Human Physio Respiratory Physiology

Single respiratory cycle

________ consists of an inspiration followed by an expiration.

HCO3

Most CO2 in blood has been converted to bicarbonate ion, ________-

Emphysema

________ (can be caused by smoking) destroyed elastin fibers in lung tissues → decreased elastance.

O2

Body brings in ________ for distribution to tissue and eliminate CO2.

CO2

Lungs alter body pH by selectively retaining or excreting ________.

surface tension

Increased ________ cause alveolar walls to stick to each other.

Capillaries

________ are in close proximity to the alveolar cells to allow gas exchange to occur efficiently.

II

Type ________ alveolar cells line the air sacs to synthesise surfactants.

Histamine

________ (released during an allergic reaction) increases resistance and secretion of mucus.

Respiratory zone sites of gas exchange within lungs

alveoli

the nose, nasal cavity, sinuses, and pharynx

The upper respiratory system consists of:

filter, warms and humidifies the air

The upper respiratory system functions to:

the larynx, trachea, bronchi, bronchioles, and alveoli

The lower respiratory system consists of:

conduct air and provide a respiratory surface for gas exchange

The lower respiratory system functions to:

Exchange of gases between atmosphere & blood, Homeostatic regulation of body pH, Protection from inhaled pathogens and irritating substances, Vocalization

Major functions of the respiratory system

intracellular reaction of O2 with organic molecules to produce CO2, H2O and ATP
cellular respiration (blood to cells)

Two types of internal respiration.

External respiration

gases exchange between environment and body tissues

Ventilation

exchange of air between atmosphere and lungs

diffusion

exchange of gas by ______ between lungs and blood (alveoli)

transportation

t______ of gases by the blood

diffusion

exchange of gas by ______ between blood and tissues

Conducting zone

(airways; nasal cavity, trachea, bronchus, bronchiole)

alveoli

Respiratory zone sites of gas exchange within lungs

thorax, abdomen

bones and muscles of t_____ and a______

to increase or decrease pressure, assist in ventilation

friction, slide across, against

Pleural fluid serves two functions:
reduce ______ to allow two layer membranes to s______ a______ one another when lungs move within thorax
hold lungs tight ______ thoracic wall (protection)

collapsing

Air is warmed before entering the lungs to prevent alveolis from _____

dry out

Air is humidified before reaching lungs so that epithelium does not ________

foreign, filtered

______ materials like viruses, bacteria, inorganic particles are ______ before reaching alveoli

I

Type __ alveolar cells carries out gas exchange

macrophage

Alveolar m_______ ingests foreign material that may harm the alveolus

Capillaries

C______ are in close proximity to the alveolar cells to allow gas exchange to occur efficiently

diaphragm
external intercostals
scaleness

Primary muscles involved in quiet breathing:

internal intercostals
abdominal muscles (rib cage)

Muscles involved during active expiration

Compliance, Elastance

Factors affecting ventilation

elasticity, surface tension

Compliance depends on e______ of lungs and s_____ t_____ of liquid in alveoli

volume over pressure

Compliance expressed as change in _______________ exerted

Elastance

ability to return to its resting volume when stretching force is released

Surface tension

created by thin fluid layer between alveolar cells & air

Surfactants

reduces surface tension, decrease resistance of lungs to stretch

passive, diameter, mucous

Resistance is affected by:

_____ force on the airways - changes in the transpulmonary pressure during inspiration and expiration

changes in the _______ of bronchioles

secretion of _______ in the airways

acidic, oxygen

If high hydrogen ions, more a_____, chemoreceptors will detect and the respiratory control centres (pons and medulla) will increase ______ uptake (increased ventilation)

PO2

binding of oxygen to haemoglobin depends on _____ of plasma

PO2 in plasma surrounding the RBCs
Number of potential Hb binding sites available in RBCs (amount of haemoglobin available)

Amount of O2 bound to haemoglobin (Hb) depends on: