BSCI 202 lab practical 1

How to perform Blood Hematocrit

1. place capillary tube into blood sample to draw up blood

2. seal one end of cap tube and then centrifuge

3. measure total length, RBC, WBC and plasma

4. calculate RBC/total, WBC/total and plasma/total

afferent lymphatic vessels

bring lymph into a lymph node.

efferent lymphatic vessels

carries lymph out of a lymph node.

megakaryocytes

the giant bone‑marrow cell that makes platelets.

antigens

foreign substance body may attack

antibodies

• Y-shaped protein

• identifies and recognizes foreign invaders by binding specifically to their unique antigens

agglutination

blood is typed by using antibodies that will cause blood to clump

happens because specific, lock-and-key chemical reaction between surface antigens on red blood cells and added antibody reagents

AB

no antibodies

O

no antigens

cross matching

testing for agglutination of donor RBCs by recipient's serum and vise versa

lymphatic system consists 2 parts

1. lymphatic vessels

2. lymphoid tissues and organs

lymphatic system functions

1. transports escaped fluids back to blood

2. body defense and resist diseases

3. digestion

lymphatic vessels

one way system TOWARDS heart, no pump

how does lymph move through lymphatic vessels?

1. squeezing motion of skeletal muscle

2. rhythmic contraction of smooth muscle in vessels walls

lymph nodes

filters lymph fluid before returned to blood

lymph nodes defense cells

1. macrophages engulf & destroy foreign substances (antigen-presenting cell)

2. lymphocytes provide immune repose to antigens

harmful material that may enter lymph vessels

1. bacteria

2. viruses

3. cancer cells

4. cell debris

flow of lymph thru nodes

1. enters convex side thru afferent lymphatic vessels

2. flows thru number of sinuses inside node

3. exits thru efferent lymphatic vessels

(fewer efferent than afferent causes flow to be slowed)

lymphatic collecting vessels

1. collect lymph from lymph capillaries

2. carry lymph to and away from lymph nose

3. return fluid to circulatory veins near the heart (right lymphatic and thoracic duct)

lymph capillaries

1. walls overlap to form flap like mini valves

2. fluid leaks into lymph capillaries

3. capillaries anchored to connective tissue (endothelial) by filaments

4. higher pressure on inside closes mini valves

5. fluid is forced along the vessel

lymph node structure

central lymphoid tissue

• bone marrow + thymus

• where lymphocytes are made and trained

bone marrow

hematopoietic stem cells: starter for all blood cells

leukocytes except T lymphocytes fully dev here

peripheral lymphoid tissue

spleen, lymph nodes, tonsils, adenoid, appendix, peyer's patches

peripheral lymphoid tissue function

collections of B & T cells and macrophages, function to trap microorganisms and foreign particles, expose them to leukocytes in high concentrations

Spleen: located on the left side of the abdomen

Filters blood and destroys worn out blood cells

Forms blood cells in the fetus

Acts as a blood reservoir

Thymus: located low in the throat, overlying the heart

Functions at peak levels only during childhood

Produces hormones (like thymosin) to program

lymphocytes

T lymphocytes migrate from bone marrow to thymus and develop maturity

tonsils

• Small masses of lymphoid tissue around the pharynx

• Trap and remove bacteria and other foreign materials

• Tonsillitis is caused by congestion with bacteria

Peyer's patches

• Found in the wall of the small intestine & capture and destroy bacteria in the intestine

• Resemble tonsils in structure

Innate defense system (nonspecific defense system)

Mechanisms protect against a variety of invaders

Responds immediately to protect body from foreign materials

Adaptive defense system (specific defense system)

specific defense is required for each type of invader

size of heart

• size of a human fist

• weighs less than a pound

arteries

• carry blood AWAY from heart

• deliver under high pressure

• control blood distribution and blood pressure

veins

• carry blood TO heart

• work under low pressure

• must prevent backflow and help blood move upwards

chambers

2 atria- receive blood from venae cavae

2 ventricles- receive blood superior atria, forces blood thru arteries

4 heart valves

2 semilunar (SL) valves- pulmonary & aortic

2 atrioventricular (AV) valves- tricupsid and bicupsid

semilunar valves

location: opening to arteries

3 moon shaped flaps

pushed flat against artery wall during ventricular contraction

atrioventricular valve (AV)

2 AV b/w atria and ventricle

right av valve

tricuspid (3 flaps endocardium)

left av valve

bicuspid (2 flaps endocardium)

av valve function

blood flows into ventricle from atria (diastole)

av closes passively as pressure builds in ventricle (systole)

chordae tendineae

cords prevent AV valves inversion

Papillary muscle

anchors chordae tendineae

pericardium (tissue components)

double walled sac, outer fibrous and inner serous (double)

parietal pericardium (tissue components)

outer layer lining fibrous pericardium

visceral pericardium (tissue components)

inner layer which forms the outermost layer of the heart wall called EPICARDIUM

epicardium (heart wall)

visceral epicardium; outermost layer

myocardium

middle layer consists cardiac muscle, striated intercalated discs; under involuntary control

and fibrous skeleton composed of a dense network of fibrous CT that supports the cardiac muscle fibers and the heart valves

endocardium

innermost layer composed of endothelium (simple squamous epithelium)

systemic circulation

carries blood to all tissues, left ventricle, aorta, arteries, capillaries, venae cavae, right atrium

pulmonary circulation

necessary for gas exchange, brings O2 into bodies, right ventricles, pulmonary (trunk) arteries, lungs, pulmonary veins, left atrium

blood flow

1. body tissues

2. inferior/ superior venae cavae

3. right atrium

4. tricuspid to right ventricle

5. pulmonary semilunar valve

6. pulmonary trunk/ arteries

7. lungs

8. pulmonary veins

9. left atrium

10. bicuspid to left ventricle

11. thru aortic semilunar valve

12. aorta to systemic system

coronary circulation

heart not nourished by blood in heart

regions of major arteries from aorta

ascending aorta: leaves left ventricle

aortic arch: arches to left

thoracic aorta: travels downward through thorax

abdominal aorta: passes through the diaphragm into the abdominopelvic cavity

left coronary artery

branches into anterior inter ventricular & circumflex arteries

cardiac veins

great, middle and small: drain into coronary sinus to right atrium

conduction

The intrinsic conduction of the heart include non contractile cells called autorhythmic cells

autorhythmic cells

located in sinoatrial (SA) node, signal transmitted to atrioventricular (AV) node to AV bundle to bundle branches (left/right) to purkinje fibers

muscle contraction

change in electric potential (depolarization) and generation of action potential

cardiac muscle cells

connected thru gap junctions which allow for spread of action potential

role of nervous system

Heart muscle has the intrinsic ability to generate action potentials with the SA node as the natural pacemaker which sets the rate of depolarization of the heart

Autonomic nervous system

1. sympathetic (SNS)- accelerates heart rate

2. parasympathetic (PNS)- decelerates heart rate

sinoatrial node

superior right aritum, sets depolarization rate (pacemaker)-stimulus travels through atria (atrial contraction) and internodal pathway to AV node

Atrioventricular (AV) node

inferior atrial septum in the right atrium - the impulse is delayed

What is the significance of the delay of the impulse in the AV node?

allow for atrial contraction to be completed before ventricular depolarization begins to prevent the closure of the AV valves.

Electrical conduction through ventricles requires

1.Atrioventricular (AV) bundle- interventricular septum

2. Bundle branches- interventricular septum

3. Purkinje fibers- in muscles of ventricular walls- Simultaneous ventricular contraction,

Denser in left ventricle

Atrioventricular (AV) bundle

superior part of the interventricular septum

Bundle branches

interventricular septum bifurcates into the left and the right branches leading into the left and right ventricular wall

Purkinje fibers

in direct contact with the cardiac muscle cells in the

ventricular walls

The order of impulse transmission

1.SA node

2.AV node

3.AV bundle

4.Bundle branches

5.Purkinje fibers

electrocardiography

Measure of changes in electrical charge (mV) over time, using ECG monitor

P wave

single action wave;

depolarization of atria, immediately

before atrial contraction

QRS complex

multi-action wave; depolarization of ventricles, immediately before ventricular contraction, atrial repolarization occurs during ventricular contraction

T wave

single action wave; repolarization of ventricles

PQ interval

time of swim thru AV node, >.2 sec may indicate partial heart block, total heart block ventricles beat @ own rhythm

QRS interval

Prolonged interval may indicate partial blockage of right or left bundle branch

QT interval

From ventricular depolarization

through repolarization, faster heart rate means shorter interval

Junctional rhythm

he P wave is absent, SA node is not acting as the pacemaker leading to the AV node pacing the heart

A second degree heart block

Not all P waves are followed by QRS waves due damage to the AV node

Ventricular fibrillation

the impulses generated in the atria do pace

ventricular contractions. Typical tracing in acute myocardial infarction

Bradycardia

heart rate < 60 bpm, considered abnormal except in a well-conditioned athlete.

Causes: infection of heart tissue (myocarditis), heart tissue damage (old age or heart disease or heart attack)

risks: fainting, extreme fatigue, shortness of breath, heart failure, etc.

Tachycardia

heart rate > 100 bpm, abnormal when at rest, if untreated may lead to fibrillation.

Causes: anemia, exercise, smoking, caffeine, stress

Risks: dizziness, lightheadedness, fainting, palpitations, shortness of breath, chest pain, blood clots, stroke, etc.

Fibrillation

rapid, uncoordinated contractions of atria & ventricles rendering heart useless pump. Causes: heart attack, coronary artery disease, abnormal heart valves

Myocardial infarction

heart attack; when coronary arteries (blood vessels supply blood to heart) become blocked, starved of O2 and nutrients

distal

farthest from attachment (trunk)

proximal

closest to attachment (trunk)

medial

closest to middle

inferior

under something

superior

above something

posterior

towards back

anterior

towards front

coronal

divides front and pack

sagittal

divides right and left

transverse

divides top and bottom

lateral

away from middle

superficial

closer to surface of body

deep

farthest away from surface of body

ipsilateral

on the same side of body (right arm and right leg for example)

contralateral

on opposite side of body (right and left leg for example)

how do the various units of the metric system relate to each other?

By powers of 10