KIN 101 Final (14 & 16) Flashcards
What is blood made up of?
Blood:
- Plasma is the extracellular matrix
- Fluid matrix of blood
○ Water (92%)
○ Protiens (7%) (usually help transport)
○ Remaining 1%
§ Ions (Na+, K+, Cl+, H+, Ca2+, HCO3-)
§ Organic molecules
§ Gases (O2 and CO2)
§ Trace elements
§ Vitamins
- Identical in composition to interstitial fluid but has plasma protiens
○ Albumins, globulins, fibrinogen, transferrin
Plasma (functions and what manages it?)
Plasma:
- Functions:
○ Transport materials
○ Solvent for cellular elements
- Management:
○ Primarily by the kidneys
Involves the absorption and excretion of water
What are the 4 major components of blood? (Albumins)
- Albumins: major contributors to plasma colloid osmotic pressure: carriers for various substances
- Albumins are the most prevalent PRO, interestingly they transport free fatty acids
What are the 4 major components of blood? (Globulins)
- Globulins: Clotting factors, enzymes, antibodies, carriers for various substances
What are the 4 major components of blood? (Fibrinogen)
- Fibrinogen: forms fibrin threads (essential for blood clotting)
What are the 4 major components of blood? (Transferrin)
- Transferrin: ion transportation
Plasma protiens (what do they do?)
Plasma protiens
- Act as carriers
- Participate in blood clotting
- Defense against foreign invaders
- Create colloid osmotic pressure
Blood (what three cells are within?)
Blood is composed of
- Red blood cells (RBCs) - also called Erythrocytes (make up most of the cellular elements)
- Platelets - split off from megakaryocytes
○ (how it clots but they are not living)
○ (they are not cells)
- White blood cells (WBCs) - also called leukocytes
1. Lymphocytes (immunocytes)
2. Monocytes - develop into macrophages (phagocytes)
3. Neutrophils (most common) - phagocytes and granulocytes
4. Eosinophils - granulocytes, eosinophils can be phagocytic however the present evidence is all from vitro studies
5. Basophils - granulocytes: tissue basophils are called mast cells
White blood cells (WCBs) (What are phagocytes?)
White blood cells (WCBs)
- Phagocytes
○ Lymphocytes: produce specific immune responses directed against invaders
○ Monocytes: phagocytes: after migrating into tissues they develop into macrophages
- (Both Granulocytes and Phagocytes)
○ Neutrophils: mobile phagocytes that ingest foreign substances and pathogens
White blood cells (WCBs) (what are granulocytes?)
White blood cells (WCBs)
- (Both Granulocytes and Phagocytes)
○ Neutrophils: mobile phagocytes that ingest foreign substances and pathogens
- Granulocytes
○ Eosinophils: produce toxic compounds directed against invading pathogens
○ Basophils: tissue basophils are also called mast cells
Measuring blood composition (CBC)
Complete blood count (CBC): provides information about plasma volume, white blood cells, and packed red blood cell volume
What does a CBC include?
- Mean Corpuscular Volume (MCV): the average volume of one red blood cell. (a corpuscle is a small unattached cell - diminutive of corpus, body)
- Mean Corpuscular Hemoglobin (MCH): amount of hemoglobin per RBC
- Mean Corpuscular Hemoglobin Concentration (MCH C): the amount of hemoglobin per volume of one red blood cell
What are normal blood count ranges?
Hematocrit: amount of red blood cells
males: 40-54% females: 37-47%
Hemoglobin: Oxygen carrying capacity
males: 14-17 females: 12-16
Anemia
Anemia: occurs when you do not have red blood cells OR when your red blood cells do not function properly
(it is diagnoses when a blood pressure test shows a hemoglobin value of less than 13.5 gm/dl in a man OR less than 12.0 gm/dl in a woman)
Blood cell production (where are blood cells produced?)
Blood cell production:
- Blood cells are produced in the bone marrow
○ Hematopoiesis: Production of blood cells
○ Red bone marrow is red because it contains Hemoglobin; Active
§ 25% RBCs, 75% WBCs
○ Yellow bone marrow contains adipose cells; Inactive
- Hematopoiesis is controlled by Cytokines
○ Interleukins (lls)
Cytokines (what are they?)
Cytokines: are peptides or protiens released from one cell that affect the growth or activity of another cell
- (involved in the production of red blood cells)
Platelets (what are they made from?)
Megakaryocytes disperse into fragments and these are platelets
What is red blood cell production regulated by?
Blood cell production is regulated by
- Colony stimulating factors (regulate leukopoiesis)
○ CSFs
○ Leukopoiesis: production of white blood cells
- Thrombopoietin (regulates platelet production)
○ TPO
- Erythropoietin (regulates red blood cell production)
○ EPO
○ Erythropoiesis: production of red blood cells
Red blood cell (characteristics)
Red blood cells
- Are usually a biconcave disc
- Mature red blood cells lack a nucleus
○ Morphology can provide clues to the presence of disease
○ Mean corpuscular volume (MCV): size of red blood cells
- Hematocrit: Ratio of red blood cells to plasma, expressed as a percentage
Bone marrow (Characteristics)
Bone marrow:
- Is a tissue
- Collectively makes up the same size and weight as the liver does
- Highly vascular tissue
- Filled with blood sinuses
- Widened regions are lined with epithelium
- Consists of red blood cells in different stages of development
Red blood cell production (how is it regulated?)
Regulation of Erythropoiesis (Red blood cell production)
- Controlled by Erythropoietin (EPO)
- Stimulus for EPO release is low )2 levels in the tissue (hypoxia)
- Hypoxia stimulates Hypoxia-inducible Factor 1 (HIF-1)
- This turns on the EPO gene to increase EPO synthesis in the kidneys
- Increases RBC production in the bone marrow
How long can a red blood cell live for?
When the nucleus disappears it makes the cell unable to divide and survive for more than 120 days
- It loses this so it can fit through the capillaries
- White blood cells also come out of the marrow
What is Heme?
- Heme is a porphyrin ring with an iron atom in its center
○ Iron comes from diet
○ Transported in the blood by transferrin
○ Iron taken up in bone marrow
○ Excess iron stored in liver by ferritin
Platelets (how long do they last for?)
Megakaryocytes are much smaller compared to RBCs
- Platelets last 10 days
- They are important in stopping blood loss, immunity and inflammation
How does blood clotting occur?
- When collagen is exposed the platelets get the signal that they need to go there
- To actually plug the hole it follows the intrinsic pathway which activates the coagulation cascade
- This causes more aggregation at the puncture
- The fibrin fibers become part of the clot and reinforces existing aggregate of platelets (this begins with thrombin)
What two mechanisms lead to blood clotting?
There are two mechanisms that lead to a blood clot
- Extrinsic (begins with the tissue factor being exposed)
- Intrinsic (begins with collagen exposed)
Endogenous anticoagulants (what are they?)
Endogenous anticoagulants: they essentially act the opposite to collagens and make the blood unable to clot
- Heparin is an anticoagulant (it can interrupt the blood clotting process)
- Antithrombin lll
- Protien C
Arteries (where do they carry blood?)
Arteries: carry oxygenated blood from the left ventricle to the tissues
Veins (where do they carry blood?)
Veins: carry deoxygenated blood back to the right atrium
Heart development in a child (what day does what occur?)
The heart develops from a single tube
- At day 25 it is a single tube
- By week 4 the atria and ventricle can be distinguished
○ The heart begins to twist so that the atria move on top of the ventricle
- At one year of development the atriums and ventricles are developed
Cardiovascular system (what are the four main components?)
Cardiovascular system
- Blood vessels (vasculature)
○ Arteries and veins
○ Capilaries
○ Portal system joins two capillary beds in series
- Heart
○ Septum divides heart into two halves (left and right)
○ Atrium receives blood returning to the heart
○ Ventricle pumps blood out of the heart
- blood
○ Cells
○ Plasma
- Pulmonary vs systemic circulation
○ Pulmonary arteries vs pulmonary veins
○ Aorta vs inferior vena cava and superior vena cava
What is the highest pressure blood should reach and where?
- The mean blood pressure of systemic circulation ranges from a high of 93mm Hg in the aorta
What is the lowest blood pressure and where?
- A low of only a few mm Hg in the venae cava
Fluid in motion has two components
(What are they?)
Fluid in motion has two components
- Dynamic (kinetic energy)
- lateral (hydrostatic pressure)
Hydrostatic pressure (What is it?)
Hydrostatic pressure: pressure exerted by a fluid not in motion that is exerted in all directions
What are the 3 layers of the heart?
Layers of the heart and lung system
- Endocardium (inner)
○ Layer of endothelial cells
- Myocardium (middle)
○ Cardiac muscle
- Epicardium (outer)
○ External membrane
The Pericardium (what is it?)
The heart:
- Pericardium:
○ Is encased in a strong membranous sac that encases and protects the heart
○ Fused to the diaphragm
○ Within the sac is pericardial fluid that lubricates and allows the heart to operate in a friction free environment
Echocardiogram (what does it tell us?)
Echocardiogram
- Provides info on
○ Size and shape of heart
○ Pumping strength
○ Location and extent of any damage
- It is especially useful for assessing disease of the heart valves and cardiac hypertrophy
Blood flow through the heart (steps)
One way flow through the heart is ensured by the two sets of valves in the heart
- Deoxygenated enters heart through vena cava into right atrium then into right ventricle
- Then is pumped out via the left pulmonary arteries to the lungs
- Blood is returned by the left pulmonary veins to the left atrium
- Enters the left ventricle and leaves through aorta
Autorhythmic cells (what do they do?)
- Autorhythmic cells: spontaneously fire action potentials
○ These depolarizations rapidly spread to connected contractile cells through gap junctions and cause the ventricles to contract
Cardiac muscle (Characteristics)
Cardiac muscle
- Spiral arrangement of ventricular muscle allows for ventricular action to squeeze the blood upward from the apex of the heart
- Intercalated disks contain desmosomes that transfer force from cell to cell and gap junctions that allow electrical signals to pass rapidly from cell to cell
- The spiral arrangement is what produces the “wringing” motion when the atria or ventricles contract
Cardiac muscle (Desmosomes)
Desmosomes
- Strong protiens that surrounds sarcomeres and bind neighboring sarcomeres
- Allow force to be transferred
Cardiac muscle (Gap junctions)
Gap junctions
- Provide electrical connection
- Electrical signals are rapidly transmitted via these protien pores providing the basis for synchronous contraction
What makes cardiac muscle different from skeletal muscle?
- Large volume of mitochondria (1/3rd of volume)
a. This is due to the dependence of the heart on aerobic ATP production that only occurs in the mitochondria- Spontaneously contract
a. Pacemaker cells within the sinoatrial node control heart rate
- Spontaneously contract
Atrioventricular valves (what are they called?)
The heart valves create a one way only flow through the heart
- Mitral valve is another name for the BICUSPID valve on the left side of the heart
- Tricuspid valve is the valve for the right atrium
Semilunar valves (what are they?)
Semilunar valves prevent blood that has entered the arteries from flowing back into the ventricles durring ventricular relaxation
Coronary vessels (what do they do?)
The coronary circulation
- Coronary vessels supply and drain the anterior surface of the heart
Facts about the heart
Facts about the heart
- Heart is made up of mostly myocardium
○ Encased in pericardium
- Upper atria are separated by thin wall
- Lower ventricles are separated by thick walled lower chambers
- Blood vessels emerge from base of the heart
○ Aorta and pulmonary trunk carry blood from heart
○ Vena cava and pulmonary veins return blood to the heart
○ Deoxygenated: vena cava -> right atrium -> right ventricle -> pulmonary trunk
○ Oxygenated: pulmonary veins -> left atrium -> left ventricle -> aorta
○ Connective tissue rings serve as origin and insertion for cardiac muscles
The force generated in the heart is proportional to what?
The force generated in heart muscles is proportional to the number of active crossbridge
- This is determines by how much calcium is bound to troponin
Steps of a cardiac muscle contraction (all)
How a cardiac muscle contracts
- Action potentials enter from adjacent cells
- Voltage gated Ca2+ channels open and Ca2+ enters
- The entrance of calcium induces more calcium release through RyR receptors
- Local release causes calcium spark
- These summed sparks create a calcium signal
- Relaxation occurs when calcium unbinds from troponin
- Calcium is pumped back into the sarcoplasmic reticulum
- Calcium is exchanged with Na+
- Gradient is maintained by the Na+, K+, ATPase
What effects the force of a contraction?
Sarcomere length affects force of contraction
Charactaristics of pacemaker potential (what makes it different than action potential)
It is called pacemaker potential because it never sits at a resting potential
1. Na+ flows in until it reaches threshold
2. Calcium starts entering once it reaches threshold
3. At peak it stays there for longer than regular action potential
4. K+ then flows out of the cell during repolarization
What is the membrane potential of cardiac muscle?
Its membrane potential is -90mV
Waves of a Heart contraction (P wave)
P wave: the SA node depolarizes and then the atria
Waves of a Heart contraction (R wave)
R wave: the Purkinge fibers depolarize located in the apex and outer walls of the heart
Waves of a Heart contraction (Q wave)
Q wave: the SA node depolarizes and then the bundled branches located in the septum
What order does the heart contract?
- Top contracts
- Middle contracts
- Then bottom apex to force up the
pulmonary artery
- Then bottom apex to force up the
- Middle contracts
What does an ECG consist of?
A normal ECG consists of
- Waves: deflections above or below baseline
- Segments: sections of baseline between waves
- Intervals: combinations of waves and segments
What are the waves of an ECG
P wave: is pre spike
Q: is dip of pre spike
R: is peak of spike
S: is dip after spike
T wave: is post spike
P wave: atrial depolarization
QRS complex: ventricular depolarization
T wave: ventricular repolarization
Systole/Diastole
- Systole=atriums contract and ventricle contract
- Diastole=after the ventricle contraction and before the next atrial contraction
Internodal pathway (what is its purpose?)
Internodal pathway from SA node to AV node
- Routes the direction of electrical signals so the atria contact first and then the ventricles from the apex to the base
Purkinje fibers (what do they do?)
Purkinje fibers transmit electric signals down the atrioventricular bundle to the left and right bundle branches
What does the SA node do and what does it set heart rate at?
The SA node sets the pace of the heart at 70BPM
- The AV node (50BPM) and purkinje fibers (25-40BPM) act as pacemakers under some conditions
The SNS what does it do?
SNS
- Uses beta1 receptors of autorhythmic cells
- Na+ and Ca2+ influx
- Increases rate of depolarization
- Heart rate increases
Isovolumic contraction (what is it?)
- Isovolumic contraction: the point where the heart has both valves closed and it is about to open the valves to release but pressure is the greatest (mitral valve closes)
How much percent of the blood enters without the atria actually contracting?
80% of blood enters before contraction (only 20% actually is driven into the ventricles)
Stroke volume SV (Formula)
SV = End diastolic V - End systolic V
Ejection Fraction (EF)
EF = SV/EDV x 100
3 factors that effect stroke volume
- Preload
- Contractility is how much or hard the heart contracts
- Afterload is in the aorta or pulmonary vessel as its pressing down on the heart
What two hormones affect SV?
Epinepherine and norepinephrine bind to beta1 receptors
- This increases the level of calcium release
- Phospholamban is a secondary messenger
- This allows us to release calcium faster
Increased sympathetic activity means what for our heart?
Increased sympathetic activity =
- Increased epinepherine release
- Increases strength of contraction
- Increases rate of both contraction and relaxation
○ Decreased duration of contraction
How can we increase blood volume in the heart?
How can we increase blood volume in the ventricles
- Increased venous return happens
○ The amount of blood that returns to the heart from venous circulation
○ Venous return is affected by
§ Skeletal muscle pump
□ The muscle pushes blood up the tube buy squeezing it
§ Respiratory pump
□ The respiratory pump works more at rest
□ Works like a syringe
® Creates an area of lower pressure that pulls in more blood
□ It pulls and pushes blood out using a vacuum
§ Venous constriction
□ The vessel squeezes it through
