Exam 5 Flashcards
Systolic versus diastolic blood pressure
Typical values
Systolic: pressure in large arteries during contraction+ejection (systole)
Less than 120 mm of mercury/mmHg
Diastolic: pressure in large arteries during relaxation and filling (diastole)
Less than 80 mmHg
Explain the origins of the heart sounds S1 and S2
Murmurs
S1: “Lubb”, sound of AV valves closing
S2: “Dupp”, sound of semilunar valves closing
Murmurs: noise in the heart
Explain the anatomical features of the different blood vessels and the physiological significance of these features
Arteries, arterioles, capillaries, veins, venules
Larger arteries are more muscular and elastic=more durable=can accommodate influx of blood
Smaller arteries are greater in number=less resistance (like traffic)
Arterioles: small and highly branched
Capillaries: larger surface area and thin walls facilitate transport
Venules, veins: many, very compliant
Which type of blood vessel does not have SNS innervation?
Capillaries
Describe the relationship between the cross-sectional area of blood vessels and the velocity of flowing blood
What vessels have the largest CSA?
Increased surface area (eg. capillaries, arterioles, venules)=decreased velocity
Capillaries have the largest surface area
Which blood vessels are the most compliant?
A. Arteries
B. Veins
C. Venules
D. Capillaries
B. Veins
Veins are semi-collapsed, so they can “pop” open with an influx of blood
Which blood vessels have the largest surface area in the body?
A. Arteries
B. Veins
C. Venules
D. Capillaries
D. Capillaries
Which blood vessels have the most elastic proteins?
A. Arteries
B. Veins
C. Venules
D. Capillaries
A. Arteries
Allows systolic and diastolic pressure changes
Describe how blood flows through arteries and veins and differentiate between laminar and turbulent flow
Arteries: pulsatile
Veins: steady
Blood flow is usually laminar (smooth, parallel, streamlined)
Turbulent flow occurs with high flow rates or narrowing vessels, can be heard
Pulse pressure and MAP
Pulse pressure: represents force that heart contraction generates=systolic-diastolic pressure
MAP: average pressure of blood on the arteries=diastolic+(pulse pressure/3)
Takes into account longer diastolic phase
Alternate: cardiac output x systemic vascular resistance
Measuring blood pressure
Kortkoff sounds
- Cuff inflates beyond 120 mmHg->closes vessel
- Some air is let in, partially opens vessel
Rapid flow through semi-compressed artery=Korotkoff sounds
1st=systolic, 5th=diastolic
Know the equations for pressure, resistance and flow and why they are important in the regulating blood pressure
Flow= difference in pressure/resistance
Pressure=force/area
Heart creates pressure gradient from aorta to venae cavae
Decreased surface area=decreased pressure
Which blood vessels have valves?
A. Large Arteries
B. Veins
C. Arterioles
D. Capillaries
B. Veins
Promotes one-way flow of blood
Why does pressure drop by so much as you move from the aorta to the capillaries?
A. The long blood vessels slows the flow of blood
B. Reduced elastic fibers in the vessels further
away from the heart.
C. The increased cross-sectional area of vessels
D. The decreased cross-sectional area of vessels
C. Increased CSA
Central blood volume
Amount of blood in the heart and lungs (core)
Distribution of blood from laying down to standing and standing to
laying down
Supine->standing:
Blood pressure drops, decreased CBV, venous return, EDV, stroke volume
Standing->supine: blood pressure increases
Increased CBV, increased venous return, increased EDV, stroke volume
Describe how the body alters cardiac output and systemic vascular resistance to maintain blood pressure
Blood pressure drops:
Increase flow in: increase cardiac output
Decrease flow out: vasoconstrict, increased SVR
Blood pressure increases:
Decrease flow out: decrease cardiac output
Increase flow out: vasodilate, decreased SVR
Describe how the body responds to an acute increase or decrease in blood pressure
What is the homeostatic set point?
Receptor, effector, control center
Homeostatic setpoint=93 mmHg
Decrease:
Receptors: baroreceptors/stretch receptors in carotid sinus and aorta transduce signal to decrease action potentials
Control center: medulla oblongata
Effectors: heart (increased HR+contractility), blood vessels (vasoconstriction)
Increase:
Receptors detect greater stretch, transduce to higher AP frequency, control center decreases HR and contractility, vasodilation
SNS and PNS activity for increased versus decreased blood pressure
Increased BP eg. standing->supine: remove SNS tone, add PNS tone
Decreased BP eg. supine->standing: remove PNS tone, add SNS tone
In a response to a drop in blood pressure the body will _______ heart rate and ________ systemic vascular resistance
A. Decrease/decrease
B. Decrease/increase
C. Increase/increase
D. Increase/decrease
C. Increase/increase
Increased SVR increases central blood volume
Vasoconstriction increases SVR
In a response to an increase in blood pressure the body will _______ sympathetic activity and
________ parasympathetic activity
A. Decrease/decrease
B. Decrease/increase
C. Increase/increase
D. Increase/decrease
B. Decrease/increase
Functions of the respiratory system (5)
- Air passageways
- Protection
- Exchange site for O2 and CO2
- Odor detection
- Sound production
Left versus right lung
Right lung is typically larger, has 3 lobes
Left lung is smaller, has 2 lobes because of the heart
Structural organization of respiratory system
A) Upper respiratory tract
Nose->nasal cavity->pharynx (throat)->larynx (voice box)
B) Lower respiratory tract
Trachea (wind pipe)->bronchus (larger right, smaller left)->bronchioles->terminal bronchioles->respiratory bronchioles->alveolar duct->alveoli
Functional organization of respiratory system
What happens at the alveoli?
A) conducting zone: bulk flow of air, no alveoli
Nose to the terminal bronchioles
B) Respiratory zone: gas exchange, contains alveoli
Respiratory bronchioles to the alveoli
Oxygen diffuses from alveoli to blood, carbon dioxide diffuses from blood to alveoli
Features and functions of the nasal cavity
Nasal conchae: bony projections that increase surface area and create turbulence
Warms air via blood vessels, cleans air via mucus and hair, humidifies air
Rhinorrhea
Runny nose
Caused by cold virus, increased mucus production, allergy, spicy foods, cold air condensation
Boyle’s Law
Relationship between pressure and volume
What creates air pressure gradients?
Inverse relationship
When temperature is constant, as the pressure of gas decreases, volume increases
Decreased volume increases pressure of gas
Air flows from high to low concentration
Gradient created when pressure is higher in one area than another
True or false, the trachea/wind pipe is part of the upper respiratory system?
A. True
B. False
B. False
Upper respiratory system ends at larynx
True or false, gas exchange occurs in the terminal bronchiole?
A. True
B. False
B. False
Respiratory exchange starts at respiratory bronchioles
Quiet breathing
2 phases
Typical rate
Volume and pressure, airflow
Largely passive and unconscious
1. Inspiration: thoracic cavity volume increases vertically (diaphragm contracts) and laterally (external intercostals/ribs elevate)
Increased volume=decreased pressure, allows air to flow from high pressure outside to low pressure in
2. Expiration: largely passive, muscles relax and recoil
TC volume decreases, pressure increases allows air to flow from high pressure in to low out
Usually 12-16 breaths/minute, 3mL/breath, 3.6-4.8 L/minute
Respiratory rate versus minute ventilation
Respiratory rate: breaths per minute ~12-20
Minute ventilation: volume of air per minute ~6-8 L/min
Pressure changes during quiet breathing
Atmospheric pressure is ~760 mmHg
Pleural cavity/intrapleural pressure ~756 mmHg to keep lungs inflated
Intrapulmonary/lung pressure must drop below 760 mmHg for air to flow from atmosphere into the lungs
Intrapleural pressure will always be slightly lower than intrapulmonary
Inspiration=decreased intrapulmonary pressure, intrapleural decreases too
Identify and briefly describe the four types of tissues in the body
- Epithelial: covers surface of the body and hollow organs (cuboid, columnar, squamous)
- Connective, found all over the body
- Muscle: skeletal, cardiac, and smooth. All can contract, all contain actin and myosin
- Nervous: neurons and support cells
Describe how the calcium and sodium/potassium pumps work to create/maintain concentration
gradients
Electrical and chemical gradients
Electrical gradient: more positive outside cell than in
Chemical gradient: sodium concentration higher outside, potassium higher inside
Calcium concentration low outside, high inside
Vesicular transport
Endocytosis versus exocytosis
Allows more movement of large substances/large amounts of substance to move across membrane using vesicles
Endocytosis: uptake of large amounts/substances INTO cell eg. nutrients
Exocytosis: vesicle binds to membrane, contents released OUTSIDE cell eg. neurotransmitter release
Describe the cardiac cycle and define the two phases of the cardiac cycle, systole and diastole
Diastole: relaxation and filling, 3x longer at rest
Systole: contraction and ejection
Define the terms stroke volume, heart rate, and cardiac output
Stroke volume: amount of blood pumped per beat avg. 70mL/beat, range 50-110
Heart rate: number of beats per minute average 60-80bpm
Cardiac output: amount of blood pumped by one ventricle of the heart in a minute, avg. 5 L/min
Tidal volume
Residual volume
Volume of air inhaled/exhaled per breath
~500mL
Residual volume: air remaining in lungs after maximal expiration
Inspiratory reserve volume
Expiratory reserve volume
ISV: amount of air you can inhale over and above tidal volume- maximal inspiration
ESV: maximal expiration
Vital capacity
Total lung capacity
Vital capacity: tidal volume+IRV=ERV
Total lung capacity: TV+ERV+IRV+RV
Chemical reaction of carbon dioxide in erythrocytes (RBC)
CO2+H2O->carbonic anhydrase(CA)->H2CO3 (carbonic acid)->CA splits carbonic acid into->bicarbonate (HCO3-) and H+
H+ binds to hemoglobin, bicarbonate exits RBC
Feedback loop of breathing control
Sensory input: central (medulla) and peripheral (aortic arch+carotid sinus) chemoreceptors, central (hypothalamus) and peripheral (skin) thermoreceptors, skeletal muscle mechanoreceptors
Control center: pons (rate and depth of breathing) and medulla (inspiration and expiration)
Motor output: somatic motor nerves, diaphragm, external intercostals
Central versus peripheral chemoreceptors
Central: monitors only PCO2 changes through H+ concentration changes
Peripheral: monitors changes in PCO2, H+, and large changes in PO2
ANS involvement in breathing
SNS versus PNS
SNS: norepinephrine beta-adrenergic receptor stimulation promotes bronchodilation of smooth muscle=increased airflow
PNS: acetylcholine cholinergic receptor stimulation promotes bronchocontraction of smooth muscle=decreased airflow
Somatic versus autonomic nervous systems and breathing
Somatic nervous system innervates skeletal muscles of breathing eg. diaphragm, external intercostals, motor nerves
Autonomic nervous system innervates smooth muscle and glandds
Which chemoreceptors are sensitive to changes in PO2?
A. Central chemoreceptors
B. Peripheral chemoreceptors
C. Both A and B
B. Peripheral chemoreceptors
Which chemoreceptors are sensitive to changes in pH?
A. Central chemoreceptors
B. Peripheral chemoreceptors
C. Both A and B
D. Neither A nor B
C. Both
Both monitor H+ concentration
4 processes of movement of respiratory gases
- Pulmonary ventilation: movement of air between atmosphere and alveoli (O2 from atmosphere->alveoli, CO2 from alveoli to atmosphere)
- Pulmonary gas exchange: exhange between alveoli and blood (O2 into blood, CO2 into alveoli)
- Gas transport: blood transport of gases from lungs to systemic cells (O2 from lungs to cells, CO2 from cells to lungs)
- Gas exchange: movement of gases from blood to systemic cells (O2 diffuses from blood to cells, CO2 from cells to blood)
Bronchial tree
Highly branched system of air-conducting passages beginning at main bronchi and branches into narrower and narrower tubes, terminating at alveoli
Explain the process of bronchoconstriction and bronchodilation
Bronchoconstriction: PNS activity stimulates smooth muscles to contract, decreasing airflow
Bronchodilation: SNS activity stimulates smooth muscles to relax, increasing airflow
Asthma is episodes of bronchoconstriction triggered by airborne agent
3 types of alveolar cells
- Type 1: most abundant, simple squamous, make up internal surface
- Type 2. smaller, cuboidal, produce and secrete surfactant (oily fluid that prevents collapse of alveoili)
- Alveolar macrophages: mobile scavengers engulf foreign material
3 layers of respiratory membrane
- Alveolar epithelium
- Fused basement membranes of capillary endo and alveolar epi
- Capillary endothelium
What alveolar cells produce surfactant?
A. Type I
B. Type II
C. Alveolar macrophages
D. None of the above
B. Type II
What alveolar cell is most abundant?
A. Type I
B. Type II
C. Alveolar macrophages
D. They are about the same in terms abundance
A. Type I
Dalton’s Law
The total pressure in a mixture of gases is equal to the sum of the individual partial pressures
Partial pressure= % of gas x total pressure
PN2= 760 x 79.04=600.7 mmHg
PO2= 760 x 20.93= 159.1 mmHg
PCO2= 760 x 0.03= 0.2 mmHg
Partial pressure of oxygen and CO2 in inspired air, alveoli, and arterial blood+ venous blood
- Inspired air= 159.1 mmHg
Water vapor and residual air mix
CO2= 0.3 mmHg - Alveoli= 104 mmHg
Diffuses into venous blood carry deoxygenated blood from cardiac and lung tissue
CO2=40 mmHg - Arterial blood: 100 mmHg
CO2=40 mmHg - Systemic cells: PO2=40, PCO2=45
- Venous blood: PO2=40, PCO2=45
Oxygen decreases, CO2 increases
Components of alveoli
How many per lung?
Alveolar pores
Pulmonary capillaries
Interalveolar septum
300-400 million/lung
Alveolar pores allow air to circulate between alveoli
Pulmonary capillaries form a “hair net” around each alveolus
Interalveolar septum between alveolus contains elastic fibers to stretch and recoil
