Physiology Flashcards
Apparatus used in determining hemoglobin content
Sahli which has 2 readings (gram/100 or % of normal)
Sahli is used in
Determination of Hb content
Material/principle used in determining hemoglobin content
0.1 HCl to 10% in Sahli tube + 0.02 ml anti-coagulated blood using pipette
Add distilled H2O to acid hematin and match colors
What is the role of HCl in the hemoglobin content experiment
Blood + diluted HCl (hypotonic) ——> Repture of RBC’s (hemolysis) + formation of acid hematin (dark brown color)
Intensity of color alpha Hb content
Can HCL be replaced with sulphuric acid (H2SO4)?
No, gives another color
Precautions in determining Hb content
Sterilization, No air bubbles in blood column, avoid compression of finger
Normal value of Hb content for males?
15-16 gm/100ml
Normal Hb value for females?
13-14 gm/100 ml
Why is Hb content lower in females?
male androgen (increases erythropoietin) in males. Also females have periods
As one ages, Hb content…….
decreases
State the variation in Hb% could happen due
Chronic bleeding: ↓due to iron loss—> microcytic hypochromic anemia
Newborn: ↑due to relative intra-uterine hypoxia—-> stimulate erythropoietin release—–> ↑ RBC’s
High altitude: ↑ due to hypoxia—>stimulate erythropoietin release—> ↑RBC’s
Renal failure: anemia (↓ erythropoietin)
Hb above physiological level is called
polcythemia
Functions of Hb
gas transport, buffer (maintaining PH at 7.4)
blood ph?
7.4
Each 1 gm of Hb carries _____ml of O2
1.34 ml
Apparatus used in ESR
Westergren tube
Clinical significance of ESR?
Prognostic not diagnostic test (used in follow up)
Materials used in ESR
Anticoagulant = (0.5 ml Na citrate → Deionization of ca++ ion) + 2ml blood (ratio 1:4) in tube to 0
Read plasma on top of RBCs after 1 & 2 hours
ESR possible mechanism
- Plasma proteins neutralize charges on RBCs →↓ repulsion forces→ favors adhesion, sedimentation.
- specific gravity of RBC’s 1090 > plasma 1030
Rate of sedimentation depends on…..
number of RBC’s, repulsion force between RBC’s, specific gravity of RBC’s, plasma
ESR normal values for male and females at 1st hour and 2nd hour
Factors that increase ESR
Pregnancy, menstruation, infection, inflammation, malignant and anemia
Factors that decrease ESR
Afibrinogenemia and Polycythemia
Why ESR is increased in inflammatory conditions:
↑ plasma antibodies (proteins) neutralize charges on RBCs→↓ repulsion forces→ favors adhesion, sedimentation.
Agglutination is
antigen antibody reaction →hemolysis of RBC’s
Rouleaux formation
adhesion of RBC’s together
Hematocrite ratio (PCV) apparatus
capillary tube ( contains heparin as anticoagulant) and centrifuge
What is hematocrite ratio (PCV) ?
% of RBCs volume to total blood volume
Specific gravity of RBC’s is
1090
Specific gravity of plasma
1030
Specific gravity of blood
1060
Normal hematocrit values (PCV) for male is_____and for females is _____
46%, 42%
High PCV is caused by
Polycythemia (as in high altitude), dehydration, and venous blood
Low PCV is caused by
Anemia, overhydration, arterial blood
Why hematocrit value of venous blood more than arterial blood?
Due to chloride shift phenomenon
Mean corpuscular volume (MCV) is
volume of single RBC. Normal is normocytic, low is microcytic (80) and high is macrocytic (95)
(PCV x 10)/RBC count
Mean corpuscular Hemoglobin (MCH) is _________.Normal is called _______and it is considered low if less than ____. The formula for this is?
Hb concentration in single RBC. normochromic. 25.
(Hb contentx10) / RBCs count
Mean corpuscular hemoglobin concentration (MCHC) is ________, the formula is ________ and the range is _______
Hb concentration in 100 ml PCV, (Hb contentx 100)/PCV, 32-38
Osmotic fragility test apparatus is
test tubes
materials in osmotic fragility test
5ml NaCl with different concentration in test tubes + 1ml blood in each tube
RBCs in NaCl is 0.9%, this is a _______solution
isotonic solution
RBC’s in NaCl greater than 0.9% is a _______solution
hypertonic/hyperosmotic solution
RBC’s in NaCl is less than 0.9%, this a ______solution
hypotonic
If RBC’s in 0.3% or less it is _______
not detected, completely hemolyzed
Hemolysis begins at ____, hemolysis completes at _____
0.45, 0.3
Why is there a range of hemolysis
Older hemolyze before new ones
Fragility of RBC’s is increased in
Hereditary spherocytosis
higher saline concentration
G6PD
drugs
infections
fragility decrease in
Thalassemia, iron deficiency anemia
Causes of hemolysis of RBC’s
malaria
Incompatible blood transfusion
Snake venom
Hypotonic solution
Osmosis is:
Diffusion of H2O according to conc. gradient
Osmotic pressure is
pressure needed to stop osmosis
Hemostasis is
stoppage of bleeding from injured vessels
Bleeding time is about
1-3 min
Coagulation time is
3-10 min
Bleeding time depends on
VC, number and functions of platelets
Coagulation depends on
clotting factors (liver function, Vit K)
Bleeding time prolonged in
purpura, which is caused by vascular disorders (vitamin C deficiency) , thrombocytopenia and thrombasthenia
Coagulation time prolonged in
Hemophilia ( A ↓8 factor or B ↓IX or C ↓XI ) Liver disease ↓ vit K as in new born, prolonged antibiotic use of anticoagulant
In Purpura, bleeding time is ______ while clotting time is ______
prolonged, normal
In Purpura, bleeding time is ______ while clotting time is ______
prolonged, normal
In hemophilia , bleeding time is ______ while clotting time is ______
normal and prolonged
In Vitamin K deficiency, bleeding time is ______ while clotting time is ______
normal. prolonged
Average thrombocytes is
300000/mm3
Thrombocytopenia means you have fewer than ______ platelets
150000
Thrombocytosis is defined as a platelet count above ________
350,000
Vivo anticoagulant
heparin, dicumarol
In vitro anticoagulant
Na citrate, oxalate and heparin
Sources of heparin in body?
Mast cell and basophil
Prothrombin is a test for the
extrinsic pathway, 15 second in vitamin k deficiency
Activated partial thromboplastin time is a test for
intrinsic pathway
Blood types rarest to most common are
AB, B, A and O
A type blood can donate to ______and receive from ______
A, AB A, O
B type blood can donate to ________and receive from _______
B, AB B,O
AB type blood can donate to ______and receive from _______
AB, all (universal recipient)
O blood can donate to ________and receive from________
All, O
Rh positive is about ____% of population while RH negative is ____%
85, 15
RH positive can receive from _______ while RH negative can receive from _________
RH negative or positive, ONLY RH negative
Indications of blood transfusion
Hemorrhage, erythroblastosis, fetalis, severe anemia
Complications of incompatible blood transfusion includes
Agglutination of RBC,s which results in:
-Blockage of capillaries
-Intravascular Hemolysis ( which releases)—>
Histamine
K—>cardiac arrhythmia
Hb—> hemolytic jaundice
Erythroblastosis fetalis is
hemolytic disease of Rh+ve newborn. It is caused by development of anti-D (IgG) following delivery of first baby
Conditions in which erythroblastosis fetalis is possible?
- 2nd baby for RH –ve female married RH+ male
* 1 st baby may be affected in previously sensitized female
Erythroblastosis fetalis manifestation
Anemia, jaundice, born dead
How to prevent Erythroblastosis fetalis
Anti-D injection within 48 hours of delivery
A fibers are ______fibers for _______muscles. They are blocked by_________
Thick somatic, skeletal muscles, pressure
B fiber are ________, blocked by _________
Thin autonomic, hypoxia
C fibers are _______nerve, and are _______. They are blocked by ____________
Unmyelinated thin, postganglionic, anesthesia
Nerve conduction velocity is
Distance between stimulating and recording electrodes/ latent period
The firing level is _____mv. depolarization is caused by ________, repolarization is caused by _______ and hyperpolarization is caused by _______
-65, Na inflow, K outflow, slow closure of K channels
Compound action potential is
sum of all action potentials recorded from nerve trunk. It has many peaks and doesn’t obey the all or none law.
Two tests for carpal tunnel syndrome
Phalen or wrist flexion test (tingly or numbness after 1 minute is abnormal)
Tinel test: Tap or press on median nerve (abnormal if its shock or tingly)
Causes of Normocyte normochromic anemia`
Acute blood loss
Bone marrow depression
Causes of microcytic hypochromic anemia
Deficiency of iron in diet
deficient iron absorption
Chronic blood loss
Causes of macrocytic anemia
Folic acid and vitamin B12 deficiency
Causes of Iron deficiency
Lower Iron intake as in growing children and during pregnancy
deficiency of iron absorption as in partial gastrectomy, vitamin C deficiency, and disease of small intestines.
Causes of vitamin B12 deficiency
Defective absorption as after gastrectomy, absence of intrinsic factors and small intestine disease
Deficiency in diet in cause of vegetarians
Pernicious anemia
Autoimmune disease that attacks the intrinsic factor that absorbs vitamin B12
Items used in frog leg experiment
Gastrocnemius and sciatic nerve
Ringer’s solution poured on them (0.6% NaCl)
Stimulus: single maximal electric stimulus
Transducer, computer system for recording
The single muscle twitched (SMT) is represented on the graph as……..
a curve
what is a single muscle twitch (SMT)
single maximal stimulus → results in isotonic contraction followed by relaxation.
Is SMT a physiological event
No, as muscle receives train of action potentials
→cause tetanic contraction→ useful work
What are the phases of SMT
- Latent period (0.01)
- Contraction period (0.04)
- Relaxation period (0.05)
causes of latent period
- Conduction through nerve
* Neuromuscular transmission
To shorten latent period, you must
- Shorten distance between applied electrode & muscle
- Put electrodes directly on muscle
- Use warm ringer
Effect of warming on SMT?
↓duration of all phases (shortened) &
↑force (amplitude) (height) of contraction
↑ enzymes activity, ↓muscle viscosity
Effect on SMT cooling?
↑ duration of all phases (prolonged) &
↓force of contraction
↓enzymes activity, ↑ muscle viscosity
true or false? Nerves fatigue
False
Effect of fatigue on SMT
- ↑Duration of all phases
- ↓Force (height) of contraction
- Incomplete relaxation (contracture)
Causes of SMT fatigue
- Neuromuscular fatigue: ↓acetyl choline
- Muscle fatigue (chemicals accumulated): ↑ lactic acid, CO2, K, adenosine, ↓ATP
➢ Intact animal: fatigue is caused mainly due to muscle fatigue
➢ in the experiment: neuromuscular fatigue
To differentiate between Neuromuscular fatigue & Muscle fatigue:
• Put electrode directly on muscle
➢ If there is Response→ Neuromuscular fatigue
➢ No response→ Muscle fatigue
Why muscle shows normal contraction on direct stimulation after being fatigued:
direct stimulation→ bypass neuromuscular fatigue
How could we obtain forcible contraction?
Increase intensity of stimulus Increase frequency of stimulus Increase temperature (warm ringer)
Structures that obey all or none law
Nerve fiber
Muscle fiber
Visceral smooth muscle
Atria and venricles
What structures DONT obey the all or nothing law?
nerve trunk
Skeletal muscle
Clonus when warmed results in
separated twitches
Clonus when cooled/fatigued result in
tetanus (no relaxation)
Tetanus when warmed results in
clonus
Separated twitches when cooled results in
clonus
chemicals in fatigued muscles are
CO2, lactic acid, K, adenosine
Low frequency of stimulation result in
separate twitches
A moderate stimulations result in
clonus
High frequency stimulation results in
tetanus
Stair case phenomenon
multiple sperate twitches (contractions followed by complete relaxation)
clonus definition
contraction followed by incomplete relaxation
why does multiple stimuli increase peak of contraction?
accumulation of calcium
Diastolic pulse pressure is
Minimum pressure during diastole (60-90)
Pulse pressure formula
Difference between systolic and diastolic pressure
MAP (Mean systemic arterial pressure) 2 formulas are
MAP=Diastolic pressure+ 1/3Pulse pressure
MAP= CO X resistance
Gravity affect on ABP
each 1 cm below heart → ↑ABP by 0.77 mmHg.
Each 1 cm above heart → ↓ ABP by 0.77 mmHg
Types of blood flow:
✓ Laminar (streamline): flow in layers (fastest in center, slowest at periphery) → no sound
✓ Turbulent flow: → Korotkoff sounds
Why sounds are heard just between systolic and diastolic pressures?
a. Above systolic: closed artery→ no flow → no sound.
b. Between systolic and diastolic: partially opened artery→ turbulent flow →sound.
c. Below the Diastolic: opened artery→ laminar flow →no sound
Why blood flow in artery normally soundless:
Laminar flow
Korotkoff’s sounds:
Sounds heard over brachial artery during deflation of cuff due to turbulent blood flow
a. Phase1: sharp clear sound → systolic pressure. systolic pressure when sound first appears
b. Phaes2: soft
c. Phase3: louder sound
d. Phase4: ↓ intensity
e. Phase5: sound disappear → diastolic. Diastolic pressure when sounds disappear.
Effect of exercise on ABP
↑systolic pressure due to ↑SV (due to ↑EDV, VR) , ↓diastolic pressure (due to
peripheral VD→↓ resistance)
HESS (tourniquet) TEST (determination of capillary fragility)
• Mark one inch circle on forearm
• Apply cuff on upper arm → ↑pressure to 60 mmHg for 15 min (interfere with venous return)→↑
capillary pressure
- Count number of red spot (petichea) in the circular area
- Petichea >8= + ve test→ purpura
in frogs: pacemaker is
sinus venosus
Factors affecting HR (Chronotropic state):
✓ in frog experiment
warming , cooling
Very slow conduction at AV node:
allow sufficient time for ventricular filling before ventricular contraction
Very fast conduction in purkinje fiber:
allow ventricular muscle to contract at same time→ work as one unit
Vagal tone importance
under rest, parasympathetic effect on SAN is stronger than sympathetic (↓ SAN to 70)
Physiological significance of the long ARP of the cardiac muscle:
prevent cardiac tetanus
Effect of stimulus while heart in systole:
no effect due to ARP
Effect of stimulus while heart in diastole:
Premature Ventricular Beat (ventricular extrasystole) due to RRP
Ascending
(Anacrotic) limb
↑ reach 120 mmHg (Systolic Blood Pressure) Due to rapid ejection of blood coincides with Maximum ejection phase
Diacrotic Notch=
Incisura
Sharp small drop Of pressure Due to small back
flow of blood from aorta to left ventricle coincides with End of reduced ejection phase
Diacrotic wave
↑ pressure (Due to bouncing of blood up by closed valve & elastic recoil). coincides with Isovolumetric
relaxation phase
water hammer pulse
wide pulse pressure as in anemia, pregnancy, hyperthyroidism
pulsus alternans
: alternating strong & weak pulse in heart failure
Positive A wave
high atrial pressure, atrial contraction during atrial systole
Negative X wave
Low atrial pressure, escape of blood from atria to ventricle
Positive C wave
increase of atrial pressure , due to bulge of tricuspid valve cups into atria
Negative X wave
decrease in atrial pressure and downward pull of Av cusps
Positive Y wave
Increase atrial pressure, accumulation of VR in atrium while tricuspid is closed
Negative Y wave
decrease in atrial pressure, blood flow from atria to ventricle
Ventricular systole is between __________and _______
begging of positive C wave and peak of positive v wave
First heart sound is caused from
closure of A-V valves
First heart sound is timed with
isometric contraction phase and early rapid ejection phase
First heart sound has a ______pitch and a duration of _____seconds
low, 0.15 seconds
Mitral component of first heart sound is at
left of 5th intercostal space (apex of heart)
Third heart sound is caused from ________. It coincides with________and is normally ________
Rapid flow from atria to ventricles, rapid filling phase, non-audible
Fourth heart sound (S4) is caused by _________, and coincides with ________. It is ________
rapid flow of blood from atria to ventricles, atrial systole, very faint.
Causes of Autonomic dysfunction
Diabetes mellitus: Vitamin B12 deficiency Metabolic Central cause Idiopathic cause
During inspiration HR _______, and in expiration HR________
Increase, decrease
Respiratory sinus arrhythmia
HR doesnt increas during inspiration
Why HR increase during inspiration?
Stretch receptors in alveoli inhibit vagus N
Respiratory center inhibits Vagus N
increase VR, causes stretch in heart wall, activate stretch Receptors which inhibits vagus N
HR during respiratory cycle normal, borderline and Abnormal
15 or greater, 11-14 , 10 or less
Valsalva maneuver is __________. when preformed correctly you can see_______
Forced expiration against closed glottis for 15 seconds. distend jugular vein
Phase 1 of heart in Valsalva maneuver
increase BP and decrease HR
Phase 2 of heart cycle during Valsalva maneuver
BP decrease, HR increase
Phase 3 of heart cycle during Valsalva maneuver
BP decrease and HR increase
Phase 4 of heart cycle during Valsalva maneuver
BP increase, HR decrease
Atrial fibrillation
P wave absent, irregular beats
Heart block
PR interval is longer than normal. Makes QRS late
Premature beat
An extra beat due to premature electric impulse.
ST elevation in ECG is caused by
Myocardial infarction
ST depressed caused by ischemia
Ischemia
Effects of hypokalemia on ECG
Flat T wave
Prominent U wave
Depressed S-T segment
Prolonged PR intreval
Effects of hyperkalemia on ECG
Tall, peaked, narrow T wave
P wave diminishes in size
Shortened Q-T interval
Tidal volume
volume of air inspired or expired during rest. About 500 ml
Inspiratory reserve volume (IRV)
max volume of air inspired after normal inspiration (3000ml)
Expiratory reserve volume
Max volume of air expired after normal expiration (1100)
Residual volume
volume that remains in lungs unless punctured, 1200 ml
Total lung capacity is
volume of air in the lungs after maximum inspiration
TLC= IRV + TV + ERV + RV = 5800 ml
Inspiratory capacity
max volume of air inspired after normal expiration
= IRV + TV + ERV = 4600
Functional residual capacity
Volume of air between breathes when respiratory muscles relaxes
= ERV + RV = 2300 ml
Pathological decrease in vital capacity
Paralysis of respiratory muscles Bone deformities Obstructive lung disease Restrictive lung disease Loss of lung elasticity Abdominal tumor
Forced vital capacity (FVC)
rapid forced expiration after max inspiration
Respiratory rate is normally
12-16 cycles per minute
Pulmonary ventilation
Respiratory rates X tidal volume
Alveolar ventilation
(TV-DS) X respiratory rate
Dead space
TV X ((PCO2 artery -PCO2 air)/ PCO2 arterial blood))
Measurement of maximal voluntary ventilation
Maximum amount of air subject can respire in 1 minute. Use nasal clips.
Where to preform auscultation
➢ Anteriorly
- Apex of the lung: above middle 1/3 of the clavicle
- Upper lobe: 2nd space MCL
- Middle lobe: 4th space MCL
- Lower lobe: 6th space MAL
➢ On the back of the chest:
• Upper lobe: C7 – T3
• Lower lobe: T3- T10
