Shared Flashcard Set

Details

vessels
blood vessels
83
Anatomy
Undergraduate 1
04/03/2009

Additional Anatomy Flashcards

 


 

Cards

Term

Blood vessels form

Definition

a closed system composed of arteries, arterioles, capillaries, venules, and veins.

Term

An artery is a

Definition

vessel taking blood away from the heart

Term

 Vein

Definition

is a vessel returning blood to the heart.

Term

Walls of arteries and veins have three coats

Definition

A. Tunica intima

B. Tunica media

C. Tunica externa or tunica adventicia

Term

Tunica intima

Definition

inside lining of vessel

Term

Tunica intima - 2 layers

Definition

1. Layer of simple squamous endothelium

2. Layer of elastic fibers (found only in artery)

Term

Tunica media

Definition

layer of smooth muscle and elastic fibers

(veins have more connective tissue fibers mixed with the smooth muscle)

Term

Tunica externa or tunica adventicia

Definition

connective tissue located on the outside.

Term

Arteries - Characteristics

Definition

1. Walls are thicker and contain more smooth muscle.

2. Lumen is round (particularly in smaller vessels)

3. Valves are absent

Term

Types of arteries

Definition
 

1. Elastic or conducting arteries

2. Distributing or muscular arteries

Term

Elastic or conducting arteries

Definition

large vessels that contain more elastin and muscle fibers. (Aorta and its direct branches)

Term

Distributing or muscular arteries

Definition

distributes blood to various parts of the body and is composed of a thick tunica that constricts and dilates

Term

Arterioles

Definition

are small arteries that contain all three coats on the arterial end, but are composed of an endothelial lining with a few smooth muscle cells towards the capillary end

Term

Capillaries - size

Definition

Smallest are 7-10 microns in diameter

Term
Capillaries - walls
Definition

are composed of a single layer of simple squamous epithelium with a basement membrane

Term

Amount of blood flowing through a capillary is determined by 

Definition

a precapillary sphincter muscle located at the origin of the capillary

Term

With few exceptions a capillary should be located within

Definition

60-80 microns of any tissue cell

Term

Capillaries contain approx. 

Definition

250 ml. of blood out of the 5000 ml. of blood flowing through the vessels at any time

Term

Capillaries function

Definition

as the area of exchange between the blood and the body tissues

Term

Types of Capillaries

Definition

1. Continuous

 

2. Fenestrated

 

3. Discontinuous

Term

Continuous

Definition

adjacent endothelial cells closely joined. 

Term

Fenestrated

Definition

capillaries contain large pores covered with the basement membrane.

Term
Where are fenestrated capillaries located?
Definition

Located in the kidneys, endocrine glands, intestines, and choroid plexus of brain

Term
discontinuous
Definition
larger spaces between the endolthelial cells.
Term
where are the discontinuous capillaries located?
Definition
liver, spleen, and bone marrow
Term
Metarteriole
Definition
connects arteriole to venule
Term
True Capillary
Definition
are not the direct flow round from arteriole to venule
Term
Venules
Definition
Capillaries come together to make venules composed of a tunica interna and a ternica externa
Term
Veins
Definition
vessels that return blood to the heart
Term
Characteristics of Veins
Definition

1. have less smooth muscle and more connective tissue

 

2.  lumen partially collapsed

 

3. contain valves

Term
Functions of Veins
Definition

1.  return blood to heart

 

2.  act as blood reservoirs (approx. 2/3 of blood volume located in veins)

Term
Anastomosis
Definition
junction between two vessels supplying same area
Term
collateral circulation
Definition
two vessels supplying the same area and providing an alternate route for blood flow due to an anastomosis
Term

End Arteries

Definition
vessels that do not anastomos
Term

blood pressure

Definition
pressure blood exerts on any vessel
Term
Factors that affect arterial pressure
Definition

1. cardiac output

2. blood volume

3. peripheral resistance

 

Term

Blood volume

Definition
 

directly proportional to blood pressure. Anything that increases blood volume increases blood pressure.

1. ADH

2. Aldosterone

Term

Peripheral resistance

Definition

resistance to blood flow by force of friction between blood and walls of vessels

Term

Any condition that increases viscosity increases 

Definition

blood pressure

Term

The smaller the diameter of the vessel

Definition

 the more resistance

Term

The longer the vessel

Definition

the more resistance

Term

How many additional miles of capillaries are made for each pound?

Definition

200 additional miles of capillaries

Term

Control of Blood Pressure

Definition

Increase in heart rate and muscular contractions increases blood pressure.

Term

Factors controlling heart rate and force on contractions also affect?

Definition

affect blood pressure

Term

Factors acting on blood vessels

Definition
 

1. Vasomotor center in medulla controls diameter of blood vessel.

2. Pressoreceptors in aortic arch and carotid sinus

3. Chemoreceptors in aortic arch and carotid sinus (monitors low oxygen by checking for high hydrogen ions. High carbon dioxide levels lead to high hydrogen ion concentrations. This causes vasoconstriction of non-essential vessels.

4. Higher brain centers - emotions

5. Chemicals

6. Autoregulation - Oxygen is the principal stimulant. Low oxygen causes vasodilator substances to be released.

 

Examples are K+ , H+ , CO2 , lactic acid, and adenosine. This causes localdilation and relaxation of precapillary sphincter muscles.

 

Term
Venous Pressure
Definition

Highest in venules (16 mm Hg) and lowest at junction of vena cava with right atrium (0 mm Hg)

Term

Aids venous blood returning to heart

Definition
 1. Pressure differences

2. Sympathetic nerve activity

3. Skeletal muscle pump

4. Pressure difference between thoracic and abdominal cavities

Term

Velocity of blood in inversely related to TOTAL cross-sectional area

Definition
 

Aorta

Capillaries

Vena cava

Term

Aorta

Definition

cross-sectional area of 2.5 cm2 and velocity of 40 cm/sec.

Term

Capillaries

Definition

cross-sectional area of 4500 - 6000 cm2 and velocity of .1 cm/sec.

Term

Vena cava

Definition

cross sectional area of 8 cm2 and velocity of 5 to 20 cm/sec.

Term

Distribution of Blood

Definition

1. systemic veins

2. systemic arteries

3. Capillaries

4. Head and lungs

Term
Systemic veins
Definition

60%

1.  Act as blood reservoirs

2. veins have thinner, less muscular walls, therefore higher compliance.

Term
Systemic arteries
Definition
13%
Term
Capillaries
Definition
7%
Term
Head and Lungs
Definition
20%
Term

Capillary Exchange

Definition

A. Exchange dependent on pressure

B. Effective filtration pressure

C. Starling's Law of the Capillaries

 

Term

Exchange dependent on pressure

Definition

1. Blood Hydrostatic Pressure

2. Interstitial Fluid Hydrostatic Pressure

3. Blood Osmotic Pressure

4. Interstitial Fluid Osmotic Pressure

Term

Blood Hydrostatic Pressure

Definition

blood pressure in capillaries average 35 mm Hg at arterial end and 16 mm Hg at venous end

Term

Interstitial Fluid Hydrostatic Pressure

Definition

pressure of fluid against cells of tissue and capillaries. Averages O mm Hg.

Term

Blood Osmotic Pressure

Definition

due to large number of plasma proteins in blood. Moves fluid into capillaries. Averages 26 mm Hg at both ends.

Term

Interstitial Fluid Osmotic Pressure

Definition

 due to small number of proteins in interstitial fluid. Averages 1 mm Hg at both ends

Term

Interstitial Fluid Osmotic Pressure

Definition

due to small number of proteins in interstitial fluid. Averages 1 mm Hg at both ends

Term

Effective filtration pressure

Definition

direction of fluid movement

 

Peff = (BHP + IFOP) - (IFHP + BOP). If the calculations equal a positive number, fluid is flowing from the capillary to the interstitial fluid, but if the calculations equal a negative number fluid is flowing from the interstitial fluid to the capillary.

Term

Starling's Law of the Capillaries

Definition

amount flowing out of the arterial end almost equal the amount flowing in the venous end and the amount flowing into the lymphatic capillary.

Term

Pulse

Definition

alternate expansion and recoil of artery as blood passes through

Term

Average pulse is                per minute.

Definition

 60-80 beats per minute.

Term

Tachycardia

Definition

 rapid pulse over 100 beats per minute at rest

Term

Bradycardia

Definition

slow pulse, under 50 beats per minute at rest

Term

Blood Pressure

Definition

 pressure of blood in arteries

Term

How is BP expressed?

Definition

                             as 120

80

Term

Top number represents

Definition

pressure of blood in arteries during systole

Term

Bottom number represents

Definition

pressure of blood in arteries during diastole

Term

Difference in two numbers is called

Definition

 the pulse pressure

Term

Ratio of systolic pressure to diastolic pressure to pulse pressure should be

Definition

3:2:1.

Term

Types of Circulation

Definition

A. Systemic

B. Pulmonary

 

Term

Systemic

Definition

1. Coronary

2. Hepatic portal circulation

3. Circles of Willis

4. Fetal circulation

Term

2. Hepatic portal circulation

Definition

veins that drain blood from capillaries in intestines, pancreas, spleen, stomach and gall bladder drain into capillaries in liver.

Term

The hepatic vein drains blood from _____and empties blood into the ___________

Definition

 liver    

inferior vena cava

Term

Circles of Willis

Definition

 provides alternate pathway for blood to reach brain in case of arterial occlusion. Also aids in equalizing blood pressure to brain

Term

Fetal circulation

Definition

special structures associated with fetus

Term

Pulmonary

Definition

all deoxygenated blood leaving the right ventricle and returning to left atrium

Supporting users have an ad free experience!