Unit3- Circulation and Hemodynamics
After birth the "Ductus Arteriosus" turns into...
After birth the Ductus Arteriosus turns into the Ligamentum Arteriosum
After Birth the "Forman Ovale" turns into..
After birth the Foramen Ovale closes down and creates an indentation known as the FOSSA OVALIS.
After Birth what does the "Ductus Venous" turn into..
After birth the ductus venous closes down to create a ligament called Ligamentum Venosum.
Define Aneurysm
Aneurysm is a weakness in walls of blood vessels. - If blood pressure rises these blood vessels can rupture
Define Atherosclerosis
Atherosclerosis blocks lumen of blood vessels, so blood vessels get more narrow, and there is INCREASE in BP. - Leads to hardening of blood vessel wall
Describe Blood Colloidal (Capillary) Osmotic Pressure, BOP-
Blood Colloidal Osmotic Pressure, or BOP is the movement of fluid towards the blood (going in) - OP of blood is the same at arterial and venous end. - N.V. is 25 mm hg *AIDS REABSORPTION
Discuss the role of pressure gradient in blood perfusion...
Blood pressure gradient is when there is an area of high blood pressure and area of low blood pressure. Blood flows from the area of high blood pressure to an area of low blood pressue. > Total Blood flow = pressure gradient/ resistance *Blood pressure gradient is more important in deciding blood flow rather than absolute blood pressure. - Bloow Pressure Gradient is directly proportionate to blood flow or blood perfusion. - Higher the pressure gradient, the higher the blood flow. BY CONTROLLING THE PRESSURE GRADIENT (VIA controlling CO & resistance) CARDIOVASCULAR CENTERS MAINTAIN PROPER BLOOD FLOW TO CAPILLARIES.
Describe "Bypassing the hepatic portal circulation" in fetal circulation..
Bypassing the Hepatic Portal in Fetal Circulation - The umbilical vein bings oxygenated blood to the fetus and enters through the liver (But liver does NOT need direct blood supply). - The Ductus Venous connects the umbilical vein to the inferior vena cava, SO bypasses the liver
Describe "Bypassing the Pul. Circualtion" in fetal circulation..
Bypassing the Pulmonary Circulation in Fetal Circulation is when.. - Blood reaching the right atrium via inferior vena cava is partly oxygenated. - The superior vena cava brings deoxygenated blood to the R atrium. 3 possible paths: 1. Atrium: Right Atrium > Tricuspid Valve > R Ventricle > Semilunar Valve > Pul. Trunk > Pul. Arteries > Lungs > Pul. V. > L Atrium > Bicuspid Valve > L ventricle > AV valve > Ascending Aorta 2. Foramen Ovale: Located in the interatrial septum (right atrium). Pressure is higher in the right side of the heart than the left side, so most of the blood from the right atrium enters the atrium via foramen ovale, and bypasses the lungs. 3. Ductus Arteriosus: connects the pul, trunk to arch of aorta. So blood from Pul. trunk bypasses the lungs and goes directly into the aorta.
Describe the blood pressure, diameter of BV, cross sectional area of a BV, and velocity of blood in the CAPILLARIES-
Capillaries have the: - a low blood pressure - the smallest diameter - largest cross sectional area - and the slowest velocity of blood flow
Describe Circulatory Shock...
Circulatory shock is reduced blood volume due to blood loss or dehydration. During Circulatory Shock, blood flow through the body reduces, metabolic needs of the body NOT met, and there is a WEAK pulse due to reduced amount of blood. EFFECTS: - BP reduces - Reduced blood supply to organs including the brain and this can lead to confusion, disorientation - Urine Formation reduces Mild Case of Circulatory Shock: > can be compensated by cardiovascular centers (neural compensation) > BP will be low Advanced Case of Circulatory Shock: + Can be non reversible + Venous return is dangerously slow, CO is low, BP is very low + Blood Circulation to brain reduces, so cardiovascular centers are NOT functioning properly. + Compensatory mechanism of brain (neural control) does NOT function, which results in further reduction of blood pressure, which results in further reduction in blood supply to the brain.
Describe Colloidal Osmotic Pressure, OP-
Colloidal Osmotic Pressure, OP - Attracts fluid toward itself 1. OP of blood (BOP) 2. OP of IF (IFOP) ^ The Osmotic Pressure is due to LARGE solutes including proteins found in the fluid. *OP of blood is higher than IF, because proteins can NOT leave the blood.
Compare and Contrast the histological structure of Veins & Arteries....
Compare and contrast Veins & Arteries VEINS: -Veins have a thinner wall -Veins have less smooth muscles in the Tunica Media - Veins have an irregular-shaped collapsed lumen - Blood pressure in veins is LOW, so there is a need for VALVES. ARTERIES *Arteries are more thicker *Arteries have two types: Elastic (Conducting)Arteries & Muscular (Distributing) Arteries * T Interna have a pleated appearance and Internal Elastic Lamina *ELASTIC (Conducting) Arteries: -Tunica Media have less smooth mu. but MORE ELASTIC fibers. Elastic Fibers act as a blood pump, and since these arteries are closer to the Aorta the elastic fibers expand to accomodate the amount of blood. -Some examples are: Aorta, Pul. Trunk, Pul. Arteries.. etc. *MUSCULAR (distributing) Arteries: -Transport blood to skeletal muscles and viscera -Tunica media contains more smooth fibers because they determine the amount of blood that is distributed to an area or an organ
Describe Contionous Capillaries-
Continous Capillaries account for a MAJORITY OF the capillaries in the body. -Endothelial Cells are continous (connected) to eachother - Continous Capillaries allow for diffusion of water, small solutes, and water soluble materials. DOES NOT ALLOW PROTEINS OR CELLS. - In brain these endothelial cells have even tighter junctions which provides a blood-brain barrier
Describe Coronary Circulation-
Coronary Circulation supplies blood to the tissues of the heart or the wall of the myocardium. - Ascending Aorta > Coronary Arteries > Capillaries of myocardium or tissues of the heart > cardiac (coronary veins) > Coronary Sinus > Right Atrium - Oxygenated blood is brought to the myocardium (tissues of the heart) by coronary arteries. -Deoxygenated blood is drained by the cardiac (coronary veins) into the coronary sinus.
Define Diastolic Blood Pressure-
Diastolic Blood Pressure is the blood pressure in the arteries during ventricular diastole. - N.V. 80 mm Hg
Define Edema
Edema is a large amount of interstitial fluid which can lead to swelling. Can be due to: 1. Damage to blood vessel wall -when proteins leak out of blood vessel = the osmotic pressure of interstitial fluid increases & speeds up filtration. 2. Increased Blood pressure -Hydrostatic pressure of blood increases and speeds up filtration 3. increased rate of filtration (which can be due to damage to BV) or reduced rate of reabsorption (As in case of obstruction against reabsorption)
What are Elastic Conducting Arteries?
Elastic Conducting Arteries have thicker walls and are closer to the heart. Elastic Arteries have more elastic fibers in their tunica media becuase they are closer to the Aorta, and elastic fibers expand to accomadate the amount of blood. The elastic fibers act as an extra pump. -Examples: Aorta, Pul. Trunk, Pul. arteries, common carotid arteries, common iliac arteries, and subclavin arteries.. etc..
What is Elastic Recoil? What role does it play in flow of blood?
Elastic Rebound or Elastic Recoil is stretching and recoiling of elastic fibers in the elastic arteries. Elastic rebound or reocoil helps PUMP blood through elastic arteries. - ElASTIC FIBERS act as an extra pump
List factors affecting blood pressure......
Factors affecting blood pressure include: 1. Cardiac Output: - The higher the cadiac output, the higher the BP (running = increases bP) 2. Peripheal Resistance (R): - An INcrease in R, will increase the BP 3. Diameter of a blood vessel: - the wider the diameter of a BV= less resistance= LOWER blood pressue - the NARROWER the diameter of the BV, the more resistance, and the higher the blood pressure. 4. Viscosity of Blood - the more viscous blood, the higher the resistance, the higher BP
List factors responsible for regulating BP...
Factors responsible for regulating BP: 1. Autoregulation - Vasodilation: Blood Vessel widens & BP reduces - Vasoconstriction: blood vessels narrow or constrict, and BP increases. 2. Neural Control or ANS + Reflex Arc: Receptor, Sensory Neuron, Center (Cardiovascular center), Motor neuron, then the effector organ. ^ Cardiac Center: Cardio- Accelerotory controlled by the sympathetic NS and INCREASES BP. ^ #2 Cardiac Center: Cardio Inhibitory Center controlled by parasympathetic NS, and REDUCES BP. * In the Vasomotor Center, the diameter of the blood vessels are controlled by sympathetic stimulation and parasympathetic stimulation. - In sympathetic stimulation, theres is vasoconstriction of the blood vessels so they get more narrow and BP rises. - In parasympathetic stimulation, there is vasodilation where the blood vessels get wider and BP reduces. 3. Chemical and Hormonal Control Mechanism: - Adrenal Medulla Hormones: NE & E = increased HR and BP - ANF, secreted by the walls of the right atrium in response to excessive stretching of the atrial wall during atrial systole. Due to increased blood volume return or venous return. AND REDUCED BP. - ADH, secreted by the hypothalamus. ADH causes vasoconstriction, conserves water and reduces urinary output (kidneys) so BP INCREASES -Erythropoietin or EPO, is secreted by the kidneys in response to a fall in BP, to increase RBC production, viscosity of blood and SO BP INCREASES. 4. Renal Regulation -Kidneys secrete renin and renin increases BP
Describe the differences between prenatal and post natal circulation
Fetal Circulation: - The Fetal Lungs do NOT oxygenate blood, the lungs receive just enough blood to maintain their own tissue. - The placenta is attached to the maternal uterus and OXYGENATES FETAL blood. (Fetal and Maternal blood are separated by the Placenta) - Umbilical Cord connects the uterus to the fetus. Contains 2 umbilcal arteries, and one umbilical vein. >Umbilical Vein brings OXYGENATED blood to the fetus, from the placenta. > R & L Umbilical Arteries drain partly oxygenated blood from the fetus back to the placenta. - Fetal Liver does not function to detoxify fetal blood, the liver receives just enough blodo to maintain its own tissue. MAJORITY OF BLOOD BYPASSES FETAL LUNGS AND LIVER.
Describe Fetal Circulation
Fetal Circulation: 1. Oxygenated Blood from the placenta enters the body of the fetus through the umbilical vein. 2. The blood from the umbilical vein is shunted away from the liver and directly toward the inferior vena cava through the ducutus venous. 3. Oxygenated blood in the ductus venous mixes with deoxygenated blood in the inferior vena cava. 4. Blood from the suprerior & inferior vena cava empties in the Right atrium. 5. BC BP is greater on the right side of the heart as comapred to the left side, most of the blood is shunted from the right atrium to the left atrium VIA the foramen ovale. This blood flows into the right ventricle and then is pumped out by the aorta. 6. A small amount of blood enters the right ventricle and pul trunk, but much of this blood is shunted from the pul. trunk to the aorta through a vessel detour called the ductus ateriosus. 7. Blood travels to the rest of the body, and the deoxygated blood returns to the placenta through a pair of umbilical arteries. 8. Nutrient and gas exchange occurs at the placenta, and the cycle repeats.
Define Filtration-
Filtration is the process of fluid leaving capillary blood and entering interstitial space. *FLUID LEAVES blood = FILTRATION
Describe Finestrated Capillaries
Finestrated Capillaries have pores (finestra) between endothelial cells. - Finestrated Capillaries allow rapid movement of water and LARGE molecules like polypeptides. - Found in organs where transport of materials other than gases and nutrients is necessary between the blood and brain tissues. - ^Found in Choroid Plexus of the brain ,filtration membrane of the kidneys - Sinousoids - found in liver
Define Hydrostatic Pressure
Hydrostatic Pressure of a fluid will PUSH (pressurehydro) water away from itself. -HP of Blood -HP of IF
Describe Interstitial Fluid Osmotic Pressure., IFOP
Interstitial Fluid Osmotic Pressure or IFOP is the movement of fluid OUT of blood. -N.V. is very low, because the IF does not contain proteins. - N.V. is close to 1 mmhg - Same value at the arterial and venous end. *AIDS FILTRATION
Define Interstitial Fluid-
Interstitial Fluid is interstitial space that contains interstitial fluid.
Define Interstitial Space-
Interstitial space is the microscopic space between cells.
Describe Muscular Distributing Arteries
Muscular Distributing Arteries transport blood to skeletal muscles and viscera. Muscular Arteries have MORE SMOOTH muscles in their tunica mediabecause smooth muscles determine the aount of blood distributed to an area or organ. -Examples: External Carotid A., Internal Carotid A., Brachial A., Femoral A.,.. etc
Define Osmotic Pressure:
Osmotic Pressure of a fluid BRINGS H2O toward itself.
Define Phlebotomy-
Phlepotomy is the puncturing of a vein ro draw blood.
What is pressure gradient?
Pressure Gradient is an area of high blood pressure and an area of low blood pressure. - Blood flows from an area of high blood pressure to an area of low blood pressure. - Blood pressure gradient is more important in DECIDING blood flow rather than absolute blood pressure. - Higher the blood pressure gradient, higher & faster the blood flow. - Blood Flow is directly proportionate to presure gradient^
Define Primary Hypertension
Primary Hypertension has.. - No underyling identified cause - Mainly due to lifetsyle choices - Risk Factors include: obesity, smoking, sedentary lifestyle, consistent high sodium or high fat diet, persistent stress, genetics - Controllable but not curable
Describe Pulmonary Circulation
Pulmonary Circulation is when deoxygenated blood going from the right ventricle > pul. trunk > Pul. arteries > lungs (oxygenated) > Pul. Veins - The PURPSE of pulmonary circulation is to get BLOOD OXYGENATED
What is Pulse Pressure?
Pulse Pressure is the difference between systolic BP and diastolic BP. - Pulse Pressure = Systolic BP - Diastolic BP. - N.V. 40 mm Hg
Define Reabsorption-
Reasbsorption is the process of a fluid entering capillary blood from interstitial space. *FLUID ENTERS blood= REABSORPTION
Define Secondary Hypertension
Secondary Hypertension... - Has an identifiable underlying pathology - Adrenal tumor > Adrenal cortex Tumor aka. over secretion of aldosterone. -Aldosterone retains sodium, which retains water, so BP goes up (Due to higher blood volume, CO increases) > Adrenal Medulla Tumor (over secretion of E or NE) - E and NE have the same effect as sympathetic stimulation, so BP increases - High level of renin increases BP - High level of EPO increases BP - High levels of ADH increases BP
Describe Systemic Circulation
System Circualtion is when oxygenated blood from the L ventricle enters the Aorta > circulates through the body and back to the right atrium as deoxygenated blood. - PURPOSE of systemic circulation is to provide oxygen and nutrients to the tissues of the body.
Define Systolic Blood Pressure (BP)-
Systolic Blood PRessure (BP) is blood pressure in arteries during ventricular systole. - N.V. 120 mm Hg
Describe the blood pressure, diameter of BV, cross sectional area of a BV, and velocity of blood in the AORTA-
The Aorta has the: - Highest Blood Pressure - A large diameter - low cross sectional area of BV - fastest velocity of blood.
Describe the Circle of Willis..
The Circle of WIllis is a circle pattern of blood vessels, provding oxygenated blood to the tissues of the brain. The Circle of Willis is created by branches of R & l Vertebral A. and R & L Internal Carotid A. - The circular pattern reduces chances of obsrtruction of blood supply to brain tissue and creates anastomosis (intermingling of the blood vessels)
Describe HP of Blood in capillary (BHP)...
The HP of Blood in the Capillary or BHP -BHP is the same as capillary blood pressure or BP. - Fluid MOVES AWAY from blood. - Value is higher at arterial end because BP is higher-> 35 mm hg at the arterial end and 18 mm hg at venous end *AID FILTRATION
Describe HP of Interstitial Fluid (IFHP or IHP)-
The HP of Interstitial Fluid (IFHP or IHP) - Has an opposing force to BHP. - Forces fluid back INTO THE BLOOD. - N.V is 0 at both ends *AIDS REABSORPTION
What is the Hepatic Portal Vein?
The Hepatic Portal Vein is created when the splenic and mesenteric vein combine. - Blood enters liver and breaks down into capillary network * BRINGS DEOXYGENATED BUT NUTREINT RICH BLOOD TO THE LIVER.
Describe the Structure of Arterioles-
The Structure of Arterioles consists of small microscopic branches of arteries, larger arterioles have al 3 tunics but as we get closer to the capillaries they get thinnner in diameter and # of tunics reduces. Arterioles CONTROLS blood pressure and the amount of blood flowing to the capillary network.
Describe the Tunica Externa (general histological structure of blood vessel)
The Tunica Externa is the most superficial layer of a blood vessel. *The Tunica Externa is made up of loose areolar C.T., which contain collagen fibers with some elastic fibers. & Vasavsorum (blood vessel off a blood vessel) *FUNCTIONS; to anchor the blood vessel to surrounding structures.
Describe the Tunica Interna (general histological structure of blood vessel)
The Tunica Interna is the deepest layer of the blood vessel that surrounds the lumen. The Tunica INterna is made up of two parts: 1. Endothelium- layer of simple squamos epithelium resting upon the basal lamina. 2. Connective Tissue- connective tissue surrounds the epithelium, contains collagen fibers, and contains elastic fibers (allow blood to expand as blood enters arteries during ventricular systole) INTERNA- "Innermost" or "IN"
Describe the Tunica Media (general histological structure of blood vessel)
The Tunica Media makes up the MIDDLE layer of the blood vessel. The Tunica Media is made up of smooth muscles and C.T. *Functions to control blood pressure and blood flow by controlling diameter of blood vessels -Contraction: reduces size of diameter and reduces blood flow - Relaxation: increases size of diameter and increases blood flow.
Discuss the relationship of the cross sectional area of a blood vessel...
The cross sectional area of a blood vessel INCREASES as we move from the aorta to the capillaries. The cross sectional area of blood vessels DECREASES as we move from the capillaries to vena cava. Capillaries have the biggest cross sectional area (combined)
Discuss the relationship between diameter of blood vessels....
The diameter of blood vessels passing from the aorta going towards the capillaries, REDUCES. The diameter of the blood vessels passing from capillaries to the vena cave, iNCREASES. Capillaries having the smallest diameter.
What is the difference between Muscular Arteries & Elastic Arteries
The difference between elastic and muscular arteries... Elastic Arteries have more elastic fibers in the tunica media due to being closer to the Aorta. So the Elastic Fibers can expand to accomadate an amount of blood. The elastic fibers act as a pump. Muscular Arteries have MORE smooth muscle due to smooth muscles being able to determine the amount of blood distributed to an area or organ. Muscular Arteries transports blood to skeletal muscles.
What is the difference between Continous and Finestrated capillaries?
The difference between finestrated and continous capillaries is.. -Finestrated capillaries have finestrea, aka pores between endothelial cells. Allows rapid movement of polypeptides or large molecules -Continous Capillaries account for a majority of the capillaries in the body. Endothelial cells are continous (connected) w each other. Allows diffusion of water, small solutes, and water soluble materials. -provide blood brain barrier
Describe general histological structure of blood vessels, make sure to include- Tunica Intima, Tunica Media, and Tunica Externa
The histological structure of a blood vessel includes lumen and a wall that surrounds the lumen made up of 3 layers called tunics: Tunica Intima (deepest, IN), tunica media (middle), and tunica externa (superficial).
What are the factors or pressure that aid filtration?
The pressures that aid filtration are: 1. Interstitial Fluid Osmotic Pressure or IFOP 2. HP of Blood in capillary, BHP
What are the pressures that aid in reabsorption?
The pressures that aid in reabsorption or fluids entering the blood are: 1. HP of Interstitial Fluid, IHP or IFHP 2. OP of Blood, BOP
Describe Hepatic Portal Circulation
The purpose of Hepatic Portal Circulation is: - Digested food is absorbed into venous blood from digestive organs. - Blood coming from digestive organs may be contaminated or might contain toxins. - This nutrient RICH, but deoxygenated blood goes to the liver first and then the liver detoxifies that blood and takes out the extra nutrients and stores them. NOW the blood enters systemic circulation. Circulation: Inferior Mesenteric V. -> Splenic V. > Superior Mesenteric V. > Hepatic Portal V. > Gastric V. > Hepatic Vein
Describe the structure of Capillaries-
The structure of capillaries consisit of ... -Capillaries are microscopic blood vessels made up from endothelial cells. - Capillaries have a VERY thin wall due to being able to exchange material. -Capillaries LACK tunica media so no smooth muscles - Capillaries lack tunica externa. -Capillaries form a network to create large surface area. -Blood from the Arterioles enter the capillaries.
Discuss the relationship of velocity of blood flow....
The velocity of blood flow as we move from the aorta to thw capillaries, arterial branching occurs, cross sectional area increases, but VELOCITY OF BLOOD DECREASES. - Capillaries have the most reduced velocity of blood flow. Thie significance of slower blood flow through the capillaries is it provides enough time for exchange of materials between blood and cells. As we move from the capillaries to the vena cava cross sectional area reduces, but the velocirty INCREASES. So the velocity of blood flow is the highest in the aorta, falls towards capillaries, and then gets faster towards the vena cavae.
What is Tissue Perfusion? Discuss the factors that affect the Tissue perfusion...
Tissue Perfusion is the BLOOD FLOW through tissues. Tissues need nutrients and oxygen to meet their metabolic demands, which are borught to them via blood. - Increases during tissue activity to meet increased demand. - Blood Flow is directly proportionate to Blood Pressure, Cardiac Output, and... - Blood Flow is INVERSELy proportionate to resistance (higher the resistance, lower the blood flow) - Blood Flow is directly proportionate to pressue gradient. The factors that affect tissue perfusion is: 1. Cardiac Output 2. Blood Pressure 3. Peripheal Resistance
Define Varicose Veins
Varicose Veins have an incompetent valve in veins. - Gravity pulls blood to distal ends of veins (especially in leg veins) so veins dilate and lose their elasticity.
Describe the blood pressure, diameter of BV, cross sectional area of a BV, and velocity of blood in the VENAE CAVA-
Vena Cavae have: - The lowest blood pressure - a large diameter - low cross sectional area of BV - a fast velocity