Lecture 5: muscle, blood, immune Flashcards
Muscle, blood, & immunology (246 cards)
1
Q
1) Is skeletal muscle voluntary?
2) Describe its fibers
3) What is it usually attached to?
A
1) Yes
2) Striated, tubular, and multi-nucleated
3) The skeleton
2
Q
1) Is smooth muscle voluntary?
2) Describe its fibers
3) Where is it usually found?
A
1) Involuntary
2) Non-striated, spindle shaped, uninucleated
3) Usually covering wall of internal organs
3
Q
1) Is cardiac muscle voluntary?
2) Describe its fibers
3) Where is it usually found?
A
1) Involuntary
2) Striated, branched, uninucleated
3) Only covering walls of the heart
4
Q
Is skeletal muscle always voluntary?
A
No; both voluntary and reflex control
5
Q
1) What kind of movement does skeletal muscle do?
2) What is abundant in skeletal muscle cells?
3) What two things do they provide?
A
1) Both voluntary and reflex control
2) Abundant mitochondria
3) Movement and production of heat
6
Q
How is skeletal muscle organized?
A
Myofibrils-> Muscle Fiber-> Muscle fascicle -> Skeletal Muscle
7
Q
Skeletal muscle:
1) What does endomysium bind?
2) What does perimysium bind? What is in this layer?
3) What does epimysium bind?
A
1) Muscle fibers
2) Fascicles; nerves and blood vessels
3) Muscles
8
Q
1) What do protein filaments of skeletal muscle do?
2) What are the two kinds of filaments?
3) What two regulatory proteins are involved in skeletal muscle?
A
1) Provide the architecture and contractile machinery
2) Thick (myosin) and thin (actin) filaments
3) Troponin and tropomyosin
9
Q
1) What are sarcomeres in skeletal muscle?
2) What do they create?
A
1) Structural and functional unit of actin and myosin; linked muscle contraction
2) Dark and light bands (striated appearance)
10
Q
1) What maintain skeletal muscle?
2) List them
A
1) Cytoskeletal proteins
2) A band, H zone, M line, I band, & Z line
11
Q
What makes up the A band?
A
Overlapping actin and myosin
12
Q
1) Where is the H zone?
2) What filament(s) is/ are here?
A
1) Middle of A band, lighter area
2) Only myosin filaments (thick) reach here
13
Q
What is the M line made of?
A
Supporting proteins holding myosin filaments
14
Q
What is the I band?
A
Remaining portion of thin filaments
15
Q
1) Where is the Z line?
2) What is the area between Z lines called?
A
1) Middle of I band
2) A sarcomere; the functional unit of skeletal muscle
16
Q
1) What is the functional unit of skeletal muscle?
2) How is it defined?
A
1) Sarcomere
2) Area between Z lines
17
Q
What forms each thick filament [of skeletal muscle]?
A
Hundreds of myosin proteins
18
Q
1) Each myosin molecule contains what?
2) Describe what it looks like
A
1) Two identical subunits shaped like golf clubs
2)
-Tails are intertwined, heads project outward at regular intervals
-Tails project towards center and can bend at “neck” or tail
19
Q
What do the heads that make up a myosin molecule form?
A
Cross bridges between thick and thin filaments
20
Q
What are the two crucial sites of each myosin molecule’s head?
A
1) Actin-binding site
2) Myosin ATPase site
21
Q
What 3 things make up thin filaments? [of skeletal muscle]
A
1) Actin
2) Tropomyosin
3) Troponin
22
Q
1) What is actin shaped like?
2) What is its significance [in skeletal muscle]?
A
1) Spherical and twisted into actin helix
2) Binding site for myosin cross bridge
23
Q
1) What is tropomyosin shaped like?
2) What does it do [in skeletal muscle]?
A
1) Threadlike
2) Wraps around helix and covers binding sites
24
Q
What makes up troponin?
A
3 small spherical subunits
25
1) When skeletal muscle is at rest, what is troponin doing?
2) At rest, what blocks actin binding sites?
1) Not bound to calcium
2) Tropomyosin ribbon
26
What happens when calcium binds to troponins [in skeletal muscle]?
Slips the ribbon, which exposes myosin binding site
27
What do troponin and tropomyosin act as?
Regulatory proteins (determine if muscle can contract or not)
28
1) What do cross bridges extend from and towards?
2) What do they project from, and in how many directions?
1) Extend from thick myosin filaments towards actin
2) Project from each myosin filament in six directions
29
A single muscle fiber can contain:
____ billion thick myosin filaments
____ billion thin actin filaments
16 billion thick, 32 billion thin
30
1) Electrochemical events at a neuromuscular junction [of skeletal muscle] link what?
2) What is key here?
1) Nerve action potentials to the skeletal muscle action potentials that trigger contraction
2) Calcium
31
1) What branches into the NMJ (neuromuscular junction)?
2) What does it contain?
1) Motor neuron
2) Acetylcholine
32
Intracellular _________ concentration is the key variable in switching muscle between relaxation and contraction
calcium
33
1) What are the Transverse tubules (T tubules)?
2) What direction do they go?
3) What do they allow?
1) Continuations of the surface membrane
2) Dip down perpendicular to A and I bands
3) AP’s on surface to spread down
34
1) What is the sarcoplasmic reticulum?
2) What do its lateral sacs do?
1) Modified ER that surrounds myofibrils like a sleeve
2) Store Ca+ that releases with AP’s down T tubules
35
What 5 things happen when the T tubule of skeletal muscle transmits an AP?
1) SR releases Ca+
2) Ca+ moves troponin and tropomyosin out of the way of the actin binding sites
3) Actin links with myosin cross bridges
4) Sarcomeres shorten
5) Muscle contracts
36
What is the process between the T tubule transmitting an action potential and a muscle contracting called?
Excitation-contraction coupling
37
What happens during muscle contraction [microscopically]?
Cross-bridge binding and bending pulls the actin filaments inward (via the sliding filament mechanism)
38
Describe how the sliding filament mechanism works (3 steps)
1) Thin (actin) filaments slide inwards over stationary thick filaments
2) Slide over sarcomere’s A band, pulling Z lines closer
3) Sarcomeres shorten throughout length of muscle, causing contraction
39
What happens right after the sliding filament mechanism [of skeletal muscle contraction]? What does this allow for
Ca+ pulls regulatory proteins “out of the way”; this allows for myosin to bind with actin
40
What does myosin do after it binds to actin?
It's a motor protein, so it "walks” along actin filament, pulling it inwards
41
True or false: Myosin stays stationary, but bends at the tail and neck
True; the helix itself stays still
42
1) What is myosin bending at the tail and neck called?
2) How many times does this happen during muscle contraction?
1) Power stroke
2) Repeated power strokes are needed
43
1) All cross bridges stroke _______ so that all 6 thin filaments are pulled
2) Is this done simultaneously? Describe.
3) Why is it done simultaneously or not simultaneously?
1) inward
2) No; some cross bridges are “holding on” while others are “letting go”
3) So the sarcomere does not slip back to resting position in the middle of a stroke
44
Muscle relaxation is facilitated by what?
Calcium’s return to the lateral sacs
45
What does SERCA pump stand for?
Sarcoplasmic Endoplasmic Reticulum Ca+ ATPase pump
46
1) What does the SERCA pump do? (2 things)
2) What happens after it does its job?
1) 1. Transports Ca+ back to lateral sacs
2. Troponin-tropomyosin complex slips back into blocking position
2) Thin filaments return to resting position
-Sarcomeres widen
-Muscle relaxes
47
What happens to the sarcomeres when the thin filaments return to resting position and the muscle relaxes?
They widen
48
What are the 3 types of contraction? Describe and give an example of each
1) Isotonic
-Muscle changes length, load remains constant
-Ex: Lifting weights
2) Isokinetic
-Muscle changes length, velocity remains constant
-Ex: riding elliptical
3) Isometric
-Muscle prevented from changing length, tension develops
-Ex: Holding a weight with your arm still
49
Explain the difference between concentric and eccentric muscle contractions
1) Concentric: Muscle shortens
2) Eccentric: Muscle lengthens
50
True or false: Not all muscle contractions move bone
True
51
1) Give an example of muscles that are not attached to a bone at the free end
2) Describe how these muscles work and what they do
1) Contractions in the tongue
2) Maneuver the unattached end; facilitate speech and eating
52
1) Where do the external eye muscles attach?
2) What are sphincters?
1) Attach to the skull at the origin and insert onto the eye
2) Rings of muscle that contract to close an opening
53
1) Define asynchronous recruitment
2) What affect does this have?
1) When a motor unit is activated all fibers contract, but only a portion of the muscle's motor units are recruited at a time
2) Motor unit activity is alternated like shifts at a factory; delays muscle fatigue
54
1) When is asynchronous recruitment possible?
2) Why?
1) Only possible for submaximal contractions
2) Maximal contractions recruit all motor units (by definition)
55
What does asynchronous recruitment explain?
Why you can hold a light object for a long time, but a heavy object for a short time
56
What causes a stretch reflex?
Muscle spindles sense a change in length
57
What are the 3 classes of motor activity? Give an example of each
1) Reflex: Patellar reflex
2) Voluntary: Choosing to move your arm
3) Rhythmic: Walking or chewing
58
What are the 3 types of skeletal muscle fibers?
What are the main differences between the 3?
1) Slow-oxidative (type I)
2) Fast-oxidative (type IIa)
3) Fast-glycolytic (type IIx)
-Speed of contraction and their enzymatic machinery
59
True or false: Most muscles are a mixture of the three fiber types
True
60
1) What are slow-oxidative (type I) muscle fibers good for?
2) Give 2 examples of where they're prolific
1) Low intensity contractions for longer periods without fatigue
2) Back and leg muscles
61
1) What are fast-glycolytic (type IIx) muscle fibers good for?
2) Give an example of where they're prolific
1) Rapid forceful movements
2) Arm muscles
62
What does having more of one fiber type than another suggest?
Individuals who have different amounts of one fiber type over another might be better suited for different athletic activities
63
1) How much do muscle fibers adapt to demands placed on them?
2) What are two ways in which they adapt?
1) Considerably
2) Oxidative capacity and hypertrophy
64
1) How is oxidative capacity of muscles increased? Why?
2) When oxidative capacity increases, what two things increase in number?
3) Do muscles change in size when this happens? If not, what do they do?
1) Regular aerobic endurance exercise; promotes metabolic changes in oxidative fibers
2) Mitochondria and capillaries increase
3) Utilized O2 more efficiently, do not change in size
65
1) What causes hypertrophy?
2) What increases when this happens?
3) What does this allow for?
1) Regular anaerobic short-duration high-intensity exercise
2) Diameter of fast-glycolytic fibers increase
3) More area for cross-bridge interaction = greater strength
66
1) True or false: muscle cells can divide to replace lost cells.
2) Explain what this causes
1) False; cannot divide
2) Limited capacity for repair
67
Muscle stem cells that are close to muscle surface are called what? Are they abundant?
Satellite cells; small amount
68
1) What do satellite cells do?
2) What are their limitations?
1) Local damage activates them, and this gives rise to myoblasts which can fuse to form a muscle fiber
2) Cannot repair extensive damage
69
When satellite cells are activated to repair damage, what do the remaining fibers often do?
Remaining fibers will often hypertrophy to compensate
70
1) Muscle that is not used loses _______ and _______ content
2) What does this do to the muscle?
1) actin and myosin
2) Fibers become smaller
71
What are 3 causes of muscle atrophy? Explain each
1) Disuse: muscle not used, nerve is intact (bedrest, casting)
2) Denervation: nerve supply lost (severed nerve)
3) Age-related atrophy: natural motor neuron loss beginning around 40yo
72
1) What fibers are most affected by age-related atrophy?
2) What occurs during age-related atrophy?
3) Why does this happen?
4) What can delay this type of atrophy?
1) Fast-glycolytic fibers
2) Reduced rates of protein synthesis
3) Lower rates of growth hormone, testosterone, and IGF-1
4) Diet and training
73
How do cardiac and smooth muscle contract? Describe
Similarly to skeletal muscle:
1) Actin filaments slide over myosin filaments after Ca+ rise
2) Use ATP for cross-bridge cycling
74
True or false: smooth and cardiac muscle have unique characteristics and vary in their structure, organization, and mechanisms for excitation
True
75
1) Describe smooth muscle cells
2) Where are they found?
3) What does smooth muscle do?
1) Small and unstriated
2) In walls of hollow organs and tubes
3) Contractions regulate flow of contents
76
1) Do skeletal muscle cells extend the length of the muscle? What about smooth muscle cells?
2) How are smooth muscle cells arranged?
1) Unlike skeletal muscle, smooth muscle cells do not extend the length of the muscle
2) Not arranged in sarcomeres; groups of cells are arranged in sheets
77
1) What protein is missing from smooth muscle?
2) What keeps actin and myosin from binding all the time in smooth muscle? Describe this structure.
3) What must happen to this structure for actin and myosin to bind?
1) Troponin
2) Actin and myosin binding is prevented by protein chains that act like necklaces over myosin heads; light chains
3) Must be phosphorylated
78
How is smooth muscle divided into categories? List those categories
According to pattern of contractile activity; tonic and phasic
79
1) When is phasic smooth muscle contracted?
2) Where is it found?
1) Contracts in bursts
2) Hollow organs that push contents, like digestive organs
80
1) When is tonic smooth muscle contracted?
2) Where is it found?
1) Usually contracted to some degree at all times, but resting tone that can incrementally increase or decrease
2) Arteriole walls
81
True or false: Smooth muscle is typically only parasympathetically innervated
False; typically by both branches of the autonomic nervous system
82
1) Do smooth muscles vary in their sensitivity to autonomic NTs?
2) Explain your answer
1) Yes; sensitive to varying degrees and in varying ways to autonomic neurotransmitters
2) Depends on distribution of cholinergic and adrenergic receptors
83
True or false: Cardiac muscle is only found in heart
True
84
Name 3 things skeletal and cardiac muscle have in common
1) Striated
2) Filaments organized into bands
3) Contain troponin and tropomyosin
85
Name 2 things smooth and cardiac muscle have in common
1) Have gap junctions that enhance spread of action potentials
2) Innervated by autonomic system
86
Name 2 characteristics unique to cardiac muscle
1) Fibers joined in branching network
2) Action potentials last much longer after depolarizing
87
1) What does blood provide the ability to do?
2) What does it play a major role in?
1) To transport viral components to the body
2) Immunity
88
1) What percent of body weight does blood make up?
2) How much is this in liters?
3) What type of tissue is blood?
1) Represents 6-8% of total volume weight.
2) 5L in females, 5.5L in males.
3) Type of specialized connective tissue
89
What makes up blood?
Three cellular elements suspended in plasma:
1) Erythrocytes (RBCs)
2) Leukocytes (WBCs)
3) Thrombocytes (platelets)
90
1) Describe the viscosity of blood
2) Compare blood's viscosity to that of water
3) When is the viscosity of blood decreased?
1) Blood is viscous
2) 3.5-5.5 x that of H2O
3) Decreased viscosity seen with anemia
91
What does a CBC tell you?
The number and types of cells in the blood
92
1) What keeps the components of blood mixed?
2) What does blood look like when in a tube?
1) Movement of blood keeps components “mixed”
2) Heavier components settle, plasma rises
93
1) What is hematocrit (Ht, HTC) ?
2) What is the average in both males and females?
1) The percent volume of red blood cells per volume of whole blood
2) 42% avg in females, 45% for males
94
What makes up blood's "buffy coat"? What percent of blood is this?
WBCs and platelets; less than 1% of blood volume
95
1) When does plasma become serum?
2) Plasma is about ______% water
1) Plasma becomes serum after the removal of clotting factors
2) 90% water
96
1) What makes up 1% of plasma's weight?
2) Give examples
1) Inorganic substances
2) Electrolytes (Na+, Cl-, HCO3-, K+, Ca+)
97
1) What makes up 99% of plasma's non-water weight?
2) What makes up most of this category?
3) What are the 4 other groups of things in this category?
1) Organic substances
2) Mostly plasma proteins
3)
-Nutrients: glucose, amino acids, lipids, vitamins
-Waste: creatinine, bilirubin, urea
-Gases: O2, CO2
-Hormones
98
What synthesizes plasma proteins?
The liver
99
What are the 3 groups of plasma proteins? List their categories if they have any
1) Albumins
2) Fibrinogen
3) Globulins (alpha, beta, gamma)
100
1) What is the most abundant plasma protein? What percent of proteins is this?
2) What does this protein do?
1) Albumins; 60%
2) Bind substances that are poorly water-soluble for transport
101
What does fibrinogen do?
It's a key factor in blood clotting
102
1) What do alpha and beta globulins do?
2) What are they heavily involved in?
3) What are gamma globulins?
1) Bind substances for transport, but are highly specific
2) Clotting
3) Gamma globulins are immunoglobulins (antibodies)
103
True or false: globulins serve as precursor molecules waiting to be activated
True
104
1) Name 3 lipids found in plasma
2) What does a blood lipid profile tell you?
1) Cholesterol, phospholipids, and triglycerides
2) Total cholesterol, LDL, HDL and triglycerides
105
Which lipid found in plasma is a precursor for steroid hormone synthesis?
Cholesterol
106
1) Erythrocytes consist mainly of what? Describe this substance
2) What is the primary function of erythrocytes?
1) Hemoglobin, a unique pigment containing heme group in which oxygen binds to iron atoms
2) Transporting O2
107
What 3 features of RBCs make them ideal for transporting oxygen?
1) Biconcave shape
2) Flexible membrane
3) Contain hemoglobin
108
1mL of blood contains avg ______________RBCs
5 billion
109
1) What is the only place hemoglobin is found?
2) What percent of oxygen in blood is bound to hemoglobin?
3) Where is the rest of the oxygen in blood?
1) In RBCs
2) 98.5%
3) Dissolved in plasma
110
What are the 2 parts of hemoglobin? Describe each
1) Heme groups: 4 iron-containing groups bound to the globins
2) Globin: 4 folded polypeptide chains
111
1) Why do RBCs lack a nucleus or organelles?
2) How many hemoglobins (HgB) are found in one RBC? How many O2 molecules?
1) Maximize Hgb
2) 250 million Hgb; 1 billion O2
112
What are the two main enzymes within mature RBCs? Describe what each does.
1) Glycolytic enzymes: Needed to power transport mechanisms within the cell
2) Carbonic anhydrase
-Converts CO2 to bicarbonate (“bicarb”) (HCO3)
-Primary transport form of CO2
113
1) What is the primary transport form of CO2?
2) What is needed to power transport mechanisms within the cell?
1) Carbonic anhydrase
2) Glycolytic enzymes
114
1) What happens to RBC components when they die?
2) Can RBCs repair or divide? Why?
1) RBC components are recycled
2) No DNA/RNA, cannot repair or divide
115
1) What is the average lifespan of an RBC?
2) Why? (2 reasons)
1) Avg lifespan 120 days
2)
a) Runs out of its initial supplies
b) Plasma membrane gets worn out from squeezing through capillaries
116
Where do most RBCs rupture? Why?
Spleen contains narrow capillary network where most RBCs finally rupture
117
Changes in erythrocyte morphology gives us insight into what?
Specific blood disorders
118
1) Formation of new RBCs occurs where?
2) What is this the source of?
1) In red bone marrow
2) All blood cells
119
1) Most bones of children are filled with what?
2) What is this gradually replaced by?
1) Red bone marrow
2) Fatty yellow bone marrow
120
1) Where is red bone marrow found in adults?
2) What does it produce besides RBCs?
1) Sternum, ribs, pelvis, proximal long bones
2) Leukocytes and platelets
121
1) What do the kidneys secrete? When?
2) What does this stimulate?
1) Erythropoietin (EPO) upon detecting low O2
2) Stimulates red marrow
122
Rate of erythropoiesis can be increased up to _______ times normal levels to replace blood after massive loss
6
123
As an RBC nears maturation, what happens?
Nucleus and organelles are extruded and Hgb is synthesized
124
1) What is not having enough RBCs called?
2) What does this lead to?
3) What are these two things combined called?
4) What are some causes of low RBCs?
1) Low hematocrit
2) Decreased O2 capacity
3) Anemia
4) Decreased EPO, increased blood loss, deficient Hgb
125
What are the 6 types of anemia? Give examples of each
1) Nutritional: dietary deficiency, especially iron (most common)
2) Pernicious: inability to absorb B12
3) Aplastic: bone marrow fails to produce RBCs, can be due to toxic chemicals, radiation, cancer
4) Renal: inadequate EPO due to kidney disease
5) Hemorrhagic: blood loss
6) Hemolytic: rupture of circulating RBCs
126
1) What is hemolytic anemia?
2) What is polycythemia?
1) Increased rupture of circulating RBCs
2) Too many RBCs, elevated hematocrit
127
Name two causes of hemolytic anemia, define them, and explain why they cause it
1) Malaria: Infectious disease caused by parasites transmitted by mosquitos
-Invade RBCs and multiply, causing them to rupture and invade more RBCs
2) Sickle cell disease: Genetic defect in shape of RBCs
-Deformed RBCs can clump together, blocking vessels and causing pain
-Shape causes them to be destroyed more easily.
128
Name the two types of polycythemia, and define them and describe why they happen
1) Primary polycythemia: Excessive, uncontrolled rate of erythropoiesis in red marrow
-Hematocrit up to 80%
-No extra O2 benefit because far exceeds upper limit of max capacity for O2 delivery
2) Secondary polycythemia: Adaptation in response to prolonged O2 reduction
-People living at high altitudes, chronic lung disease, cardiac failure
129
What is a form of relative "polycythemia"? Why?
Dehydration; because plasma volume smaller but RBC count still normal
130
1) Blood types depend on what?
2) Define this
1) Surface antigens on erythrocytes
2) Antigen: large complex molecule that triggers WBC to produce antibodies against them, destroying the antigen
131
List the different antigens that can be found on RBCs
Human erythrocytes have inherited antigens of A, B, or both A and B, or lack of AB surface antigens (O)
132
Type A blood contains _______ antibodies
Type B blood contains _______antibodies
1) anti-B
2) anti-A
133
Type AB blood contains __________ antibodies
Type O blood contains ___________ antibodies
1) no
2) anti-A and anti-B
134
1) Define transfusion reaction
2) What two things interact during a transfusion reaction?
1) Exposure to incompatible blood
2) Recipient’s plasma antibodies vs donor’s erythrocyte antigens
135
1) What is happening during a transfusion reaction?
2) What does this cause?
3) What is the worst case scenario?
1) Agglutination reaction (clumping) and hemolysis of RBCs
2) Blocks vessels, released Hgb can block kidneys causing acute kidney failure
3) Can be fatal
136
True or false: Type O erythrocytes have no A or B antigens and can be donated to anyone (universal donor) but can only receive type O blood
True
137
1) What antibodies do type AB individuals have?
2) What blood can they accept?
3) Who can they donate to?
1) No anti-A or anti-B antibodies
2) Either type of blood (universal recipient)
3) Can only donate to other AB individuals
138
1) What is Rh factor?
2) Do Rh- people always have antibodies against this? Explain.
1) Erythrocyte antigen first discovered in rhesus monkeys
2) Antibodies to the antigen do not occur naturally; developed after first exposure in Rh- individuals to Rh+ blood
139
1) Rh+ can have __________blood
2) Rh – can have _______ blood
1) Rh+ can have Rh + or Rh – blood
2) Rh – can only have Rh – Blood
140
1) What are thrombocytes also called?
2) Where do they come from?
1) Platelets
2) Shed from megakaryocytes
141
1) How long do platelets last? What happens when they stop working?
2) What causes the body to create more of them?
1) 10d; removed by macrophages
2) Liver produces thrombopoietin which increases megakaryocytes
142
1) Do thrombocytes have nuclei or organelles? Why?
2) What proteins do thrombocytes have? Why?
3) What are these proteins important in?
1) Lack nuclei, but have organelles and cytosolic enzymes for generating energy and synthesizing secretory products
2) High concentration of actin and myosin, enabling contraction
3) Important for hemostasis (stopping bleeding)
143
Name the 3 steps of hemostasis
1) Vascular spasm: Myogenic contraction
2) Formation of platelet plug
3) Blood coagulation (clotting)
144
1) What does step one of hemostasis, vascular spasm, do?
2) When does this happen?
3) What causes this?
4) How does it do its job?
1) Reduces blood flow through injured vessel
2) Torn blood vessel immediately constricts
3) Possibly through paracrine release from endothelial lining
4) Opposing ends of vessel are pressed together, adhering to each other and sealing the vessel
145
True or false: Platelets normally do not adhere to smooth endothelial lining but will stick to damaged vessels
True
146
1) What protein allows for platelet plug formation? How?
2) What activates this and what does this help with?
1) Von Willebrand factor (vWF); a plasma protein that adheres to exposed collagen that is normally under the endothelial lining
2) Collagen activates the platelets which reorganize their actin to become “spiky”; helps to adhere to collagen and other platelets
147
1) What does Von Willebrand factor (vWF) have? What does it serve as?
2) What does it form?
1) Binding sites to which platelets attach, serves as bridge between platelets and vessel wall
2) Foundation of platelet plug
148
During platelet plug formation, what do activated platelets do? What does this cause?
Activated platelets also release chemicals which make nearby platelets stickier which causes them to become activated and so on
149
What two chemicals are released by activated platelets during platelet plug formation? Define each and what they do
1) Thromboxane A2: Eicosanoid paracrine similar to prostaglandins
2) ADP: already know what this is
-Stimulates release of prostacyclin and nitric oxide from nearby normal endothelium; this profoundly inhibits platelet aggregation and preventing platelet plug from growing forever
150
What inhibits platelet aggregation and prevents platelets from growing forever?
ADP's stimulation of the release of prostacyclin and nitric oxide
151
1) Define coagulation
2) What proteins are involved in this? What do they do?
3) How do these proteins cause coagulation?
1) Transformation of blood from liquid to a solid gel
2) Thrombin converts fibrinogen into fibrin, an insoluble threadlike molecule
3) Fibrin adheres to damaged vessel and forms net that traps cells, including aggregating platelets
152
1) What is fibrinogen?
2) How far can it be stretched before it breaks?
1) A plasma protein produced by the liver
2) 4x length before it breaks
153
What does thrombin do in addition to catalyzing the conversion of fibrin? (3 things)
1) Activates factor XIII (“fibrin-stabilizing factor”) which stabilizes the fiber into a clot
2) Acts in a positive-feedback loop facilitating its own formation
3) Enhances platelet aggregation
154
Why is thrombin itself not always initiating clotting?
Because it exists in plasma inactivate form called prothrombin
155
What is Factor X?
Activated plasma protein that converts prothrombin to thrombin
156
1) Altogether, _____ plasma clotting factors participate in converting fibrinogen to fibrin
2) Most of them are synthesized by the ______
3) Their combined reactions is called the _____________
1) 12
2) liver
3) clotting cascade
157
What two things can trigger the coagulation cascade?
Intrinsic or extrinsic pathway
158
1) What does the intrinsic pathway cause?
2) Where are its elements found?
3) What is it and when does it begin?
1) Clotting within damaged vessels
2) Present in blood
3) A 7 step process that begins when factor XII comes into contact with exposed collagen
159
1) How many steps is the extrinsic pathway?
2) Where are its elements found? What happens?
1) Only requires 4 steps
2)
-Tissue factors come into contact with tissue thromboplastin, which is external to blood
-Damaged tissue releases tissue thromboplastin which activates factor X and bypasses preceding steps
160
True or false: A clot is not a permanent solution, stops the bleeding until tissue is repaired
True
161
Aggregated platelets secrete what to aid in healing?
A chemical that promote fibroblasts (fiber formers) in nearby connective tissue
162
1) What dissolves blood clots after coagulation?
2) What activates this?
3) What removes the dissolved blood clots?
1) Plasmin, a fibrinolytic enzyme, dissolves the clot
2) Activated from plasminogen by tPA (tissue plasminogen activator) in a reaction cascade that involves many of the factors
3) Phagocytic WBCs
163
1) What is another name for leukocytes? What are leukocytes?
2) What do WBCs have an ability to do that RBCs don't?
1) WBCs, mobile immune defense units
2) Can exit blood by amoebalike behavior
164
List the 5 types of WBCs
1) Neutrophils
2) Eosinophils
3) Basophils
4) Monocytes
5) Lymphocytes
165
1) What is in the A band of a sarcomere?
2) What is in the middle of the A band? What is found here?
1) Overlapping actin and myosin
2) H zone; only myosin
166
Calcium’s return to the lateral sacs facilitates what?
Muscle relaxation
167
What type of contraction is occurring when muscle changes length and produces movements of a constant speed ?
Isokinetic
168
Why don't all muscle fibers in an area contract during a movement?
To prevent fatigue from happening too quickly
169
Chewing is an example of what kind of motor activity?
Rhythmic
170
What type of skeletal muscle fibers use more glucose as fuel instead of oxygen?
Fast-glycolytic (type IIx)
171
What type of muscle fibers fatigue the slowest?
Slow-oxidative (type I)
172
What type of runner can you expect to have more hypertrophy, long distance or short distance?
Short distance
173
Muscles don’t replace themselves, so what happens instead?
Nearby muscles around hypertrophy to make up for it
174
What two things are found in abundance in smooth muscles? Why?
Collagen and elastin; to stretch
175
What type(s) of muscle have filaments organized into bands?
Both skeletal and cardiac
176
Is a liquid with a high viscosity very watery or thick?
Thick
177
What is whole blood?
Blood in the same state it's in in the body
178
Why is blood loss a concern for patients with poorly functioning livers?
Because their liver probably isn't making enough fibrinogen
179
How can you tell if a patient has too much cholesterol or other plasma lipids (dyslipidemia)?
You can see their plasma will be more opaque/ white when spun in a centrifuge
180
True or false: hemoglobin is only found in RBCs
True
181
What line of pluripotent stem cells makes RBCs?
Mesoderm
182
If your kidney doesn't function, what could you expect to see? Why?
Anemia due to low EPO secretion
183
If someone has pernicious anemia, what organ is likely not working properly?
Stomach (involved in B12)
184
What two things keep platelets from growing forever?
Prostacyclin and nitric oxide (both released by ADP)
185
Is thrombin made via positive feedback loop or negative?
Positive
186
What do the intrinsic and extrinsic pathways of coagulation have in common?
They enter the common pathway
187
What is the first step of the common pathway of coagulation?
Factor X
188
How can leukocytes be divided into two groups? What are those two groups?
Depending on nuclei and granules; Polymorphonuclear Granulocytes and Mononuclear Agranulocytes
189
1) Describe polymorphonuclear granulocytes
2) What are granules?
3) Give 3 examples of polymorphonuclear granulocytes
1) Have multiple nuclei, cytoplasm contains membrane-enclosed granules
2) Granules are stored chemical that are released when triggered for variety of functions
3) Neutrophils, eosinophils, basophils
190
1) Describe the composition of mononuclear agranulocytes
2) Give 2 examples
1) Single nucleus, few granules
2) Monocytes and lymphocytes
191
1) What do neutrophils do?
2) What is neutrophilia highly indicative of?
1) Phagocytic specialists, engulf bacteria
2) Bacterial infection
192
1) What do the granules of neutrophils contain? What do these do?
2) What can they release granules into? How?
1) Antimicrobial proteins that fuse and kill bacteria once engulfed
2) ECF by exocytosis (“degranulation”)
193
1) Increased circulation of eosinophils is associated with what?
2) Give examples
1) Allergic conditions
2) Asthma, hay fever
194
What can eosinophils do regarding parasites?
Cannot engulf parasites, but attach to it and secrete substances that kill it
195
1) What is the least numerous leukocyte?
2) What is it structurally similar to?
3) What do they do? What else does this?
1) Basophils
2) Mast cells which never circulate in blood but are dispersed in connective tissue
3) Both mast cells and basophils synthesize and store histamine and heparin
196
1) What do monocytes and neutrophils have in common?
2) When are monocytes released and where do they go?
3) How long do monocytes last? What shortens their lifespan?
1)Both are phagocytes
2) Released while immature and settle into tissues where they mature into macrophages
3) Lasts months to years if inactive, engulfing targets will shorten lifespan
197
What are lymphocytes? What are the two types?
1) Immune defense against specific targets
2) B and T
198
What do B lymphocytes do?
What type of immunity does this convey?
1) Produce antibodies which mark a target for destruction
2) Antibody-mediated immunity
199
T lymphocytes
1) Do T lymphocytes make antibodies?
2) What do they do?
3) What type of immunity do they convey?
1) Do not produce antibodies
2) Attack targets directly by releasing chemicals
3) Cell-mediated immunity
200
1) What directs the differentiation and proliferation of leukocytes?
2) Where can they be produced?
1) Erythropoietin analogs for WBCs
2) Bone marrow and lymphoid tissues (like lymph nodes and tonsils)
201
Cancer of WBCs and bone marrow is called what?
Leukemia
202
1) What is the first line of defense?
2) What does this category include?
3) Is it a part of the immune system?
1) Epithelial barriers
2) Skin, body cavity linings (digestive tract, lungs)
3) Part of defense but not technically part of the “immune system”
203
What are the 3 jobs of the immune system?
1) Defending against pathogens
2) Removing worn-out or damaged tissue
3) Destroying cancer cells
204
The primary pathogens are _____ and ________
bacteria and viruses
205
1) What do pathogenic bacteria do?
2) Are viruses self-sustaining?
1) Release enzymes or toxins that disrupt or damage cells
2) No; not self-sustaining
206
Viruses
1) What makes up viruses?
2) What are viruses lacking?
3) What must viruses do to divide?
4) What do they cause the body defenses to do?
1) DNA or RNA and a protein coat
2) Machinery for cellular activity
3) Invade host cells, hijack organelles, and use it to divide
4) Also causes body defenses to attack the hijacked cells
207
What are the two types of immunity? Define each
1) Innate immunity: Nonspecific responses from inherent defense mechanisms
2) Acquired (adaptive) immunity: Immune responses against specific targets to which body has been previously exposed
208
Everyone has the same __________ immunity
innate
209
Name and define 4 innate defenses
1) Inflammation: nonspecific response to tissue injury
2) Interferon: proteins that nonspecifically fight viruses
3) Natural killer cells: nonspecifically lyse viral and cancerous cells
4) Complement system: sequentially activated plasma proteins that attack pathogen plasma membranes
210
What cells nonspecifically lyse viral and cancerous cells?
Is this innate or acquired immunity?
Natural killer cells; innate
211
1) Inflammation recruits what two things?
2) What are their 3 jobs?
1) Phagocytes and plasma proteins to damaged tissue
2) -Isolate, destroy, or inactivate pathogens
-Remove debris
-Prepare for tissue healing
212
Do inflammatory responses of innate immunity change? Explain
Response is very similar regardless of triggering event (bacteria, virus, etc.)
213
What are the 9 steps of innate immunity's response to cause inflammation?
1) Local tissue macrophages phagocytize microbes
2) Mast cells of damaged tissue release histamine which vasodilates local arterioles
3) Histamine increases capillary permeability, allowing plasma proteins into the inflamed tissue
4) Local IF volume increases due to leaked plasma proteins (edema)
5) Inflamed area is walled off by fibrin clot, which isolates the microbes. This limits their spread and makes it easier for phagocytes to attack them.
6) Neutrophils (within an hour) and monocytes (8-12 hours) increase locally
7) Leukocytic destruction of microbe continues.
8) Phagocytes release many chemicals that function as inflammatory mediators. All chemicals other than antibodies that WBCs secrete are called cytokines.
9) Tissue repair
214
1) What does histamine do to capillary permeability?
2) When do neutrophils respond to inflammation? What about monocytes?
1) Increases capillary permeability
2) Neutrophils (within an hour) and monocytes (8-12 hours)
215
All chemicals (other than antibodies) that WBCs secrete are called what?
Cytokines
216
True or false: Many drugs suppress inflammation
True
217
What are the 2 most common anti-inflammatory medications?
NSAIDs and glucocorticoids (steroids)
218
What does aspirin do? (what does it decrease? what does it inhibit?)
1) Decreases histamine release, reducing pain, swelling, redness.
2) Inhibits prostaglandins, an inflammatory mediator.
219
1) What do glucocorticoids suppress, destroy, and reduce?
2) What are they useful for? What's the downside?
1) Almost every aspect of the inflammatory response, destroy lymphocytes, and reduce antibody production.
2) Useful for treating undesirable immune responses like allergic reactions but decrease body’s resistance to infection
220
1) Define interferon
2) When is it secreted by cells?
3) What does it bind with?
4) What does it markedly enhance?
1) A group of 3 related cytokines released from virus-infected cells
2) Upon exposure to viral nucleic acid
3) Receptors on healthy neighboring cells
4) Natural killer cells
221
1) Interferon is a part of ___________ immunity
2) Complement system is a part of ___________ immunity
1) Innate
2) Innate
222
What is the complement system?
Group of more than 30 plasma proteins
223
What are the 2 ways the complement system can be activated?
1) Exposure to carbohydrate markers on microbes that are not present on human cells
2) Exposure to antibodies produced against a specific invader (adaptive immune response)
224
1) What does the complement system do?
2) What does it augment?
1) Forms MACs (Membrane Attack Complexes) that embed into invader membranes, creating large channels in their walls that makes them extremely leaky
2) Inflammatory response in many other ways including activating inflammatory mediators
225
1) What mediates acquired immunity?
2) What can each one of these respond to?
3) Do they normally circulate? If so, why? If not, then when?
1) B and T lymphocytes
2) Can only respond to a specific type of foreign material, like one bacterium
3) Are not normally circulating; only produced and released for the task of defending against their specific target
226
1) Antibody-mediate acquired immunity involves ___ cells
2) Cell-mediated acquired immunity involves ____ cells
1) B cells
2) T cells
227
1) What can lymphocytes respond to?
2) What do B cells do?
3) What do T cells do?
1) Can selectively respond to an almost limitless variety of cells
2) Recognize free-existing invaders like bacteria and some viruses; combat these by secreting specific antibodies.
3) Recognize and destroy improperly functioning cells like virus-infected or cancerous cells.
228
1) Each B and T cell has what?
2) What happens when BCRs (B cell receptors) bind with an antigen?
3) What then happens to plasma cells?
1) Receptors for binding to one specific antigen
2) The cells differentiate into active plasma cells and some become dormant memory cells
3) Plasma cells greatly expand their rough ER, becoming protein factories producing 2000 antibodies per second
229
List the 5 antibody subclasses and their functions. Which is most abundant?
1) IgG: most abundant, secreted copiously when body is re-exposed to antigen
2) IgA: found in secretions of digestive, breast milk, respiratory, urogenital systems
3) IgM: produced in early stages of plasma cell response
4) IgE: allergy mediator and helps against parasites
5) IgD: function unclear
GAMED
230
What are the two ways in which antibodies work? Define/ describe these two terms.
By neutralization and agglutination:
1) Neutralization: bind to bacterial toxins, preventing them from harming body cells. Also bind to viruses, preventing them from entering cells.
2) Agglutination: causes foreign cells to clump together
231
Each B cell is preprogrammed to respond to what?
Only 1 of more than 100 million antigens
232
1) After initial response to microbial antigen, what begins?
2) What mediates this step?
3) What occurs?
1) "Primary response” begins
2) IgM
3) Plasma cells form, won’t reach peak for a couple of weeks
233
1) What does re-exposure initiate?
2) What occurs during this?
3) How slow or quick is it?
1) "Secondary response”
2) Memory cells differentiate into plasma cells
3) Occurs much more quickly than primary response
234
Define vaccination
The deliberate exposure to a pathogen that is attenuated (virulence negated) but can still induce antibody formation
235
1) Define active immunity
2) What are the two ways it can be conveyed?
3) Is this short-term immunity, or long-term?
1) When antibodies are formed by the person in response to direct exposure
2) Natural disease or vaccination
3) Long-term
236
1) Define passive immunity
2) Give examples
3) Is this short-term immunity, or long-term?
1) Passive immunity is the transmission of pre-formed antibodies
2) Maternal transfer, artificial/exogenous administration
3) Short-term
237
What is required for cell mediated immunity?
T cells must directly contact their targets
(antigen specific)
238
What are the primary and secondary responses of T cells? Note when most T-cell apoptosis occurs.
1) Primary: 90% die of apoptosis after initial infection, 10% become memory T cells
2) Secondary: activation of memory T cells
239
1) What is required for a T-cell to respond to antigens?
2) What do APCs do?
1) T cells only respond to antigens presented to them by antigen-presenting cells (APCs)
2) APCs process the antigens and present them on their surface along with self-antigen MHC molecules
240
List the 3 types of T cells
1) Cytotoxic/killer T cells
2) Helper T cells
3) Regulatory T cells
241
1) What do cytotoxic/killer T cells do?
2) Give 3 examples of things it affects
1) Destroy host cells that bear a foreign antigen. Various mechanisms.
2) Cancer, virus, transplanted cells
242
1) What do helper T cells do?
2) What do they orchestrate?
3) How much of the T-cells does this type make up?
4) What virus are helper T-cells related to? What happens?
1) Modulate other immune cells, augment nearly all aspects of the immune response
2) Most of the immune system
3) 60-80%; most abundant T cell
4) AIDS virus selectively invades helper T cells
243
What do regulatory T cells do?
Suppress the immune response, act as a type of check-and-balance system to minimize out of control immune activity.
244
1) Define allergy
2) What is the offending agent called?
3) What does re-exposure cause?
1) Acquisition of inappropriate specific immune reactivity (hypersensitivity)
2) Allergen
3) An attack of variable severity
245
Define anaphylactic shock. What can it cause?
Histamine-induced widespread vasodilation with potential for circulatory shock
246
1) What is the hygiene hypothesis?
2) What does hypersensitivity response resemble?
1) Studies suggest that allergies are increased in a country as the presence of parasites decreases
2) Hypersensitivity response resembles how the body would respond to parasitic worms
