39 terms

Blood Vessels

Blood Vessels
tubelike structures that carry blood throughout the body
blood vessels that carry blood away from the heart
blood vessels that carry blood back to the heart
Vessel Lumen
Inner space of the vessel
Tunica Intima
innermost layer; squamous epithelium surrounded by connective tissue with elastic fibers
Tunica Media
middle layer of artery; made up of smooth muscle fibers and thick layer of elastic connective tissue
Tunica Externa
outermost tunic, composed of fibrous connective tissue
Elastic Arteries
largest type of artery; contains many elastic fibers that allow it to stretch in response to each pulse; close to the heart.
Conducting arteries
also known as elastic arteries. Leading the blood to all parts of the body.
Muscular arteries
arteries that deliver blood; active in vasoconstriction; thick tunica media. Distribute to all parrts of the body.
Arterioles vessels
resistance vessels. These vessels control your blood pressure.
Lymphatic System
This system's funtions are (1) to transport tissue fluid to the blood vessels, and (2) to protect the body by removing foreign material such as bacteria from the lymphatic stream and by serving as a cite for lymphocytes "policing of body fluids and lymphocyte multiplication. It is a one-way system that carries lymph only towards the heart.
Terminal arteriole
Last vessel before capillaries. They lead up to capillary bed.
Precapillary Sphincter
a ring of muscle that contracts to close an opening. Exchange vessels
Postcapillary Venule
smallest venule---Form part of microcirculatory exchange unit with capillaries
Small veins
smooth muscle cells from a continuous layer. addition of tunica adventiatia made of collagenous connective tissue
Continuous Capillaries
capillaries found in skin and muscles; uninterupted lining; held with tight junctions
Fenestrated capillaries
secretions enter the circulation through these that contain open spaces between their epithelial cells. Pores, holes
Are like fenestrated capillaries but they have gaps between adjacent endothelial cells and thin or absent basal lamina.
Sinusoidal capillaries
leaky capillaries; found only in the liver, bone marrow, lymphoid tissues and some endocrine glands; allow large molecules to pass between blood and surrounding tissues
Capillary Beds
Interweaving network that capillaries form
form by venules, blood vessels that carry blood back to the heart
small vessels that gather blood from the capillaries into the veins
True Capillaries
exchange vessels; 10-100 per capillary bed
Vascular Anastomoses
Interconnections of blood vessels
Arterial Anastomoses
When two arteries merge and provide alternative routes of blood supply to a tissue:
Collateral Channels
what are vascular anastomoses especially with veins that provide alternative pathways for blood to reach a given body region
Arteriovenous Anastomoses
allow arteries to have direct connections w/ veins and bypass the capillary bed when needed
hardening of the arteries
condition in which fatty deposits called plaque build up on the inner walls of the arteries
Blood Flow
volume of blood that flows through any tissue in a given period of time
Blood Pressure
the pressure of the circulating blood against the walls of the blood vessels
Blood Viscosity
resistance to flow; thickness/stickiness of blood; fairly constant
Total Blood Vessel Length
Resistance directly proportional to length of vessel
Blood Vessel Diameter
most important source of resistance
Systolic Pressure
the blood pressure (as measured by a sphygmomanometer) during the contraction of the left ventricle of the heart
Diastolic Pressure
the blood pressure (as measured by a sphygmomanometer) after the contraction of the heart while the chambers of the heart refill with blood
Pulse Pressure
difference between systolic and diastolic pressure
Mean Arterial Pressure
Diastolic + 1/3 pulse pressure