module 16

what does the upper respiratory track do

1. warms and moistens air

2. smells, tastes , shewing, swallowing

what is the nose and nasal cavity separated by

this is separated from the mouth by the palate

what separates the nasal cavity

the septum

how many regions does the pharynx have

three regions

what does the nasopharynx do (region of the pharynx)

1. food doesn’t pass through here

2. this warms and moistens air

3. has opening to Eustachian tube

4. just behind the soft palate

what does the oropharynx do (region of the pharynx)

1. food and air both pass

2. this contains the tonsils

3. between the soft palate and base of tongue

what does the laryngopharynx do (region of the pharynx)

1. this connects to the esophagus

2. this is dorsal to larynx

3. food and air passes thro

what does the larynx do

1. this is formed by 9 pieces of cartilage

2. prevents food and liquids from entering the trachea

3. produces sound

what is part of the lower respiratory track

1. the trachea

2. the bronchi

3. the lungs

what are the alveoli

1. this is the site of gas exchange

2. wrapped in capillaries

3. the inside is coated with surfactant which reduces surface tension so that the alveoli doesn’t collapse

what keeps the trachea from collapsing

1. its a rigid tube

2. their c-shaped rings of cartilage

what does the trachea branch into

into two primary bronchi

what do the primary branchi branch into

into the secondary bronchi

what do the secondary bronchi branch into

smaller tertiary bronchi

what do the tertiary bronchi branch into

bronchioles, which branch into alveolar duct, and the alveolar duct terminates in clusters of alveoli

what is the visceral pleura

this is when the serous membrane covers the surface of lungs

what is the parietal pleura

this lines the thoracic cavity

what is the pleural cavity

this is potential space that contains thin layer of pleural fluid

what does inspiration and expiration depend on

1. respiratory muscles

2. difference between air pressure within the lung, and outside the body

what are the respiratory muscles

1. external/internal intercostals

2. the diaphragm

what is the main muscle responsible for pulmonary ventilation

the diaphragm is

what happens during inspiration

the chest cavity enlarges

how do the external intercostal muscles work during inspiration

they pull the ribs upwards and outwards

how do internal intercostal muscles work in inspiration

these elevate the ribs

what does the diaphragm do in inspiration

this contacts, flatten, enlarges the thoracic cavity

what does expiration do

it reduces the chest cavity

what do the intercostal muscles do in expiration

the muscles relax

what does the diaphragm do in expiration

it relaxes, bulges upwards reducing the size of the thoracic cavity

what muscles help deep inspiration

the muscles of the neck and the chest help

what muscles help forced expiration

abdominal muscles contract to help this

what does atmospheric pressure do

this drives respiration

what happens when pressure within lungs drop lower than atmospheric pressure

air flows in

what happens pressure in the lungs rise above atmospheric pressure

air flows out

what factors affect airflow

1. diameter of bronchioles - autonomic NS

2. pulmonary compliance (elasticity of lungs tissue

3. alveolar surface tension (surfactant to lower surfactant to lower surface tension and prevent collapse

what do they use to measure ventilation

we use a spirometer

what is tidal volume

the amount of air inhaled and exhaled during normal breathing

what is inspiratory reserve volume

this is the amount of extra air that can be inhaled after normal inhalation

what is expiratory reserve volume

this is the amount of extra air that can be exhaled after normal exhalation

what is vital capacity

this is the amount of air inhaled and exhaled in deepest possible breath

what is the total lung capacity

this is the maximum amount of air the lungs can contain

what is the apneustic center (the pons controls it)

this increases length and depth of inspiration

what is pneumotaxic (the pons)

this prevents lung over-inflation

what is the expiration center (medulla)

this is used for forceful exhalations

what is the regulator for respiration

carbon dioxide

how does gas exchange work

gas diffuses from higher to lower partial pressure until partial pressures are equalized

what does the difference in partial pressure cause co2 and 02 to do

1. o2 moves out of the alveoli and into the capillaries

2. co2 moves out of the capillaries into the alveoli

what does optimum exchange depend on

this depends on partial pressure/concentration gradients, amount of alveolar surface

how does the transport of oxygen work

1. most oxygen forms oxyhemoglobin which is attached to hemoglobin, in the blood

2. 98.5% of oxygen

3. oxyhemoglobin travels to the cells

4. oxygen is released to the tissue

what does the difference in ph between venous and arterial blood do

this breaks the bond with hemoglobin

how does the transport of co2 work

1. 10% is dissolved in plasma

2. 20% is bound to hemoglobin

3. 70% is carried as bicarbonate ions

what are the first three steps of inspiration

1. intercostal muscles contract pull ribs up and out

2. diaphragm contracts and moves downward. Chest cavity enlarges.

3. Lungs expand, pulled by pleura.

what are the final two steps of inspiration

1. Intrapulmonic pressure drops

2. When the intrapulmonic pressure is lower than atmospheric pressure air flows into the lungs

what are the steps of expiration

1. normally a passive process

2. Diaphragm and intercostals relax. Thoracic cage springs back to original size.

3. The lungs are compressed, and intrapulmonic pressure rises

4. •Air flows down the pressure gradient and out of the lungs.