Lab Exam 2 Flashcards
What did we use to measure muscle contraction
Transducer
Where are the two places we stimulated the ulnar nerve
Elbow
Wrist
What is a muscle twitch
Single contraction and relaxation due to single stimuli
What is recruitment
What does it result in
Increase in amplitude of twitch
Beacuse of increase in amplitude of stimulus
Increased stimulus strength = increased no. of muscle fibers stimulated = greater tension
What does the Epimysium surround
Whole muscle
What does the Perimysium surround
Fascicles of muscle fibers
What does the Endomysium surround
Individual muscle fibers
Each muscle fiber is a single…
muscle cell
Each muscle fiber has many…
Myofibrils
Each myofibril contains…
myofilaments
Threshold stimulus is…
the amount of voltage necessary to start a response from the muscle
What is a suprathreshold stimulus
a stimulus above the threshold stimulus
What is a submaximal stimulus
amount of stimulus necessary to start a reponse between threshold and maximum response
What is maximal response
amount of stimulus necessary to start a maximal response
The interaction between what type receptors causes Ca channels to open
DHP
Ryanodine
What is EMG
the electrical activity of the many muscle fibers controlling the gross anatomical muscle
What is co-activation
One muscle forcefully activated, there is a minor increase in activity of the other muscle
What is the reason for co-activation
To stablise the joint
What nerve was stimulated in the evoked EMG
Median nerve
Increased stimulus results in an increased… of EMG
Amplitude
What is Latency
The time elapsed from stimulation to start of muscle contraction
What two things need to be known in order to work out conduction velocity
Distance - between stimulating electrodes to recording electrodes
Time - to travel from stimulus site to recording site
Conduction velocity formula
Conduction Velocity (m/s) =
Distance (mm or cm) / Difference in latencies (s or ms)
15cm / 5ms - 2.5ms =
15cm / 2,5ms x 1m/100cm x 1000ms/1s = 60m/s
What 3 things influence conduction velocity
Diameter of fiber
Temperature
Myelinated vs non myelinated
What is muscle fatigue
decline in ability of muscle to generate force
What is more efficent to stimulate: the muscle directly or the nerve that innervates it
Explain why…
The nerve
Smaller piece of tissue to stimulate
Therefore requires less stimulus energy and it branches throughout the muscle
What main thing occurs during fatigue
Muscle can no longer generate or sustain force
What causes submaximal contraction fatigue
Depletion of glycogen stores
What two things cause short duration maximal exertion fatigue
Increase in inorganic phosphate = slows release of P from myosin
Increase in extracellular K = decreases release of Ca from SR
Oxygen makes up… of whole blood
1/5
Hemoglobin has…
4 polypeptides:
2 are alpha
2 are beta
Each has heme group with Fe atom to bind with O2
What is unique about red blood cells (3)
- They respire anaerobically
- They have no nuclues
- Produced in bone marrow = regulated by Erythropoietin
What destroys red blood cells
Where is it located
Phagocytic cells of the Reticuloendothelial system
Located in the spleen, liver and marrow
What is Jaundice
What are the physical appearance
Increase in Bilirubin in tissues because of:
- increased RBC destruction
- Liver dysfunction
- Bile duct obstruction
Yellow skin colour
What is used to measure RBCs
Hemocytometer
What is Hematocrit
Ratio of volume of packed RBCs to the total blood volume
What causes Anemias
- Decreased oxygen carrying capacity of blood
- Decreased Hb content of blood
- Decreased no, of RBCs
- Iron deficiency
- Vitamin B12/folic acid deficiencies
- Bone marrow disease
- Sickle cell
- Hemorrhage
What does MCV stand for and what does it measure
Mean Corpuscular Volume
Measures volume of RBC
What does MCHC stand for and what does it measure
Mean Corpuscular Hemoglobin concentration
Measures average RBC
What is anemias
Reduced oxygen carrying capacity of blood
What is Macrocytic anemia
MCV > 94 , MCHC = normal
- Folic acid deficiency
- B12 deficiency
What is folic acid needed for
RBC maturation
What is Normocytic normochromic anemia
MCV and MCHC = normal
- Blood is loss via hemorrhage
- Decreased marrow function
What is Microcytic hypochromic anemia
Low MCV , Low MCHC
Decreased Iron
What is Diapedesis
When WBCs leave the vasculature during inflammatory responses
What is unique about neutrophils
- Granulocyte
- Phagocytosis
- Three lobed nucleus
- Purple nucleus, light, small granules
50-75% of WBC
10-12um in diameter
What is unique about Eosinophil
- Granulocyte
- Secretions destroy parasites
- Bilobed nucleus
- Large, red-orange granules, blue nucleus
1 - 5% WBC
13um diameter
What is unique about Basophil
- Granulocyte
- Release of Histamine during inflammatory response
- Bilobed nucleus
- Dark blue granules which cover nucleus
Will become mast cells
0.5% of WBC
What is unique about Small Lymphocytes
- Agranulocyte
- T and B cells
- Large nucleus with small band of cytoplasm
- Light blue cytoplasm, purple nucleus
- B cells will become plasma cells
30% WBCs
7 ym in diameter
What is unique about monocytes
- Agranulocyte
- Tissue macrophage
- Blue-gray cytoplasm, kidney shaped dark nucleus
- Will become macrophage
2-8% WBCs
15 ym in diameter
What is agglutination Rxn
Clumping caused by reaction between RBC surface antigen and plasma antibodies
What is Erythroblastosis fetalis
Mother had Rh-
Fetus has Rh+
Results in blue baby
What blood type is the universal donor
O
What blood type is the Universal acceptor
AB
What are the two clotting pathways and what is released in both
Extrinsic = thromboplastin released when vessel is damaged
Intrinsic = Hageman factor when vessel is damaged and it is exposed to collagen
What is needed in order to activate these clotting pathways
Calcium
What vitamin is needed for formation of prothrombin
K
What is the main function of Neutrophils
Blood phagocytes
What is the main function of Monocytes
Transform into tissue macrophages
What is the main function of Lymphocytes
Specific immune reactions (B and T cells)
What is the main function of Basophils
Secrete histamine for inflammatory response
What is the main function of Eosinophils
Secretions destroy parasites
What is fibrin
Protein that makes threads in the blood clot
What is Thrombin
An enzyme that catalyzes the conversion of fibrinogen into fibrin
Steps of auscultation of blood pressure
- Pressure cuff at 180
- Blocks blood flow
- Reduce pressure
- BP = Cuff pressure - Korotkoff sound = systolic
- Stopping of sound = diastolic
What happens to pulse when arm is lowered and raised
Explain why
Lowered = increase
Reason - hydrostatic and blood pressure in same direction = increases systolic pressure
Raised = decrease
Reason - Hydrostatic pressure and blood pressure in opposite directions = decrease systolic pressure
What occlusion eliminates pulse reading
brachial artery
What occlusion decreases pulse amplitude by half
Radial artery
Ulnar artery
What is contractility controlled by
Conduction of APs along motor neurons and subsequent release of Ach at the neuromuscular junction
Steps up to Ca returning to SR and muscle relaxing (8)
- Ach binds to nicotinic Ach receptor
- AP moves down muscle membrane - depolarises muscle fiber
- Signal moves down T-Tubules - releases Ca from SR
- Ca binds to troponin
- Troponin moves tropomyosin out of the way
- Myosin head binds to actin - powerstroke
- After contraction, muscle cell repolarises - Ca transported back to SR
- Tropomyosin covers actin binding site
What is the normal range for Conduction Velocity
Range 1 - 120 m/s
Normally 50 - 60 m/s
What is the main substance that causes yellow skin in Jaundice
Bilirubin
How does the cold affect pulse
- Vasocontriction of blood vessels
- Causes increase in blood pressure and heart rate
- Reduces blood flow and pressure in extremities = reduces heat loss from extremities
What is the proportion of muscle fibers contracted at:
- Threshold
- Max stimulus
- Above maximum stimulus
- Few
- 100%
- Cant go over 100%
What can be the issue with chemical agents that cause tetanus
Can cause breathing problems
Antigens are known as…
agglutinogens
Antibodies are known as…
agglutinins
Where are Rhesus factor found in the body
All body cells
What is heparin
An anticoagulant
What are MCV and MCHC used to determine
if a person has anemia
What 2 things does the skeleton provide
Support
Articulation
What can the EMG allow us to discover
Nerve and muscle disorders
Location
Extent
What was special about the capillary tube used in the hematocrit test
It was heparinised
Which gender has the higher hematocrit
Males
However the ranges overlap
What is a hemocytometer
a special microscope that counts individual RBCs
How do you calculate MCV
MCV = Hematocrit x 10 / RBC count
How do you calculate MCHC
Hemoglobin g/dL x 100 / Hematocrit
What formulas do we use to figure out if someone has anemias
MCV
MCHC
What does the interval between T and P represent
Blood filling
Where are ryanodine receptors located
SR
Where are DHP receptors located
T tubule
Exam question: Describe recruitment in skeletal muscles
Increase in amplitude of twitch because of increase in stimulus strength
Increase in stimulus strength increases the number of muscle fibers stimulated which generates an greater tension
Exam question: What 3 factors affect conduction velocity? what is the normal physiological range for conduction velocity
Diameter of fiber
Temperature
Myelinated vs non myelinated
range: 1-120 m/s
Exam question: What are the histological differences between skeletal and smooth muscle
Skeletal:
Striated = regular orientation
Multinucleiated = nucleus along the edge because if cytoplasm - gives appearance of striated
Smooth:
Single nucleus
Unstriated = no regular orientation
Exam question: What is the function of neutrophils? how would one identify one
Phagocytosis - ingesting bacteria or other material
Three lobed
Purple nucleus
Light small granules
50-75% WBC
Exam question: What is agglutination reaction and why is it significant
Agglutination is clooting of blood as RBCs clump together
Does this by antibodies binding to foreign antigens
Antigens located on cell surface
Significant because blood clumps cause blocking of vessel which can cause death
Exam question: What causes jaundice
Increase in bilirubin in tissues
This is because of RBC destruction, where heme is released and is then converted by the liver into bilirubin
Can also occur when liver is dysfunctional or if there is bile duct obstruction
Causes yellow skin colour and sclera in eyes
Exam question: How and why does the cold affect pulse
Cold causes vasoconstriction in extremities
Reduces Blood flow
Reduces pressure
Reduces EMG amplitude
Reduces heat lost from extremities
Exam question: Describe the cause of the opening and closing of the AV valves. How does lub sound relate to AV valve
Greater pressure in Atria compared to ventricle = AV valve open
Atria contracts increasing pressure = blood flows through AV valve
Pressure now greater in ventricle compared to atria = closes AV valve to make sure blood doesnt flow back
Closing of AV valve produces lub sound
The opening and closing of the AV valve is influenced by pressure gradient
Exam question: Describe the physiological events that occur during the latency period (essay)
Latency is the time from stimulation to start of muscle contraction
- Motor neuron the AP moves down axon into neuromuscular junction terminal
- ACh released
- Diffuses across synaptic cleft
- Binds to nicotinic ACh receptors
- Opens NA channels - allows NA to diffuse in and depolarise
- AP generated - moves across membrane and down t tubule
- SR release CA
- Binds to troponin
- Causes change in shape of tropomyosin
- Actom ex[psed - myosin head binds to actin
- Myofilaments slide
- Creates muscle tension
Exam question: Describe the conduction pathway of electrical activity in the heart
SA node generates own electrical impulses in right atrium
- Travels down and across atriums
- Causes contraction of atriums via depolarisation
- Reaches AV node - slight pause to allow ventricles to fill with blood
- Electricle impulse travels down septum via bundle of His
- Reaches purkinji fibers located in interventricular septum
- Contraction of ventricles via depolarisation
Lub occurs after what wave
QRS
Dub occurs after what wave
T wave
What happens when T-P interval decreases as a result of increase exercise
Less time for ventricles to fill
Heart rate increases
What is the ranges for RBC in males and females
Males = 4.5 - 6 million Female = 4.0 - 5.5 million
What is the ranges for hematocrit in males and females
Males = 47 +-7 Females = 42 +-5
What is the ranges for Hemoglobin in males and females
Females = 12 - 15 g % Males = 13 - 16 g %
What is the range for MCV
82 - 92 micro meter 3
What is the range for MCHC
32-36 %
