfactant

keeps the alveoli from collapsing

Volumes

amount of space occupied

Compliance

the ease with which the lungs and thorax expand

↑ compliance is a sign of

healthy lungs

↓ compliance is a sign of

sickly or compromised lungs

Tidal volume

normal breathing in and out

Inspiratory Reserve Volume

space left to inhale

Expiratory Reserve Volume

space left to exhale

Residual Volume

air still remaining after forced exhale (cannot be manipulated due to risk of lung collapse)

Capacity

max amount to be filled

Inspiratory Capacity

tidal volume + inspiratory reserve volume; everything else that can be inhaled

Functional Residual Capacity

expiratory reserve volume + residual volume; everything that can be exhaled after normal exhale

Vital Capacity

inspiratory reserve volume + tidal volume + expiratory reserve volume; all the air you can manipulate

Total Lung Capacity

inspiratory reserve volume + tidal volume + expiratory reserve volume + residual volume; EVERYTHING

Diffusion

the movement of across or throughout something due to a difference in concentration

Movement always occurs

from areas of high concentration to low concentration

O2 diffuses

from the alveoli to the bloodstream

CO2 diffuses

from the bloodstream to the alveoli

Once O2 diffuses across the respiratory membrane

it attaches to hemoglobin

At the tissues capillaries

oxygen is released

CO2 then attaches to

hemoglobin or is dissolved in the plasma

Hemoglobin is 100% saturated when

four molecules of oxygen are attached

Hemoglobin is 75% saturated when

at rest

Hemoglobin is 25% saturated when

during vigorous exercise

↓ pH

↓ O2 bound to hemoglobin

↑ pH

↑ O2 bound to hemoglobin

↓ pH!

↑ CO2; ↓ O2 bound to hemoglobin

↑ pH!

↓ CO2; ↑ O2 bound to hemoglobin

↑ temperature

↓ O2 bound to hemoglobin (temp.)

↓ temperature

↑ O2 bound to hemoglobin (temp.)

The brainstem controls regulation through two nerves

Phrenic nerves and Intercostal nerves

Phrenic nerves

(C3 - C5); controls the diaphragm

Intercostal nerves

(T1 - T11); control the intercostal muscles

Chemical Control

Chemoreceptors can detect changes in pH, CO2, and O2 levels within the blood

pH Control - ↓ pH

↑ respiration rate

pH Control - ↑ pH

↓ respiration rate

CO2 Control

drives our need to breathe

CO2 Control - ↓ CO2

↓ respiration rate

CO2 Control - ↑ CO2

↑ respiration rate

O2 Control - ↓ O2

↑ respiration rate

O2 Control - ↑ O2

↓ respiration rate

Upon beginning exercise

ventilation rates increase

Movement of limbs have an effect on

respiratory rate

pH, CO2, and O2 levels remain constant even though

there is a large consumption of O2 and large production of CO2

pH remains constant during

aerobic exercise

pH will change as

exercise progresses into anaerobic range

Training leads to - ↑ vital capacity with

↓ in residual capacity

Training leads to - ↓ respiration rate at

rest and during exercise compared to those untrained

Training leads to - ↑ movement of air in and out of

lungs compared to those untrained