Lecture #8 Flashcards Preview

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Flashcards in Lecture #8 Deck (61):
1

Major Functions of Respiration

1. Gas Exchange
2. Communication
3. Olfaction: sense of smell
4. Acid-Base Balance
5. Blood and lymph flow

2

Pulmonary Ventilation is:

Consist of repetitive cycle of inspiration (inhaling) and expiration (exhaling)

3

Respiratory Cycle

one complete inspiration and expiration

- flow of air in and out of the lung depends on pressure different inside and outside the body

4

The flow of a fluid is proportional to ..

the pressure different

5

the flow of a fluid is inversely proportional to

the resistance

6

Boyle's Law

at a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume

7

What pulls air into the lungs

the lung volume↑,the internal pressure of the lungs(intrapulmonary pressure) ↓ and pulls air into the lungs

8

What pushes are out of the lungs?

If the lung volume↓,intrapulmonary pressure↑and pushes are out of the lungs

9

Intrapleural Pressure causes...

lungs to expand with expansion of the thoracic cage

Intrapleural pressure: is define as negative pressure that exists between the two pleural layers

10

Resistance influenced by:

1. Diameter of the bronchioles Bronchodilation: increase in diameter of the bronchus, thus increases airflow

Brochoconstriction" decrease in diameter of bronchus, thys decrease air flow

2. Pulmonary Compliance
- ease so lungs can expand
- decrease by lungs disease which the lungs are stiffened by scar tissue

11

What is the Iron Lung

Device used for patients with Polio, it is artificial ventilation

changes pressure on lungs so inspiration and expiration can occur

Decreased pressure = inspiration
Increased pressure = expiration

12

Spirometer

device that recaptures expired breath
- records rate and depth of breath, speed of expiration and rate of oxygen consumption

13

Spirometry

the measurement of pulmonary function
used in determining restrictive or obstructive lung disorders

14

Tidal volume (TV)

volume of air inhaled and exhaled in one cycle of breathing (~500 mL)

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Inspiratory reserve volume (IRV):

air in excess of tidal volume that can be inhaled with maximum effort

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Expiratory reserve volume (ERV):

air in excess of tidal volume that can be exhaled with maximum effort

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Residual volume (RV):

air remaining in lungs after maximum expiration

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Vital capacity (VC) (ERV + TV + IRV):

total amount of air that can be inhaled and then exhaled with maximum effort

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Inspiratory capacity (IC) (TV + IRV):

maximum amount of air that can be inhaled after a normal tidal expiration

20

Functional residual capacity (FRC) (RV + ERV):

amount of air remaining in lungs after a normal tidal expiration

21

Total lung capacity (TLC) (RV + VC):

maximum amount of air the lungs can contain

22

Pulmonary Aveoli

1. Squamous (type I) alveolar cells:
thin, rapid gas diffusion

2. Great (type II) alveolar cells: repair alveolar epithelium and secretes pulmonary surfactant that coast the alveoli

3. Alveolar macrophages (dust cells): keep alveoli free from debris

23

Composition of air

78.6% nitrogen
20.9% oxygen
0.04% carbon dioxide
0-4% water vapour

24

Dalton's Law

total atmospheric pressure is the sum of the contributions of the individual gases

25

Partial pressure

the separate contribution of each gas in a mixture

26

Composition of Air

composition of inspired and alveolar air differs because:

1. Air is humidified by contract w mucous membrane

2. air in alveoli mixes with residual air left from previous respiratory cycle

3. Alveolar air exchanges O2 and CO2 with blood

27

Alveolar Molecular Gass Exchange

Gases diffuse in downward gradient until the partial pressure of each gas molecule in the air is equal to its partial pressure in the water

28

Alveolar Gas Exchange

is the swapping of (loading) O2 and (unloading) CO2 across the respiratory membrane

there is a film of water that covers alveolar for O2 to get in and Co2 to get out it must pass through this water film layer

29

Efficiency of Alveolar Gas Exchange

1. Pressure gradient of gases
2. Solubility of the gases
3. Membrane surface area
4. Membrane thickness
5. Ventilation-perfusion coupling

30

Gas Transport

The process of carrying gas from the alveoli to the systemic tissues and vice versa

O2 is mostly transported by hemoglobin in the RBCs

CO2 is mostly transported by carbonic acid

31

Hemoglobin

molecule specialized for O2 transport
bind to 4 portions, and carry 4 O2 thus its 100 saturated
- helps loading at alveoli and unloading at tissues

32

Gas Transport of CO2

1. Carbonic Acid (H2CO3) - 90%
2. Carbamino Compounds - 5%
3. Dissolved in plasma - 5%

33

Systemic Gas Exchange

the unloading of O2 and loading of CO2 at systemic capillaries

producing CO2 and using O2

34

Systemic Gas Exchange:
CO2 Loading


Oxygen unloading

- Co2 diffuses into the blood
- Carbonic anhydrase (CAH) in RBC catalyzes
- Chloride Shift

Oxygen unloading:
H+ binding to HbO2 reduces its affinity for O2
makes Hb release O2

35

Alveolar Gas exchange

reactions that occur in the lungs are reverse of systemic gas exchange

CO2 unloading
Hb loads O2, it affinity for H+ decreases, H+ dissociates from Hb and binds with HCO3
reverse chloride shift

36

Factors that adjust the rate of O2 unloading:

1. Ambient PO2
- active tissue has decreased PO2, O2 is released from Hb

2. Temperature
- active tissue increase temp. promotes O2 unloading

3. Bohr Effect
-active tissue increase CO2, lowers pH, promotes O2 unloading

4. Bisphosphoglycerate (BPG)
- RBCs produce BPG and binds to Hb, allows O2 unloading


- increase temp. = promoted O2 unloading
- decrease pH = promotes O2 unloading

37

Acidosis

blood pH 7.35 less than

38

Alkalosis

blood pH greater than 7.45

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Hypocapnia

Most common cause of alkalosis PCO2 <37 mmHg(less than)

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Hypercapnia

Most common cause of acidosis PCO2 >43 mmHg (greater than)

41

Respiratory acidosis and alkalosis

pH imbalances resulting from a mismatch between the rate of pulmonary
ventilation and CO2 production

42

Ketoacidosis

acidosis brought about by rapid fat oxidation releasing acidic ketone bodies, reduces CO2 concentration

43

Hyperventilation

an be a corrective homeostatic response to acidosis, using CO2 faster than the body can produce

44

Hypoventilation

an be a corrective homeostatic response to alkalosis

45

Urinary System

consists of six organs: two kidneys, two ureters, urinary bladder, and urethra

46

Functions of the kidneys

1. Filter the blood plasma, excrete toxic waster

2. Regulate BV, pressure and osmolarity

3. regulates electrolytes and acid-base balance

4. secretes erythroprotein which stimulates the products of RBCs

5. Clear hormones and drugs from blood

6. Detoxify free radicals

7. In starvation they synthesize glucose from amino acids

47

Waste

any substance that is useless to the body or presents in excess of the body's needs

48

metabolic waste

waste substance produced by the body

49

Urea formation

proteins break down amino acids and remove forms of ammonia

liver converts ammonia to urea

50

Uric acid

product of nucleic acid catabolism

51

Creatinine

product of creatine phosphate catabolism

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Excretion

separating wastes from body fluids and eliminating them

53

Four body systems that carry out excretion

1. Respiratory system
2. Integumentary system
3. digestive system
4. urinary system

54

The Nephron

Each kidney has 1.2 mill. nephrons

It has two parts:
1. renal corpuscle
2. Renal tubule

55

Renal Tubule

duct leading away from the glomerular capsule

Divided into:
1. proximal convoluted tubule
2. nephron loop
3. distal convoluted tubule

56

Stages of Urine Formation

1. Glomerular Filtration
- creates a plasma-like filtrate of blood

2. Tubular Reabsorption
- removes useful solutes from filtrate and returns them to the blood

3. Tubular Secretion
- removes wastes from the blood and adds them to the filtrate

4. Water conservation
Removes water from the urine and returns it to the blood

57

Glomerular Filration

capillary fluid exchange in which water and some solutes in the blood plasma pass from the capillaries of the glomerulus into the capsular space of the nephron

58

Gllomerular Filtrate

Fluid production, the fluid in the capsular space

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Tubular Fluid

fluid from the proximal convoluted tubule through the distal convoluted tubule

60

Urine

Fluid that enters the collecting duct

61

Filtration Pressure a Function of

1. Blood hydrostatic Pressure (BHP)
2. Colloid Osmotic Pressure (COP)
3. Capsular Pressure (CP)

High BP makes kidneys vulnerable to hypertension