Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
47 Cards in this Set
- Front
- Back
|
Boyle's Law |
A change in volume leads to a change in pressure - if you increase the volume, pressure decreases. |
|
|
Inspiration occurs when... |
alveolar pressure is less than atmospheric pressure - air will flow into the lungs due to the pressure gradient established. |
|
|
Thoracic Cavity boundaries |
Superiorly - root of neck Inferiorly - Diaphragm Anteriorly - Sternum Posteriorly - Vertebrae Lateraly - Ribs/Intercostal muscles |
|
|
Thoracic Joints - Anterior |
Sternocostal Costochondral Interchondral |
|
|
Sternocostal joints |
sternum - cartilage synovial except for 1st rib which is fibrocartilaginous. |
|
|
Costochondral joints |
rib - cartilage cartilagenous |
|
|
Interchondral joints |
cartilage - cartilage synovial |
|
|
Thoracic joints - Posterior |
Costovertebral Costotransverse
Articulation between thoracic vertebrae and ribs. Bilateral facets Synovial joints |
|
|
Contents of the Thoracic Cavity |
Heart, Lungs and major vessels
|
|
|
Muscles of respiration |
Diaphragm, intercostal muscles, accessory muscles |
|
|
Diaphragm |
Primary respiratory muscle Lower boundrary of the thoracic cavity Skeletal muscle Innovated by the phrenic nerve Contacts in inspiration (flattens) - concentric contraction - increases thoracic cavity length |
|
|
Intercostal muscles |
Secondary respiratory muscles two layers of muscles between the ribs External + Internal intercostalsExtern |
|
|
External Intercostals |
inspiration - elevate ribs therefore expanding the thoracic cavity laterally. direction of muscle fibres inferior and medial - hands in pockets
|
|
|
Internal Intercostals |
Used in forced expiration - decrase volume of thoracic cavity by pulling in laterally direction of muscle fibres inferior and lateral |
|
|
Accessory Muscles |
-muscles attatched to thoracic cage eg abdominals, accessory muscles -used during forced expiration or inspiration |
|
|
Thoracic Cavity movement - Pleura |
Serous membranes line body cavities and secrete serous fluid Within the thoracic cavity, serous membranes are called pleura. Visceral pleura - covers lungs Parietal pleura - lines thorax and mediastinum |
|
|
At the end of expiration... |
Atmospheric pressure (Pb) = avleolar pressure (Pa) Therefore there is no air movement |
|
|
Expiration |
A passive process as the respiratory muscles relax. Elastin in the lungs helps with recoil |
|
|
Average volume of oxygen inspired per min |
250mL |
|
|
Average volume of carbon dioxide expired per min |
200mL |
|
|
Functions of the respiratory system |
-Provide oxygen -Eliminate carbon dioxide -Filters,warms and humidifies the air we breathe -Communication -Sense of smell -Regulate pH of the blood (in assoc. with kidneys) - Defend against microbes -Production of chemical mediators -Trapping and dissolving blood clots -Temperature regulation |
|
|
Percentages of gases in the air |
Oxygen - 20.93% Carbon dioxide - 0.03% Nitrogen - 79.04% |
|
|
Intrapleural pressure |
negative in regards to atmospheric pressure is changed by muscles acting on the thoracic wall which causes the lung volume to change. |
|
|
Upper respiratory tract consists of... |
Nose and nasal cavity -Paranasal sinuses Pharynx Larynx |
|
|
External part of the nose |
External nares (nostrils) Paired nasal cartlages - lateral and alar (thicker) Septal cartilage - down midline Cartilage important for patent, unobstructed airway |
|
|
Nasal septum |
Formed by hyaline cartilage (anterior) and bone (posterior) |
|
|
Roof of nasal cavity formed by... |
Ethmoid and sphenoid bones |
|
|
Floor of nasal cavity formed by... |
Hard (anterior) and soft (posterior) palates |
|
|
Turbinates/Chochae |
Three mucous covered projections on the lateral wall of the nasal cavity -superior, middle, and inferior Swirl the incoming air creating a turbulent flow which makes larger particles stick to the mucous. Sensory nerve endings can be triggered ina sneeze reflex. |
|
|
Forms in which oxygen is carried in the blood |
Dissolved, combined with Hb |
|
|
Dissolved oxygen |
Arterial blood with PO2 -100mmHg contains only 3 ml dissolved O2/Litre |
|
|
Combined with Hb |
O2 forms an easily reversible combination with Hb to give oxyhaemoglobin. Binding depends on PO2 - dissociation curve - saturation |
|
|
O2 saturation in arterial blood |
PaO2 = 100mmHg SaO2 - 97% |
|
|
O2 saturation in venous blood |
PvO2 = 40mmHg SvO2 - 75% |
|
|
What is P50 |
P50 is the PO2 at which Hb is 50% saturated - 25mmHg |
|
|
O2 capacity is |
the amount of O2 carried when Hb is 100% saturated |
|
|
Normal blood has about ...... g Hb/Litre |
150 |
|
|
One gram of Hb can combine with ....... ml O2 |
1.34 |
|
|
Normal O2 capacity |
200mL/litre of blood |
|
|
O2 content = |
O2 capacity * saturation (+dissolved) |
|
|
Arterial-venous O2 difference |
a-v difference of -50ml O2 CO=5L/min Therefore total O2 extracted by tissues at rest is 250ml/min |
|
|
Leftward shift |
more loading of O2 in the lungs increased O2 affinity, decreased P50R
|
|
|
Rightward shift |
more unloading of O2 to the tissues decreased O2 affinity, increased P50 |
|
|
Shifts caused by change in |
temperature, PCO2, [H+], BPG |
|
|
Bohr effect |
Right and left shifts in saturation curves. |
|
|
Rightward shift caused by |
incrase in PCO2, [H+], temperature and 2,3 BPG Occurs when exercising |
|
|
2,3 BPG/DPG |
-is a by-product of glycolysis -increases with intense exercise training,altitude,due to severe lung diseases or anemia -helps deliver O2 to tissues, increases PO2 unloading |
