Bio 2011 Midterm 2

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  1. What takes up nearly half of body's mass? What does it do with ATP? What are the 3 types and what are the common prefixes for them?
    • - Muscle tissues
    • - Transforms chemical energy (ATP) to direct mechanical energy which exerts force. 
    • - Skeletal, cardiac and smooth. 
    • - Myo, mys and sarco-
  2. Skeletal muscles:
    What do they attach to?
    what are the elongated cells called?
    How do they look like?
    What type of control does it use?
    3 things to describe it?
    What's required?
    • - organs attached to bones.
    • - Muscle fibers
    • - Striated
    • - voluntary 
    • - contracts rapidly, tires easily and powerful.
    • - nervous system stimulation.
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  3. Cardiac muscle:
    Found only where?
    Looks like?
    What is it able to do on its own?
    What type of control does it use?
    • - Heart; bulk of heart walls
    • - striated 
    • - can contract without nervous system stimulation
    • - Involuntary
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  4. Smooth muscle:
    Found where?
    Looks like?
    What can it do without the nervous system?
    Type of control it uses?
    • - walls of hollow organs like the stomach and urinary bladder and airways. 
    • - not striated 
    • - can contract without nervous system.
    • - Involuntary.
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    which is which?
    • - skeletal 
    • - cardiac 
    • - smooth
  6. Look at table 9.3
  7. There are 4 special characteristics of muscle tissues. What are they and define.
    • - Excitability (responsiveness) : ability to receive and respond to stimuli.
    • - Contractactility : ability to shorten forcibly when stimulated 
    • - Extensibility : ability to be stretched 
    • - Elasticity : ability to recoil to resting length.
  8. What are the four important functions of the muscle? + additional functions
    • - Movement of bones or fluids (blood)
    • - Maintaining posture and body position 
    • - stabilizing joints 
    • - heat generation (especially skeletal muscle)

    - Protects organs, forms valves, controls pupil size and causes goosebumps (arrestor pili muscles)
  9. Skeletal muscle is served by what?
    • - each muscle served by one artery, one nerve and one or more veins. 
    • - Every skeletal muscle
    • fiber supplied by nerve
    • ending that controls its
    • activity.
  10. What's the purpose of connective tissue sheaths found in the skeletal muscles?
    What is its order from external to internal?
    • - supports cells; reinforces whole muscles. 
    • - Epimysium : dense irreugular connective tissue surrounding entire muscle; may blend with fascia. 
    • - Perimysium : fibrous connective tissue surrounding fascicles (groups of muscle fibers)
    • - Endomysium : fine areolar connective tissue surrounding each muscle fiber.
  11. Skeletal muscle attaches in at least two places:
    • - Insertion : movable bone
    • - Origin : immovable (less movable) bones.
  12. muscles attaches directly or indirectly?
    • - directly : epimysium fused to periosteum of bone or perichondrium of cartilage. 
    • - indirect : connective tissue wrappings extend beyond muscle as rope like tendon or sheetlike aponeurosis.
  13. Define sarcolemma
    plasma membrane
  14. define sarcoplasm

    Two different things store something; state these.

    - glycosomes for glycogen storage, myoglobin for O2 storage.
  15. Name the 3 modified structures:
    myofibrils, sarcoplasmic reticulum and T tubules.
  16. What are myofibrils?
    • - densely packes, rodlike elements. 
    • - 80% of cell volume.
    • - contains sarcomeres - contractile units. (sarcomeres contain myofilaments.) 
    • - exhibit striations - perfectly aligned repeating series of dark A bands and light I bands.
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    What is this?
    What's the z-line, thick filaments, thin filaments and sarcomeres?
    • it's a Striation. 
    • - Z disc (line) : coin-shaped sheet of proteins on midline of light I band that anchors thin filaments and connects myofibrils to one another.
    • - Thick filaments : run entire length of an A band.
    • - Thin filaments : run length of I band partway into A band. 
    • - Sarcomere : region between two successive Z discs.
  18. Go into detail of a sarcomere:
    - how does it pertain to the muscle fiber?
    - Where is it found in?
    - What does it contain?
    - What is it composed of?
    • - Smallest contractile unit of muscle fiber
    • - Aligns along myofibril like boxcars of train.
    • - contains A band with 1/2 I band at each end.
    • - Composed of thick and thin myofilaments made of contractile proteins.
  19. What is the Thick Filament composed of?
    - Composed of protein myosin
  20. Referring to the thick filaments : What's the difference between myosin tails and myosin heads? What does the myosin head do?
    • - Myosin tails : contains 2 interwoven, heavy polypeptide chains. 
    • - Myosin heads : contain 2 smaller, light polypeptide chains that act as cross bridges during contraction. 
    • - Binds sites for actin of thin filaments. Binds sited for ATP. ATPase enzymes.
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  21. What is the Thin Filament composed of?
    There's a "letter" actin: what does it do?
    Two other two proteins that do something..?
    • - twisted double stand of fibrous protein.
    • - G (globular) actin subunits for myosin head attachment during contraction.
    • - Tropomyosin and troponin - regulatory proteins bound to actin.
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  22. What's Sarcoplasmic Reticulum? What is its function?
    • - Network of smooth endoplasmic reticulum surrounding each myofibril.
    • - Functions in regulation of intracellular Ca 2+ levels. (Stored and releases Ca 2+)
  23. What are T Tubules?
    What does it do to a muscle fiber?
    How does it relate to the A band and I band?
    • - continuation of sarcolemma 
    • - Increases muscle fiber's surface area.
    • - Penetrates cell's interior at each A band - I band junction.
  24. What happens during the sliding filament model of contraction : Relaxed vs Contracted?
    • - In relaxed state, thin and thick filaments overlap only at ends of A band.
    • - During contraction, thin filaments slide past thick filaments and actin and myosin overlap more. This occurs when myosin heads bind to actin (cross bridges)
  25. What needs to happen for skeletal muscle to contract?
    • - Activation (at neuromuscular junction) where there must be nervous system stimulation and must generate action potential in sarcolemma. 
    • - Excitation-contraction coupling where action potential propagates along sarcolemma and intracellular Ca2+ levels must rise briefly.
  26. There are 5 steps to Phase 1 of muscle fiber contraction, what are they?
    • - Action potential (AP) arrives at axon terminal at neuromuscular junction.
    • - ACh released; binds to receptors of sarcolemme
    • - Ion permeability of sarcolemma changes.
    • - Local change in membrane voltage (depolarization) occurs
    • - Local depolarization (end plate potential) ignites AP in sarcolemma
  27. 4 things happen in Phase 2 of muscle fiber contraction, what are they?
    • - AP travels across the entire sarcolemma.
    • - AP travels along T tubules.
    • - SR releases Ca2+ ; Ca2+ binds to troponin; myosin-binding sites (active sites) on actin exposed.
    • - Myosin heads bind to actin; contraction begins.
  28. The Nerve Stimulus and Events at the Neuromuscular Junction:
    What is the skeletal muscle stimulated by?
    How do the Axons of motor neurons travel?
    What do each axon endings form?
    • - somatic motor neurons
    • - travel from central nervous system via nerves to skeletal muscle.
    • - forms neuromuscular junction with single muscle fiber.
  29. Neuromuscular Junction:
    Where is it situated in?
    What is separates by gel-filled space; what's it called?
    What does the synaptic vesicle of axon contain?
    Where can you find ACh receptors?
    What does NMJ include?
    • - midway along length of muscle fibers.
    • - Axon terminal and muscle fibers is separated by the gel-filled space called synaptic cleft.
    • - contains the neurotransmitter acetylcholine (ACh)
    • - Junction folds of sarcolemma 
    • - axon terminal, synaptic cleft and junction folds.
  30. State the events that happen in the Neuromuscular Junction.
    • - Nerve impuse arrives at axon terminal 
    • - ACh released into the synaptic cleft.
    • - ACh diffuses across cleft and binds with receptors on sarcolemma. 
    • - Electrical Event generates action potential.
  31. Excitation- Contraction (E-C) coupling :
    What do the events that transmit AP along sarcolemma lead to?
    When does AP end and what does it cause?
    What is the Latent period?
    • - leads to sliding of myofilaments
    • - AP brief, ends before contraction. Causes Ca2+ to rise which causes contraction.
    • - Time when E-C coupling events occur. AP propagated along sarcomere to T Tubules. Voltage-sensitive proteins stimulate Ca2+ release from SR.
  32. Cross Bridge cycle:
    how does it continue?
    what happens during this?
    What goes where?
    • - continues as long as Ca2+ signal and adequate ATP present
    • - high energy myosin head attaches to thin filaments.
    • - Myosin head pivots and pulls thin filament towards M line
  33. How is the force of muscle contraction affected?
    • depends on number of cross bridges attached.
    • These increase the force:
    • - Number of muscle fibers stimulated (recruitment)
    • - relative size of fibers - hypertrophy of cells increases strength 
    • - frequency of stimulation 
    • - degree of muscle stretch. Length-tension relationship. (Muscle fibers at 80-120% normal resting length.)
  34. What does aerobic exercise do? 
    What does it result in?
    • - increases muscle capillaries, number of mitochondria and myoglobin synthesis 
    • - results in greater endurance, strength and resistance to fatigue.
  35. What are the effects of resistance exercise?
    • - Muscle hypertrophy (increase in fiber size)
    • - Increased mitochondria, myofilaments, glycogen stores and connective tissue. 
    • - Increased muscle strength and size.
  36. What is the overload principle? (5)
    • - forcing muscle to work hard promotes increased muscle strength and endurance.
    • - muscle adapt to increased demands
    • - muscles must be overloaded to produce further gains
    • - overuse injuries may result form lack of rest
    • - best programs alternate aerobic and anaerobic activites.
  37. Where are smooth muscles found in?
    What are the two types of layers?
    • - walls of most hollow organs (except heart) 
    • - longitudinal and circular
  38. Explain the spindle shaped fibers for smooth muscles. 
    What does it lack?
    How does the SR look like compared to skeletal?
    What's the infolding called?
    What does it NOT have?
    • - thin and short compared to skeletal muscle fibers; only one nucleus ; no striations.
    • - lacks connective tissue sheaths; endomysium only. 
    • - caveolae of sarcolemma. 
    • - No sarcomeres, myofibrils or T-tubules
  39. Explain longitudinal layer of smooth muscle fibers. 
    Explain circular layer of smooth muscle fibers.
    What does it allow?
    • - fibers parallel to long axis of organ; contraction -> dilates and shortened.
    • - fibers in circumference of organ; contraction -> constricts lumen, elongates organ. 

    - allows peristalsis (alternating contractions and relaxations of smooth muscle layer that mix and squeeze substances through lumen of hollow organs.
  40. myofilaments in Smooth Muscles:
    What's the ratio?
    What's the difference with the head of thick filaments?
    What does it not have and what binds to what?
    How is it arranged and why?
    Describe its dense bodies.
    • -thick to thin filaments is smaller (1:13) compared to skeletal where it's (1:2). 
    • - Thick filaments have heads along entire length. 
    • - Doesn't have troponin complex and Ca2+ binds with calmodulin. 
    • - spirally arranged, causing smooth muscle to contract in corkscrew manner. 
    • - Dense bodies : proteins that anchor non contractile intermediate filaments to sarcolemma at regular intervals. Corresponds to Z discs of skeletal muscle.
  41. How do Smooth Muscles contract?
    • - Actin and myosin interact by the sliding filament mechanism.
    • - Final trigger is ^ intracellular Ca2+
    • (Ca2+ is obtained from the SR and extracellular space.
    • - ATP energized sliding process.
  42. How are contractions regulated?
    How does Ca2+ increase?
    What does the response depend on?
    • - by nerves, hormones or local chemical changes. 
    • • Neural Regulation:
    • - Neurotransmitter binding increases Ca2+ in sarcoplasm; either graded (local) potential or action potential. 
    • - Response depends on neurotransmitter released and type of receptor molecules. 

    • •Hormones and local chemicals
    • - some smooth muscle cells have no nerve supply
    • - some respond to both neural and chemical stimuli 
    • - Chemical factor include hormones, CO2, pH.
  43. Smooth Muscle contraction:
    What's stress-relaxation response?
    What happens when the length and tension changes?
    • - responds to stretch only briefly, then adapts to new length. 
    • - Retains ability to contract on demand.
    • - Enables organs, stomach and bladder, to temporarily store contents. 

    - Can contract when between half and twice its resting length.
  44. What's hyperplasia and give an example
    • special feature of smooth muscle contraction. 
    • It's where smooth muscle cells can divide and increase numbers.
    • example: estrogen effects on uterus at puberty and during pregnancy.
  45. The pulmonary and systematic circuits:
    What type of system is the heart and what two things does it have?
    That do each of these sides do?
    • - transport system 
    • - two side-by-side pumps
    • - Right side receives oxygen-poor blood from tissues. Pumps to the lungs to rid CO2 and pick up O2 via the pulmonary circuit 
    • - Left side receives oxygenated blood form lungs and pumps to body tissues via systematic circuit.
  46. There are two receiving chambers of the heart; what are they and that does it receive?

    There are two pumping chambers of the heart; what are they and that does it pump?
    • - Right atrium : receives blood returning from systematic circuit
    • - Left atrium: receives blood returning from pulmonary circuits

    • - Right ventricle : pumps blood through pulmonary circuit.
    • - Left ventricle : pumps blood through systematic circuit.
  47. What can you use to describe the size of the heart? 
    There are four ways to state its Location.
    - size of a fist.

    • - In mediastinum between second rib and fifth inter coastal space.
    • - On superior surface of diaphragm.
    • - two thirds of heart to left of midsternal line.
    • - anterior to vertebral column, posterior to sternum.
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  48. What covers the heart and what does it do?

    Go into detail.
    - Pericardium protects, anchors to surrounding structures, and prevents overfilling.

    • Deep two-layered serous pericardium. 
    • Parietal layer : lines internal surface of fibrous pericardium
    • - Visceral layer (epicardium) on external surface of heart.
    • - Two layers are separated by fluid filled pericardial cavity (decreases friction)
  49. There are three layers of the heart WALL. State these
    • - Epicardium : visceral layer of pericardium 
    • - Myocardium : muscle cells and cardiac skeleton
    • - Endocardium : lines heart chamber
  50. What are the four chamber of the heart? 
    What separates the atria? 
    What separates the ventricles?
    • - Two superior atria and two inferior ventricles.
    • - Interatrial septum. Also includes fossa ovals which is the remnant of foramen oval of fetal heart. 
    • - Interventricular septum .
  51. Atria : receiving chambers. 
    Describe it.
    What does it contribute?
    What are the three veins that empty into the right atrium?
    How many pulmonary veins empty ingot he left atrium?
    • - small, thin walled.
    • - contributes little to propulsion of blood.
    • - Superior vena cava, Inferior vena cava, coronary sinus 
    • - Four.
  52. Ventricles : The Discharging Chambers 
    What does it contain the most of?
    There are four major parts; name them and define.
    • - most of the volume of the heart.
    • - Right ventricle : most of anterior surface
    • - Left ventricle : most of posteroinferior surface
    • - Trabeculae carneae : irregular ridges of muscle on walls
    • - Papillary muscles : anchors chordae tendineae.
  53. Ventricles : The Discharging Chambers 
    How is it different from the aorta?
    What is its actuality? 
    Right ventricles pumps what to where?
    Left ventricles "
    • - thicker walls than atria 
    • - actual pumps of the heart
    • - blood -> pulmonary trunk
    • - blood -> aorta
  54. Heart Valves :
    What does it ensure?
    How does it respond?
    What does AV stand for, how many and what does it do/consist of?
    • - ensures unidirectional blood flow through heart.
    • - opens and closes in response to pressure change
    • - Two atrioventricular (AV) valves. Prevents back flow into atria when ventricles contract.
    • Tricuspid valve (right AV valve). Mitral valve (left AV valve, bicuspid valve.) Chordae tendineae anchor cusps to papillary muscles and holds valve flaps in closed position.
  55. Heart valves : 
    What does SL stand for, how many and what does it do/consist of?
    • - Semilunar valves 
    • - prevents back flow into ventricles when ventricles relax. 
    • - Opens and closes in response to pressure changes.
    • - Aortic semilunar valve
    • - Pulmonary semilunar valve.
  56. Pathway of Blood through the heart via Pulmonary circuit.
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  57. Pathway of Blood through the Heart vis Systematic circuit.
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  58. Pathway of Blood through the Heart :
    What equalizes?
    What type of circulation does the pulmonary provide?
    What type of circulation does the Systematic provide?
    How does the anatomy of ventricles differ?
    • - Equal volumes of blood pumped to pulmonary and systematic circuits.
    • - short, low-pressure circulation
    • - long, high-friction circulation
    • - Left ventricle wall is 3X thicker than right. Pumps with greater pressure
  59. Microscopic Anatomy of Cardiac Muscle :
    How does it look like?
    What connects to what?
    Refer to the T-Tubules 
    Refer to mitochondria
    • - striated, short, branched, fat, interconnected, 1 or 2 central nuclei. 
    • - Connective tissue matrix (endomysium) connects to cardiac skeleton. 
    • - T tubules wide, fewer; SR simpler than in skeletal muscle
    • - Numerous large mitochondria (25-35% of cell volume)
  60. Microscopic Anatomy of Cardiac Muscle :
    What are the junctions between cells called? There are two major things related to them; what do they do?
    • - Intercalated discs.
    • - Desmosomes : prevent cells from separating during contraction
    • - Gap junctions : allows ions to pass from cell to cell; electrically couple adjacent cells which allows heart to behave as single coordinated unit.
  61. Cardiac Muscle Contraction :
    How does it differ to skeletal muscles?
    What does it not need?
    It can do something to the entire heart?
    All in one or none for all? 
    What does long absolute refectory periods do?
    • - 1% of cells have automaticity (autorhythmicity) 
    • - don't need nervous stimulation 
    • - can depolarize entire heart
    • - all cardiomyocytes contract as unit, or none do.
    • - Long absolute refectory period (250 ms) which prevents tetanic contractions.
  62. Cardiac Muscle Contraction :
    What are the similarities with skeletal muscle?
    • - depolarization opens few voltage-gated fast Na+ channels in sarcolemma. Membrane potential from -90 mV to +30 mV. Brief; Na channels close rapidly. 
    • - Depolarization wave down T-tubules -> SR to release Ca2+
    • - Excitation-contraction coupling occurs; Ca2+ binds troponin -> filaments slide.
  63. Heart sounds :
    What does the sound make and what is associated with it?
    What are heart murmurs?
    • - (lub dub).
    • - First, AV valves close; beginning of systole 
    • - Second, as SL valves closel beginning of ventricular diastole. 

    - Heart murmurs : abnormal hart sounds; usually indicate incompetent or stenotic valves.
  64. Mechanical events : The Cardiac Cycle 
    What is the cardiac cycle?
    What's another way to say contract/relax?
    • - Blood flow through the heart during one complete heartbeat : atrial systole and diastole followed by ventricular systole and diastole.
    • - Systole : contraction
    • - Diastole : relaxation
  65. Phases of Cardiac Cycle 
    Part 1?
    • 1. Ventricular filling - takes place in mid-to-late diastole 
    • - AV valves are open; pressure low
    • - 80% of blood passively flows into ventricles 
    • - Atrial systole occurs, delivering remaining 20%
    • - End diastolic volume (EDV) : volume of blood in each ventricle at end of ventricular diastole.
  66. Phases of Cardiac Cycle 
    Part 2?
    • 2. Ventricular systole 
    • - atria relaxes; ventricles begin to contract.
    • - Rising ventricular pressure -> closing of AV valves.
    • - Isovolumetric contraction phase (all valves are close)
    • - In ejection phase, ventricular pressure exceeds pressure in large arteries, forcing SL valves open. 
    • - End systolic volume (ESV) : volume of blood remaining in each ventricle after systole.
  67. Phases of the Cardiac Cycle 
    Part 3?
    • 3. Isovolumetric relaxation - early diastole
    • - ventricles relax; atria relaxed and filling 
    • - Backflow of blood in aorta and pulmonary trunk closes SL valves.
    • - When atrial pressure exceeds that in ventricles -> AV valves open; cycle begins again at step 1
  68. What are some factors that influence heart rate?
    • - Age (fetus has fastest HR)
    • - Gender (females faster than males)
    • - Exercise (increases HR)
    • - Body temperature (increases with increases temp.)
  69. What's the purpose of Blood Vessels?
    There are three components of a blood vessel. What are they and define
    - delivery system of dynamic structure that begins and ends at heart 

    • - Arteries : carry blood away from heart; oxygenated except for pulmonary circulation and umbilical vessels of fetus. 
    • - Capillaries : contact tissue cells; directly serve cellular needs.
    • - Veins : carry blood toward the heart
  70. What is the structure of Blood vessel walls?
    • - Lumen : central blood-containing space.
    • - The three wall layers in arteries in veins :(tunica intima, tunica media, and tunica externa)
    • - Capillaries : lined with endothelial cells.
  71. What's vasoconstriction and Vasodilation?
    • - Vasoconstriction : lumen diameter decreases as the smooth muscle contracts. 
    • - Vasodilation : lumen diameter increases as the smooth muscle relaxes.
  72. Tunica Intima : 
    What does it contain; How does it look like/ why?
    What is the layer related to this?
    - contains endothelium which lines lumen of all vessels. Continuous with endocardium; slick surface reduces friction. 

    - Subendothelial layer in vessels larger than 1 mm; connective tissue basement membrane.
  73. Tunica Media :
    What does it contain?
    Something controls something in here..? And why?
    • - smooth muscle and sheets of elastin 
    • - Sympathetic vasomotor nerve fibers control vasoconstriction and vasodilation of fibers. (Influence blood flow and blood pressure.)
  74. Tunica externa :
    a.k.a what?
    What does it do?
    What nourish what?
    • - tunica adventitia 
    • - collagen fibers protect and reinforce the vessel; anchor to surrounding structures.
    • - Contains nerve fibers, lymphatic vessels.
    • - Vasa vasorum of larger vessels nourishes external layer.
  75. Three groups of arteries, name them only.
    • - Elastic Artery 
    • - Muscular Artery 
    • - Arterioles
  76. Arterial System : Elastic Arteries 
    How does it look like?
    What does it make up?
    A large what offers what?
    How does it behave during vasoconstriction?
    What do they act as?
    • - large thick-walled arteries with elastin in all three tunics 
    • - aorta and its major branches 
    • - Large lumen offers low resistance 
    • - Inactive in vasoconstriction 
    • - Acts as pressure reservoirs - expands and recoils as blood ejected from heart
  77. Arterial System : Muscular Arteries 
    Where is located at?
    What's its purpose?
    How does it differentiate from all the other arteries?
    How does it behave during vasoconstriction?
    • - distal to elastic arteries 
    • - Delivers blood to body organs
    • - Thick tunica media with more smooth muscle.
    • - active in vasoconstriction
  78. Arterial System : Arterioles 
    How does it differentiate to the rest of the arteries?
    Where does it lead to?
    What does it control and what does it use to accomplish this?
    • - smallest of arteries 
    • - leads to capillary beds
    • - controls flow into capillary beds via vasodilation and vasoconstriction.
  79. Capillaries :
    What are they?

    Something helps capillaries do something...?
    Something allows only certain things to pass through?
    • - microscopic blood vessels 
    • - walls of thin tunica intima (in smallest one cell forms entire circumference.)
    • - Pericytes help stabilize their walls and control permeability 
    • - Diameter allows only single RBC to pass at a time.
  80. Capillaries :
    Found where?
    What does it provide?
    What are its functions?
    • - in all tissues except for cartilage, epithelia, cornea and lens of eye. 
    • - Provides direct access to almost every cell.
    • - Function : exchange of gases, nutrients, wastes, hormones, etc. between blood and interstitial fluid.
  81. There are three types of capillaries, state them only and know how they look like.
    • - Continuous
    • - Fenestrated 
    • - Sinusoid 

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  82. Continuous Capillaries :
    Where are they the most abundant in?
    What connects what?
    How do things pass?
    What's unique about them?
    • - abundant in skin and muscles.
    • - Tight junctions connect endothelial cells.
    • - Intracellular clefts allow passage of fluids and small solutes. 
    • - tight junctions complete, forming blood brain barrier.
  83. Fenestrated capillaries :
    Only some contain these.
    How do they differ to continuous capillaries?
    What are its functions? (found where?)
    • - some endothelial cells contain pores (fenestrations)
    • - More permeable than continuous capillaries.
    • - Function in absorption or filtrate formation (small intestines, endocrine glands and kidneys.)
  84. Sinusoid Capillaries :
    How are they unique compared to other capillaries?
    Describe the blood flow.
    Where is it only found in?
    What helps destroy what?
    • - Fewer tight junctions; usually fenestrated; larger intercellular clefts; large lumens.
    • - Blood flow sluggish - allows modification. (Large molecules and blood cells pass between blood and surrounding tissues.)
    • - Found only in the liver, bone marrow, spleen, adrenal medulla.
    • - Macrophages in lining to destroy bacteria.
  85. Capillary beds : 
    What's microcirculation?
    There are two types of vessels; what are they and describe them.
    - Microcirculation : interwoven networks of capillaries between arterioles and venules.

    • - 1. Vascular shunt : (metarteriole - thoroughfare channel), directly connects terminal arteriole and post capillary venule.
    • - 2. True Capillaries : 10 to 100 exchange vessels per capillary bed; branch off metaerteriole or terminal arteriole.
  86. Blood flow through capillary beds :
    Where does true capillary go?
    What helps regulate blood flow where?
    How is it regulated by?
    • - true capillaries normally branch from metartiole and rerun to thoroughfare channel. 
    • - Precapillary sphincters regulate blood flow into true capillaries. (Blood may go into true capillaries or to shunt.)
    • - Regulated by local chemical conditions and vasomotor nerves.
  87. Venous System : Venules 
    How are they formed?
    What do larger venules have?
    • - Formed when capillary beds unite. 
    • - Larger venules have one or two layers of smooth muscle cells.
  88. Veins : 
    How are they formed?
    How are they compared to corresponding arteries. 
    How is the pressure compared to arteries?
    • - Formed when venules converge 
    • - Have thinner walls, larger lumens compared with corresponding arteries. 
    • - Blood pressure lower than in arteries.
  89. Veins : 
    Why is adaptation important?
    Why do larger sizes offer?
    What are venous valves?
    What are the "popping" out veins called?
    • - ensure return of blood to heart despite low pressure. 
    • - Large diameter lumens offer little resistance.
    • - Venous valves prevent back flow of blood; most abundant in veins of limbs.
    • - Varicose veins.
  90. Physiology of Circulation : 
    Define Bloodflow. 
    How is it measured?
    When is it constant?
    How does it vary?
    • - Volume of blood flowing through vessel, organ or entire circulation in given period. 
    • - Measured as ml/min
    • - Relatively constant when at rest 
    • - Varies widely through individual organs, based on needs.
  91. Physiology of Circulation :
    Define Blood Pressure (BP).
    How is it expressed as?
    How is it measured?
    What keeps blood moving from ___ to ___ areas?
    • - Force per unit area exerted on wall of blood vessel by blood. 
    • - Expressed in mm Hg
    • - Measured as systematic arterial BP in large arteries near heart.
    • - Pressure gradient provides driving force that keeps blood moving from higher to lower pressure areas.
  92. Physiology of Circulation :
    Define resistance.
    What does it measure?
    There are three important sources of resistance, what are they?
    • - Opposition to flow 
    • - Measure of amount of friction blood encounters with vessel walls, generally in peripheral (systematic circulation)
    • - Blood viscosity, Total blood vessel length, blood vessel diameter.
  93. Resistance : Blood Viscosity 
    What is it?
    How does viscosity relate to resistance?
    • - The "stickiness" of blood due to formed elements and plasma proteins.
    • - Increased viscosity = increased resistance.
  94. Resistance : Blood vessel length 
    How does length relate to resistance?
    - Longer vessel = greater resistance encountered.
  95. Resistance : Blood vessel diameter 
    How does this differ to the other resistances? 
    What alter what?
    How does it vary?
    Give examples.
    • - Greatest influence on resistance.
    • - Frequent changes alter peripheral resistance.
    • - Varies inversely with fourth power of vessel radius. 
    • - ex : if radius is doubled, the resistance is 1/16 as much.
  96. Resistance :
    What is the major determinant of peripheral resistance?
    Something dramatically increases something when what happens? 
    What happens when there's a disruption in the laminar flow?
    • - Small diameter arterioles major determinants of peripheral resistance.
    • - Abrupt changes in diameter of fatty plaques from atherosclerosis dramatically increase resistance. 
    • - Disrupt laminar flow and cause turbulent flow. Irregular fluid motion -> increased resistance.
  97. Relationship between blood flow, Blood Pressure and Resistance : 
    What is directly proportional to what? Give the equation.
    What is inversely proportional to what? Give the equation.
    What is more important in influencing local blood flow and why?
    • - Blood Flow (F) directly proportional to Blood Pressure gradient (*triangle* P) a.k.a If P increases, blood flow speeds up.
    • - Blood flow inversely proportional to peripheral resistance (R) a.k.a If R increases, blood flow decreases : F = *triangle* P/R
    • - Peripheral Resistance is more important in influencing local blood flow because easily changed by altering blood vessel diameter.
  98. Systematic Blood Pressure:
    What is it?
    What happens when flow is opposed by resistance?
    Where is the systematic pressure highest; when does it decline; what's its measurement in the right atrium?
    Where does the steepest drop occur at?
    • - pumping action of heart generates blood flow. 
    • - Pressure results when flow is opposed by resistance. 
    • - Highest in aorta; declines throughout pathway; 0 mm Hg
    • - Steepest drop occurs in arterioles.
  99. Arterial Blood Pressure :
    It reflects two factors which are?
    What's Systolic pressure, Diastolic pressure and Pulse pressure?
    • - 1. How much the elastic arteries close to the heart can stretch.
    • - 2. The volume of blood forced into them at any time.
    • - Systolic pressure : pressure exerted in aorta during ventricular contraction.
    • - Diastolic pressure : lowest level of aortic pressure 
    • - Pulse pressure : difference between systolic and diastolic pressure *subtract em'*
  100. Arterial Blood Pressure :
    What's "MAP"?
    How do you calculate this?
    Pulse pressure and MAP ___ with ___ distance from heart. 
    What's the MAP of a BP = 120/80
    • - Mean arterial pressure : pressure that propels blood to tissues.
    • - MAP = diastolic pressure + 1/3 pulse pressure.
    • - Pulse pressure and MAP both decline with increasing distance from heart.
    • - BP = 120/80 ; MAP = 93 mm Hg
  101. Capillary Blood Pressure : 
    What's its range?
    Why is low capillary pressure desirable?
    • - Ranges from 17 - 35 mm Hg
    • - High BP would rupture fragile, thin-walled capillaries. Most very permeable, so even low pressure forces filtrate into interstitial space.
  102. Venous Blood Pressure :
    How is it change during cardiac cycle?
    What's the small pressure gradient?
    What causes low pressure?
    • - Changes little during cardiac cycle?
    • - about 15 mm Hg
    • - cumulative effects of peripheral resistance. (Energy of blood pressure lost as heat during each circuit.)
  103. Factors Aiding Venous Return : 
    What are the three factors aiding venous return and go into detail!
    • - 1. Muscular Pump : contraction of skeletal muscles "milks" blood toward heart ; valves prevent back flow.
    • - 2. Respiratory Pump : pressure changes during breathing move blood toward heart by squeezing abdominal veins as thoracic veins expand. 
    • - 3. Venoconstriction : under sympathetic control pushes blood toward the heart.
  104. Maintaing Blood Pressure : 
    What are the requirements? 
    These main factors influence blood pressure.
    • - Requirements : Cooperation of heart, blood vessels and kidneys; Supervision by brain.
    • - Main factors : Cardiac Output (CO); Peripheral Resistance (PR); Blood volume.
  105. Monitoring Circulatory Efficiency :
    There are four ways, name them and go into detail!
    • - Vital signs : pulse and blood pressure, along with respiratory rate and body temperature.
    • - Pulse : pressure wave caused by expansion and recoiled of arteries.
    • - Radial pulse : (taken at the wrist) routinely used.
    • - Pressure points : where arteries close to body surface. Can be compressed to stop blood flow.
  106. Measuring Blood Pressure :
    How do you measure Systematic arterial BP?
    • - Measured indirectly by auscultatory method using a sphygmomanometer. 
    • - Pressure increased in cuff until it exceeds systolic pressure in brachial artery. 
    • - Pressure released slowly and examiner listens for sounds of Korotkoff with a stethoscope.
  107. Measuring Blood Pressure :
    What is a normal systolic pressure?
    Diastolic pressure?
    • - Systolic pressure : normally less than 120 mm Hg, is pressure when sounds first occur as blood starts to spurt through artery. 
    • - Diastolic pressure : normally less than 80 mm Hg, is pressure when sounds disappear because artery no longer constricted; blood flowing freely.
  108. Variations in Blood Pressure :
    When do transient elevations occur?
    What can cause the BP to vary?
    • - posture, physical exertion, emotional upset, fever.
    • - Age, sex, weight, race, mood, and posture
  109. Alterations in Blood Pressure :
    What's hypertension?
    How much pressure is it for hypertension?
    What's prehypertension?
    When does this happen and to whom does it usually happen?
    • - High Blood Pressure
    • - sustained elevated arterial pressure of 140/90 or higher.
    • - if values elevated but not ted in hypertension range.
    • - during fever, physical exertion and emotional upset; persistent in obese people.
  110. Homeostatic Imbalance : Hypertension 
    What can a prolonged hypertension cause? 
    Why does this happen?
    What accelerates?
    • - heart failure, vascular disease, renal failure, and stroke.
    • - Heart has to work harder -> myocardium enlarges, weakens, becomes flabby.
    • - Accelerates atherosclerosis
  111. Primary of Essential Hypertension :
    What are some risk factors?
    How can you control/ prevent this?
    • - heredity, diet, obesity, age, diabetes mellitus, stress and smoking.
    • - Restrict salt, fat, cholesterol intake.
    • Increase exercise, lose weight, stop smoking.
    • Antihypertensive drugs.
  112. Homeostatic Imbalance : Hypertension 
    How often does secondary hypertension occur?
    What causes it?
    How can it be treated?
    • -Less common.
    • - obstructed renal arteries, kidney disease and endocrine disorders like hyperthyroidism and Cushing's syndrome.
    • - Treatment focuses on correcting underlying causes.
  113. Alterations in Blood Pressure :
    What's Hypotension? 
    What's the Blood pressure measurement?
    Is it serious?
    What is it associated with?
    • - low blood pressure 
    • - below 90/60 mm Hg
    • - Usually not a concern (only if it leads to inadequate blood flow to tissues.
    • - Often associated with long life and lack of cardiovascular illness.
  114. Blood Flow through body tissues :
    What is tissue perfusion involved in?
    • - Delivery of O2 and nutrients to, and removal of wastes from tissue cells.
    • - Gas exchange (lungs)
    • - Absorption of nutrients (digestive track)
    • - Urine formation (Kidneys)
  115. Velocity of Blood flow :
    When does it change?
    What is it inversely related to?
    Where is it fastest, slowest and when does it increase?
    What does slow capillary flow allow?
    • - as it travels through systematic circulation.
    • - total cross-sectional area.
    • - Aorta ; Capillaries ; Veins.
    • - adequate time for exchange between blood and tissues.
  116. Active or exercise hypermia
    • -blood flow increases in direct proportion to metabolic activy
    • -muscle blood flow can increase 10x
Card Set:
Bio 2011 Midterm 2
2014-02-21 20:25:07
Bio 2011 Midterm
Bio 2011 Midterm 2
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