Lymphatic Flashcards
The __________ system is composed of a network of vessels that penetrate nearly every tissue, and a collection of tissues and organs that produce immune cells.
lymphatic
T or F: 1. Interstitial fluid and lymph are basically the same (lymph is lower in protein).
true
what is the major difference between interstitial fluid and lymph?
location
The blood vessels form a _____ circuit to and from the heart.
closed
B. The blood vessels in this circuit include:
- Arteries : carry oxygenated blood (except for pulm artery = deoxy) away from the heart to various parts of the body
- Arterioles : regulate the blood flow from arteries into capillaries
- Capillaries: sites of exchange of gases, nutrients, and waste products
- Venules : collect deoxy blood from capillaries and transport it to larger veins
- Veins : carry deoxy blood (except for pulm veins = oxy) back to the heart
What are the 3 basic structures of a vessel
- The tunica interna: innermost layer of the blood vessel wall
a. continuous with the endocardium
b. endothelium: a single layer of cells that line the inside of blood vessels - The tunica media : middle layer of a blood vessel wall
- The tunica externa: outermost of blood vessel wall
a. vasa vasorum: small BVs that supply nutrients and molecules to the tunica externa
why are arteries sometimes called resistance vessels?
they are a relatively strong structure that resists blood pressure
- Being more muscular than veins, they retain a round shape even when ______
empty
______ Arteries: large, flexible tubes that carry blood away from the heart and are vital for supplying oxygen/nutrients to the body’s cells (ie aorta)
elastic
________ arteries: branch off from elastic arteries and distribute blood throughout the body (ie smooth muscle)
muscular
Arterioles have only one to three layers of smooth muscle and are the primary site of blood pressure regulation by ______________/______________
vasoconstriction/vasodilation
in arterioles, what is the difference between local (autoregulation) and sympathetic of blood flow
a. Local (autoregulation) regulation of blood flow: intrinsic ability to adjust its own bf by altering the diameter of its blood vessles
b. Sympathetic regulation of blood flow: sympathetic nervous sytem controls bf and bp
Capillaries are the vessels where exchange takes place with other body tissues. Capillaries are the smallest diameter blood vessels – call the _______________ and they connect the smallest arteriole and the smallest venule.
microcirculation
C. The walls are endothelium only and a _______ _______
basal lamina
3 types of capillary beds
- Microvascular unit: network of small blood vessels that include arterioles and venules
- Metarteriole: A short microvessel that connects arterioles to capillaries
- Precapillary sphincters: smooth muscle bands that control blood flow into capillary beds
Are capillaries found everywhere in the body?
yes
where are capillaries scarce?
tendons and ligaments (non existent in epithelia and lens/cornea)
what is an example of a continuous capillary?
intercellular cleft: small gaps (allows glucose to pass)
what do fenstrated capillaries have and what do they do
filtration pores, rapid passage of small molecules but take bigger too
what are sinusoids and what can pass thru
endo cells seperates by wide gaps with no basal lamina and large fenstrations (even proteins and BCs can pass thru)
Is blood flow slow or fast in capillaries
SLOW
what draws fluid back into the capillary at the venous end
osmotic pressure
what are the 4 routes that molecules can pass in and out of capillaries
- direct diffusion thru endo membrane
- intercellular clefts (small)
- fenestrations (larger, faster)
- pinocytotic vesicles (small and large)
Venule: they have a tunica interna with only a few fibroblasts surrounding it and no _______
muscle
Veins: Veins are considered the __________ vessels of the cardiovascular system because they are relatively thin-walled and flaccid and expand easily.
capitance
At rest, is more blood found in the systemic veins or arteries
veins
Being distant from the ventricles, veins are subjected to relatively low blood pressure and thus have _______ walls.
thinner
venous valves ensure what
1 way flow of blood
________ ________ pump: helps heart circulate blood by squeezing blood back to the heart during exercise
skeletal muscle pump
_________ veins: swollen, twisted veins -> one way veins don’t work properly, cause blood to pool and swell
vericose
T or F: The simplest and most common circulatory route of blood flow is heart → arteries → capillaries → veins → heart, but there are exceptions, notably portal systems and anastomoses.
T
In a _______ system, blood flows through TWO consecutive capillary networks before returning to the heart. Examples are between the hypothalamus and pituitary and the hepatic portal system between the small intestine and the liver.
portal