final Flashcards
what is blood pressure caused by?
ventricular contraction
how is blood pressure in the blood vessels maintained when the ventricles are in diastole?
the elastic recoil of the arteries
what is systolic blood pressure caused by?
what is diastolic blood pressure caused by?
systolic BP caused by ventricular contraction
diastolic BP caused by elastic recoil of arteries
what is the korotkoff sound?
the pulsating sound arteries produce when BP is being measured
what is pulse pressure?
strength of pressure waves in blood vessels
how do you calculate pulse pressure?
pulse pressure = systolic pressure - diastolic pressure
describe the strength of BP at you go from the left ventricle to the right atrium
left ventricle - syst is full strength dia is very low
arteries - normal BP values ex. 120/80
arterioles - sys and dia BP become progressively lower
capillaries venules, and veins - sys/dia waves disappear and BP becomes progressively less until pressure completely disappears at the right atrium
where can pulse pressure be found?
arteries and arterioles
Pulse pressure drops out in arterioles
what is mean arterial pressure (MAP) and how do you calculate it?
the driving pressure in arteries and arterioles
mean arterial pressure = diastolic pressure + 1/3 of pulse pressure
what is mean arterial pressure determined by?
1) blood volume
2) cardiac output
3) resistance of the system to blood flow
4) relative distribution of blood between arterial and venous blood vessels
what is blood volume determined by?
1) fluid intake
2) fluid loss (which may be passive or regulated at the kidneys)
what is cardiac output determined by?
1) HR
2) stroke volume
what determines the resistance of the circulatory system to blood flow?
diameter of blood vessels
what is relative distribution of blood between arterial and venous blood vessels determined by?
diameter of veins
what is the negative feedback mechanism that regulates high blood pressure?
*HIGH BLOOD PRESSURE DETECTED** (fast response-cardiovascular system) * vasodilation *reduced cardiac output reduced BP
(slow response- compensation by the kidneys)
*excretion of fluid in urine leads to lower blood volume
reduced BP
what is hydrostatic pressure?
what is colloid osmotic pressure?
hydrostatic pressure is the pressure that forces fluid out of a capillary
colloid osmotic pressure is the pressure of proteins within a capillary that pulls fluids into the capillary
how do you calculate net pressure?
net pressure = hydrostatic pressure - colloid osmotic pressure
when the value is a positive number filtration is occurring and fluids are moving out of the capillary
when the value is negative absorption is occurring and fluid is moving into the capillary
which plasma protein is largely responsible for colloid osmotic pressure?
albumin
what is the difference between filtration and absorption in a capillary?
filtration - fluid is moving out of the capillary and into surrounding tissue
absorption - fluid is moving from the tissue surrounding the capillary into the capilarry
what do carotid and aortic baroreceptors detect?
they detect BP by monitoring blood vessel wall stretch
what is aorta and carotid sinus?
they are the location for the carotid and aortic baroreceptors
describe the baroreceptor reflex related to blood pressure
HIGH BLOOD PRESSURE DETECTED
- *INCREASED BP DETECTED BY BARORECEPTORS**
- carotid and aorta baroreceptors fire AP which travels through sensory neurons to the cardiovascular control center in the medulla
- the cardiovascular center increases parasympathetic output while decreasing sympathetic output
- *INCREASED PARASYMPATHETIC OUTPUT**
- more acetylcholine is released on muscarinic cholinergic receptors at the SA node which leads to reduced heart rate> reduced cardiac output>reduced BP
- *DECREASED SYMPATHETIC OUTPUT**
- less norepinephrine is released at BETA 1 adrenergic receptors at the SA node which helps reduce heart rate>reduces cardiac output>reduced BP
- less norepinephrine is released at beta 1 adrenergic receptors on the ventricular contractile cells which leads to reduced contraction force > reduced cardiac output>reduced BP
- less norepinephrine is released at alpha adrenergic receptors on arterial smooth muscle>vasodilation>reduced peripheral resistance>reduced BP
what is orthostatic hypotension?
sudden drop of BP when you go from lying or sitting to a standing position and blood pressure to the brain drops (makes you feel dizzy)
describe the orthostatic hypotension negative feedback mechanism
- mean arterial blood pressure drops upon standing
- carotid and aortic baroreceptors signal cardiovascular center in the medulla
- sympathetic output is increased while parasympathetic output is decreased
- *INCRASED SYMPATHETIC OUTPUT**
- arterioles and veins vasoconstrict = increased peripheral resistance
- ventricular force of contraction increases>increased cardiac output
- heart rate increased at SA node>increased cardiac output
- *DECREASED PARASYMPATHETIC OUTPUT**
- less acetylcholine binding to muscarinic receptors at the SA node increases heart rate > increases cardiac output
BP returns to normal and baroreceptors start firing at a normal rate
describe the effects of vasovagal syncope (emotional fainting)
1) parasympathetic activity increases while sympathetic activity decreases
2) HR and BP drop
3) blood vessels vasodilate
4) cardiac output and peripheral resistance drop
5) insufficient blood flow to the brain causes person to faint
what are the three stages of atherosclerosis?
1) fatty streak
2) stable fibrous plaque
3) vulnerable plaqu
what are some of the theories behind why people develop primary hypertension?
- increased arterial resistance
- decreased endothelial cell secretion of molecules responsible for vasodilation
- increased endothelin release which causes increased vasoconstriction
- reduced blood vessel compliance (blood vessel wall become rigid and resist vasodilation
- lifestyle, diet, genetics
what are the categories of blood pressure measurements?
normal - less than 120 (sys) 80 (dia)
prehypertension - 120-139 (sys) 80-89 (dia)
hypertension stage 1 - 140-159 (sys) 90-99 (dia)
hypertension stage 2 - >160 (sys) > 100 (dia)
hypertensive crisis - >180 (sys) >110 (dia)
what are some treatments for high BP?
1) Thiazide diuretics
2) beta blockers
3) ACE inhibitors
4) Angiotension 2 antagonists
5) alpha blockers
6) calcium channel blockers
describe thiazide diuretics
cause kidneys to increase urine which removes excess fluid from blood vessels.
diuretics or water pills have minimal side effects
describe beta blockers
make the heart beat slower by blocking nerve stimulating hormones.
describe ace inhibitors
expand blood vessels by blocking certain hormones.
ace inhibitors linked to strokes
describe angiotension 2 antagonists
like ace inhibitors they expand blood vessels by blocking certain hormones but they have fewer major side effects
describe alpha blockers
slows brains action on the nervous system which lowers blood pressure
describe calcium channel blockers
relax blood vessels by interupting the movement of calcium ions into nearby muscles. linked to heart attacks, depression, and suicide
what is the difference between primary hypertension and secondary hypertension?
secondary hypertension is hypertension that is the result of another condition. primary is not due to underlying condition.
what is the respiratory pathway in order?
1) nasal cavity
2) pharynx
3) larynx
4) trachea
5) primary bronchi
6) secondary bronchi
7) bronchioles
8) alveoli
what is included in the respiratory zone?
respiratory bronchioles and alveoli
what is covers the lungs?
pleural membranes
what is the parietal pleura attached to?
the inside of the chest wall
what is the visceral pleura attached to?
the lungs
what does it mean when you say the lungs are compliant?
they are stretchable
what do the elastic fibers in the lungs allow them to do?
it allows them to recoil during exhalation
how is surface tension produced and what can it do to alveoli?
surface tension is produced by hydrogen bonding between water molecules and it will cause alveoli to collapse without intervention from pulmonary surfactant
what does pulmonary surfactant do in alveoli?
it prevents hydrogen bonding which decreases surface tension and keeps alveoli from collapsing
how does the nasal cavity condition inhaled air?
1) humidifies air
2) purifies air
3) warms air
what muscle is the parietal pleura attached to?
the diaphram
what is active inspiration during normal quiet breathing?
inhalation of air to the lungs. it is called active because it relies on muscles to draw air into the lungs
what muscles are involved in active inspiration?
the diaphram and external intercostals/scalenes
describe the air pressure in the lungs when air is being inhaled
when air is inhaled it creates a low pressure condition within the lungs which draws more air in
describe passive expiration during normal quiet breathing
exhalation. it is passive because the cause of exhalation is relaxation of the muscles and the recoiling property of the lungs causes exhalation
describe active expiration
when we force additional air out of our lungs by contracting internal intercostals and abdominal muscles
what is the formula for boyles law?
p1 x v1 = p2 x v2
what happens to alveolar pressure during inhalation and exhalation?
inhalation causes a 1 mmHg pressure drop from atmospheric pressure
exhalation causes 1 mmHg pressure increase compared to atmospheric pressure
in between inhalation and exhalation, alveolar pressure is equal to atmospheric pressure
describe intrapleural pressure during inhalation and expiration
pressure is always less than atmospheric pressure however:
it increases when you exhale and decreases when you inhale
what is pneumothorax?
collapsed lung
what are the different types of pneumothorax?
1) closed- lung is punctured allowing air into the pleural space
2) open- chest wall is punctured allowing air into the pleural space
3) tension- puncture in the chest wall allows air in and then seals to prevent air from escaping which causes air volume to continuously increase within the pleural space. begins to push heart
what is a pulmonary function test?
measures air volume moved with each breath
describe the different air volumes in the lungs
1) tidal volume - air moved in one inspiration or expiration during normal quiet breathing
(approximately 500mL)
2) inspiratory reserve volume (IRV) - the additional air that you can inhale after a normal quiet breathing inhalation
(approximately 3000mL)
3) expiratory reserve volume (ERV) - the air your lungs are capable of forcefully exhaling after a normal quiet breathing exhalation
(approximately 1100mL)
4) residual volume (RV) - the air that remains in the lungs after max exhalation
(approximately 1200mL)
what are lung capacities?
the sum of 2 or more lung volumes
what is vital capacity(VC)?
how do you calculate it?
maximum air moved in and out with one breath
tidal volume + inspiratory reserve volume + expiratory reserve volume
what is total lung capacity?
how do you calculate it?
total air capacity of the lungs
TV + IRV + ERV + RV
how do you calculate inspiratory capacity?
tidal volume + inspiratory reserve volume
how do you calculate functional residual capacity?
expiratory reserve capacity + residual capacity
what lung volumes increase in patients with emphysema?
damage to the lung tissue makes it lose elasticity and residual air volumes increase. patients cant get old air out of lungs
what is total pulmonary ventilation aka and how do you calculate it?
total minute volume - the volume of air move in a minute
total pulmonary ventilation = ventilation rate x tidal volume
what is alveolar ventilation and how do you calculate it?
the total mount of fresh air in alveoli per minute
ventilation rate x (tidal volume - volume of anatomical dead space)
what is anatomical dead space?
the space within the conducting zone of the respiratory tract
what is the approximate volume within the anatomical dead space?
about 150mL
how do you calculate the percentage of fresh air in the alveoli per breath?
(tidal volume - volume in anatomical dead space) / tidal volume
what is eupnea?
normal quiet breathing
what is hyperpnea?
increased respiratory rate and/or volume in response to increased metabolism
ie. exercise
what is hyperventilation?
increased respiratory rate and/or volume without increased metabolism
ie. emotional hyperventilation or blowing up a baloon
what is hypoventilation?
decreased alveolar ventilation
ie. shallow breathing, asthma, restrictive lung disease
what is tachypnea?
rapid breathing. usually increased respiratory rate with decreased depth
ie. panting
what is dyspnea?
difficulty breathing
ie. various pathologies or hard exercise
what is apnea?
cessation of breathing
ie. voluntary breath holding or depression of CNS control centers
what are the three gas exchange locations for CO2 and O2?
exchange 1 = atmosphere-alveoli
exchange 2 = alveoli-blood
exchange 3 = blood-cells/tissue
what are the venous and arterial CO2 and O2 pressures normally?
what is normal venous and arterial blood PH?
VENOUS
Pco2 = 46 mm Hg
Po2 = 40 mm Hg
PH = 7.37
ARTERIAL
Pco2 = 40 mm Hg
Po2 = 95 mm Hg
PH = 7.4
what are normal co2 and o2 pressures in alveoli and tissue cells?
ALVEOLI
Pco2 = 40 mm Hg
Po2 = 100 mm Hg
TISSUE CELLS
Pco2 = 46 mm Hg
Po2 = 40 mm Hg
what is movement of gasses to and from the blood due to?
pressure gradient of the gasses. gasses move diffuse down their concentration gradients to areas of lower concentrations
what determines the PH of the blood?
co2 levels in the blood
what does more co2 in the blood do to PH levels?
more co2 = more acidic
describe conditions that can make it difficult for gasses to diffuse between blood and alveoli
EMPHYSEMA - destruction of alveolar walls reduces surface area of alveoli which reduces gas exchange capability
(Po2 in alveoli = normal or low//Po2 in blood vessels = low)
FIBROTIC LUNG DISEASE - thickened alveolar membranes make it difficult for gas exchange between alveoli and blood vessels. reduced compliance of the lungs may also decrease alveolar ventilation.
(Po2 in alveoli = normal or low//Po2 in blood vessels = low)
PULMONARY EDEMA - fluid in interstitial space between alveoli and capillaries increase the distance gasses need to diffuse across which reduces efficiency. arterial Pco2 levels may be normal due to the solubility of co2 in water.
(Po2 in alveoli = normal// Po2 in capillaries = low)
ASTHMA - constricted bronchioles increases airway resistance and decreases alveolar ventilation
(Po2 in alveoli = low//Po2 in capillaries = low)
what is hypoxia?
when the body (or region of the body) is deprived of o2
what is hypoxic hypoxia and what are some causes?
low arterial Po2 levels
can be due to:
high altitude or alveolar hypoventilation
what is anemic hypoxia and what are some possible causes?
decreased total amount of o2 bound to hemoglobin
can be due to:
blood loss/anemia
carbon monoxide poisoning