Resp 3,4,5,6 Flashcards
PHYSICAL PRINCIPLES OF GASEOUS EXCHANGE.
(1) Gases are in ____ motion and move (diffuse) from area of ____ concentration to ____ concentration.
(2) ____ energy is provided by the motion of the molecules.
(3) The total pressure of the gas is ____ proportional to the ______ of the gas molecules.
(4) Pressure of gas in solution is also determined by its _________.
random ; higher ; lower
Kinetic
directly; concentration
solubility coefficient
Solubility coefficient of respiratory gases are given as
CO2 (_____ )
O2 ( ______ )
CO (_____)
N2 (______)
He (______ ).
- 57
- 024
- 018
- 012
- 008
CO2 has a (high or low?) solubility coefficient
High
Co2 is not attracted to water
T/F
F
It is
Henry’s law is used to define the relationship:
Pressure =__________/______
Concentration of dissolved gas
Solubility coefficient
Iseoluwa, for the partial pressure stuff, say how it is moving
Starting from inspired air😉
Inspired air
Alveolus
Arterial blood
Venous blood
Expired air
Partial pressure of water vapor in venous blood and the rest
Inspired air is 5.7mmHg
The rest are 47.0mmHg
Unit for inspired air is ????
MmHg
Between , oxygen, co2, h20, and N2
Which ones have the lowest and highest PP on inspired air and what’s their values
Lowest :Co2 ;0.3
Highest: oxygen; 158.0
From inspired air to expired air, partial presssure of oxygen reduces all through
T/F
F
It increases from venous blood to expired air
Describe the trend of oxygen partial pressure with values from inspired air to expired air
158
100
95
40
116
Describe the trend of co2 partial pressure with values from inspired air to expired air
0.3
40
40
46
32
FACTORS AFFECTING GASEOUS EXCHANGE
1. Pressure difference: Gases will diffuse from an area of ____ concentration to an area of ____ concentration.
- Thickness of respiratory membrane.
Normally about _____.
Factors that increase thickness (like ____) (increase or reduce?) diffusion - Surface area of membrane.
When surface area available for diffusion is reduced (eg._______ or _____) , exchange is (impeded or augmented ?) even under resting conditions.
higher
lower
0.5μm; fibrosis; reduce
Emphysema or pneumonia
Impeded
Arterial PO2 < Alveolar PO2 because of ______________:
(a) ______ veins drain blood from ____ direct to _______.
(b) _______ anastamosis: Parts of ______ (systemic blood) draining into _____.
artero-venous shunts
Thebesian; myocardium; left ventricle
Broncho-pulmonary
bronchial venous blood
pulmonary veins
Diffusing capacity of a gas refers to the ____ of gas that diffuses through the membrane each ____ for a pressure difference of ______.
Volume
minute
1 mmHg
Unit of diffusing capacity is??
Ml/min
Diffusing capacity of O2 is about ___ml/min.
For CO2 it is about ____-____ ml/min/mmHg. (___ times (greater or lesser?) than O2).
21
400 - 450
20; greater
For a given gas the diffusing capacity is
(a) _______ proportional to the size of the respiratory membrane.
(b) _______ proportional to the thickness of respiratory membrane.
directly
Inversely
Effect of exercise on diffusing capacity on O2, Co2, and CO
Exercise increases the diffusing capacity of O2, CO2 and CO.
TRANSPORT OF OXYGEN
The delivery of O2 to the different parts of the body is made possible by :
(a)the _____ system
(b) the _______ system.
respiratory
cardiovascular
O2 delivery to a particular tissue depends on:
- amount of O2 entering the \_\_
- adequacy of \_\_\_\_\_\_ exchange
-\_\_\_\_\_ flow to tissue
-degree of (constriction or dilatation?) of vascular bed in tissue \_\_\_\_\_
-capacity of \_\_\_\_ to carry O2
amount of \_\_\_\_\_ O2
amount of \_\_\_\_ in blood
affinity of \_\_\_\_ for \_\_\_\_lungs
pulmonary-gas
blood
constriction
cardiac output
blood; dissolved; Hb
Hb for O2
Theoretically,
At 100% saturation 1g of Hb binds _____ ml of O2
Called the ___________ capacity of Hb.
1.39
theoretical O2 binding
The theoretical O2 binding capacity of Hb is theoretical because :
____% of binding sites cannot function as O2 carriers because some Hb is present as _______ (____%).
Other sites are occupied by ___ (____%).
2-4
methemoglobin; 1-2
CO; 1-2
Realistically, at 100% saturation,
1g of Hb contains ____ ml of O2.
1.34
100 ml of blood contains ___ ml (___ x __) of O2 bound to Hb when fully saturated.
- 1
1. 34 x 15
in systemic circulation, blood is 100% saturated
T/F
If T , why
If F , why
F
97
because of slight admixture
in systemic circulation, blood is 97% saturated and at this level of saturation,
1g of Hb contains ___ ml of O2 or ____ ml of O2/100 ml blood.
- 30
19. 8
Oxygen is transported in 2 forms in blood
(a) In \_\_\_\_\_. In arterial blood \_\_\_ ml or \_\_\_% is carried (b) In combination with \_\_. \_\_\_\_ ml or \_\_\_% is carried
solution
0.29; 1.5
Hb
19.5; 98.5
In venous blood, Hb is ____% saturated.
75
In venous blood, Hb is 75% saturated.
At this level of saturation,
1 g of Hb contains ___ ml of O2.
The total O2 content is therefore ____ ml/100ml blood.
___ml/100 ml or ___% of blood is carried in solution
___ ml or ____% is carried in combination with Hb.
- 02
- 3
- 1; 0.7
- 2; 99.3
At rest, ___ ml O2 /100ml blood (___-___) are extracted.
____ ml (3.8%) is in solution.
_____ ml (96.2%) is in combination with Hb.
- 5
- 8 - 15.3
- 17
- 33
Two pigments, ______ and _____, play important roles in the transport of oxygen.
hemoglobin (Hb) and myoglobin
HEMOGLOBIN
- Protein made up of ___ subunits.
- A subunit contains a ____ moiety attached to a _____ chain.
4
heme
polypeptide
Heme is made up of _____ and __ atom of ______ iron.
porphyrin
1
ferrous
Each of the 4 iron atoms in heme can bind (reversibly or irreversibly?) with ___ molecule.
Reaction is ____ and iron stays in the ____ state.
Reversibly
O2
OXYGENATION
ferrous
______ structure of Hb determines its affinity for O2.
Quaternary
Oxygenation Reaction of Hb with O2
Ise!!!, say it line by line
Hb4 + O2 Hb4O2
Hb4O2 + O2 Hb4O4
Hb4O4 + O2 Hb4O6
Hb4O6 + O2 Hb4O8
Hb Dissociation curve is ____ shaped
sigmoid
MYOGLOBIN.
____ containing pigment found in ____ muscle.
- Binds __ mol of oxygen per mole
- Dissociation curve is ________ shape
- Picks up O2 from Hb in blood (because its curve is to the ____ of Hb curve.
- Releases O2 only at ___ PO2 eg. In exercising muscles.
- Facilitates diffusion of O2 from ____ where _____ reactions occur.
Iron
skeletal
1
rectangular hyperbola
Left
low
blood to mitochondria
oxidative
Factors affecting the affinity of Hb for O2.
Answer with right or left
- A fall in pH
- an decrease in pCO2
- an increase in temperature
- an decrease in [2,3-DPG]
Right
Left
Right
Left
In a state of the oxy-Hb curve moving to the right,
a (higher or lower?) pO2 is required for Hb to bind to a given amount of O2.
This implies (lesser or greater?) dissociation of oxygen from hemoglobin and Therefore (lesser or greater?) unloading of oxygen to the tissues.
Higher
Greater
Greater
During exercise or in active tissues:
pCO2 is ____, pH is ___ and temperature is ____.
More O2 is therefore (loaded or unloaded?) to the active tissues where it is needed.
high
low
high
Unloaded
P50
The ____ at which Hb is ___ saturated with O2
Describes the shifts.
The higher the P50, the (lower or higher?) the affinity of Hb for O2.
PO2
Half
Lower
Bohr effect is the ___ease in O2 affinity of Hb when the pH of blood ____.
Decr
falls
Which bind more H?
Deoxygenated Hb or Oxygenated Hb
deoxygenated Hb binds H+ more actively than oxyhemoglobin.
an increase in pH, a fall in pCO2 a fall in temperature or a fall in [2,3-DPG] shifts the curve to the _____ and ___eases unloading of O2 to the tissues.
left
Decr
The following factors affect the concentration of 2,3-DPG.
a) pH: 2,3-DPG ____ when pH is low
_____,______,and _______ Hormones increase the concentration of 2,3-DPG.
falls
Thyroid, Growth hormone and Androgens.
TRANSPORT OF CARBON MONOXIDE
Carboxyhemoglobin
CO displaces ___ from Hb and is carried through _____ resulting in ________.
O2
systemic capillaries
CO poisoning
Bond between CO and Hb is about ____ times (weaker or stronger?) than bond with oxygen
210
Stronger
Treat CO poisoning with _______
(___% O2 at ____ atmospheres pressure).
hyperbaric oxygen
100
2 – 3
Carboxyhemoglobin in blood of active nonsmokers is not more than _____%
1.5
TRANSPORT OF CARBON DIOXIDE
CO2 is carried in 3 forms in blood.
(1) In _____
(2) As _______
(3) As _____
solution
Carbamino compound
bicarbonate ion
Venous blood contains about ____ml of CO2 per 100 ml of blood.
52.7
About _____ ml of CO2 is produced in the adult human body per minute.
200
CO2 is carried in 3 forms in blood.
(1) In solution: ___% of CO2 is carried in the dissolved form in plasma.
(2)As Carbamino compound:___% of CO2 is carried as a chemical compound with ___.
(3) As bicarbonate ion (The chloride shift).
___% of CO2 is carried in the bicarbonate form.
10
30; Hb
60
The dissolved CO2 is inversely proportional to the PCO2.
T/F
F
Directly
CO2 (reversibly or irreversibly ?) combines with hemoglobin to form a carbamino compound.
Reversibly
HCO3- is formed directly by the ______ of _____ by ____ inside the ____.
Reaction is catalysed by _____
• present inside the _____
• absent in _____.
Carbonic acid so formed breaks down into _____ and _____
hydoxylation; CO2
water; red cells
carbonic anhydrase
red cells
plasma
H+ and HCO3-.
Carbonic acid so formed breaks down into H+ and HCO3-.
- The excess HCO3- in the red cell (about ____%) leaves the red cell in exchange for ____ ions.
- The exchange is called the _____ and is mediated by the membrane protein ______.
70
Cl-
chloride shift
Band 3
THE ALVEOLI.
• High PO2 causes ___ to replace ____ on the Hb molecule (_____ effect).
• ______ reactions take place and ___ diffuses (up or down?) the gradient into the _____
• Deoxygenation shifts the composite CO2 curve (upward or downward ?)
• Change in CO2 content occurs as arterial blood passes through ______ and becomes ________
O2; CO2
Haldane
Reversed; CO2; down; alveolar sacs.
Upward
systemic capillaries
venous blood.
Elements of the control system include the sensors (_____,____), which make input to the central controller (_____,_____ and other parts of brain). The central controller analyses input and sends output through ______ portions of cord to the effectors (___________) which modify the activity of the sensors.
Chemoreceptors, lungs
pons, medulla
ventrolateral
respiratory muscles
NEURAL CONTROL OF RESPIRATION. There are 2 distinct mechanisms (a) _______ (b) _______ control.
voluntary
automatic
Voluntary control of respiration (e.g __________ ) is controlled by the _______.
Impulses are sent to the respiratory motor neurons via the _____ tract.
Automatic control of respiration is by ______ and ______
breath holding
cerebral cortex
corticospinal
medulla oblongata and pons.
THE RESPIRATORY CENTERS
Found in ______ and ______
Produce ______ respiration.
Function is to receive, evaluate and emit signals to ____________.
medulla oblongata and pons.
Automatic
respiratory muscles
Medullary centers of respiration is Made up of :
(ii) ______ group of neurons
(ii) ________ group of neurons
Dorsal respiratory
Ventral respiratory
Dorsal respiratory group of neurons (DRG) :
Located within the _________
Sensory termination of ____ and ____ cranial nerves.
Contains (INSPIRATORY or expiratory?) neurons and generates ________
nucleus tractus solitarius
IX and X
inspiratory
basic respiratory rhythm.
Nervous impulse to inspiratory muscles from DRG is instantaneous
T/F
F
not instantaneous but in a ramp fashion.
Which is longer
Inspiration time or expiration
inspiration time is longer than expiration time.
THE RAMP AND ITS CONTROL: HOW WE BREATHE
During inspiration, ramp ___eases rapidly causing the ____ to ____ rapidly.
Thus the earlier the ramp ceases the (shorter or longer?) the rate of inspiration.
This leads to an _____ease in respiration.
Incr
lungs to fill
Shorter
Incr
During respiratory cycle, medullary respiratory centers transmit a characteristic pattern of activity to motor neurons supplying muscles of _____.
respiration
There are ___ inspiratory and ___ expiratory phases.
one
two
Inspiratory phase begins with _______ in ______, followed by a ____-like ___ease in ______ throughout the remainder of inspiration.
End of inspiration is signaled by ________ which abruptly decreases the firing rate.
an abrupt increase; discharge frequency
ramp
Incr
firing rate
an off-switch
At the start of expiration, there is an ____ease in the activity of _____ motor neurons (Expiratory Phase _).
Incr
inspiratory
I
Inspiratory activity is ______ during Expiratory Phase 2.
When ventilation is increased as in exercise, active stimulation of the expiratory muscles occurs only during expiratory phase ___.
completely abolished
II
The Ventral Respiratory Group of Neurons (VRG) of the medullary respiration centers
Has 2 divisions.
Cranial division is located in the _______
Caudal division is found in ________
Functions:
(a) To drive the ___________ motorneurons (primarily the _______ and ______ muscles).
(b) To drive the auxiliary muscles of respiration innervated by the _____.
nucleus ambiguluus.
nucleus retroambigualis.
spinal respiratory ; intercostal and abdominal
vagus
B) The Pontine Respiratory Centers. Made up of:
(a) _______ Center.
(b) ______ Center
Pneumotaxic
Apneustic
The Pontine Respiratory Centers. Made up of:
(a) Pneumotaxic Center. Located in the ______ (nucleus _____).
Prevents arrest of respiration at ______ (______). ____eases rate of respiration.
(b) Apneustic Center. Located in the _______
upper pons
parabrachialis
inspiration; apneusis
Incr
lower pons.
Apneustic Center is tonically active.
T/F
T
Apneustic Center
Inhibited by ______ center.
pneumotaxic
ROLE OF PONTINE CENTERS: To make ______ discharge of medullary neurons ______ and ____
rhythmic
smooth and regular.
DESCENDING PATHWAYS
(1) Axons from the cortex, DRG, VRG and pontine centers descend in the ____ matter and influence the _____,____ and _____ motorneurons of respiration.
(2) Descending axons from cortex travel also in the ________ or _________ tracts.
(3) Projecting axons from DRG and VRG cross the midline and descend in the _________ columns of the cord.
white
phrenic, intercostal and abdominal
lateral corticospinal or cortico-rubro-spinal
ventro-lateral
CHEMICAL CONTROL OF RESPIRATION
Chemoreceptors are specialized receptors that transduce _____ stimuli in blood into _____ signals.
chemical
nervous
There are 2 types of chemoreceptors
a) The _____ Chemoreceptors
(b) The _____ Chemoreceptors or Chemosensitive areas of the ______.
Peripheral
Central
Medulla
The Peripheral Chemoreceptors.
These are the _______ and ______
carotid bodies and the aortic bodies.
The carotid bodies: These are located (ventrally or dorsally?) at the _______ of the ______
dorsally
bifurcation of the common carotid artery.
Afferent and efferent neurons run in the carotid sinus nerve and with the ___ nerve to terminate in the _____ respiratory center.
IX
medullary
In man carotid bodies weighs about __ mg and is about _ mm in length.
Blood flow is about ____ ml/min/100gm tissue.
10
4
2000
Due to the enormous flow through the carotid bodies chemoreceptors, O2 needs can be met largely by ________ alone.
dissolved O2
Carotid bodies chemoreceptors are stimulated by anemia and carbon monoxide (CO) poisoning
T/F
Why for your answer
Carotid bodies chemoreceptors are not stimulated by anemia or carbon monoxide (CO) poisoning
In each case amount of dissolved O2 reaching the receptors is normal although the combined O2 in blood is markedly reduced.
Carotid bodies Receptors are stimulated:
(a) When arterial PO2 is ___
(b) When due to ____ the amount of O2 delivered to the receptors per unit time is _____.
(c) Powerful stimulation is also produced by drugs such as ____, which prevent O2 _____ at the tissue level.
(d) In sufficient doses,______ and ____ activate the receptors.
Low
stasis
reduced
cyanide
utilization; tissue
nicotine and lobelline
The aortic bodies: Located mainly at the _____
Afferent and efferent neurons run in the aortic nerves and with the ____ nerve to end in the _______ respiratory center.
arch of aorta.
vagus
medullary
The histology of the carotid and aortic bodies are dissimilar
T/F
F
They are similar
The histology of the carotid and aortic bodies are similar.
They contain Type I ( _____ ) and Type II (______) cells.
Type I cells are _____ in nature ,10 - 15 μm in diameter , have a ____ nucleus , organelles are also found
Type II cells have a _____ nucleus and organelles.
glomus
sustentacular
epitheloid; rounded
rounded
In histology of aortic and carotid bodies
Type ___ cells surround the Type __ cells.
Nerve fibres are found between Type I and Type II cells.
T/F
II
I
T
STIMULANTS OF CHEMORECEPTORS:
These are
(a) (reduced or increased?) partial pressure of arterial oxygen
(b) ____eased partial pressure of carbon dioxide
(c) (reduced or increased? pH.
reduced
Incr
Reduced
THE CHEMOSENSITIVE AREAS OF MEDULLA
Are specialized groups of cells located within the _______ surface of the medulla.
Are sensitive to the ____ around them.
Since the ECF is in contact with the ______, changes in pH of ECF can affect ____ by acting on these chemoreceptive cells.
ventro-lateral
ECF
cerebrospinal fluid (CSF)
ventilation
The CSF is a protein free fluid.
T/F
T
CSF is formed from blood and the ionic composition is similar to that of blood.
T/F
F
CSF is formed from blood but the ionic composition is not similar to that of blood.
BLOOD BRAIN BARRIER.
Separates _____ from ____.
Has (low or high?) ionic permeability
blood
CSF
Low
CO2 diffuses slowly across the blood brain barrier.
T/F
F
Rapidly*
PCO2 in CSF parallels arterial PCO2 tension.
T/F
T
Chemosensitive area is sensitive to changes in either P___ or [H+] and in turn excites other portions of respiratory center.
CO2
The stimulatory effect of the chemosensitive area on the respiratory system is greatest in the first ______ and declines over the next _____
This is due to _____ readjustment of [H+] back to normal.
few hours
1-2 days.
renal
HYPOXIA
Defined as ____ deficiency at _____ level.
Can be classified into
(a) ______ hypoxia
(b) _______ hypoxia
(c) ________ hypoxia
(d) ________ hypoxia.
oxygen
tissue
Hypoxic; Anemic; Stagnant; Histotoxic
Hypoxic Hypoxia:
Caused by:
(1) A ___ease in the partial pressure (PO2) in (inspired or expired ?) air.
This is seen at (high or low?) altitude or by breathing an _____-poor gas mixture.
(2) ____ventilation brought about by airway _____, paralysis of respiratory muscles, depression of respiratory center with drugs like _____ or by increased airway resistance as seen in ______ or _____
(3) ———_———-diffusion block
(4) Abnormal ______-____ ratio
Decr
Inspired
High
oxygen
Hypo; obstruction; morphine
asthma or emphysema.
Alveolar – capillary
ventilation – perfusion
Alveolar – capillary diffusion block. This is seen in _____ of alveolar or pulmonary walls or pulmonary fibrosis or in cases of ___eased total area of normal alveolar membrane ( _______ ).
fibrosis
Decr
pneumonia
Abnormal ventilation – perfusion ratio
This is seen in _______ and _______ congenital heart disease.
emphysema and cyanotic
Anemic Hypoxia
In anemic hypoxia, ________ is normal but the __________________ is reduced.
arterial PO2
amount of Hb available to carry oxygen
_______ Hypoxia is seen in carbon monoxide poisoning.
Anemic
Stagnant Hypoxia: In this case,
blood flow to the tissue is ____ and adequate oxygen is not delivered to it despite a normal _____ and ________
This condition is seen in ___________ failure.
slow
PO2 and Hb concentration.
congestive heart
Histotoxic Hypoxia:
The amount of oxygen delivered to the tissue is _____
However, the tissue cannot __________ because of the action of a ______
adequate
make use of the oxygen supplied
toxic agent.
______ hypoxia is seen in cyanide poisoning due to the inhibition of _______.
Histotoxic
cytochrome oxidase
Cyanide is present in sometimes high concentrations in _________________ meals.
badly prepared cassava
HYPERCAPNEA
This is the retention of _____ in the body.
Results when the rate of CO2 ______ is greater than its ______.
carbon dioxide
formation
removal
HYPERCAPNEA
Increased PCO2 in the body would result in respiratory (acidosis or alkalosis?) and excretion of large amounts of ______.
Other effects are depression of the central nervous system, confusion, diminished sensory acuity, coma and respiratory depression.
acidosis
bicarbonate
In asphyxia and drowning, _____ and ______ are present.
There is ___eased respiration, BP, HR, catecholamine secretion and __ in pH. Eventually BP and HR ____ and individual dies of cardiac arrest.
hypoxia and hypercapnea
Incr
fall
fail
DEEP SEA DIVING
Ambient pressure increases by 1 Atmosphere for every ____ depth in sea water and every __ m in fresh water.
10m
10.4
_____ gears reduce hazards associated with deep sea diving
SCUBA
Problems associated with Increased Barometric Pressure
O2 _____ Euphoria
Lung ____ Impaired Performance
Convulsions Tremors
N2 _____ Somnolence
toxicity
damage
Narcosis
Decompression Sickness:
Related to _____ of ____
___ ascent can reduce the risk
Remedy:
Substitution of ___ for ___ in inhaled air.
Rate of ascent
Slow
He for N2
Which is more soluble and by how much
Helium or nitrogen
Nitrogen is more soluble
Helium is ½ as soluble as N2 in tissues and 1/7 M.W. of N2.
If ascent is rapid
N2 escapes from solution
_______ form in tissues and blood causing _________
Pain in ______
Itching
Obstruction in (arteries or veins?)in ___ causing paralysis and respiratory failure.
Bubbles
decompression sickness
joints
Arteries
brain
HIGH ALTITUDE
Results in (increased or reduced ?) barometric pressure and (increased or reduced ?) PO2
Thus the following will result Hypoxic stimulation of Chemoreceptors \_\_\_\_ease in ventilation (increased or reduced ?) alveolar PCO2 and thus arterial PCO2 Respiratory (acidosis or alkalosis?)
reduced
reduced
Incr
Reduced
alkalosis
In unacclimatized subjects (at ____ ft) that breathe air the following hypoxic symptoms will result:
Drowsiness, lassitude, mental and muscle fatigue, headache, nausea and euphoria
12,000
Effect of increasing altitude on barometric pressure and PO2 in air
Reduces both
Acute Mountain Sickness develops ______ after arrival at altitude and lasts for _____days
8 – 24hrs
4-8
Acute mountain sickness
Headache Nausea and vomiting Irritability \_\_\_\_\_\_ Edema Insomnia \_\_\_\_\_\_ Edema \_\_\_\_lessness Decreased \_\_\_\_\_\_\_\_\_\_
Pulmonary
Cerebral
Breath
Mental proficiency
Acute mountain sickness
Treatment
____ treatment.
Rest
____ altitude ______.
Avoid ______
O2
Ascend; slowly
physical exertion
ACCLIMATIZATION AT LOW PO2.
Due to a variety of mechanisms which include:
___ease in [2,3-DPG] leading to increase O2 delivery to tissues
___ease in erythropoetin secretion
___ease in mitochondria
____ease in myoglobin
___ease in tissue content of cytochrome oxidase
Incr
Incr
Incr
Incr
Incr
Incr
NATURAL ACCLIMATIZATION OF HUMAN BEINGS LIVING AT HIGH ALTITUDE
Living at altitude of 13,000 – 17,500 ft and working at ____ft (_____ Andes and ____)
Natives born and live all their lives at these altitudes
19,000
Peruvian
Himalayas
In a human being, acclimatization begins when??
Acclimatization begins at infancy
NATURAL ACCLIMATIZATION OF HUMAN BEINGS LIVING AT HIGH ALTITUDE
Chest size is (greatly or slightly?) ___eased
Body size is (greatly or slightly?) ____eased
Thus, a high ratio of _____capacity to _____
Hearts are considerably (smaller or larger?) than hearts of lowlamders and therefore have ___eased cardiac output.
Delivery of O2 to tissues is also highly facilitated.
Greatly; incr
Slightly; decr
ventilatory
body mass.
Largers
Incr
REDUCED WORK CAPACITY AT HIGH ALTITUDE
Hypoxia due to high altitude causes
mental _____, ___eased work capacity in all muscles (skeletal and cardiac)
Work capacity is reduced in _____ proportional to the decrease in maximum rate of oxygen uptake that the body can achieve.
depression
decr
direct
Some people that ascend altitude rapidly may develop acute ____ edema and acute _____ edema if not given oxygen and may ___.
cerebral
pulmonary
die
Cerebral edema
- results from local vaso_____ of the cerebral vessels caused by ____
- leads to severe _____ and other effects related to cerebral dysfunction.
dilation
hypoxia
disorientation
Cause of pulmonary edema is _____.
unknown
CHRONIC MOUNTAIN SICKNESS: Results from remaining at ____ altitude for _____
high
too long
Characteristics of chronic mountain sickness
(1) Red cell mass and hematocrit become _______.
Results in ____ease in blood viscosity
___eased tissue blood flow
Oxygen delivery to tissue ____eases
(2) Pulmonary arterial pressure becomes (elevated or depressed?) even more than the normal (elevation or depression ?) during acclimatization
(3) Right side of the heart becomes ____
(4) Peripheral arterial pressure begins to ___[
(5) ________ failure ensures
(6) Death often follows if person is not removed to lower altitude.
Most people recover within ____ or ____ if moved to a _____ altitude.
exceedingly high; incr; Decr; Decr
Elevated; elevation
greatly enlarged
fall
Congestive heart
days or weeks
lower
PHYSIOLOGY OF EXERCISE
- Changes In Ventilation
(b) Abrupt ____ease in ventilation with onset of exercise
(c) A more gradual ___ease
(d) Abrupt ____ease in ventilation when exercise ceases
During moderate exercise, changes in ventilation are due to:
Increase in _____ (VT) of respiration
Increase in ____ (f) of respiration as exercise becomes strenuous
Incr
Incr
Decr
depth
rate
Abrupt Increase in ventilation is due to:
_______ Stimuli
Afferents from ______ in muscles, tendons and joints
The more gradual increase in ventilation
Humoral:
Increase in _____ (Questionable)
Increase in _____
___ease in sensitivity of respiratory centre to CO2
Increase in ____
Psychic
proprioceptors
[H+]
temperature
Incr
[K+]
Physiology of exercise
2) Changes In Tissues:
(A) During exercise
Capillary beds (dilate or constrict ?)
Previously closed capillaries ____
Mean distance from blood to tissues is ___eased thus facilitating movement of O2 from blood to cells
(B) Contracting muscle uses O2 thus causing
Tissue PO2 to ____ to nearly ____
(More or less ?) O2 diffuses from blood
Blood PO2 ____ further and (More or less ?) O2 dissociates from _____ to ___
(3) ___ease in Temperature
(4) ____ease in [2,3-DPG]
Dilate
open
Decr
fall; zero
More
drops;more
Hb to cells
Incr
Incr
At end of Exercise
Abrupt ____ in ventilation
___ debt
Accumulated ___ have to be removed before ventilation can return to baseline.
fall
O2
H+
At the end of the exercise, the ventilation reaches baseline before accumulated hydrogen ions are removed
T/F
F
It doesn’t
FATIGUE
Poorly understood or phenomenon
But may be due to effects of :
(Acidosis or alkalosis?) on brain
Muscles becoming ____ during _______
Accumulation of Substance P which stimulates ____ receptors
Accumulation of interstitial fluid in muscles during _____
Acidosis
ischemic; long contractions
pain
exertion
