CV- Blood Vessels Flashcards
Arteries carry blood ____ the heart
away from
Veins carry blood______ the heart
towards
Layers of blood vessels
Tunica interna (intima) -simple squamous epithelium (endothelium)
Tunica media
-smooth muscle, elastic connective tissue
Tunica externa
-connective tissue, collagen
What is the vasa vasorum?
vessels of vessels (tunica externa)
- blood vessels located on the outside of arteries
- nourish outer region of large vessels
- inner half of large vessels receive nutrients from luminal blood
Types of arteries?
- elastic (conducting)
- muscular (distributing)
- arterioles
Purpose of elastic (conducting arteries)?
its high elastin content dampens surge of blood pressure
Location of muscular (distributing) arteries? Features?
-lie distal to elastic arteries
- thick tunica media
- internal and external elastic laminae
Diameter of arterioles controlled by:
- local factors in the tissues
- sympathetic nervous system
Purpose of capillaries?
deliver O2 and nutrients, remove CO2 and waste
Function of lung capillaries?
O2 enters blood, CO2 leaves
Function of small intestine capillaries?
receive digested nutrients
Function of endocrine gland capillaries?
pick up hormones
Function of kidney capillaries?
removal of nitrogenous waste
Where is microcirculation found?
muscles, skin, liver, kidneys, intestines, heart, lung, brain
Which tissues do not have a rich capillary supply?
tendons and ligaments
epithelia and cartilage
4 routes into and out of capillaries?
Direct diffusion- O2 and CO2
Intercellular clefts- small molecules
Vesicles- gases, nutrients, waste
Fenestrations- H2O
Types of capillaries?
Continuous- no pores
Fenestrated- pores
Sinusoid- wide and leaky
Where are continuous capillaries located? Fenestrated? Sinusoid?
- brain, skeletal muscle, smooth muscle, lungs, skin
- kidneys, SI, synovial membrane
- bone marrow and spleen
Why does blood flow occur slowly in sinusoid capillaries?
there needs to be lots of time for exchange of large materials
What type of capillaries make up the blood brain barrier?
continuous
-only vital molecules pass
What is the blood brain barrier not a barrier against?
O2, CO2, some anesthetics
_____ ______ is the thickest in veins
tunica externa
Blood pressure is ______ in veins than in arteries
lower
_____ is larger in veins than arteries
lumen
Mechanisms to counteract low venous pressure
valves
skeletal muscle pump
breathing
What are varicose veins?
twisted, dilated superficial veins
-valves weaken and fail causing blood to pool and slow drainage
Varicose veins occur in which type of individual?
those whose jobs require prolonged standing, pregnant women
Where are vascular anastomoses found?
around joints
in the brain
around the heart
How is a knee dislocation repaired?
using the saphenous vein from the other limb, it replaces the popliteal artery to supply blood to the leg
What is a portal vein?
A vein that carrier blood from one capillary network to another
Hepatic portal vein delivers blood and digested nutrients to the _______
sinusoids of the liver for processing and storage
What are the veins of the hepatic portal system?
- superior mesenteric vein
- splenic vein
- inferior mesenteric vein
- hepatic portal vein
