Chapter 27 Respiratory Flashcards
Respiratory System
Nose, nasal cavity, sinuses, pharynx, larynx, trachea, bronchiole tree, and lungs
Amphibians lungs
are small and are not effective. They rely heavily on gas diffusion across body surfaces such as skin to carry out gas exchange.
Most reptiles, birds, and all mammals depend on lungs for gas exchange.
They use a negative pressure system that allows air in by inspiration.
Air enters through the nasal cavity which contains (which type of cells)
Ciliated epithelial cells and hair that will filter dust and particles from the air. Olfactory receptors that detect smell.
Mucous membrane that lines the nasal cavity functions.
is rich in blood vessels, it warms the air that passes over it. This mucous aids in entrapping dust and small particles from the air. As the cilia moves, the particles are pushes towards the pharynx and swallowed. Gastric juice destroys the organisms preventing respiratory infection.
Pharynx
Intersection of food and air. Nasopharynx
Path of air
From the pharynx air passes through the glottis (opening) to the larynx (voicebox) which sits at the top of the trachea.
Epiglottis
Flap of tissue which covers the glottis. During swallowing the epi closes it off temporarily preventing food from entering the trachea.
Larynx is composed of
Cartilage and muscles bound together by elastic tissue.
inside the larynx
Vocal chords. Contracting or relaxing here determines the vocal sound. If mucous membrane gets inflammed the vocal cords cannot vibrate freely - laryngitis.
Trachea
Cartilage to prevent collapse. Contains cilia bearing cells and goblet cells that make mucus.
Hyaline Cartilage
Reinforces tracheal wall. Most abundant cartilage, found at ends of long bones, layrnx, trachea, bronchi, and ventral ends of ribs.
Trachea divides into
Two bronchi to the left and right lungs. Brochi branch into bronchioles which have cartilage rings, ciliated linings.
Clara cells/ club cells
Dome shaped cells containing microvilli and are in small bronchioles. Help detoxify the lungs.
Drugs and Asthma
Epinephrine cause the smooth muscles to relax and breathing to improve.
Smallest bronchioles terminate in the
Alveolar sacs which have bulges called alveoli. They are highly vascular and very thin walled.
First breath of a new born
Stim. by CO2 must be forceful bc the lungs are collapsed. Surface tension holds the moist membranes together and surfactant reduces the surface tension. After the first powerful breath, the lungs stay expanded.
Surfactant
Mixture of proteins and phospholipids.
Negative pressure breathing
Thoracic cavity expands, the diaphragm contracts and moves down.
Phrenic nerve in breathing
Phrenic nerve carries impulses to the diaphragm. The intercostal muscles contract too, raising the ribs and increasing thoracic cavity more. Internal pressure goes down. High atmospheric pressure forces air into the respiratory tract and air passages inflate.
Tidal volume
Volume of air that flows into or out of the lungs with each breath
Vital capacity
Tidal volume during maximum inhalation and exhalation.
Residual volume
After you exhale, some air still remains in the lungs.
Pleura
Serous membrane covering the lungs.
Right lung
Larger than the left (superior, middle, inferior)
Left
Superior and inferior. Smaller due to the heart.
Breathing is controlled under which areas of the brain?
Medulla oblongata and Pons.
Exercise and CO2
Metabolic activity goes up, the CO2 in blood increase as lactic acid is produced, pH is lowered. Medulla responds by increasing the breathing rate.
CO2 over O2
CO2 has the effect on breathing control centers and not the O2 concentration in the blood.
O2 sensors in the aorta and carotid arteries can signal the brain to increase the breathing rate.
CO2 transport
Most CO2 is carried in the blood as HCO3-, 70%
20% is transported by hemoglobin
10% is in blood plasma
RBC reaction
CO2+ H20 ->
HCO3- goes into ____, H+ is captured by ________. Hemoglobin acts as a ____.
Plasma, hemoglobin, buffer.
Hemoglobin prevents the blood from getting too acidic.
HCO3- diffuses into the plasma…
And carried to the lungs. In the lungs H2CO3.
HCO3- + H+ -> H2CO3.
CO2 goes into the plasma and interstitial fluid and is exhaled.
O2 transport
Almost all O@ carried in the blood is done by hemoglobin, occurring in RBC (erythrocytes).
The greater the pressure of PO2, the more O2 can combine. Hb-O2. CO2 inc, temp inc the more O2 is released. Blood pH decreases increase O2.
Emphysema
Alveoli are damaged and lose their elasticity and their walls break down with larger sacs.
Pneumonia
Can be viral, bacterial, or fungal. Alveoli filled with fluid or pus. Pleural effusion
