Exam 4 Flashcards
Describe the three general functions of blood
- Transportation of formed elements, molecules, ions, and respiratory gases
- Regulation of body temperature, pH, and fluid balance
- Protection with leukocytes, plasma proteins
List the seven characteristics of blood and explain their significance of each to health and homeostasis.
- Color- oxygen rich=bright red
- Volume- avg. 5 L, range 4-6 L
- Viscosity- 4-5x thicker than water
- Plasma concentration
- Temperature- 1/2 degrees C higher than core temp
- pH-7.35-7.45 (alkaline)
- Life cycle-60-120 days
Hematocrit
Males vs. females
Percentage of the blood that is red blood cells
42-56% in men (testosterone)
38-46% in women
Formed elements
A-nucleated erythrocytes, leukocytes, and platelets in the blood
3 components of blood
What percentage of blood do they make up?
- Erythrocytes/red blood cells ~44%
- Buffy coat ~ <1%
A) Platelets
B) Leukocytes - Plasma ~55%
92% water, 7% proteins eg. albumins, 1% electrolytes (Na+, K+, Ca++), nutrients (glucose), respiratory gases, waste products (urea, nitrogen)
Describe the structure of a red blood cell
How big are they?
Biconcave=increased surface area
7.5 microns wide, can fold down to 2-4 microns to fit inside 5 micron capillaries
Why are red blood cells and platelets more accurately called formed elements?
A. They are smaller than most cells
B. They lack a nucleus
C. They lack a cell membrane
D. They serve no function
B. They lack a nucleus
True or False: typically, the pH of the blood is slightly acidic.
A. True
B. False
B. False-slightly alkaline
True or False: typically, biological males have a higher hematocrit than biological females.
A. True
B. False
A. True-testosterone
Describe the structure of hemoglobin and explain where oxygen, carbon dioxide and carbon monoxide bind to hemoglobin
4 protein molecules (globins)- 2 alpha chains, 2 beta chains
All globin chains contain a heme group- ring with iron in the center
Oxygen binds to iron in heme for transport
Carbon dioxide binds to globin for transport through capillaries
Erythropoiesis
Stimulis, chain reaction
Process of producing erythrocytes/RBC
Occurs in red bone marrow
Stimulus: hypoxia-reduced oxygen supply/levels
Liver, kidney, brain, neurons produce erythropoietin->stimulates red bone marrow->enhance production of RBC
What is the life span of a red blood cell and how are red blood cells recycled?
60-120 days
Liver and spleen break down, recycle iron from heme and globin protein
True or False: oxygen and carbon dioxide bind to the same location on the hemoglobin protein.
A. True
B. False
False
O2 binds to iron in heme group, C02 binds to globin protein
True or False: typically, white blood cells out number red blood cells 10,000 to 1
A. True
B. False
False
Erythrocytes are the most abundant
Anemia
Causes, who is more at risk
Low levels of hemoglobin OR red blood cells
Can be caused by diet, absorption problems eg. IBS, or chronic conditions
More common in women, athletes, vegetarians
Explain the main features and function of leukocytes and relative abundance
Motile, driven by chemotaxis (chemical signals)
Defend against pathogens (immune response)
1.5-3x larger than erythrocytes, longer lifespan, contain nucleus and organelles
Granulocytes versus agranulocytes
Never Let Monkeys Eat Bananas
(most to least abundant)
Granulocytes (PHILs): neutrophils, eosinophils, basophils
Agranulocytes (CYTES): monocytes, lymphocytes
Explain the structure and function of platelets aka thrombocytes
Irregular membrane fragments
30% found in the spleen
Involved in hemostasis (blood clotting)
Describe the three phases of hemostasis
- Vascular spasm: damage to smooth muscle causes vasoconstriction
- Platelet plug formation: platelets stick to exposed collagen fibers
- Coagulation: activation of inactive proteins to form fibrin strands
Clinically anemia can defined as a which of the following?
A. Reduced hematocrit
B. Reduced hemoglobin
C. Reduced plasma volume
D. Both A and B
D. A and B
Reduced hemoglobin or RBC (hematocrit)
Which of the following is an agranulocyte?
1. Basophil
2. Neutrophil
3. Monocyte
4. Eosinophil
- Monocyte
3 components of the cardiovascular system
- Heart
- Blood vessels
- Blood
3 types of blood vessels
- Arteries carry blood away from heart-smaller, open, thicker smooth muscle walls
- Veins carry blood to the heart, larger, thinner walls, more compliant
- Capillaries have no smooth muscle, exchange site
Great vessels
Arteries+veins connected directly to heart
Right:
Superior Vena Cava (SVC): carries low oxygen blood from upper body to RA
Inferior Vena Cava (IVC): carries low oxygen blood from lower body to RA
Pulmonary trunk: carries low O2 blood from RV to pulmonary
Left:
Pulmonary veins: carry high O2 blood into LA
Aorta: transport blood from LV to peripheral/systemic circulation
Valves of the heart
Allow one way flow of blood by closing w/ pressure
Right:
Right atrioventricular valve/tricuspid: separates RA/RV
Pulmonary semilunar: separates RA/pulmonary trunk
Left:
Left atrioventricular valve/bicuspid: separates LA/LV
Aortic semilunar: separates LV/aorta
Which of the following is NOT a correct statement?
A. In general, veins are larger than arteries.
B. Capillaries dilate to increase the flow of blood to tissue.
C. Arteries have more layers of vascular smooth muscle than veins.
D. The thin walls of and large surface area of capillaries contribute
to their high capacity for transport
B. Capillaries cannot dilate, they don’t have vascular smooth muscle
Pulmonary versus systemic circulation
Vessel length, artery size, pressure and resistance
Pulmonary/lungs: shorter vessels, smaller arteries with less VSM, lower pressure and resistance
Systemic/peripheral: longer vessels, larger, more muscular arteries, higher pressure and resistance
What vessel(s) direct blood from the head and neck region back to the heart?
A. Aorta
B. Inferior Vena Cava
C. Pulmonary Veins
D. Superior Vena Cava
D. Superior Vena Cava/SVC
Which valve separates the left atria from the left ventricle?
A. Aortic Semilunar
B. Pulmonary Semilunar
C. Tricuspid
D. Bicuspid
D. bicuspid
Tri before you bi
Right then left
Pericardium and heart wall
Structure and function
- Pericardium/pericardial sac
Anchored at base of great vessels and diaphragm
3 layers, outermost is dense connective tissue - Serous fluid: oily, viscous fluid reduces friction
- Heart wall
Epicardium (simple squamous+CT), myocardium (cardiac muscle layers), endocardium (simple squamous+CT)
Right versus left sides of heart
Size of ventricles
Right ventricle is smaller, thinner, less muscular
Left ventricle is larger, more muscular
Papillary muscles and chordae tendineae
- Papillary muscles extend from ventricle wall, contract to stabilize ventricles
- Chordae tendineae connect muscle to valves
Which chambers of the heart contain
deoxygenated blood
A. right atria, left atria
B. right ventricle, left ventricle
C. right atria, right ventricle
D. left atria, left ventricle
C. Right atria and ventricle
True or False? Arteries always carry oxygenated blood away from the heart and veins always carry deoxygenated blood towards the heart?
A. True
B. False
B. False
Pulmonary veins carry high oxygen blood into left atria
Flow of blood through the heart
SVC+IVC carry low O2, high CO2 blood to the RA
Blood passes through right AV/tricuspid->RV->pulmonary semilunar->pulmonary trunk to pulmonary circulation (pick up O2, drop off CO2)
Pulmonary veins->LA->bicuspid valve->LV->aortic semilunar->aorta->systemic circulation
Cells of the heart
2 types
Gap junctions and desmosomes
- Nodal cells ~1%
Specialized pacemaker cells, autorhythmic (generate own AP), little to no myosin + actin (contractile proteins) - Cardiac myocytes ~99% short, thick, branching with multiple connections
Gap junctions: shortcut between cells
Desmosomes: proteins connecting myocytes
Pathway of electrical conduction
BPMs
- Sinoatrial node (SA)= pacemaker, 60-100 bmp
- AV node, slows to 40-60 bpm
- AV bundle/bundle of Hiss
- L and R branches
- Purkinje fibers via septum 20-40 bpm
- Cardiac tissue 15-30 bpm
Which of the following represents the correct directional flow of
blood?
A. Right Atria, Right Ventricle, Left Ventricle, Left Atria
B. Right Atria, Left Atria, Right Ventricle, Left Ventricle
C. Left Atria, Left Ventricle, Right Atria. Right Ventricle
D. Right Atria, Right Ventricle, Left Atria, Left Ventricle
C or D
Which of the following represents the correct directional flow of
the electrical signal through the heart?
A. SA Node, Purkinje Fibers, AV Bundle, AV Node, R L Bundles
B. AV Node, SA Node Purkinje Fibers, AV Bundle, R L Bundles
C. SA Node, AV Node, AV Bundle, Purkinje Fibers, R L Bundles,
D. SA Node, AV Node, AV Bundle, R L Bundles, Purkinje Fibers
D. SA node->AV node-> AV bundle-> R L bundles-> Purkinje fibers
Sympathetic versus parasympathetic control of the heart
HR, contractility, neurotransmitters
- Parasympathetic: decreases HR and contractility (force of contraction)
ACh hyperpolarizes, brings further from threshold - Sympathetic: increases HR and contractility
Epinephrine from adrenal medulla, norepinephrine
Depolarize, closer to threshold
Vagal tone
Maintains HR below intrinsic speed using parasympathetic nervous system
Blood pressure
Equation
Effects of vasodilation and vasoconstriction
Force that blood exerts on vessel walls
Pressure=force/area
Dilation decreases pressure, contraction increases
Blood flow
Equation
Relationship between pressure and flow, pressure and resistance
Effects of difference in pressure
Movement of blood through vessel
F=difference in pressure/resistance
Pressure and flow are proportional-increase in flow=increase in pressure
Pressure and resistance are inverse-increase in resistance=decrease in pressure
Greater difference in pressure=more flow ex. tall hill
Resistance
Equation
Relationship between viscosity, length, and radius and resistance
Force that opposes blood flow
R=nL/r^4, n=viscosity, L=length of vessel, r=radius of vessel
Higher viscosity, longer length=more resistance
Increased radius=less resistance
Compliance
Equation
How easily vessel stretches
C=change in volume/change in pressure
With all other things being held constant what impact would
decreasing the diameter of a blood vessel(s) have on vascular
resistance?
A. It would increase resistance
B. It would decrease resistance
C. It would not change resistance
A. Increase resistance
With all other things being held constant what impact would
decreasing the pressure along a vessel have on blood flow
through that vessel?
A. It would increase blood flow
B. It would decrease blood flow
C. It would not change blood flow
A. Increase blood flow
Blood moves from high concentration to low concentration
With all other things being held constant what impact would
increasing the length of a blood vessel have on the blood flow
through that vessel
A. It would increase blood flow
B. It would decrease flow
C. It would not change flow
B. decrease flow
Longer=decreased
Two main phases of the cardiac cycle
Length
Diastole: relaxation and filling, 3x longer at rest
Systole: contraction and ejection
Diastolic phases
What valves are open?
- Isovolumetric relaxation- no blood flow, all valves closed
- Rapid filling- largest pressure difference between atria and ventricle opens AV valves
- Atrial contraction- “top-off” 20-30% of blood
Systolic phases
What valves are open?
- Isovolumetric contraction= no blood flow, AV valves close
- Ejection- semilunar valves open, blood ejected to peripheral and pulmonary systems
During which phase of the cardiac cycle is the
heart filling?
A. Systole
B. Diastole
C. Both
D. None of the above
B. Diastole
Withdrawing/removing parasympathetic activity
to the heart would result in:
A. Increased heart rate: decreased contractility
B. Increased heart rate: increased contractility
C. Decreased heart rate: decreased contractility
D. Decreased heart rate: increased contractility
B. Increased HR and contractility
Cardiac output
Units, average
Amount of blood the heart can pump in a minute
Includes: how much blood/beat and how frequently the heart beats
Measured in L/min, avg. 5 L/min
Stroke volume
Units, average and range
Amount of blood pumped per beat
Measured in mL/beat, avg. 70 mL/beat, range 50-110
Heart rate units and average
Beats per minute BPM
60-80 bpm
Major factor that increases stroke volume
Preload
End diastolic volume
Venous return: volume of blood returning to the right atria
Greater venous return=great preload/end diastolic volume (amount of blood at the end of diastolic phase)
Increased venous return=increased preload=increased stroke volume
Describe the two subcellular mechanisms responsible for the Frank-Starling Law of the Heart
Why does increased venous return mean increased stroke volume?
A) increased EDV=greater stretch=moves thick (myosin) and thin (actin) filaments closes=more crossbridges=more forceful contraction
B) Increased calcium sensitivity
2 additional factors that increase stroke volume
SM pump and respiratory pump
- Increased venous pressure eg. during exercise
Result of skeletal muscle pump: contracted SM forces blood up to heart
Result of respiratory pump: increased thoracic pressure forces blood down into heart - Increased time to fill- slower HR
Which of the following would increase stroke volume?
A. Increased pre-load
B. Decreased preload
C. Increased venous return
D. A and C
E. B and C
D. A and C
Increased venous pressure would results in increased stroke volume by decreasing preload.
A. True
B. False
B. False
Increased pressure=increased preload
The skeletal muscle pump and the respiratory
pump will both increase ____________
A. ESV
B. EDV
C. Peripheral Resistance
D. Central Blood Volume
E. Venous Return
B. EDV, D. Central Blood Volume, E. Venous return
Factors that decrease stroke volume
- Decrease in blood volume eg. dehydration
- Lower EDV= lower preload= lower stroke volume
- Increase in ONLY HR, decreases filling time
Ions
2 types
Atom w/ electrical charge
Anion: negative charge, eg. chloride (Cl-)
Cation: positive charge eg. Na+, K+
Solution, solvent, and solute
Solution: mixture of 2+ substances
Solvent: usually a liquid, does the DISSOLVING
Solute: is DISSOLVED
Acid
Strong vs. weak
Substance that dissolves/dissociates in water, produces anion and H+
Proton donator
Strong acids dissociate more=more H+
Base
Strong vs. weak
Proton acceptor, accepts H+ in water
Decrease H+ concentration
Strong bases accept more H+=lower H+ concentration
Autonomic tone
Continuous release of a neurotransmitter by PSNS or SNS to maintain sustained baseline inhibition or activation
SNS: blood vessels maintained in partial constriction
PsNS: HR maintained below intrinsic rate
Explain how the hypothalamus controls the release of cortisol from the the adrenal gland and the region of the adrenal glans where cortisol is released
Hypothalamus produces CRH-> anterior pituitary produces ACTH (adrenocorticotropic hormone)->adrenal cortex produces cortisol
Stimuli: hypoglycemia, stress, low cortisol
Targets liver->glucose release, adipose->lipid breakdown
Explain how the production and release of epinephrine and norepinephrine from the adrenal medulla are regulated by the sympathetic nervous system
Pre-ganglion SNS neurons in thoracic spinal cord project to adrenal medulla nicotinic receptors->ACh->epinephrine (80%), norepinephrine (20%)
Explain the three reflex mechanism for regulating the secretion of hormones and examples of each
- Hormonal: one hormone triggers another, eg. TSH from hypothalamus triggers TH from thyroid gland
- Humoral: change in blood level of a nutrient or ion eg. high blood glucose triggers insulin release, low BG triggers glycogen breakdown
- Nervous: nervous system activity eg. SNS activity triggers epinephrine
