Circulatory System Flashcards
Which way does blood flow?
From the heart, through arteries, to capillaries, and back to heart from veins.
What is blood flow involved in?
Delivery of O2 and nutrients to, and removal of waste from, tissue cells.
Gas exchange (lungs)
Absorption of nutrients
Urine formation (kidneys)
What is the rate of blood flow?
precisely the right amount to provide for proper function.
What is required to maintain blood pressure?
Cooperation of the heart, blood vessels, and kidneys.
Supervision by the brain.
When is blood flow the fastest?
in the aorta, slowest in the capillaries, increases again in veins.
What does slow capillary flow allow for?
allows adequate time for exchange between blood and tissues.
Does blood flow change?
Yes, is changes as it travels through the systemic circulation.
What is blood flow inversely related to?
the total cross sectional area.
Vital Signs
pulse and blood pressure, along with respiratory rate and blood pressure.
What is pulse?
pressure wave caused by the expansion and recoil of arteries. Routinely taken at the wrist.
What are the common places to take a pulse?
Superficial temporal artery, Facial artery, Common carotid artery, Brachial artery, Radial artery, Femoral artery, Popiteal artery, Posterior tibial artery, Dorsalis pedis artery.
Superficial Temporal Artery
Temples
Facial Artery
High Jaw
Common Carotid Artery
Base of neck
Brachial Artery
inside of elbow
Radial Artery
inside of wrist
Femoral Artery
Groin
Popliteal Artery
Behind knee
Posterior tibal artery
inside of ankle
Dorsalis pedis artery
top of foot
What are some things that may vary blood pressure?
Age, sex, weight, race, mood, and posture
When does blood pressure peak?
In the morning due to levels of hormones, making it a danger time raising the risk of heart attack.
Does Blood Pressure change?
Yes, is cycles over a 24 hour period
What is hypotension?
Low blood pressure. systolic pressure below 100 mm Hg. Often associated with long life and lack of cardiovascular illness.
Orthostatic Hypotension
temporary low blood pressure and dizziness when suddenly rising from a sitting or reclined position
Chronic hypotension
hont of poor nutrition and warning sign for Addison’s disease or hypothyroidism
Acute hypotension
important sign of circulatory shock
What is hypertension?
High blood pressure, sustained elevated arterial pressure of 140/90 or higher. Often persistent in obese people. May be transient adaptations during fever, physical exertion, and emotional upset.
What can prolonged hypertension result in?
heart failure, vascular disease, renal failure, and stroke.
Primary/Essential hypertension
90% of hypertension conditions. Due to several risk factors including heredity, diet, obesity, age, stress, diabetes mellitus, and smoking.
Secondary hypertension
Less common form or hypertension. Due to identifiable disorders, including kidney disease, arteriosclerosis, and endocrine disorders such as hyperthyroidism and Cushing’s syndrome.
Pulmonary circulation
short loop that runs from the heart to the lungs and back to the heart.
systemic circulation
long loop to all parts of the body and back to the heart.
What is the sequence of electrical excitation
- The sinoatrial node (pacemaker) generates impulses
- The impulses pause at the atrioventricle node. (AV node)
- The artioventricle bundle connects the atria to the ventricles. (AV bundles)
- The bundle branches conduct the impulses through the interventricular septum.
- The Purkinje fibers depolarize the contractile cells of both ventricles.
What is the QRS complex
Electrical signal showing when ventricles are depolarized.
What are the two fetal shunts?
Ductus arteriosus and Foramen ovale
What are arteries and vein made of?
Tunica intima, Tunica, media, Tunica externa
Lumen
central blood containing space
What are capillaries made of?
Endothelium with sparse basal lamina
Tunica intima
endothelium lies the lumen of all vessels
In vessels larger than 1mm, a subendothemlial connective tissue basement membrane is present.
Inner
Tunica media
smooth muscle and sheets of elastin
Sympathetic vasomotor nerve fibers control vasocinstriction and vasodialation of vessals
Middle
Tunica externa/tunica adventitia
collagen fibers protect and reinforce
larger vessels contain vasa vasorum to nourish the external layer.
Outer
Which are thicker arteries or veins?
Arteries
Elastic (conducting) arteries
Large thick walled arteries with elastin in all three tunics
Aorta and its major branches
large lumen offers low resistance
Act as pressure reservoirs - expand and recoil as blood is ejected from the heart.
Muscular (distributing) arteries and arterioles
distal to elastic arteries; deliver blood to body organs
have thick tunica media with more smooth muscle
active in vasoconstriction
Arterioles
smallest arteries
lead to capillary beds
control flow into capillary bed via vasodialation and vasoconstriction.
Venules
Formed when capillary beds unite
very porous; allow fluids and WBCs into tissues
Postcapillary venules consist of endothelium and a few pericytes
larger venules have one or two layers of smooth muscle cells
What is blood flow involved in?
Delivery of O2 and nutrients to, and removal of waste from, tissue cells.
Gas exchange (lungs)
Absorption of nutrients
Urine formation (kidneys)
What is the rate of blood flow?
precisely the right amount to provide for proper function.
What is required to maintain blood pressure?
Cooperation of the heart, blood vessels, and kidneys.
Supervision by the brain.
When is blood flow the fastest?
in the aorta, slowest in the capillaries, increases again in veins.
What does slow capillary flow allow for?
allows adequate time for exchange between blood and tissues.
Does blood flow change?
Yes, is changes as it travels through the systemic circulation.
What is blood flow inversely related to?
the total cross sectional area.
Vital Signs
pulse and blood pressure, along with respiratory rate and blood pressure.
What is pulse?
pressure wave caused by the expansion and recoil of arteries. Routinely taken at the wrist.
What are the common places to take a pulse?
Superficial temporal artery, Facial artery, Common carotid artery, Brachial artery, Radial artery, Femoral artery, Popiteal artery, Posterior tibial artery, Dorsalis pedis artery.
Superficial Temporal Artery
Temples
Facial Artery
High Jaw
Common Carotid Artery
Base of neck
Brachial Artery
inside of elbow
Radial Artery
inside of wrist
Femoral Artery
Groin
Popliteal Artery
Behind knee
Posterior tibal artery
inside of ankle
Dorsalis pedis artery
top of foot
What are some things that may vary blood pressure?
Age, sex, weight, race, mood, and posture
When does blood pressure peak?
In the morning due to levels of hormones, making it a danger time raising the risk of heart attack.
Does Blood Pressure change?
Yes, is cycles over a 24 hour period
What is hypotension?
Low blood pressure. systolic pressure below 100 mm Hg. Often associated with long life and lack of cardiovascular illness.
Orthostatic Hypotension
temporary low blood pressure and dizziness when suddenly rising from a sitting or reclined position
Chronic hypotension
hont of poor nutrition and warning sign for Addison’s disease or hypothyroidism
Acute hypotension
important sign of circulatory shock
What is hypertension?
High blood pressure, sustained elevated arterial pressure of 140/90 or higher. Often persistent in obese people. May be transient adaptations during fever, physical exertion, and emotional upset.
What can prolonged hypertension result in?
heart failure, vascular disease, renal failure, and stroke.
Primary/Essential hypertension
90% of hypertension conditions. Due to several risk factors including heredity, diet, obesity, age, stress, diabetes mellitus, and smoking.
Secondary hypertension
Less common form or hypertension. Due to identifiable disorders, including kidney disease, arteriosclerosis, and endocrine disorders such as hyperthyroidism and Cushing’s syndrome.
Pulmonary circulation
short loop that runs from the heart to the lungs and back to the heart.
systemic circulation
long loop to all parts of the body and back to the heart.
What is the sequence of electrical excitation
- The sinoatrial node (pacemaker) generates impulses
- The impulses pause at the atrioventricle node. (AV node)
- The artioventricle bundle connects the atria to the ventricles. (AV bundles)
- The bundle branches conduct the impulses through the interventricular septum.
- The Purkinje fibers depolarize the contractile cells of both ventricles.
What is the QRS complex
Electrical signal showing when ventricles are depolarized.
What are the two fetal shunts?
Ductus arteriosus and Foramen ovale
What are arteries and vein made of?
Tunica intima, Tunica, media, Tunica externa
Lumen
central blood containing space
What are capillaries made of?
Endothelium with sparse basal lamina
Tunica intima
endothelium lies the lumen of all vessels
In vessels larger than 1mm, a subendothemlial connective tissue basement membrane is present.
Inner
Tunica media
smooth muscle and sheets of elastin
Sympathetic vasomotor nerve fibers control vasocinstriction and vasodialation of vessals
Middle
Tunica externa/tunica adventitia
collagen fibers protect and reinforce
larger vessels contain vasa vasorum to nourish the external layer.
Outer
Which are thicker arteries or veins?
Arteries
Elastic (conducting) arteries
Large thick walled arteries with elastin in all three tunics
Aorta and its major branches
large lumen offers low resistance
Act as pressure reservoirs - expand and recoil as blood is ejected from the heart.
Muscular (distributing) arteries and arterioles
distal to elastic arteries; deliver blood to body organs
have thick tunica media with more smooth muscle
active in vasoconstriction
Arterioles
smallest arteries
lead to capillary beds
control flow into capillary bed via vasodialation and vasoconstriction.
Venules
Formed when capillary beds unite
very porous; allow fluids and WBCs into tissues
Postcapillary venules consist of endothelium and a few pericytes
larger venules have one or two layers of smooth muscle cells
Veins
Formed when venules converge
Have thinner walls, larger lumens compared with corresponding arteries.
Blood pressure is lower than in arteries
Thin tunica media and thick tunica externa consisting of collagen fibers and elastic networks.
Called capacitance vessels (blood reservoirs); Contain up to 65% of the blood supply.
Capillaries
Microscopic blood vessels
Walls of thin tunica intima, one cell thick
Pedicures help stabilize their walls and control permeability
Size allows only a single RBC to pass at a time
What is the function capillaries and where can you find them?
Exchange of nutrients, waste, hormones, ECT
In all tissues except for cartilage epithelial cornea and lens of eye
Capillary beds
Interwoven networks of capillaries form the microcirculation between arterioles and venules
Sinusoidal Capillaries
Fewer tight junctions, larger intercellular class, larger lumens
Usually fenestrated
Allow large molecules in blood cells to pass between the blood and surrounding tissues
Found in the liver, bone marrow, spleen
Fenestrated Capillaries
Some endothelial cells contain pores (fenestrations)
More permeable than continuous capillaries
Function in absorption or filtrate formation (Small intestine, endocrine glands, and kidneys)
What are the four ways of transportation and capillaries
- through membrane, lipid soluble substances
- Movement through intercellular clefts, water-soluble substances
- Movement through fenestrations, water soluble substances (window)
- Transport via vesicles or caveolae, Large substances
Which type of capillaries are most permeable?
Sinusoidal capillaries
How does blood flow through capillary beds?
Precapillary sphincter’s regulate blood flow into true capillaries
Regulated by a local chemical conditions and vasomotor nerves, Sympathetic division of ANS.
What is blood?
A fluid connective tissue composed of plasma and formed elements
What are the formed elements in blood?
Red blood cells; erythrocytes
White blood cells; leukocytes
Platelets
What percent of blood volume is red blood cells(hematocrit)
47% + or -5% for males
42% + or -5% for females
What is the process to separate blood?
- With draw blood and place in tube
- Centrifuge the blood sample
Blood will separate into plasma:55% of whole blood content, least dense component, Buffy coat: leukocytes & platelets, less than 1% of whole blood, erythrocytes: 45% of whole blood, most dense component
What are the physical characteristics and volume of blood?
Sticky, opaque fluid Color scarlet to dark red pH 7.35 – 7.45 38°C (100.4°F) Approximately 8% of body weight Average volume: 5-6 L for males, 4-5 L for females
What does blood distribute?
02 and nutrients to body cells
Metabolic waste to the lungs and kidneys for elimination
Hormones from endocrine organs to target organs
What does blood regulate?
Body temperature by absorbing and distributing heat
Normal pH using buffers
Adequate fluid volume in the circulatory system
What does blood protect against?
Blood loss: plasma proteins and platelets initiate clot formation
Infections : antibodies, complement proteins,and white blood cells defend against foreign invaders
What is blood plasma?
90% water
Proteins are mostly produced by the liver; 60% albumin(transport), 36% globulins, 4%fibrinogen (clotting)
Nitrogenous by-products of metabolism- Lactic acid, urea, creatine
Nutrients – glucose, carbohydrates, amino acids
Electrolytes – Na+, K+, Cl-, HCO3-
Respiratory gases – O2 and CO2
Hormones
Erythrocytes
Red blood cells
Function is to transport oxygen and carbon dioxide
Function of WBC Neutrophil
Phagocytize bacteria
Function of WBC eosinophil
Kill parasitic worms; complex roll in allergy and asthma
Function of WBC basophil
Release histamine and other mediators of inflammation; contain heparin, and anticoagulant
What are the three types of granulocytes
Neutrophil, eosinophil, basophil
What is the function of WBC lymphocyte?
Mount immune response by direct cell attack or via anti-bodies
What is the function of WBC monocyte
Phagocytosis; Develop into macrophages in the tissues
What are the types of a agranulocytes
Lymphocyte and monocyte
What are the only complete cells?
White blood cells
What are platelets?
Formed elements
Do red blood cells have nuclei or organelles?
No
How long do most formed elements survive in the blood stream?
Only a few days
Where do most blood cells originate?
In bone marrow
Do blood cells divide?
Most do not
Erythrocytes
Biconcave discs, anucleate, essentially no organelles
Filled with hemoglobin for gas transport
Provide flexibility to change shape as necessary
Are the major factor contributing to blood viscosity
What structural characteristics of erythrocytes contribute to gas structure?
Biconcave shape, huge surface area relative to volume
>97% hemoglobin - not counting water
No mitochondria; ATP production is anaerobic no O2 is used in the generation of ATP
Erythrocyte function
Rbcs are dedicated to respiratory gas function
Hemoglobin binds reversibility with hemoglobin structure
Oxygen
Each Hb molecule can transport how many O2?
4
O2 loading in the lungs…
Produces oxyhemoglobin (ruby red)
O2 unloading in the tissues…
Produces deoxyhemoglobin or reduced hemoglobin (dark red)
CO2 loading in the tissues
Reduces carbaminohemoglobin ( carries 20% of CO2 in the blood)
Hematopoiesis
Blood cell formation - occurs in red bone marrow of axial skeleton, girdles and proximal epiphytes of humerus and femur
Hemocyteblasts
Hematopoietic stem cells - give raise to all formed elements
Erythropoiesis
Red blood cell production
Ejection of the nucleus and formation of reticulocytes
Reticulocytes then become mature erythrocytes
Too few RBCs leads to
Tissue hypoxia
Too many RBCs increases
Blood viscosity
The balance between RBC production and destruction depends on
Hormonal controls
Adequate supplies of iron, amino acids, and B vitamins
Erythropoietin (EPO)
Released by the kidneys in response to hypoxia
Direct stimulus for erythropoiesis
What are the causes of hypoxia?
Hemorrhage or increases RBC destruction reduces RBC numbers
Insufficient hemoglobin
Reduced availability of O2
What are the dietary requirements for erythrocytes?
Amino acids, lipids, carbohydrates, iron, folic acid,and B12
What is the lifespan of erythrocytes?
100-20 days
How are erythrocytes destructed?
They become fragile
Hb begins to degenerate
Macrophages engulf dying RBCs in the spleen
What happens after the heme and globin are separated from a dying erythrocytes?
Iron is salvaged for reuse
Heme is degraded to yellow the pigment bilirubin
Liver secretes bilirubin (in bile) into the intestines
Degraded pigment leaves the body in feces as stercobilin
Globin I’d metabolized into amino acids
Anemia
Blood has abnormally low O2 carrying capacity
A sign rather than a disease itself
Accompanied by fatigue, paleness, shortness of breath, and chills
Blood O2 levels can not support normal metabolism
What are the causes of anemia?
Insufficient erythrocytes Low hemoglobin content Pernicious anemia Sickle cell anemia Abnormal hemoglobin
Hemorrhagic anemia
Acute or chronic loss of blood
Hemolytic anemia
RBCs rupture prematurely
Aplastic anemia
Destruction or inhibition of red bone marrow
Iron deficiency anemia
Secondary result of hemorrhagic anemia
Inadequate intake of iron containing foods
Impaired iron absorption
Sickle cell anemia
Defective gene codes for abnormal hemoglobin
Causes RBCs to become sickle shaped in low oxygen situations
Point mutation 6- Val in stead of glu
Pernicious anemia
Deficiency of vitamin B12
Lack of intrinsic factor needed for absorption of B12
Treated by intramuscular injection of B12 or application of Nascobal
Polycythemia
Excess of RBCs that increase blood viscosity
Results from
Polycythemia Vera- bone marrow cancer
Secondary polycythemia- when less O2 is available (high altitude) or when EPO production increases
Blood doping
Leukocytes
Make up <1% of total blood volume
Can leave capillaries via diapedesis
Move through tissue space by ameboid motion and positive chemotaxis
Leukocytosis
WBC count over 11,000 mm3
Normal response to bacterial or viral invasion
Lymphocytes
Large dark purple circular nuclei with a rim of thin of blue cytoplasm
Mostly in lymphoid tissue, few circulate in the blood
Crucial to immunity
2 types
T cells
Lymphocyte that act agin sty virus infected cells and tumor cells
B cells
Lymphocytes that give rise to plasma cells, which produce antibodies
Monocytes
The largest leukocytes
Abundant pale blue cytoplasm
Dark purple staining, U or kidney shaped nuclei
Leave circulation, enter tissues, and differentiate into macrophages
Activate lymphocytes to mount an immune response
Leukopoiesis
Production of WBC
Stimulated by chemical messengers from bone marrow and mature WBCs
What do all leukocytes originate from
Hemocyteblasts
Leukocyte disorders
Leukopenia
Leukemia
Leukopenia
Abnormally low WBC count-drug induced
Leukemias
Cancerous conditions in involving WBCs
Named according to abnormal WBC clone involved
Myelocytic leukemia
Involves myeloblasts
Lymphocytic leukemia
Involves lymphocyte’s
Acute leukemia
Involves blast like cells and primarily affects children
Chronic leukemia
More prevalent in older people
Leukemia
Bone marrow totally occupied with cancerous leukocytes
Immature nonfunctional WBCs in the bloodstream
Death caused by internal hemorrhage and overwhelming infections
Treatment include irradiation anitleukemic drugs and stem cell transplants
Platelets
Small fragments of megakaryocytic
Formation is regulated by thrombopoietin
Blue staining outer region purple granules
Granules contain serotonin enzymes ADP Ca2 and platelet derived growth factor
Contain actin and myosin which allows them to contract
What do Platelets do?
Form a temporary platelet plug that help seal breaks in blood vessels
Hemostasis (coagulation)
That series of reactions for stoppage of blood
1 Vascular spasm
2. Platelet plug formation
3 Coagulation
What causes vascular spasm?
Vasoconstriction of damage blood vessel
Triggered by direct injury, thinking reflexes, and Chemicals released by endothelial cells and platelets
Platelet plug formation
At the sight of blood vessel injury, platelets stick to Exposed collagen fibers, then swell, become spiked and sticky, and release chemical messengers causing more platelets
Coagulation
A set of reactions in which blood is transformed from a liquid to a Gel
Reinforces the platelet plug with fibrin threads
Clot retraction
Actin and myosin and platelets contract with and 30 to 60 minutes
Platelets pull on the fibrin strands,squeezing serum from the clot
Clot repair
Platelet derived growth factor stimulates division of smooth muscle cells and fibroblasts to rebuild blood vessel wall
Vascular endothelial growth factor stimulates in the endothelial cells to multiply and restore the endothelial lining
Drop in blood volume results in what
A drop in blood pressure
What are the types of blood?
A, B, AB,and O
What blood type is a universal recipient?
AB
What blood type is a universal donor?
O
Thrombus
Clot that develops and persist in and on broken blood vessel
May block circulation leading to tissue death
Embolus
A thrombus freely floating in the bloodstream
Pulmonary emboli impair the ability of the body to obtain oxygen
Cerebral emboli can cause strokes
What prevents thrombrobolytic disorders
Aspirin-Anti-prostaglandin that inhibits thromboxane A2
heparin-Anticoagulant used clinically for pre-and post operative cardiac care
warfarin-Used for those prone to atrial fibrillation
Thromboembolytic disorders
Undesirable clot formation
Bleeding disorders
Abnormalities that prevent normal clot formation
Thrombocytopenia
Deficient number of circulating platelets
Widespread hemorrhage
Treated with transfusion of concentrated platelets
Impaired liver function
Inability to synthesize pro coagulants
Causes include vitamin K deficiency hepatitis and cirrhosis
Liver disease can also prevent the letter from producing bile impairing fat and vitamin K absorption
Hemophilias
Include several similar hereditary bleeding disorders
Symptoms include prolonged bleeding especially in the joint cavities
Treated with plasma infusions and injection of missing factors
Red blood cell membranes bear 30 types of glycoprotein antigens that are
Perceived as foreign if transfused blood is mismatched
Unique to each individual
Promoters of agglutination and are called agglutinogens
The presence or absence of what is used to classify blood cells into the different groups
Each antigen
How many varieties of naturally occurring red blood cells antigens do humans have
30
How many different types of Rh agglutinogens are there
45
C ,D, and E are the most common
How are anti-HR antibodies formed
If a RH-individual receives Rh+ blood
Are anti Rh antibodies Spontaneously formed Rh-individuals
No
Transfusions
Whole blood transfusions are used when blood loss is substantial
Transfusion of incompatible blood can be fatal
Packed red blood cells with the plasma remove are used to restore oxygen-carrying capacity
Transfusion reactions
Occur if mismatched blood confused
Donor cells
are attacked by the recipients plasma agglutinins
Rupture and release free hemoglobin into the bloodstream
Clot small blood vessels
Resulting in diminished oxygen-carrying capacity and hemoglobin in kidney tubules and renal failure
Restoring blood volume
Death from shock may result from low blood volume
Volume must be replaced immediately with normal saline or multiple of electrolyte solution that mimic’s plasma electrolyte composition and plasma expanders
Carotid artery
Base of neck
