respiratory system Flashcards
What is external respiration
Gas exchange between the air and blood
What is internal respiration
Gas exchange between the air and tissue fluids
What moistens the air in the nostrils
The hair, cilia, and mucus in the nostrils and nasal cavity
What detects odours in the respiratory system
Chemoreceptors on ciliated cells
What is the trachea lined by and what type of rings does it have, which part of the ring is facing the esophagus
Mucous and ciliated cells (from innate immune system)
C shaped cartilaginous rings
Open part of the “c” faces the esophagus
Why is it important for the trachea to have c shaped rings
Allows trachea to expand when the bolus is passing through the esophagus, more flexible, more space for the esophagus when swallowing, prevents trachea from collapsing
What does the trachea branch into (list everything)
Left and right bronchi, then bronchioles and alveoli
What are alveoli and what are they lined with, what does the lining do
Pulmonary surfactant (made from lipoporteins) prevents alveoli from sticking together
Alveoli are tiny air sacs surrounded by gas capillaries for gas exchange
What cavity are the lungs in and what are they between
Within the thoracic (chest) cavity, between the rib cage and diaphragm
What are the membranes in the thoracic cavity (both of them) and what do they surround
Pleural membranes
Around the lungs: visceral
surrounds the lungs and lines the thoracic cavity: parietal
What do pleural membranes do and how do they do this, what do they produce
Produces a lubricating fluid that has water called the serous fluid between the lungs and ribs, serous fluid allows lungs to adhere to walls of the thoracic cavity, reducing friction
Lungs stick to thoracic cavity, helping it move along with the cavity during inspiration and expiration
what stimulates inspiration and how is it detected (hint: theres three stimuli)
High concentrations of co2 and h+ detected by the medulla oblongata
Low concentrations of o2 in the blood are deteced by chemoreceptors in the carotid artery and aorta, which then sends the message to the medulla oblongata as well
Where does the medulla oblongata send the inspiration stimuli to and what does this cause (how do the structures contract)
Sends to the intercostal muscles and diaphragm, causing them to contract:
ribs move up and out (expands), diaphragm flattens, increasing the volume of the thoracic cavity
When the diaphragm flattens and the intercostal muscles cause the ribs to expand, is there negative or positive air pressure in the lungs, what does this cause
Negative air pressure (more volume in the lungs) compared to the outside (pressure increases when volume decreases, and vice versa)
Causes air to rush into the lungs
How is respiration inhibited (expiration)
As air rushes into the lungs, the alevoli stretch
Stretch receptors in the alveoli send messages to the medulla oblongata to inhibit inhalation (negative feedback)
During expiration how do ribs and the diaphragm move
Intercostal muscles relax, causing ribs to go down and inwards, and the diaphragm goes back into the thoracic cavity
Is there negative or positive air pressure in the lungs/cavity after the diaphragm goes up and ribs go down and inwards, what does this cause
Positive air pressure, air rushes out
What type of temperature and ph is present during external respiration, what does hemoglobin like
Cooler, more basic, hemoglobin loves oxygen
What occurs during external respiration
Oxygen diffuses from the alveoli to the capillaries, binding to hemoglobin, making oxyhemoglobin
Co2 diffuses out of the plasma into the lungs to be exhaled
How does co2 travel in the blood
Most of co2 combines with the water of rbcs in the plasma, forming carbonic acid (h2co3), which then dissociates into h+ and hco3-
H+ combines with hb to form hhb (reduced hemoglobin), which travels in the rbcs
Hco3- travels in the plasma to the lungs
What is the respiratory center
Medulla oblongata
What happens during internal respiration
Oxyhemoglobin gives up o2, which diffuses out of the blood into the tissues
Co2 diffuses into the blood from the tissues, traveling to the lungs as h+ (hhb) and hco3-
What type of temperature and ph is present during internal respiration, what does hemoglobin like
Warmer, slightly more acidic (due to h+) and hemoglobin loves h+
What does carbonic anhydrase catalyze
Reactions between carbonic acid, co2, and h2o
