Cardio-Resp 1&2 Flashcards
1
Q
What is the distribution of blood within the circulatory system at rest?
A
Veins 60-70%
- venous system functions as a reservoir
- blood is added to circulation under appropriate conditions (moves around with exercise)
2
Q
Properties of veins
A
- veins can expand and accumulate additional blood (2mmHg)
- arteries have resistance to flow of blood from heart (100mmHg)
3
Q
How is low venous pressure in the blood over come to return blood to the heart?
- in lower limbs
A
- skeletal muscle groups provide contractions
- “skeletal muscle pump”
4
Q
How is low venous pressure in the blood over come to return blood to the heart?
-abdominal and thoracic
A
- breathing
- contraction of diaphram
- pressure in abdomen
these squeeze veins and return to heart
5
Q
One way flow in veins
A
- venous valves
- one way to the heart, not reverse
6
Q
When bp increases…
-arteries ___
-ventricles ____.
+ vice versa
A
bp incr:
- arteries expand
- ventricles contract
bp decr
- arteries recoil
- ventricles relax
7
Q
Elastic recoil drives blood during
A
-diastolic phase when heart is resting and not providing pressure
8
Q
in capillaries, vasoconstriction/vasodilation ___/__ as blood flow
A
constriction:
decrease
dilation
increases
9
Q
Blood flow =
A
driving force / resistance
10
Q
Resistance depends on (3 things)
A
- blood vessel length
- viscosity
- blood vessel radius
11
Q
Vessel radius
A
radius incr = resistance decr = blood flow decr
12
Q
Vessel radius is regulated by
A
smooth muscle contraction/relaxation
13
Q
Air passageway order
A
- nasal/oral cavity
- pharynx
- larynx
- trachea
- bronchus
- lungs (bronchial trees, terminal bronchioles)
14
Q
Conducting zone includes
A
-trachea, bronchus, lungs
15
Q
Respiratory zone includes
A
- terminal bronchiole
- respiratory bronchioles
- alveolar sacs
- alveolus
16
Q
Bronchioles pass _____ alveoli
A
between
17
Q
Alveoli have ____
A
pores which air can pass from one alveolus to the next
18
Q
4 physical properties of the lungs
A
- inspiration and compliance
- expiration and elasticity
- surface tension
- lung volume and capacities
19
Q
Inspiration and compliance
A
- breathing in
- lungs ability to expand when stretched
20
Q
High compliance means
A
distensibility, stretchability, ease of the lungs to expand under pressure
21
Q
Lung compliance =
equation
A
= change in lung volume / change in transpulmonary pressure
= dV / dP
22
Q
Lung disease____ (incr/decr.) compliance
A
reduces - anything that provides resitance to distension
23
Q
Expiration and Elasticity
A
breathing out
24
Q
For expiration to occur, the lungs get ______, when tension is released
A
smaller
25
Elasticity
tendency of structure to return to initial size after being distended
26
lung is high in _______
| Therefore, are very elastic and resist distension
elastin proteins
27
Lungs are stuck to ______. Therefore, are always in a state of _______.
- lungs stuck to chest wall
| - always in a state of elastic tension
28
Tension (incr/decr) during inspiration when lungs are (stretched/relaxed) and is ______ by elastic recoil during expiration
- tension increases during inspiration
- lungs stretched
- reduced by elastic recoil during expiration
29
Lungs most be ___ in order to inflate
- the lungs cannot inflate unless they are attached to the inner wall of the chest cavity
- you can ventilate but if chest is wounded, lung will not inflate
30
Attachement of outer lung surface to inner surface of chest cavity is:
-made with membranes called pleural membranes
31
Pleural membranes
- one membrane layer attached to surface of lung
| - one membrane layer attached to inner wall of chest cavity
32
Pleural fluid
- PM produces mucous-rich lubricating fluid into the space between the two membranes - called pleural space (helps lung friction)
- Pleural fluid holds two membranes together
- lubricant that allows lungs to slide easily within thoracic cavity as inflate and deflate
33
As size of thoracic cavity changes,
so does volume of the lungs
| due to the pleural fluid that holds the two pleural membranes together
34
Surface tension
is exerted by fluid in alveoli
35
Fluid contains ____.
Surfactant
36
Surfactant:
a mixture of phospholipids and hydrophobic surfactant proteins, secreted into the alveoli by type II alveolar cells
37
Surfactant ____ surface tension in the alveoli, which ____ alveoli from _____ during expiration
- lowers surface tension in alveoli
| - which prevents alveoli from collapsing during expiration
38
Alveoli have tendency to _____.
| Surfactant _____ _____.
- collapse
| - prevents collapse
39
Respiratory distress syndrome
- surfactant is produced late in fetal life
- pre-mature babies born with lungs that lack surfactant and alveoli collapse as a result
- can inject surfactant to induce alveoli ability to take oxygen
40
Tidal volume
volume of gas inspired or expired in UNFORCED respiratory cycle
41
Inspiratory reserve
max vol of gas that can be inspired during forced breathing in addition to tidal volume
42
Expiratory reserve
max vol of gas that can be expired during forced breathing in addition to tidal volume
43
Residual volume
vol of gas remaining in lungs after max expiration
44
Total lung capacity
total amount of gas in lungs after a max inspiration
45
Vital capacity
max amnt of gas expired after a max inspiration
46
Inspiratory capacity
max amount of gas that can be inspired after a normal tidal volume
47
Functional residual capacity
amount of gas remaining in the lungs after a normal tidal epiration
48
Anatomical Dead space
Dead volume
- where no gas exchange occurs
-nose, mouth, laryn, trachea, bronchi, bronchioles
~150mL *use this for calculations
49
Hemoglobin
contains iron and present in cytoplasm of RBC
50
Hb properties
- chemically combine with O2
- release gas when cells need it
- Hb acts as O2 shuttle from lungs to body tissues (and CO2 shuttle)
51
Role of Co2 in regulating binding of O2 with hemoglobin
| In lungs
- CO2 diffuse from blood to alveoli and blood CO2 levels are low
- reduce acidity of blood in lungs
- high pH
52
Role of CO2 in regulating binding with O2 with hemoglobin
| In tissues
- blood CO2 levels high because the cells produce gas as an excretory product
- O2 levels are low because it is being used by cells
- increase acidity of blood in tissues
- low pH
53
Acidity of the plasma determines ____
whether
O2 combines with hemoglobin to form oxyhemoglobin at low acidity (high pH in lungs)
or
O2 released from oxyhemoglobin at high acidity (lower pH in tissues)
54
O2 uptake in the lungs
- o2 dissolved into lining fluid film of alveoli
-diffuse through walls of alveoli and blood capillaries into plasm
-o2 diffuse into RBC
- combine chemically with Hb
= oxyhemoglobin
(CO2 levels in lungs are low therefore formation occurs here)
55
O2 release in tissues
- O2 released from oxyhemoglobin
- diffuse into body tissues
- disassociation of Hb and O2 occurs in tissue because Co2 levels in body are high (pH decrease, more acidic)
56
What is the enzyme involved in CO2 to H2CO2
carbonic anhydrase
57
Diving
| total atmospheric pressure _____ as you go down below sea level
- increases
58
What happens to the pressure and gas in a divers body as they go down below sea level?
- partial pressure and amount of dissolved gas in blood plasma increases proportionally to water level decreasing
- increased nitrogen and oxygen dissolved in blood plasma causes serious negative effects on body
59
Free diving adaptations (4 things)
Mammalian diving reflex
- drop in heart rate (bradycardia)
- vasoconstriction (blood shuttled away from limbs to benefit heart, lungs, brain)
- spleen releases RBCs carrying O2 (reservoir tapped into when needed)
- blood shift (plasma fills up lung BVs)
60
SCUBA divers have air tanks, explain this concept.
- it is impossible to breath unpressurized air (i.e. just through a tube) below 3 feet under water
- therefore you need a pressurized regulator
- gas mix avoids O2 toxicity, but less than normal nitrogen gas levels to reduce nitrogen narcosis and decompression sickness
61
Decompression sickness
- divers ASCEND slowly so large amounts of nitrogen can diffuse through alveoli and be eliminated through expiration
- if too fast, N2 gas bubbles form in tissues and enter blood
- this blocks small blood channels producing pain and damage
62
Treatment to decompression sickness
hyperbaric oxygen therapy
- normal blood o2 conc = 0.2 - 0.3 mL O2/100mL
- treat with 100% O2 at 3ATM pressure to raise the plasma concentration to 6mL O2/100 ml
- use pure oxygen to flush nitrogen out of the tissues
63
Atmosphere
-thinner with increasing altitude
@ sea level, % oxyhemoglobin saturation is 97%
at mount everest peak at 8848m/29029ft 58% oxyhemoglobin saturation
64
Acute mountain sickenss
~5000 ft
- headache - low arterial pressure stimulates vasodilation increasing blood flow and pressure in skull
- balanced with hypocapnia (produced by hyperventilation) causes cerebral vasoconstriction
- pulmonary edema, shortness of breath (9000ft)
- cerebral edema (10,000ft)
65
How do people living at high altitudes adapt?
- higher Hb in blood
| - increased diameter of blood vessels
