Power point slides Flashcards

1
Q

Functions of Blood

A

Transportation
- 02, CO2, metabolic wastes, nutrients, heat & hormones
Protection and prevents from disease & loss of blood

Regulation
- helps regulate pH through buffers
- helps regulate body temperature
- coolant properties of water
- vasodilatation of surface vessels dump heat
- helps regulate water content of cells by interactions with dissolved ions and proteins

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2
Q

Hemopoietic Growth Factors

A

Erythropoietin (EPO)
- produced by the kidneys increase RBC precursors
Thrombopoietin (TPO)
- hormone from liver stimulates platelet formation
Cytokines are local hormones of bone marrow not kidneys

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3
Q

Red Blood Cells or Erythrocytes

A
  • Contain oxygen-carrying protein hemoglobin that gives blood its red color
  • 1/3 of cell’s weight is hemoglobin
  • Biconcave disk 8 microns in diameter
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4
Q

Hemoglobin

A
  • Globin protein consisting of 4 polypeptide chains
  • 2 Beta polypeptide chains and Alpha 2
    polypeptide chains.
  • One heme pigment attached to each polypeptide chain
  • each heme contains an iron ion (Fe+2)
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5
Q

Erythropoiesis: Production of RBCs

A
  • Erythrocyte formation, called erythropoiesis, occurs in adult red bone marrow of certain bones
  • The main stimulus for erythropoiesis is hypoxia
  • ## hypoxia is low oxygen
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5
Q

Feedback Control of RBC Production

A
  • Kidney response to hypoxia release/increase erythropoietin increase speeds up development of proerythroblasts into reticulocytes
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6
Q

WHITE BLOOD CELLS

A
  • Leukocytes (white blood cells or WBCs) are nucleated cells and do not contain hemoglobin.
  • Two principal types are granular (neutrophils, eosinophils, basophils) and agranular (lymphocytes and monocytes)
  • Leukocytes have surface proteins, as do erythrocytes. They are called major histocompatibility antigens (MHC)
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7
Q

Neutrophils (Granulocyte)

A
  • Polymorphonuclear Leukocytes or Polys or PMN or Seg
  • Nuclei = 2 to 5 lobes connected by thin strands
  • older cells have more lobes
  • young cells called band cells because of horseshoe shaped nucleus (band)
  • 60 to 70% of circulating WBCs
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8
Q

Eosinophils (Granulocyte)

A
  • Nucleus with 2 or 3 lobes connected by a thin strand
  • 2 to 4% of circulating WBCs
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9
Q

Basophils (Granulocyte)

A
  • obscure the nucleus
  • Less than 1% of circulating WBCs
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10
Q

Lymphocyte (Agranulocyte)

A
  • amount varies from rim of blue to normal amount
  • increase in number during viral infections
  • 20 to 25% of circulating WBCs
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11
Q

Monocyte (Agranulocyte)

A
  • Nucleus is kidney or horse-shoe shaped
  • Largest WBC in circulating blood
  • does not remain in blood long before migrating to the tissues
  • 3 to 8% o circulating WBCs
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12
Q

Emigration & Phagocytosis in WBCs

A
  • chemotaxis of both kinins from injury site & toxins
  • extracellular destruction
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13
Q

Lymphocyte Functions

A

Natural killer cells
- attack many different microbes & some tumor cells
- destroy foreign invaders by direct attack

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14
Q

Eosinophil Function

A
  • Leave capillaries to enter tissue fluid
  • Release histaminase
  • slows down inflammation caused by basophils
  • Attack parasitic worms
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15
Q

Basophil Function

A
  • Involved in inflammatory and allergy reactions
  • Leave capillaries & enter connective tissue as mast
    cells.
  • Release heparin, histamine & serotonin
  • heighten the inflammatory response and account for hypersensitivity (allergic) reaction
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16
Q

Monocyte Function

A
  • Take longer to get to site of infection, but arrive in larger numbers
  • Become wandering macrophages, once they leave the capillaries
  • Destroy microbes and clean up dead tissue following an infection
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17
Q

Neutrophil Function

A
  • Fastest response of all WBC to bacteria
  • Direct actions against bacteria
  • release lysozymes which destroy/digest bacteria
  • release defensin proteins that act like antibiotics & poke holes in bacterial cell walls destroying them
  • release strong oxidants (bleach-like, strong chemicals ) that destroy bacteria
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18
Q

Differential WBC Count

A

Detection of changes in numbers of circulating WBCs (percentages of each type)
indicates infection, poisoning, leukemia, chemotherapy, parasites or allergy reaction
Normal WBC counts
- neutrophils 60-70% (up if bacterial infection)
- lymphocyte 20-25% (up if viral infection)
- monocytes 3 – 8% (up if fungal/viral infection)
- eosinophil 2 - 4% (up if parasite or allergy reaction)
- basophil <1% (up if allergy reaction or hypothyroid)

  • Eosinphil and basophil together is on test
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19
Q

PLATELETS

A
  • Thrombopoietin stimulates myeloid stem cells to produce platelets.
  • Myeloid stem cells develop into megakaryocyte-colony-forming cells that develop into megakaryoblasts
  • Megakaryoblasts transform into megakaryocytes which fragment.
  • Each fragment, enclosed by a piece of cell membrane, is a platelet (thrombocyte).
  • a life span of only 5 to 9 days;
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20
Q

Hemostasis

A

Stoppage of bleeding in a quick & localized fashion when blood vessels are damaged

Prevents hemorrhage (loss of a large amount of blood)

Methods utilized
- vascular spasm
- platelet plug formation
- blood clotting (coagulation = formation of fibrin threads)

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21
Q

Vascular Spasm

A
  • Damage to blood vessel produces stimulates pain receptors
  • Only for small blood vessel or arteriole
  • Can reduce blood loss for several hours until other mechanisms can take over
22
Q

Platelet Plug Formation

A

Platelets store a lot of chemicals in granules needed for platelet plug formation

alpha granules
- clotting factors
- platelet-derived growth factor

dense granules
- ADP, ATP, Ca+2, serotonin, fibrin-stabilizing factor, & enzymes that produce thromboxane A2

Steps in the process
- (1) platelet adhesion
- (2) platelet release reaction
- (3) platelet aggregation

Fibrinogen is not in platlets!!

23
Q

Platelet Release Reaction

A
  • Platelets activated by adhesion
  • Extend projections to make contact with each other
  • Release thromboxane A2 & ADP activating other platelets
  • Serotonin & thromboxane A2 are vasoconstrictors decreasing blood flow through the injured vessel
24
Q

Overview of the Clotting Cascade

A

First step in common pathway
- Prothrombinase is formed by either the intrinsic or extrinsic pathway
- Final common pathway produces fibrin threads

25
Q

Leukemia

A

Acute leukemia
- uncontrolled production of immature leukocytes
- crowding out of normal red bone marrow cells by production of immature WBC
- prevents production of RBC & platelets

Chronic leukemia
- Adults only
- accumulation of mature WBC in bloodstream because they do not die
- classified by type of WBC that is predominant—monocytic, lymphocytic.

26
Q

Pericardium

A

The heart is enclosed and held in place by the pericardium.

27
Q

Pericardium

A

Fibrous pericardium
- dense irregular CT protects and** anchors the heart and diaphram**, prevents overstretching

28
Q

Layers of Heart Wall

A

Epicardium
- visceral layer of serous pericardium
Myocardium
- Middle layer
- cardiac muscle layer is the bulk of the heart
Endocardium
- chamber lining & valves

29
Q

Chambers and Sulci of the Heart

A

Four chambers
- 2 upper atria
- 2 lower ventricles
Sulci - grooves on surface of heart containing coronary blood vessels and fat
coronary sulcus
- encircles heart and marks the boundary between the atria and the ventricles
anterior interventricular sulcus
- marks the boundary between the ventricles anteriorly
posterior interventricular sulcus
- marks the boundary between the ventricles posteriorly

30
Q

Right Ventricle

A
  • Lungs only
  • Forms most of anterior surface of heart
  • Papillary muscles are cone shaped trabeculae carneae (raised bundles of cardiac muscle)
  • Chordae tendinee: cords between valve cusps and papillary muscles
  • Interventricular septum: partitions ventricles
  • Pulmonary semilunar valve: blood flows into pulmonary trunk
31
Q

HEART VALVES AND CIRCULATION OF BLOOD

A

Valves open and close in response to pressure changes as the heart contracts and relaxes.

32
Q

Atrioventricular Valves

A
  • A-V valves close preventing backflow of blood into atria
  • One way flow
33
Q

Coronary Arteries

A
  • Part of systemic
  • Branches off aorta above aortic semilunar valve
    Left coronary artery
  • circumtlex branch in coronary sulcus,
    supplies left atrium and left ventricle
    anterior interventricular art.
  • supplies both ventricles
    Right coronary artery
    marginal branch
  • in coronary sulcus, supplies right ventricle posterior interventricular art. supplies both ventricles
34
Q

Coronary Veins

A
  • Collects wastes from cardiac muscle
  • Drains into a large sinus on posterior surface of heart called the coronary sinus
  • Coronary sinus empties into right atrium
  • Does not suppy oxygen
35
Q

Cardiac Muscle Histology

A

Branching, intercalated discs with gap junctions, involuntary, striated, single central nucleus per cell
Not cylindrical

36
Q

Autorhythmic Cells: The Conduction System

A
  • Cardiac muscle cells are autorhythmic cells because they are self-excitable. They repeatedly generate spontaneous action potentials that then trigger heart contractions.
  • These cells act as a pacemaker to set the rhythm for the entire heart.
  • They form the conduction system, the route for propagating action potential through the heart muscle.
37
Q

Conduction System of Heart

A
  1. SINOATRIAL (SA) NODE
  2. ATRIOVENTRICULAR (AV) NODE
  3. ATRIOVENTRICULAR (AV) BUNDLE (BUNDLE OF HIS)
  4. RIGHT AND LEFT BUNDLE BRANCHES
  5. PURKINJE FIBERS
38
Q

Conduction

A
  • Components of this system are the sinoartrial (SA) node (pacemaker), atrioventricular (AV) node, atrioventricular bundle (bundle of His), right and left bundle branches, and the conduction myofibers (Purkinje fibers)
  • Signals from the autonomic nervous system and hormones, such as epinephrine, do modify the heartbeat (in terms of rate and strength of contraction), but they do not establish the fundamental rhythm.
39
Q

Rhythm of Conduction System

A
  • SA node fires spontaneously 90-100 times per minute
  • AV node fires at 40-50 times per minute
  • If both nodes are suppressed fibers in ventricles by themselves fire only 20-40 times per minute
  • Artificial pacemaker needed if pace is too slow
  • Extra beats forming at other sites are called ectopic pacemakers
  • caffeine & nicotine increase activity
40
Q

Action potential and contraction of contractile fibers

A
  • An impulse in a ventricular contractile fiber is characterized by rapid depolarization, plateau, and repolarization
  • The refractory period of a cardiac muscle fiber (the time interval when a second contraction cannot be triggered) is longer than the contraction itself
  • Therefore tetanus cannot occur in myocardial cells.
41
Q

Depolarization & Repolarization

A

Depolarization
- cardiac cell membrane resting potential is -90mv
- fast na+ opens for depolarization

Plateau phase
- slow Cat2 channels open, let Ca +2 enter from outside cell and from storage in sarcoplasmic reticulum, while K+ channels close
- Ca +2 Dings to troponin to allow for actin-myosin cross-bridge formation & tension development

Repolarization
- Ca+2 channels close and K+ channels open & -90mv is restored as potassium leaves the cell

Refractory period
- very long so heart can fill

42
Q

Electrocardiogram

A

The ECG helps to determine if the conduction pathway is abnormal, if the heart is enlarged, and if certain regions are damaged.

43
Q

Electrocardiogram—ECG or EKG

A

**EKG **
- atrial depolarization
- Action potentials of all active cells can be detected and recorded
P wave
- atrial depolarization

P to Q interval
- conduction time from atrial to ventricular excitation

QRS complex
- ventricular depolarization and atrial repolarization

T wave
- ventricular repolarization

44
Q

After QRS

A

Ventricular systole (contraction)

45
Q

THE CARDIAC CYCLE

A
  • Occurs dependently
  • A cardiac cycle consists of the systole (contraction) and diastole (relaxation) of both atria, rapidly followed by the systole and diastole of both ventricles.
  • Pressure and volume changes during the cardiac cycle
  • During a cardiac cycle atria and ventricles alternately contract and relax forcing blood from areas of high pressure to areas of lower pressure.
  • Average bp 93
  • 0 entering right atria
46
Q

One Cardiac Cycle - Vocabulary

A
  • At 75 beats/min, one cycle requires 0.8 sec.

systole (contraction) and diastole (relaxation) of both atria, plus the systole and diastole of both ventricles

End diastolic volume (EDV)
volume in ventricle at end of diastole, about 130ml

End systolic volume (ESV)
volume in ventricle at end of systole, about 60ml

Stroke volume (SV)
the volume ejected per beat from each ventricle, about 70ml SV = EDV - ESV

47
Q

Heart Sounds

A

Closing of
valves make heart sounds (heart beat)

48
Q

Preload: Effect of Stretching

A

According to the Frank-Starling law of the heart, a greater preload (stretch) on cardiac muscle fibers just before they contract increases their force of contraction during systole.
- Preload is proportional to EDV.
- EDV is determined by length of ventricular diastole and venous return.

49
Q

Afterload

A

The pressure that must be overcome before a semilunar valve can open is the afterload.

In congestive heart failure, blood begins to remain in the ventricles increasing the preload and ultimately causing an overstretching of the heart and less forceful contraction
- Left ventricular failure results in pulmonary edema
- Right ventricular failure results in peripheral edema.

50
Q

Control of Blood Pressure & Flow

A
  • Vagus nerves (parasympathetic) = Heart: decreased rate
  • Cardiac accelerator nerves (sympathetic) = Heart: increased rate and contractility
  • Vasomotor nerves (sympathetic) = Blood vessels: vasoconstriction
51
Q

Muscular Arteries

A
  • Medium-sized arteries with more muscle than elastic fibers in tunica media
52
Q

Elastic Arteries

A

Large arteries with more elastic fibers and less smooth muscle are called elastic arteries and are able to receive blood under pressure and propel it onward

  • Elastic aorta and arteries stretch during ventricular contraction
  • Elastic aorta and arteries recoil during ventricular relaxation
53
Q

Vessels

A

Blood vessels form a closed system of tubes that carry blood away from the heart, transport it to the tissues of the body, and then return it to the heart.

  • Arteries carry blood from the heart to the tissues.
  • Arterioles are small arteries that connect to capillaries.
  • Capillaries are the site of substance exchange between the blood and body tissues.
  • Venules connect capillaries to larger veins.
  • Veins convey blood from the tissues back to the heart.
  • Vaso vasorum are small blood vessels that supply blood to the cells of the walls of the arteries and veins.