Lecture midterm #2 Flashcards
What is blood pressure?
The pressure on the walls of the blood vessels
What is systolic pressure?
The “Peak” of the arterial BP. During ventricular systole
What is diastolic pressure?
“Minimum” arterial BP. At the end of ventricular diastole.
Where is Blood Pressure usually measured?
Brachial artery (inside elbow)
Where is blood pressure the highest in the body?
Arteries that are closest to the heart.
Where is blood pressure slow in the body?
In capillaries and veins
What is MAP?
(Mean arterial pressure) - diastolic pressure + (Pulse pressure/3)
What is pulse pressure?
Difference between systolic and diastolic pressure.
What is Hydrostatic pressure?
-Forces “pushes” water OUT of a solution
- Water is being “pushed” away from an area of higher hydrostatic concentration to an area of lower hydrostatic pressure.
Name some local vasodilators.
CO2 (due to increase in aerobic metabolism)
Lactic acid (due to increase in anaerobic metabolism)
which will…
lower pH (more acidic)
increase temperature
This is all due to increased cellular activity locally
Histamines
Nitric oxide
Name some local vasoconstriction
Thromboxanes
What is ANP?
atrial Natriuretic peptide
What is EPO?
Erythropoietin
What is ADH
antidiuretci hormone (aka vasopressin)
What is RAAS?
Renin-angiotensin-aldosterone-system.
Main function of the respiratory system?
Provide SURFACE AREA for gas exchange (between air and circulating blood)
VENTILATION move air into and out of the lungs.
PRODUCE sounds for communication.
PROTECT respiratory surfaces from pathogens,temp, other stuff
What is the respiratory tract split into (physically)?
Upper and Lower respiratory tract.
Upper = nose, nasal cavity, paranasal sinuses, pharynx.
Lower = larynx, trachea, bronchi, bronchioles and alveoli.
What is the respiratory tract split into (functionally)?
Conducting Division
Respiratory Division
What type of epithelium makes up the alveoli?
Simple squamous
Below is the basement membrane. (0.1um-0.5um)
What are alveolar macrophages?
Cleanup crew
What are type II alveolar cells?
Produce Surfactant
Which way will air flow in the lungs?
From an area of high pressure to an area of low pressure (it is directly proportional to the pressure gradient and inversely proportional to resistance).
Is inhalation an Active process?
Yes! Muscles contract, increasing the volume of the chest cavity and creates a partial vacuum to pull air in.
Is exhalation a passive process?
Usually, but it can be active. Muscles relax decreasing volume of the chest cavity pulling air out of the lungs.
What is the first Gas Law?
Boyles’s Law: P=1/V
Pressure (P) is inversely proportional to volume (V)
Gas will flow from an area of higher pressure to lower pressure. (Imagine a piston)
How do you decrease pressure in the lungs?
You increase the volume. DO THIS by
- Contraction of the diaphragm
- Superior movement of the rib cage (using contractions of the intercostals)
- Results in inhalation because the pressure in the lungs is lower than the pressure in the atmosphere.
What are the accessory muscles used for inspiration (contract only during forceful inspiration)?
Sternocleidomastoid
Scalenus
Whatis “Quiet breathing” called?
Eupnea
*inhalation is active, exhalation is passive
(intra-alveolar pressure)
What is “Forced breathing” called?
Hyperpnea
*inhalation and exhalation are both active
**uses “accessory muscles” for this
(intra-alveolar pressure)
What is meant by “greater compliance”?
Easier to fill and empty lungs.
What is Surfactant? What makes it?
-An oily substance used to “grease” up the lungs.
-Produced by the greater alveolar cells (Type II alveolar cells).
- Amphipathic (polar and non polar)
(Used to reduce surface tension of water on the alveoli)
Describe the Hydrophobic and hydrophilic parts of Surfactant.
Hydrophilic part interacts with the layer of water
The hydrophobic part makes a “coating” on top to reduce surface tension and prevent collapse of alveoli.
Why are the surface of each alveolus covered by water?
Keep the surface moist for gas exchange however since water is attracted to each other this could cause the alveolus to collapse. Hence why we need surfactant.
What is Tidal volume?
Amount of air moved in or out of the lungs during one respiratory cycle (during quiet breathing)
Average 500ml at rest
What is meant by respiratory rate?
Breaths per minute.
Average Breathes Per minute for an adult?
12 to 18 breaths per minute
What is IRV?
“Inspiratory Reserve Volume”
Amount of air youre able to take in, on top of your tidal volume.
males = 3300 mL
Females = 1900 mL
How to measure your total inspiratory capactiy?
IRV + tidal volume
What is ERV?
“Expiratory Reserve Volume”
Amount of air youre able to expel (voluntaryily)
= 1000 mL
For the IRV and ERV, what must be used to more more air out of the lungs during Forced breathing?
Use Accessory muscles to actively move more air out of the lungs.
How much air is left in the lungs of males even after a forced exchale?
1200 mL
How much air is left in the lungs of females even after a forced exhale?
1100 mL
What is Vital Capacity?
The maximum amount of air that can move in or out of lungs in one respiratory cycle.
ERV + tidal volume + IRV = Vital capacity
What is the vital capacity in males?
4800 mL
What is the vital capacity in females?
3400 mL
What is the TOTAL lung capacity?
Total volume of the lungs.
Vital capacity + residual volume
What is the total lung capacity in males?
6000 mL
What is the total lung capacity in females?
4500 mL
What is FEV?
Forced Expiratory Volume.
Amount of air that can be forcible expelled.
The amount expiered in the first second = FEV1
What are some things to think of for “gasses diffusing across membranes”?
-Concentration differences (gradients)
- Temp. high temp = faster diffusion
- Thickness of membrane (distance to diffuse).
shorter distance = more efficient/faster diffusion. - “Gas laws”. Dalton’s law of partial pressures
Henry’s law of gas solubilities
What is “Dalton’s Law” (partial pressures)?
Air is made up of N2, O2, H2O and CO2 and all of those elements have their own pressures that contribute to the TOTAL PRESSURE.
(eg) N2 is 78.6% of air. so partial pressure is 78.6% of the total air pressure.
P N2 + P O2 +P H2O + P CO2 = 760mmHg
Why do the lungs move with the diaphragm and ribs?
A thin film of serous fluid in the pleural cavity.
Intrapleural pressure = negative pressure. That holds the 2 membrane together.
What is Intrapleural pressure?
The pressure within the pleural cavity.
The pressure in the space of the parietal and visceral pleurae.
(-4mmHg) at average (-18mmHg) during powerful inhalation
What is Intr-alveoloar pressure?
aka intrapulmonary pressure
The pressure inside the alveoli of the lungs.
(quiet and forced breathing)
Resistance to airflow: Bronchoconstriction
- Increased resistance to airflow
- Caused by contractions of the smooth muscle due to stimulation from the Parasympathetic NS OR allergic reactions Or low concentrations of CO2 (local control)
- Diameter of the bronchioles decreases (increases resistance)
Resistance to airflow: Bronchodialation
- Decreased resistance to airflow
- Diameter of bronchioles increases (less resistance)
- Cased by sympathetic NS (epinephrine) or high concentrations of CO2 (local control)