Respiratory System (Gross Microscopic Anatomy (Alveoli (this is the site…
Gross Microscopic Anatomy
this is the site for gas exchange there are 300 million in each lung and each alveoli is surrounded by capillaries. They are like a cluster of hollow grapes that include 3 cells type 1 alveolar cells (simple squamous epithelial), type 2 alveolar cells and macrophages.
similar to a sponge with lots of holes. Right lung has 3 lobes the left only 2 lobes
A way of branching from trachea to the air sacs. There is bronchi and they keep branching to smaller and smaller bronchi until they reach the bronchioles.
made up of c shaped cartilagenous rings and runs in front of the esophagus. it has cilia that move substances back towards the mouth
also known as the voice box and its main function is for speech and singing
made of 3 parts nasopharynx, oropharynx and the laryngopharynx
Helps filter any foreign material that gets trapped in the hairs and mucous plus helps bring in oxygen
Mechanisms of Pulmonary Ventilation
- Inspiratory Reserve Volume- maximum amount of air that one can inhale above tidal volume.
Tidal Volume- normal amount of air one breathes at rest which is usually 500mL.
Expiratory Reserve Volume- max amount of air that one can exhale above tidal volume.
Residual Volume- amount of air that remains in our lungs after the most forceful exhalation average 1200mL.
VC=IRV+TV+ERV Average is 5,000mL
Air is 78% Nitrogen 21% oxygen and !% other gases
At sea level the atmospheric pressure is 760 mmHg so if we want to draw air in we need to lower the pressure in our lungs. Pressure moves from higher to lower concentration
Pleural membranes- This is how the lungs can expand using the parietal and visceral pleura that are firmly attached to the lungs.
External Intercostal muscles- This muscles contract lifting the rib cage out which also allows the chest cavity to expand
Diaphragm- when you breath in your diaphragm contracts and moves downward this increases the space in the chest cavity so the lungs expand. When you breathe out your diaphragm relaxes decreasing the space in chest cavity which decreases the volume which increases the pressure.
Mechanisms of Gas Exchange
Internal Respiration-(transfer of gases between bloodstream & cells) metabolic process in which oxygen is released to tissues and crbon dioxide is absorbed by blood. oxygen is used to create ATP when it has reached the cell.
External Respiration- (transfer of gases between lungs & bloodstream) can also be called breathing refers to inhaling oxygen into the lungs and expelling carbon dioxide from the lungs to the air. this exchange occurs simultaneously oxygen is taken up by capillaries of alveoli and carbon dioxide is released from hemoglobin.
Atmospheric pressure = 760mmHg and oxygen is 21% in atmospheric air partial pressure of O2 would be .21 X 760mmHg=Po2 159.6
Mechanisms of Gas Transport in the Blood
when acidity or temp increases the % of saturated hemoglobin decreases. Increase in CO2 increases acidity decrease in CO2 decrease in acidity. As partial pressure increases so does the % of saturated hemoglobins until they reach a % of 98% saturated which is normal when partial pressure is 100mmHg
- it can be carried in 3 ways.
1) 70% picked up from cells and transported as bicarbonate ion in plasma
CO2+H2O<----->H2CO3(carbonic acid)<----->HCO3-(bicarbonate acid) + H+
2) 20% is transported in the red blood cells as carbaminohemoglobin. 4 CO2 binds to hemoglobin.
3) about 3% of CO2 dissolves in plasma
- 98% of oxygen that moves across from the alveoli into the bloodstream binds with hemoglobin the other 2% dissolves in the plasma. When oxygen and hemoglobin bind it is called oxyhemoglobin if not bound it id called deoxyhemoglobin. 4 O2 molecules can bind to one hemoglobin