The three major types of blood vessels, what are they
Arteries, Cappillaries and Veins
What is the job of the arteries
carry blood away from the heart
What is the function of the cappillaries
carry blood into and out of tissues
Capillaries are considered what size blood vessels
Smaller
Veins do what
carry blood toward the heart
The blood vessels in the adult human stretch how far
about 100,000 km (60,000 miles)
Arteries are divided into three groups in terms of what
size and their function
What are the three groups of arteries
elastic arteries, muscular arteries and arterioles.
Elastic arteries are sometimes referred to as what
Conducting arteries
Describe elastic arteries and where they are located
thick walled arteries near the heart (at the aorta and its major branches)
The elastic arteries have large lumens that make it what type of pathway
low-resistance pathway
Elastic arteries conduct blood from and to where
from the heart to medium-sized arteries
Distally the elastic arteries give way to what type of arteries
muscular arteries
Muscular arteries are also know as
distributing arteries
Muscular (Distributing) Arteries deliver blood to where
specific body organs
these arteries have the thickest tunics "coverings" of all the vessels
Muscular (distrubuting) arteries
these arteries are more active in vasoconstriction and less distensible and why
Muscular Arteries since there tunica contains relatively more smooth muscle and less elastic tissue than do elastic arteries.
The smallest of the arteries, that lead into the capillary beds
Arterioles
What are the smaller arterioles tunica's made up of
a single layer of smooth muscle cells spiraling around the endothelial lining
Most tissues have a rich supply of what type of vessle
capillary
Structurally, there are three types of capillaries
Continuous, Fenestrated and Sinusoidal
Continuous cappillaries, which are the most common are aboundant where
in the skin and muscles
these capillaries are similare to the continuous capillaries and are located where
fenestrated capillary located in special loacations e.g. kidney, small intestine
These are considered highly modified, leaky capillaries found where
sinusoidal capillaries located in the liver, bone marrow, spleen and adrenal medulla
Capillaries function alone, true or false
False they tend to form an interweaving networks called capillary beds.
The flow of blood from an arteriole to a venule—that is, through a capillary bed—is called the microcirculation
microcirculation
Capillary bed consists of two types of vessels, what are they
a vascular shunt and true capillaries
Blood can flow through the true capillaries and take part in exchange with tissue cells. The sphincter or gates are in what mode or state
relaxed or open
After eating, the sphincter or gates in a capillary bed should be relaxed or open in what part of your body
in the gastrointestinal organs to receive the breakdown product of digestion.
When exercising vigorously blood is rerouted from the digestive organs (food or no food)to the capillary beds of the what and why
your skeletal muscles since the blood is more immediately need. The pathway or gates are closed (contracted) in the digestive region and relaxed (open) in the skeletal muscles.
What carries blood from the capillary beds to the heart
Veins
Venules ranging from 8 to 100 μm in diameter, and are formed when
when the capillaries unite
The diameter of successive venous vessels increases, and their walls gradually thicken at what point
when the venules progress to larger and larger veins.
Venules join to form thin walled, larger lumen and are then called
veins
Veins consist of thick longitudinal bundles of what
collagen fibers and elastic networks
Blood returns directly to the heart in this largest veins
the venaecavae
What percentage of the body’s blood supply is in the veins at any time
65%
these are referred to as capacitance vessels and blood reservoirs
veins
Arterial Blood Pressure Reflects two factors, what are they
how much the elastic arteries close to the heart can be stretched (their compliance or distensibility) and the volume of blood forced into them at any time
The pulse pressure (Pp) is the difference between what
the systolic pressure (Ps) and the diastolic pressure (Pd)
The pressure the propels the blood to the tissues is called what
Mean arterial pressure (MAP)
How is mean arterial pressure (MAP) measured
MAP = Pd + Pp/3 example of an average person: MAP = 80 mm Hg + 40mm HG (this is the difference between systolic and the diastolic pressures 120-80=40) / 3 = 93 mm Hg
Mean arterial pressure MAP and pulse pressure increases or declines with increasing distance from the heart? why
decline since the farther from the heart the less difference in the blood pressure
Capillary Blood Pressure dropes approximately to what?
35 mm Hg at the beginning of the capillary bed and 15 mm Hg at the end of the capillary beds.
Low capillary pressures are desirable because 2 reasons:
1.capillaries are fragile and high pressures would rupture them 2. Capillaries are extremely permeable and thus even the low capillary pressure forces solute-containing fluids (filtrate) out of the bloodstream into the interstitial space. This fluid flows are important for continuously refreshing the interstitial fluid.
Venous Blood Pressure is steady and changes very little during the cardiac cycle true or false
true
The pressure gradient in the veins, from venules to the termini of the venae cavae, is what
about 15 mm Hg (that from the aorta to the ends of the arterioles is about 60 mm Hg).
The pressure difference between the arteries and the veins becomes very clear when what happens
If a vein is cut, the blood flows evenly from the wound; a lacerated artery spurts blood.
Name three sites above the chest where the pulse is most easily palpated
Temporal artery, Facial artery and the common carotid artery.
Name three sites below the chest and above the thigh where the pulse is most easily palpated
Brachial, Radial and Femoral arteries.
Name three sites below the thigh where the pulse is most easily palpated
