Chapters 20 & 23 (Respiratory Physiology & Urinary System) Flashcards
What are the 4 types of cells in alveoli?
Type I pneumocytes Type II pneumocytes Alveolar Macrophages Fibroblasts
What is the role of surfactant & why do we need it?
Reduces surface tension & causes elastic recoil. It helps us to exhale.
Type I pneumocytes
Gas exchange
Type II pneumocytes
Secrete surfactant
Alveolar Macrophages
(Dust cells) Phagocytes
Fibroblasts
Secrete elastic fibers
Passageway of air from Nasal Cavity to Alveoli.
- Nasal Cavity
- Pharynx
- Larynx
- Trachea
- Bronchi (1, 2, 3)
- Small Bronchi
- Bronchioles
- Terminal Bronchioles
- Respiratory Bronchioles
- Alveoli
External Respiration
Pulmonary gas exchange Oxygen enters & carbon dioxide leaves the blood in the lungs.
Internal Respiration
Capillary gas exchange Oxygen enters the body tissues from the blood (through the capillaries) & carbon dioxide leaves the body tissues & enters the blood.
Explain what is happening physically during breathing. (Use Boyle’s Law)
Respiratory muscles & elastic tissue change pressure gradient following Boyle’s Law (Volume changes in the lungs lead to pressure changes in the lungs) As volume of the lungs increase, the pressure decreases dropping the pressure of the lungs below atmospheric pressure forcing air to go into the lungs & vica versa.
What are the major functions of the respiratory system?
- Gas Exchange
- pH Regulation
- Sound Production
- Olfaction
- Filtration of Air
What is the function of mucus?
To prevent foreign particles from entering the lungs.
Why is it important that the epithelial tissue of the alveoli be simple squamous?
To assist in quick gas exchange.
What is the function of the epiglottis?
Flap of cartilage that covers the larynx during swallowing.
The trachea ha c-rings of cartilage. Why is the cartilage in the shape of a c-ring?
To expand, maintain shape, & and allow the esophagus to expand during swallowing
What is the function of the smooth muscle that lines the passageways of the conductive zone?
Regulates the air going to the lungs & leaving the lungs.
What is the difference in the conduction zone & the respiratory zone?
-
Conduction
- Carries air to lungs
-
Respiratory
- Where gas exchange happens
What are the two main muscles used in breathing?
- External Intercostals
- Diaphragm
What importance do the accessory muscles have in breathing?
Elevate & Stabilize the rib cage, assist in forced breathing
Tidal Volume
Amount of air in & out of the lungs during normal breathing.
Vital Capacity
Maximum amount breathed in and out
Total Lung Capacity
Maximum amout of air lungs can hold.
What is partial pressure?
Amount of pressure a single gas contributes to a mixture of gases.
What importance does Dalton’s law have to partial pressure of gases?
The relative amount of a gas in a mixture is related to the pressure it exerts.
Henry’s Law
The solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid.
What importance does Henry’s Law have to gas exchange?
States what causes the gas to move.
How does the partial pressure of oxygen & carbon dioxide drive their movement into & out of the blood?
They equalize their partial pressures.
What causes oxygen to dissociate with iron in hemoglobin?
- Presence of CO2
- Reduced pH
- High Temperature
- Presence of BPG
What is the relationship between the partial pressure of oxygen & its saturation in hemoglobin?
The lower the partial pressure of oxygen, the more likely it is to come off of the iron.
What does it mean if the saturation curve move left or right?
-
Right
- Oxygen is more likely to come off of iron
-
Left
- Oxygen is less likely to come off of iron
How is carbon dioxide transported in blood?
- Least: In plasma
- 23%: Binds to hemoglobin
- Most: Bicarbonate ion (HCO3-) [and Carbonic Acid (H2CO3)]
What drives carbon dioxide out of blood into the lungs?
Difference in partial pressure.
Compliance
How easy it is for the lungs to expand.
Why can high or low compliance be bad?
-
Low
- Not enough air can get into the lungs
-
High
- Alveoli can burst or lose their elasticity
Resistance
How difficult it is for air to move through the conducting zone.
Why is high resistance a bad thing?
Can’t get air to the lungs
Emphysema causes high compliance. Why would that make gas exchange difficult?
Alveoli can burst or become too elastic and not go back to its original shape.
What region of the brain is responsible for involuntary breathing?
Medulla Oblongata
What region of the brain is responsible for forced breathing?
Pons
- What is hypercapnia?
- Why is it bad?
- What does the body do to combat it?
- Caused by increase in CO2 in the blood (Acidosis)
- pH goes down and interferes with tissue function
- Heart rate & Breathing rate Increase
- What is Hypocapnia?
- Why is it bad?
- What does the body do to combat it?
- Caused by decrease in CO2 in the blood (Alkalosis)
- pH goes up and interferes with gas exchange and tissue function.
- Heart rate & Breathing Rate Decrease
Functions of the Urinary System
- Remove toxins from the blood
- Expulsion from the body
- Maintains pH
- Maintains Electrolytes
- Maintains Blood Pressure
Types of Nephrons in the Kidneys
- Cortical Nephrons (Most) [In Cortex]
- Juxtomedullary Nephrons (Least) [Deep in Medulla]
Glomerulus
Filters blood (Produces Filtrate)
Proxical Convoluted Tubule
Solutes (Sugars, Amino Acids, & Lipids) are Reabsorbed into the blood
Nephron Loop
-
Descending
- Water is secreted from the loop
-
Ascending
- Solutes are secreted from the loop
Distal Convoluted Tubule
Sloutes or water can leave or enter filtrate
Collecting Duct
- Called urine when liquid enters
- More water can be reabsorbed intot he blood
What can fit through the slits formed by the pedicles of the podocytes of the Bowman’s Capsule?
- Solutes and Water
- NOT RBCs or Proteins
Glomerular Hydrostatic Pressure (GHP)
Force of fluid inside Glomerulus (Should be higher than BCOP)
Blood Colloid Osmotic Pressure (BCOP)
Force of fluid outside of Glomerulus
Why is it important to maintain GHP?
So stuff gets filtered
GFR
- Glomerular Filtration Rate
- Filtrate produced per minute
- (GFR & GHP are linked)
How is GFR autoregulated?
Makes arteries going into the kidneys dilate & Veins leaving the kidneys contrict.
- How is GFR centrally regulated?
- What are the ultimate effects of the release of renin?
- Releases Renin
- Renin causes Angiotensin I to be released which causes Angiotensin II to be released.
- Angiotensin I & II cause thrist, increase in blood volume, & vasoconstriction
- Explain what countercurrent multiplication is. What it does.
- Be able to explain the importance of maintianing a concentration gradient in the nephron loops.
- Mechanism that expends energy to create a concentration gradient.
- Overall goal is to make filtrate concentrated. Osmosis of water drives it out the descending loop and diffusion of solutes cause drives them out of ascending loop.
Obligatory Water Reabsorption
- In PCT & Nephron Loop
- Not influenced by ADH
- Water reabsorption here can’t be changed from its regulation
Facultative Water Reabsorption
Caused by ADH
How does the release of ADH affect the concentration of urine? Why?
- (Comes from pituitary gland)
- Makes urine more concentrated to reabsorb more water