Cardiovascular vessels 1 Flashcards
What is the main goal of the cardiovascular system?
To maintain adequate blood flow to peripheral tissue and organs
What are the different areas of angiography?
- Cerebral
- Cardiac
- Abdominal
- Peripheral
- Catheterization via arteries
Which arteries do we catheterize?
- Femoral artery
- Axillary artery
- Brachial artery
How many layers does a blood vessel have?
3 layers/tunics
What are the 3 tunics/layers of a blood vessel?
- Tunica interna/intima
- Tunica media
- Tunica externa
What is the tunica interna/intima?
The innermost layer (endothelium) that is in contact with blood
What is the tunica media?
The middle layer containng smooth muscle and elastic tissue
What is the tunica externa?
The outermost layyer that anchors the vessel
Which layer in a blood vessel contains the vasa vasorum?
The tunica externa
What are the 2 kinds of arteries?
- Elastic arteries
- Muscular arteries
What type of artery is the largest; elastic or muscular?
Elastic
What is the size of muscular arteries?
They are medium sized
Which type of artery has more elastic fibers? Where is it located?
The elastic arteries have more elastic fibers within the thick tunica media
What are the six main elastic arteries within the body?
- Aorta
- Pulmonary trunk
- Brachiocephalic
- Subclavian
- Common carotid
- Common Iliac
What are the 9 main musclular arteries within the body?
- Femoral
- Axillary
- Brachial
- Radial
- Intercostal
- Splenic
- Mesenteric
- Popliteal
- Tibial
Which type of artery has high compliance?
Elastic arteries
What is high compliance?
The ability to stretch without tearing in response to increased pressure
What is the function of elastic arteries?
To propel blood onward when ventricles are relaxing
What is it called when the blood is unable to get through the vessel when excersing?
Angina
Which type of artery contains more smooth muscle fibers?
The musclular arteries
What controls the flow/distribution of blood to organs or structures?
Vasoconstriction and vasodialation of musclular arteries
What type of artery has high vascular tone?
Muscular arteries
What is vascular tone?
The ability to maintain pressure and efficient flow
What happens in elastic arteries when the ventricles contract?
The walls stretch storing energy, which then is recoiled by elastic fibers converting stored E to kinetic E
What artery provides the ability to contract?
The muscular layer within muscular arteries
What does arterioles mean?
Small arteries
What is a metarteriole?
A terminal end of arterioles that joins to the capillary beds
What is the difference between stable and unstable angina?
Unstable: Occurs at rest, worsens and can lead to heart attack
Stable: Occurs when excersing
What are resistance vessels?
Resistance that occurs as a result of friction between th blood and the inner walls of a vessel
What happens when the vessel of an arteriole constricts?
-Increase in friction, increase in resistane, decrease in blood flow
Where is the precapillary sphincter located and what is its function?
-Located at the metaarteriole-capillary junction
-It controls blow flow into the capillary
What do the 3 structures of cappillaries vary by?
They vary by thier function
What are the 3 structures of capillaries?
- Continous
- Fenestrated
- Sinusoids
Where are ccontinous cappillaries located within the body?
CNS, muscles, skin, lungs
Where are the fenestrated capillaries located within the body?
Kidneys, small intestine villi, choroid plexus
Where are the sinusoid capillaries located within the body?
-Liver, spleeen , red bone marrow
How many cappillaries arise from a single metarteriole? What is this known as?
10-100
-This is known as a capillary bed
Approximetley how many capillaries are located in the body?
20 billion
Where are capillaries absent within the body?
Absent in the cartilage, cornea, les of the eye, epithelial tissues
Will vasoconstriction of arterioles increase or decrease blood pressure?
Increase blood pressure
What is the function of a capillary bed?
Increase SA so that cells can rapidly recieve O2 and nutrients and remove waste products back into the blood
Where are capillaries more extensive in number?
-In areas where metabolic activity is high
-Ex: Kidney, liver, brain, muscle
What layers of a vessel do cappillaries lack?
They lack the tunica media and the tunica externa
Where are capillaries located?
Between the blood and interstitial fluid
What is a capillary made of?
A single layer of endothelial cells and a basement membrane
What is the main function of venules?
They drain the capillaries
T/F
Venules may loose thier shape
True
What are the 2 types of venules?
- Muscular venules
- Post cappillary venules
What is the function of post capillary venules?
Exchange of nutrients and wastes
T/F
ONly postcapillary venules are distensible
False; both muscular and postcapillary venules are very distensible
What does distensible mean in relation to blood vessels?
That they are an excellent reservoir of blood
What exchange occurs with muscular venules?
No exchange occurs
What is the typical range of the diameters of veins?
0.5mm-3cm
What are some charecteristics of veins that vary greatly from arteries?
- Veins have larger lumens
- Veins have relatively no smooth muscle or elastic tissue
- Veins have a thinner tunica interna and media
Which way do cusps point in veins?
Cusps point towards the heart
What is the function of the valves within veins?
They aid in venous return by preventing backflow
Which is larger in veins, thier diameter or their walls?
Their diameter
What is a consequence of the larger lumens within veins?
A decrease in blood pressure causing the vein to collapse
What is a vein formed by?
Formed by the union of several venules
What is the largest vein?
IVC
Label 1-3
- Tunica interna
- Tunica media
- Tunica externa
What is an anatomoses?
A union of 2 or more branches of arteries supplying the same tissue or rergion
What type of cappillary is this?
Continous cappillary
What type of cappilary is this?
Fenestrated
What type cappilary is this?
Sinusiod
What is another term for the built in alternate route known as an anastomoses?
Collateral circulation
T/F
End arteries always anastomose
False; End arteries do nnot anastomose
What can blockage of an anastomose lead to?
Necrosis and death
T/F
An anastomoses can occur between veins, or between arterioles and venules
True
What is the function of anastomoses?
Protects the tissues or organs
Where is the majority of blood located within the body?
Systematic veins and venules (blood resiviours)
How much blood from the body do pulmonary vessels contain?
9% of blood from the body
How much blood from the body does the heart contain?
7%
How much blood from the body do systemic arteries and arterioles contain?
13%
How much blood from the body do systemic capillaries contain?
7%
What forces at the capillaries determine how much fluid leaves the arterial and of the capillary and how much is reabsorbed at the venous end?
Starling forces (Hydrostatic and osmotic forces)
What is the name of the force that describes filtration?
The hyrdostatic force
What is the name of the force that describes reabsorption?
Osmotic forces
What movement is being described here?
The movement of fluid and solutes from blood capillaries into the interstitial fluid.
Filtration
What movement is being descsribed here?
The movement of fluid and solutes from the interstitial fluid back into the capillary.
Reabsorption
What are the 2 pressures assosiated with filtration?
- Blood hydrostatic pressure (BHP)
Interstitial fluid osmotic pressure (IFOP)
What is the purpose of the IFOP?
Pulls fluid out of capillaries to intersitial fluid
What is the interstitial fluid osmotic pressure in mmHg?
1mmHg
What is the purpose of the blood hydrostaic pressure?
Pushes fluid out of capillaries to interstitial fluid
What is the blood hydrostatic pressure at the arterial end in mmHg?
35mmHg
What is the blood hydrostatic pressure at the venous end in mmHg?
15 mmHg
What 2 pressures promote reabsorption in the cappillaries?
- Blood colloid osmotic pressure (BCOP)
- Interstitial fluid hydrostatic pressure (IFHP)
What is the blood colloid osmotic presssure caused by?
Caused by large protiens in the blood
What is the purpose of the blood colloid osmotic pressure?
It pulls fluid from interstitial spaces into capillaries pressure?
What is the blood colloid osmotic pressure in mmHg?
26 mmHg
What is the purpose of interstitial fluid hydrostatic pressure?
It pushes fluid from interstitial spaces back into the capillaries
What is the interstitial fluid hydrostatic pressure in mmHg?
0mmHg
How do you calculate total net filtration pressure?
NFP=filtration-reabsorption
NFP=(BHP+IFOP)-(BCOP+IFHP)
How do you calculate NET filtration pressure at the arterial end?
NFP=(35+1)-(26+0)
NFP=10
How do you calculate NET filtration pressure at the venous end?
NFP=(16+1)-(26+0)
NFP=-9
If the NET filtration pressure is negative what does this indicate?
Reabsorption is taking place
If the NET filtration pressure is positive what does this indicate?
Filtration is taking place
T/F
In the capillaries, normally there is nearly as much fluid rabsorbed as there is filtrered.
True
How much fluid that is filtered from the capillary gets reabsorbed?
About 85% of fluid filtered is reabsorbed
What happens to the other percentage of filtered fluid that is not reabsorbed?
The rest is in the lymphatic system
How do you calculate cardiac output?
CO=SV x HR
What is the average blood flow from each ventricle?
5L/min from each ventricle
What is the distrubution of cardiac output to circulatory routes dependant on?
Dependant on Pressure and resisitance
How do you calculate blood flow?
Blood flow=P/R
What are the 3 factors that effect resistance?
- Diameter of lumen
- Viscosity of blood
- Lenth of blood vessel
As the length of the vessel increases, will resistance increase or decrease?
Increase
As the viscosity of the blood increases, will resistance increase or decrease?
Increase
As the diameter of the lumen decreases, will resistance increase or decrease?
Resistance will increase
What is this describing?
Hydrostatic fluid pushing against the wall of a vessel.
Blood pressure
T/F
Blood travels from areas of high pressure to low pressure.
True
Where is the lowest blood pressure in the body?
In the ventricles
Where is the highest blood pressure in the body?
In the aorta and large systemic arteries
What is blood pressure most dependant on?
Total blood volume
What is a normal blood pressure?
120/80
What pressure is this describing?
The highest pressure in the arteries during ventricular systole.
Systolic blood pressure (SBP)
What pressure is this describing?
The lowest pressure in arteries at the end of ventricle diastole.
Diastolic blood pressure (DBP)
What pressure is this describing?
Te average blood pressure in arteries?
The mean arterial pressure (MAP)
What is the blood pressure in the aorta during systole?
120mmHg
What is the blood pressure in the aorta during diastole?
80mmHg
What is the blood pressure in arterioles as they pass into the capillaries?
35 mmHg
What is the blood pressure at the venous end of the capillaries?
16 mmHg
What is the blood pressure as blood enters the right ventricle?
0mmHg
What are the 2 types of venous return?
- Skeleteal muscle pump
- Respiratory pump
How does the skeletal muscle pump work?
Through contractions of leg muscles that compresss the veins, pushing blood through the valve
On average, how many times does you heart beat in a year?
35 million times in a year
How far does blood travel in one day in miles?
12000 miles
How long does it take for a drop of blood to go from the right atrium and back?
1 minute
What are the hormonal controls of blood pressure?
- ANP
- ADH
- Epinephrine and norepinephrine
- Renin-angiotensin-aldostrone system
What are the neural controls of blood pressure?
- Baroreceptors
- Chemoreceptors
Where are baroreceptors located?
Loacted in aortic arch and internal carotid artery
What is the function of barorecptors?
To sense changes in pressure
What is the purpose f chemoreceptors?
To sense changes in chemical composition of blood
Where are chemoreceptors located?
Located close to baroreceptors
T/F
Superficial veins do not have muscle around them
True
What does a DVT cause?
DVT causes a clot in the pulmonary artery which causes a pulmonary embolism
How do you fix a DVT?
Put in an IVC filter to collect the clot
How does the respiratory pump work?
-During inspiration, due to P and V change, veins in the abdomen compress, and force blood into the lower pressure veins in the thorax
-During expiration, the increased pressure in thoracic cavity forces blood from thoracic veins back to the heart.