Blood Vessels Flashcards
Name blood vessels going from and back to the heart
Arteries, arterioles, capillaries, venules, veins
Arteries typically ______ the heart with _________ blood. The _____________ is an exception.
leave
oxygenated
Pulmonary Artery
Name the three layers of large and medium-sized arteries and veins (which one is elastic?)
1) Tunica externa
2) Tunica media (elastic fibers)
3) Tunica interna
Name the three layers of arterioles:
1) Precapillary sphincter
2) Endothelium
3) Lumen
What is the main kind of cell in blood vessels? What kind of muscle is the precapillary sphincter?
Endothelial cells
Smooth muscle
Name and describe 3 types of capillaries (with three specific terms to describe spacing):
1) Continuous (with Tight Junctions)
2) Fenestrated (with Fenestrae, or small holes)
3) Sinusoidal (with spaces between cells, called INTRACELLULAR CLEFT)
What is a difference between arterioles and venuoles?
No smooth muscle around venuoles!
What is the primary roles of arteries? How do they do this?
Serve as a PRESSURE RESERVE, by undergoing VASODILATION and VASOCONSTRICTION. The ELASTICITY of arteries (especially in LARGE DIAMETER ARTERIES) helps to propel blood onward even after ventricular relaxation. ex. AORTA
What is the primary roles of capillaries? How do they do this?
Important for GAS EXCHANGE and molecule exchange, do this by being extremely thin
What is the primary roles of veins?
Serve as a VOLUME RESERVE
What is a path directly from arteriole to venule called? Describe how it works
- Metarteriole
- If the precapillary sphincter tightens, it can shunt blood away from a capillary bed, through the metarteriole and directly to venule.
The precapillary sphincter controls blood flow to a ______________
Capillary Bed
What does sympathetic stimulation of blood vessels cause?
Narrowing of artery diameter, increase in blood pressure
Arteries have ______ blood pressure, veins have _______ blood pressure
High, low
Where does the majority of blood pressure drop occur? Why?
in the Arterioles and Capillaries. Because there are so many paths to take
Name the pressure in the aorta (during systole and diastole)
Name the pressure for blood entering the capillaries
Name the pressure for blood entering the right atrium
- Aorta: 120 mm Hg during systole, 80 mm Hg during diastole
- 35 mm Hg entering the capillaries
- 0 mm Hg entering the right atrium
What doe we call the continual sympathetic stimulation of arterioles in the skin and abdominal viscera? Describe it it four words. Why does this happen?
- Vasomotor Tone
- “Baseline level of vasoconstriction”
- Provides an additional degree of flexibility in regulation, more or less sympathetic stimulation= more or vasoconstriction
Name three molecules that are exchanged between capillaries and muscles, with direction
Capillary to Muscle: Oxygen and Glucose
Muscle to Capillary: Carbon dioxide
Discuss the response of the vascular system to low oxygen/ high waste levels in tissues
The SYSTEMIC ARTERIOLES DILATE, to get more oxygen to the tissues (e.g. skeletal muscle). But, the arterioles in the lung actually CONSTRICT to reduce flow to unventilated areas! This entrie system has NEGATIVE FEEDBACK
What do we call flow out of a capillary? What do we call flow into a capillary? What do we use to quantify this idea? Describe how this changes through space
Filtration
Re-Absorption
Net Filtration Pressure
The osmotic pressure is constant, but the pressure on the walls of the capillary changes and gets lower as we get farther from the heart. When the capillary pressure is higher than the capillary osmotic pressure, we get filtration, and vice versa to get reabsorption.
How do we quantify net filtration pressure (give the name of the equation and the equation)?
Starling principle
Net filtraiton pressure= Pcap+Osmotic force(interstitial fluid)- P(intersitial fluid)-Osmotic force (cap)
So, filtration occurs by the ________ end of the capillary, and reabsorbtion by the ______ end
Arterial
Venous
Discuss the ratio of fluid filtered vs. reabsorbed by capillaries (and give specific theory name)
Starling’s Law: the volume of fluids and solutes reabsorbed vs. filtered by the capillary is almost exactly equal. 20 L is filtered every day, 17 L is reabsorbed by the capillary, and 3 liters are collected by the lympatic system and returned.
What happens when filtration exceeds reabsorbtion, give a specific:
- Name
- Cutoff
- Causes
Edema
Not noticeable until 30% above normal
Can be the result of excess filtration caused by hypertension (increased blood pressure), or inadequate reabsorbtion (due to decreased concentration of blood plasma proteins)
What are two common external symptoms of edema?
Swollen ankles Swollen stomach (due to inadequate blood proteins)
Describe the distribution of blood volume in the body
60% in systemic veins and venuoles 15% in systemic arteries and arterioles 12% in pulmonary vessels 8% in the heart 5% in systemic capillaries
Name the two mechanisms that power blood through the veins and back to the heart
1) Skeletal Muscle Pump
2) Respiratory Pump
Name the three parts of a skeletal muscle pump. Where are they found?
Two valves (one before and one after) and skeletal muscle. Found within large veins in skeletal muscles. A muscle contraction squeezes the pump and pumps the blood.
What causes vericose veins?
1) Leaky venous valves (mechanical stress from standing or pregnancy)
Are deeper veins susceptible to becoming varicose? Why/why not?
No, b/c they are supported by the surrounding muscle
Describe how the respiratory pump works
During inhalation, the diaphragm moves down and increases pressure in the abdomen, compressing veins
Discuss vasoconstriction/dilation in the giraffe
When standing up, constricts vessels in lower part of body to force blood to head, relaxes them when lowering head to avoid overload
What do we call the space between capillaries?
Interstitial space
What does the lymph system do?
Collects blood that is not reabsorbed by the veins. Called interstitial fluid
Name the lymph vessels in order from smallest to largest
lymph capillaries, lymp ducts, lymphatic vessels
Where does the lymph system connect to the venous system?
At the vena cava
Describe one interesting feature of the lymph system
Lymph nodes: collecctions of cells from the immune system, serve as collecting zones for bad things
What do we call the partial blockade of a vessel by plaque? What is in the plaque?
Atherosclerosis
Plaque contains fat, cholesterol, macrophages, smooth muscle cells, connective tissue
Name two possible responses to Coronary Artery Occlusion
1) Balloon catheterization
2) Surgical coronary artery bypass
Describe blood composition (name 3 proteins for the relevant category)
55% plasma- Plasma proteins: Albumins, Globulin, Fibrinogen
45% Red Blood Cells (erythrocytes)
1% White blod cells: leukocytes and platelets
What is the term for the percent of blood that is red blood cells?
Hematocrit
Do erythrocytes have nucleus? Organelles?
Both no!
What in erythrocytes binds and transports oxygen?
Hemoglobin
What shape are erythrocytes? Why?
Concave, to increase surface area
What is the average human erythrocyte lifespan?
120 days
How many erythrocytes do we have per microliter of blood?
5 million
How many erythrocytes wide is a capillary?
About one!
Where are red blood cells…
- Produced?
- Stored?
- Broken down?
- Produced in bone barrow
- Stored in liver and spleen
- Broken down in spleen
What element is important to red blood cell fucntion? where is this metabolized
Iron, metabolized in liver
Describe the blood types by percentage. What is the universal donor? What are the anibodies that each has?What is the universal acceptor?
A- 42% (anti-B)
B 10% (anti-A)
AB-3% universal acceptor (neither anti-A nor anti-B)
O- 45% universal donor (both anti-A and anti-B)
What is the term for white blood cells:
Leukocytes
Name four white blood cell types, and give a function:
- Lymphocytes (e.g. T-cells and B- cells)(immune response)
- Macrophages (engulf foreign particles)
- Granulocytes
=neutrophils (engulfforeign particles)
= eosinophils (allergic response)
= basophils (inflammation) - Thrombocytes (i.e. platelets) (clotting)
What is the major kind of stem cell for all blood cells? What is the stem cell for erythrocytes, platelates, macrophages, granulocytes and thrombocytes (plateltes)? How about for lymphocytes?
Hematopoietic stem cell
Myeloid stem cell
Lymphoid stem cell
What is it called when a macrophage engulfs a foreign particle?
Phagocytosis
What are the projections on macrophages called?
Pseudopods
What are the three components of a blood clot?
1) Platelets (thrombocytes)
2) Red blood cells
3) Fibrin mesh
What is the purpose of the Fibrin network?
To trap red blood cells!
Discuss the formation of a blood clot.
When the vessel is damaged, COLLAGEN is exposed. This causes the activation and aggregation of PLATELETS. It also causes the synthesis of THROMBOXANE, which leads to the release of NO and PGI2, which all 3 lead to the constriction of SMOOTH MUSCLE and the vessel. Also activated is PROTHROMBIN, which is cleaved to THROMBIN, which activates FIBRINOGEN, which activates FIBRIN.
What disease means “white blood”? Describe it
Lukemia:
A type of cancer of the blood or bone marrow, leads to abnomral increase in the number of immature white blood cells. Causes unknown. Results in a lack of blood platelets andfewer red blood cells. Leads to problems clotting, anemia, and less ability to fight off infection.
What is anemia?
Low red blood cell count
What are the two types of lukemia? Describe
Actute lukemia: rapid buildup of immature white blood cells
Chronic lukemia: Excessive build up of mature, but still abnormal, white blood cells
What are the sounds we hear when taking blood pressure? What do we get when we first start hearing them? When they disappear? How does it work?
Korotkoff sounds
Systolic Pressure (~120)
Diastolic Pressure (~80)
Heart can only pump blood when blood pressure is greater than cuff presssure. Amount of TURBULENCE corresponds to pressure and sound.
What is Mean Arterial Pressure at average heart rates? At high heart rates? Why?
average heart rate: =2/3 diastolic pressure + 1/3 systolic pressure (so 93 mm Hg)
high heart rate: = true average
b/c we spend more time in systole than diastole!
What regulates blood pressure? What are two specific ones called?
Baroreceptors
Carotid Bodies, Aortic Bodies
What nerve carries information from the carotid bodies?
Carotid Sinus Nerve
What nerve carries information from the aortic bodies bodies?
Vagus Nerve
What is the main vessel that carries blood to the head?
Carotid artery
What do the baroreceptors sense? How about chemoreceptors?
- Baro: MEAN ARTERIAL PRESSURE!
- Chemo: Changes in blood levels of oxycen (hypoxia), carbon dioxide (hypercapnia), or protons (acidosis).
What do the baroreceptors stimulate?
Cardiovascular center
Describe the baroreceptor response to increased MAP
- Baroreceptors fire, sending signal through afferent neurons to the CARDIOVASCULAR CONTROL CENTER (in medulla), results in PARASYMPATHETIC OUTPUT and decreased NOREPINEPHRINE RESLEASE. Increases VASODILATION (via arteriolar smooth muscle),decreases FORCE of VENTRICULAR CONTRACTION (via ventricular myocardium) and decreases HEART RATE (via SA node). Leads to negative feedback. Overall effect is to decrease stroke volume (called INOTROPIC EFFECT).
What do we call volume loss?
Hemorrhage
What is the body’s response to hemmorhage?
The opposite of its response to increased MAP
Name four inputs to Cardiovascular Conrol Center in Medulla.
1) Higher brain centers (cerebral cortex, limbic system, and hypothalamus)
2) Proprioceptors: monitor joint movements
3) Baroreceptors: monitor blood pressure
4) Chemoreceptors: monitor blood acidity, carbon dioxide levels, and oxygen levels
What are the outputs from the Cardiovascular Control Center, with effect and sympathetic/parasympathetic
- Vagus nerve (X): Decreased heart rate, parasympathetic
Cardiac accelerator nerve: increased heart rate, sympathetic
Vasomotor nerves: vasoconstriction, sympathetic
What do we call sudden fainting? What are three causes
Syncope
1) vasodepressor syncope: sudden emotional stress
2) drug-induced syncope
3) orthostatic hypothension: decrease in blood pressure upon standing
