Physio Lab Exam 2

Where is the heart located?

between the 2nd and 5th intercostal spaces

Where is the heart located?

within the thoracic cavity in the mediastinum

Types of pericardium

fibrous pericardium and serous pericardium

Layers of the serous pericardium

parietal layer, pericardial cavity, and visceral layer (epicardium)

Layers of the heart

epicardium, myocardium, and endocardium

What is myocardium composed of?

cardiac muscle and forms the bulks of the heart

Pericarditis

inflammation of the pericardium

visceral and parietal pericardium stick together and impede heart activity

Cardiac tamponade

excess fluid compresses the heart and limits its ability to pump blood

Describe blood flow in the heart

SVC/IVC/coronary sinus > right atrium > tricuspid valve > right ventricle > pulmonary semilunar valve > pulmonary trunk > pulmonary arteries > lungs > pulmonary capillaries/veins > heart > left atrium > mitral valve > left ventricle > aortic semilunar valve > aorta > systemic capillaries > body

Semilunar valves

prevents backflow into the ventricles when ventricles relax

2 types of semilunar valves

pulmonary valve and aortic valve

Pulmonary valve

controls blood flow of deoxygenated blood from right side of heart into pulmonary trunk

Aortic valve

regulates the oxygenated blood flow from the left side of the heart into the aorta

In diastole (relaxation) phase, which valves are open and closed?

AV valve - open

SV valve - closed

In systole (contraction) phase, which valves are open and closed?

AV valve - closed

SV valve - open

Atrioventricular valves (AV)

prevents backflow into the atria when ventricles contract

2 types of atrioventricular valves

tricuspid valve and bicuspid valve

Tricuspid valve

right side between right atrium and ventricle

Bicuspid valve

left side between left atrium and ventricle

Diastole

filling phase

Systole

ejection phase

Pulmonary circuit

bloods vessels that carry blood to and from the lungs.

receives oxygen poor blood from tissues and pumps this blood to the lungs to pick up oxygen and dispel carbon dioxide.

Systemic circuit

blood vessels that transport blood to and from all body tissues.

receives oxygenated blood returning from the lungs and pumps this blood throughout the body

S1 "Lub"

first sound

produced by turbulent blood flow through the AV valves

S2 "Dub"

second sound

produced by turbulent blood flow through the semilunar valves

5 areas of auscultation

tricuspid, bicuspid (mitral), primary pulmonic, secondary pulmonic, aortic

Systole

phase of ventricular contraction

0\.3 seconds

Diastole

phase of ventricular relaxation

0\.5 seconds

Cardiac output

amount of blood pumped out by each ventricle in one minute.

product of heart rate and stroke volume

Heart rate

number of contractions per minute

Resting heart rate

60-100 bpm

Stroke volume

volume of blood ejected from the ventricles with each beat (70 mL)

End systolic volume

total volume of blood left in the ventricles at the end of systole (50 mL)

End diastolic volume

total volume of blood in the ventricles at the end of diastole (120 mL)

Systolic pressure

maximal arterial pressure following ejection

Diastolic pressure

minimal arterial pressure following ventricular relaxation

Aortic blood pressure is usually measured directly. True or False?

False. Aortic blood pressure is NOT usually measure directly but estimated by using a sphygmomanometer

Systolic pressure

the pressure at which first Korotkoff sound is heard

Diastolic pressure

the pressure at which the sound disappears

"Normal" blood pressure

less than 120 and less than 80

"Elevated" blood pressure

120-129 and less than 80

"High (hypertension) Stage 1" blood pressure

130-139 or 80-89

"High (hypertension) Stage 2" blood pressure

140 or higher or 90 or higher

"Hypertension Crisis"

higher than 180 and/or higher than 120

Conduction System

SA node > AV node > bundle of HIS > R + L bundle branches > Purkinje fibers

P wave

atrial depolarization/contraction

QRS complex

ventricular depolarization/contraction

T wave

ventricular repolarization

PR or PQ interval

amount of time for the signal to be transduced from atria to ventricle

QT interval

time ventricles depolarize/repolarize

RR interval

* 1 cardiac cycle
* used to calculate heart rate

ST segment

plateau phase

leads to heart attack

Sinus Bradycardia

rhythm rate less than 60 beats per minutes

Sinus Tachycardia

rhythm rate greater than 100 beats per minute

Atrial Flutter (A-flutter)

* atrial depolarization waves or "flutter" waves
* “saw tooth” appearance
* different ratios possible

Atrial Fibrillation (A-Fib)

* caused by many ectopic atrial foci firing at rapid rates
* no distinguishable P waves because the atria are sending impulses erratically
* irregular QRS response/distances

Ventricular Tachycardia (V-tach)

* wide QRS complexes
* P waves blends within the QRS

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Ventricular Fibrillation (V-fib)

* cardiac arrest. no effective pumping action by the heart and thus there is no circulation
* lack of identifiable waves on EKG: appears erratic, rapid twitching of the ventricles
* requires immediate CPR and defribillation

First degree AV block

* consistently prolonged PR interval
* PR interval greater than 0.2 seconds or one large square
* not a “block” but a “delay”

Second degree AV block

* allows some atrial depolarizations to conduct to the ventricles, while some are blocked, leaving lone P waves without QRS
* repeated P waves prior to the QRS complex or P waves that are missing their QRS complex

Third degree AV block

* total block of conduction from the atria to the ventricles
* atria and ventricles have lost communication and are now functioning independently of one another
* no relationship between the P and the QRS waveforms

Hematopoiesis

the process by which blood cells (connective tissue) are formed

Functions of blood

transportation

* respiration, nutrition, excretion, hormonal

regulation

* thermoregulation

Protection

* immune response

Plasma

* 55%
* water
* proteins
* electrolytes, blood gases, nutrients, enzymes, waste products, etc

Formed elements

* 45%
* erythrocytes
* buffy coat (

Blood plasma

consists of 90% water, remaining 10% consists of proteins, electrolytes, gases, hormones, waste, etc

Plasma proteins

make up 7-9% of the plasma

* albumin
* globulin
* fibrinogen

Albumin

* maintains osmotic pressure, helps keep water from diffusing out of the bloodstream into the extracellular matrix of tissues
* maintain blood volume/pressure

Globulin

* Alpha and Beta globulins transport lipids and fat soluble vitamins
* Gamma globulins are antibodies produced by lymphocytes

Fibrinogen

* forms fibrin threads essential in blood hemostasis
* stops bleeding to form blood clot
* thrombin converts fibrinogen to fibrin, which forms fibrin threads
* active form of zymogen

Zymogen

inactive form of an enzyme, don’t need all thetime, but ready to use

Formed elements structure

* lack nuclei and organelles
* biconcave discs

How do these structural characteristics contribute to their ability to transport oxygen?

* increased surface area means oxygen exchange is more efficient
* no mitochondria = no aerobic respiration

Life span of RBC

100-120 days

“Shear effect”

unaligned forces pushing 1 part of the body in 1 direction and another part of the body in the opposite direction

Hematocrit

proportion of blood that consists of red blood cells

* men: 46% +/- 5%


* women: 44% +/- 5%

Erythropoietin (EPO)

maintains the balance between production and destruction of RBC

WBC

* move in an amoeboid fashion via cytoplasmic extensions
* squeeze through the intracellular junctions between capillary walls via diapedesis or extravasation
* classified based on staining properties

Granulocytes

cells that have brightly stained granules

* basophils
* eosinophils
* neutrophils

Agranulocytes

cell that don’t have brightly stained granules

* lymphocytes
* monocytes

neutrophils

* most abundant WBC
* multilobed nucleus
* lightest stained, able to see nucleus
* phagocytic, help respond to bacterial infections

eosinophils

* more red than others
* bilobed nucleus
* phagocytic
* large quantities responding to parasitic invaders

basophils

* darkest stain, sometimes cover nucleus
* release histamine

monocytes

* massive, twice the size of RBC
* lot of cytoplasm
* big nucleus (curved)
* called macrophages when migrate out of cell and enter tissues, engulf lots of pathogens

lymphocytes

* smalles
* round, dark-staining nucleus
* little room for cytoplasm
* T cells: attack virus-infected cells and tumor cells
* B cells: produce/secrete antibodies

Antigens

found on the surface of cells to help the immune system recognize self cells

Antibodies

secreted by lymphocyte in response to foreign cells or antigens

Which blood type is the universal donor and why?

O- has no antigens

Which blood type is the universal recipient and why?

AB+ has no antibodies, so won’t attack

\+ blood type is determined by:

presence of Rh factor

\- blood type is determined by:

lack of Rh factor

Rh negative blood is given to:

Rh negative patients

Rh positive blood or Rh negative blood may be given to:

Rh positive patients

Anemia

* inability of erythrocytes to deliver the needed amount of oxygen to the cells of the body
* insufficient number of erythrocytes
* inability of the erythrocytes to bind the normal amount of oxygen

pernicious anemia

vitamin B12 deficiency

iron-deficiency anemia

lacking iron

aplastic anemia

destruction of bone marrow

sickle cells anemia

RBC has crescent shape and affects hemoglobin

hemorrhagic anemia

acute or chronic blood loss

polycythemia

* “many blood cells”
* abnormal excess of erythrocytes in the blood