Unit 2 Lecture Flashcards

Question

What are the concentrations of Hemoglobin in Blood?

Answer 1

* 16 g/dL (g/100mL) of blood in men * 14 g/dL (g/100mL) of blood in women * The hematocrit and the hemoglobin level are diagnostic for anemia

Answer 2

RBC formation

Answer 3

* Occurs in the red bone marrow * RBCs are formed from a lineage of precursor stem cells * Precursor myleoid stem cells differentiate into proerythroblasts * Proerythroblasts then become erythroblast then reticulocytes * When a reticulocyte reaches maturity, hemoglobin is produced and the nucleus is ejected, resulting in the formation of a mature erythrocyte * The nucleus with undergo phagocytosis

Answer 4

In red bone marrow

Answer 5

* Role: regulation of differentiation and proliferation of blood cells * Erythropoietin (EPO) * Stimulates erythropoiesis * Produced by the kidneys * Because the kidneys receive 25% of the blood at rest and they remove waste and produce urine * Increases RBC precursors * Thrombopoietin (TPO) * Hormone from liver * Stimulates platelet formation * Cytokines * Local hormones of bone marrow * Produced by some marrow cells to stimulate proliferation in other marrow cells * Colony-stimulating factors (CSFs) and interleukins stimulate WBC production

Answer 6

* Available through recombinant DNA technology * Recombinant erythropoietin (EPO) is very effective in treating decreased RBC production of end-stage kidney disease * Other products given to stimulate WBC formation in cancer patients receiving chemotherapy which kills bone marrow * Thrombopoietin (TPO) helps prevent platelet depletion during chemotherapy

Answer 7

* RBCs live only 120 days * Weat out from bending to fit through capillaries * No repair possible due to lack of nucleus * Also, since they don't have a nucleus they won't get as destroyed when they are crashed into

Answer 8

* Worn out red blood cells are removed by fixed macrophages in the spleen and liver * Breakdown products are recycled

Answer 9

* Destruction and recycling of RBCs is done by macrophages of the liver and spleen * Globin portion broken down into amino acids and recycled * Heme portion split into iron (Fe3+) and biliverdin (green pigment)

Answer 10

* Iron is transported in blood attached to transferrin protein * Stored in liver, muscle or spleen (attached to ferritin or hemosiderin protein) * Transported to bone marrow for use in hemoglobin synthesis

Answer 11

* Biliverdin (green) converted to bilirubin (yellow) * Bilirubin is secreted by liver as part of bile, and bile is secreted into the intestine for use in digestion * Bile breakdown products are excreted via kidneys and intestine

Answer 12

Bilirubin is converted in the large intestine into urobilinogen. Some urobilinogen is reabsorbed, converted into urobilin, and then excreted vis the kidneys in urine

Answer 13

* All WBCs (leukocytes) have a nucleus, but no hemoglobin * Contain DNA * Granular or Agranular classification based on presence of cytoplasmic granules made visible by staining * Granulocytes are neutrophils, eosinophils and basophils * Agranuloctes are monocytes and lymphocytes

Answer 14

1 WBC for every 700 RBC

Answer 15

* Leukocytosis is a high white blood cell count * Microbes, strenuous exercise, anesthesia or surgery, Stress hormones, and fighting infections * Leukopenia is low white blood cell count * Radiation, shock or chemotherapy * Destroy precursor cells so leukocytes won't even be able to develop * Only 2% of total WBC population is in circulating blood at any given time * Rest is in lymphatic fluid, skin, lungs, lymph nodes and spleen * They eat dust and ash in the lungs

Answer 16

* WBCs roll along endothelium, stick to it, and squeeze between cells * Adhesion molecules (selectins) help WBCs stick to endothelium * They are basically hooks on the walls of the vessels * They are displayed near the site of injury * Integrins found on neutrophils assist in movement through wall * Integrins get stuck on the selectins and help them move

Answer 17

* "cell eating" of bacteria * Performed avidly by monocytes and neutrophils * Macrophages identify foreign particles or bacteria * Eosinophils have weaker phagocytic activity * The process involves: chemotaxis; adherence and ingestion; and destruction

Answer 18

* It is the attraction of phagocytic cells to the site of infection * Chemicals released by the pathogen and/or the infected cell attract the phagocytes

Answer 19

* Adherence is the attachment of the phagocyte to the pathogen's membrane * Ingestion is facilitated by enveloping pseudopodia, resulting in a phagosome

Answer 20

* Destruction is initiated when the phagosome fuses with a lysosome, resulting in a "phagolysosome" * Lysozymes and other destructive chemicals from the lysosome destroy the membrane and internal structures of the pathogen * Residual fragments of the dead pathogen can be removed from the cell by exocytosis

Answer 21

* Intravenous transfer of healthy bone marrow * Procedure * Destroy sick bone marrow with radiation and chemotherapy * Put sample of donor marrow into patient's vein for reseeding of bone marrow * Success depends on histocompatibility of donor and recipient * Treatment for leukemia, sickle-cell, breast, ovarian or testicular cancer, lymphoma or aplastic anemia

Answer 22

* Cell fragments that circulate for 5-9 days, then die * 2/3 of mature platelets circulate, whereas 1/3 reside in the spleen

Answer 23

Thrombosis refers to clot formation; a clot is caleed a thrombus

Answer 24

An embolus is a circulating clot \*\*A pulmonary embolism is a stroke and can cause a heart attack

Answer 25

Hemorrhage is defined as severe, uncontrolled bleeding

Answer 26

* Myeloid stem cells produce megakaryocytes * They have a diameter of 160 micrometers * Thrombopoietin, or TPO, causes fragments to slough off the megakaryocyte * 2000-3000 fragments, or platelets, enter the circulation * Each platelet is roughly 2-4 micrometers in diamere and about 1 micrometer in thickness

Answer 27

* A series of reactions designed for stoppage of bleeding * During hemostasis, three phases occur in rapid sequence 1. Vascular spasm - immediate vasoconstriction in response to injury 2. Platelet plug formation 3. Coagulation (blood clotting)

Answer 28

* Occurs only in vessels with smooth muscle in wall * Reaction to injury * Reduces velles diameter * Stops blood flow almost instantly * Effective only in small vessels

Answer 29

* Blood flow is proportional to the driving pressure, and inversely proportional to the "resistance" to flow * Flow = driving pressure / Resistance

Answer 30

* Platelets NORMALLY do not stick to each other or to the endotherlial lining of blood vessels * Upon damage to a blood vessel, platelets: * Stick to exposed collagen fibers and are activated, allowing them to stick to one another * Phosphoserine from the injury makes the platelets sticky other than that they are never sticky * The Platelets also release ADP which makes it sticky and help in the formation of the platelet plug * Liberate thromboxane A₂, serotonin and ADP, which attract and activate still more platelets * Release ADP which makes platelets sticky, while thromboxane A₂ and serotonin cause cell contraction. This results in the formation of a tight platelet plug

Answer 31

* Very complex (about 30 substances) * 13 clotting factors (most from your liver) * A set of reactions in which blood is transformed from a liquid to a gel * Has intrinsic and extrinsic pathways * Intrinsic pathway tends to be slower than extrinsic pathway * The final 3 steps constitute the "common pathway" which must be completed in order for effective clotting to occur * Once prothrombinase is activated, it converts prothrombin into thrombin * Thrombin has two main functions * Converts fibrinogen (soluble) to fibrin (insoluble, stable threads) * Activates factor XIII, which stabilizes the fibrin network

Answer 32

* Intrinsic pathway is an internal injury with a cell missing exposing the basement membrane or something * Extrinsic pathway is an external injury with a cut exposing to the inner core of the vessel

Answer 33

* Clots must be dissolved so that they do not enter the circulation as an ambolus * The dissolution of a clot is known as fibrinolysis * Tissue plasminogen activator, thrombin and plasminogen all react to form plasmin, which then digests the fibrin strands and breaks the clot

Answer 34

\*\*\*Angiotensin 1 is in the pulmonary cells that turn into angiotensin 2 ## Footnote Angiotensinogen is made in the liver and that’s what Angiotensin 1 comes from

Answer 35

* The fastest way to change the pH of blood is to either hold your blood or breathe to fast * -Breath to fast, lost too much CO2 and become basic * -Hold breath, maintains and increases CO2, and becomes acidic

Answer 36

* External respiration refers to the exchange of gases between the atmosphere and blood * Occurs in pulmonary capillaries and alveoli * Internal respiration refers to gas exchange between capillary blood and the cells in tissues * Occurs in pulmonary capillaries, oxygen goes out CO₂ is picked up * BTW: Cellular respiration refers to the use of oxygen by cells to produce ATP by oxidizing glucose * Oxygen takes the old not very useful already used electrons so that new useful ones can come in

Answer 37

* Stratified squamous in the Laryngopharynx * Pseudostratified columnar epithelium in the Naspharynx

Answer 38

* Pulmonary ventilation: refers to the alternating flow of air into and out of the lungs * This cyclic airflow is due to the actions of various respiratory muscles

Answer 39

* Inspiratory muscles: expand the rib cage during inspiration and drive airflow into the lungs * Inspiration increasts the diameter of the thoracic cavity this also helps with the respiratory pump of blood

Answer 40

* Expiratory muscles: depress the rib cage and force air out of the lungs

Answer 41

* The skeletal portion of the thorax is called the thoracic cage * It includes the ribs, costal cartilages, thoracic vertebrae, and sternum

Answer 42

* Respiratory mechanics is the study of how the respiratory muscles move the rib cage

Answer 43

* The "respiratory pump" refers to the respiratory muscles, rib cage, pleural membranes, and lung elastic tissues

Answer 44

Diaphragm is the primary inspiratory muscle

Answer 45

External intercostal muscles move ribs upward and outward, expanding the rib cage.

Answer 46

The sternocleidomastoid elevates the sternum

Answer 47

The scalenes elevate the top two ribs

Answer 48

* Internal intercostal muscle pull ribs downward and inward, reducing the diameter of the rib cage * Reduce thoracic cavity volume to force air out of lungs

Answer 49

* Abdominal muscles depress the lower ribs and elevate the diaphragm by increasing abdominal pressure * Reduce thoracic cavity volume to force air out of lungs

Answer 50

Breathing, or ventilation, depends on periodic pressure changes in the lungs

Answer 51

Inspiration/inhalation occurs when pressure in the lungs becomes lower than the pressure in the atmosphere -During inspiration, the parietal pleura is pulled outward, and the visceral pleura -- and lungs -- move with it

Answer 52

Expiration/exhalation occurs when pressure in the lungs is high than the pressure in the atmosphere

Answer 53

Pleural membranes

Answer 54

* Increasing the volume decreases the pressure * Fewer collisions * Decreasing the volume increases the pressure * More collisions

Answer 55

1. Lung tissue will always rapidly collapse inward 1. This is why punctures are incredibly dangerous 2. We are always pushing a lot of force to keep the lungs inflated 2. Chest wall will always spring outward 3. Between breaths, the recoil forces are equal and the respiratory muscles are at rest

Answer 56

Physiologists define the amount of air present in the lungs in this state as the "end-expiratory lung volume" (also called functional residual capacity or FRC)

Answer 57

* Transpulmonary pressure (P_tp) = distending pressure exerted on (i.e. experienced by) the lungs * P_tp is calculated by subtracting the intra-pleural pressure (P_ip), the fluid pressure in the pleural cavity (space) which surrounds the lungs, from the air pressure inside the alveoli, called the intra-alveolar pressure (P_alv) P_tp = P_alv - P_ip

Answer 58

1. Contraction of diaphragm enlarges the thoracic cavity (increasing its volume) 2. Parietal pleura is pulled outward, which pulls on the pleural fluid and "enlarges" the intra-pleural space, lowering the intra-pleural pressure (Pip) 3. Lower P_ip "pulls" the visceral pleura and lungs outward, enlarging the volume of the lungs and decreasing the pressure inside (the alveolar pressure of P_alv) 4. Air flows down the pressure gradient: atmosphere -\> lungs

Answer 59

1. As the diaphragm relaxes, the P_ip falls 2. Lower P_ip allows elastic tissues in each lung " recoil inwards" 3. As lungs recoil, they decrease in volume and compress the air inside, raising alveolar pressure (P_alv) "above the atmospheric pressure" 4. Air flows down the pressure gradient: lungs -\> atmosphere

Answer 60

1. Once the diaphragm is relaxed, the recoil force of lung elastic tissues is equally opposed by the opposite recoil force of the thoracic cage 2. The alveolar pressure (P_alv) is now equal to atmospheric pressure 3. Air does not move because there is no pressure gradient: lungs \<-\> atmosphere

Answer 61

1. Chest wall recoils outwards 2. Elastic lung tissue recoils inward 3. P_alv = atmospheric pressure 4. P_ip \< atmospheric pressure 5. P_tp is still positive (healthy elastic lung tissue is always more distended than it would prefer to be) \*\*Also, physiologists define the amount of air present in the lungs in this state as the "end-expiratory lung volume" (also called functional residual capacity or FRC)

Answer 62

The spirogram is used to measure: vital capacity, residual volume, expiratory reserve volume, tidal volume, inspiratory reserve volume, inspiratory capacity, and total lung capacity

Answer 63

* FRC (function residual capacity) defines the volume that fresh air must mix with in order to increase lung oxygen stores, and decrease lung carbon dioxide stores * Large FRC = labored breathing * Small FRC = large fluctuations in O₂ and CO₂

Answer 64

* Lung compliance refers to the ease at which the lungs can be inflated * Compliance = (delta)V_L / (delta)P_tp * Thickening or stiffening of lung tissue by disease, such as asbestosis, decreases the compliance * Emphysema increases compliance and raises FRC

Answer 65

* The amount of air that doesn't reach the actual lungs to mix with alveolar air * out of 500ml tidal breath, only 350mL reaches alveoli to mix with alveolar air * The remaining 150mL fills the upper respiratory system, larynx, trachea and bronchi through which no gas exchange occurs

Answer 66

* Pulmonary ventilation is a measure of the rate of lung ventilation * Pulmonary Ventilation (L/min) = tidal volume (L/breath) x breathing frequency (breaths/min) * Alveolar ventilation is a measure of the rate at which air actually ventilates the alveoli * Alveolar Ventilation (L/min) = (tidal volume - dead space volume) (L/breath) x breathing frequencey (breaths/min)

Answer 67

* In a mixture of gases, each gas will exert a pressure that is proportuonal to its concentration (Dalton's Law) * The pressure exerted by each gas will be a function of the total gas pressure (the atmospheric pressure in our case)

Answer 68

* The [O₂] in the alveroli is increased slightly and the [CO₂] is decreased slightly, but average alveolar values do not change very much * The volume of fresh gas inhaled is relatively small compared to the volume already present in the lungs (the FRC) 2400mL

Answer 69

* Expired air has a lower O₂ concentration and a higher CO₂ concentration than the inspired air * This is because the O₂ is removed from the lungs by the blood during inspiration * At the same time, CO₂, which is produced in the tissues, moves from the blood to the lungs and is exhaled

Answer 70

* O2 leaves the capillaries and diffuses into the cells * CO2 prodcued in the tissues enters the capillary * Because of this, venous blood has relatively low [O2] and high [CO2]

Answer 71

It is a buffer for acid/base pH changes in our blood

Answer 72

O2 consumption (mL/min) Rest: 250 Max Ex: 3500 CO2 production (mL/min) Rest: 200 Max Ex: 3800

Answer 73

* The amounts of oxygen consumed and carbon dioxide produced are not equal * _The amount of CO2 produced divided by the O2 consumed represents the respiratory quotient_ * The "RQ" varies with the type of nutrient being used by the cell * For pure fat, RQ = 0.7 * For pure carbohydrate, RQ = 1.0

Answer 74

1. Dissolved in the plasma (about 1.5% of the total) 2. bound to the protein hemoglobin (about 98.5% of the total)

Answer 75

It depends on the PO2 in the plasma -The relationship between the extent of oxygen binding to hemoglobin and PO2 is described by constructing an "oxy-hemoglobin dissociation curve"

Answer 76

* Shows that the binding and release of O2 from hemoglobin is critically dependent on the PO2 * Lung PO2 exceeds the PO2 in the blood that is entering the pulmonary capillaries (the "mixed venous blood") * O2 then diffuses into blood and binds to hemoglobin * Tissue PO2 is low, resulting in the release of O2 from hemoglobin

Answer 77

A reduction in blood pH, and increases in blood PCO2 and increase in temperature causes the curve to shift to the right

Answer 78

It is that the hemoglobin molecules will release more oxygen at any given PO2

Answer 79

This is most important at tissue capillaries because the hemoglobin in blood flowing through these vessels will release oxygen more readily

Answer 80

* Higher temperature * CO2 levels go up * The more CO2 you dissolve, the more acidic the blood is

Answer 81

As pH decreases, the affinity of hemoglobin for oxygen declines, so less O2 combines with hemoglobin and then more O2 is available for the tissures

Answer 82

As P_co2 increases, the affinity of hemoglobin for oxygen declines, so less O2 combines with hemoglobin and then more O2 is available for the tissures

Answer 83

As temperature increases, the affinity of hemoglobin for O2 decreases

Answer 84

It diffuses into the plasma and then into RBCs * In RBCs both H2CO3 and "carbaminohemoglobin" are formed * about 70% of the total CO2 is transported in plasma as bicarbonate ions * About 23% of the CO2 transported is carbaminohemoglobin * About 7% of the CO2 transported is dissolved in plasma * The above products are made in RBCs by CO2 and then spit out into the plasma

Answer 85

\*\*This is why CO2 makes things in the body more acidic because of the H+

Answer 86

CO2 diffuses out of tissue cells that produce it and enters red blood cells, where some of it binds to hemoglobin, forming carbaminohemoglobin (Hb–CO2). This reaction causes O2 to dissociate from oxyhemoglobin (Hb–O2). Other molecules of CO2 combine with water to produce bicarbonate ions (HCO3−) and hydrogen ions (H+). As Hb buffers H+, the Hb releases O2 (Bohr effect). To maintain electrical balance, a chloride ion (Cl−) enters the RBC for each HCO3− that exits (chloride shift).

Answer 87

As carbon dioxide (CO2) is exhaled, hemoglobin (Hb) inside red blood cells in pulmonary capillaries unloads CO2 and picks up O2 from alveolar air. Binding of O2 to Hb–H releases hydrogen ions (H+). Bicarbonate ions (HCO3−) pass into the RBC and bind to released H+, forming carbonic acid (H2CO3). The H2CO3 dissociates into water (H2O) and CO2, and the CO2 diffuses from blood into alveolar air. To maintain electrical balance, a chloride ion (Cl−) exits the RBC for each HCO3− that enters (reverse chloride shift).

Answer 88

* Oxygen loading at the pulmonary capillary is a time dependent process * It depends on the rate of gas diffusion, and the rate of blood flow through the pulmonary capillaries...or "transit time" * In a healthy lung, complere diffusion of oxygen occurs in about 0.25 seconds in most alveolar-capillary units * Transit time at rest is about 0.8 seconds, so there is plent of time for oxygen diffusion

Answer 89

* The respiratory muscles are skeletal muscles, and therefore they must be made to contract by the action of motor neurons * Unlike other skeletal muscles, the respiratory muscles are under both automatic and voluntary control

Answer 90

Automatic respiratory muscle control depends on groups of inspiratory and expiratory neurons in the medulla oblongata

Answer 91

* Breathing is rhythmic and depends on "pacemaker-like" activity in brain stem neurons that alternately turn the inspiratory neurons on and off * Expiratory neurons are generally silent at rest, but are activated when breathing activity must

Answer 92

They depend on information from various specialized receptors that inform the neurons about the body's needs for ventilation 1. Pulmonary stretch receptors 2. Central chemoreceptors 3. Peripheral chemoreceptors

Answer 93

* Receptors are located in the smooth muscle that lines some of the large conducting airways, bronchi and bronchioles * They respond when bronchioles are inflated or stretched * The main stimulus appears to be the rate of change of lung stretch * The receptors are innervated by axons in the vagus nerve (CN X)

Answer 94

* Receptors are located just beneath the ventral surface of the medulla * They respond to low pH and high P_co2 in the cerebrospinal fluid (CSF) * Low pH in the CSF is the result of CO2 that diffuses into the CSF from the blood and forms hydrogen ions (this is when we start breathing faster) * This is why central chemoreceptors are call "CO2 sensitive receptors"

Answer 95

* Peripheral chemoreceptors are located in the aortic arch and in the carotid sinus * These receptors respond to low levels of oxygen in the arterial blood (that is heading to the brain) * They also respond to low pH, and high carbon dioxide levels, but weakly * These receptors are innervated by axons that travel in CN IX (glossopharyngeal nerve) and X (vagus nerve) and synapse on neurons in the DRG

Answer 96

On a run, CO2 starts increasing, air pH decreases, so we need to breathe more

Unit 2 Lecture Flashcards

(137 cards)