Lecture 3: Vessels & Bloodflow Flashcards
What is the largest vessel and the first place blood goes as it leaves the heart?
aorta
What are the layers of vessels?
- intima -> inner
- media -> middle
- externa -> outer
What are the characteristics of the tunica intima?
- made of squamous epithelial cells
- surrounded by mesh connective tissue
- found in all blood vessels
What type of epithelial allows for exchange in vessels?
simple squamous
What are the characteristics of the tunica media?
- muscular layer
- connected to other layers by collagen fibers
- circular smooth muscles
Where is the tunica media thick?
in arteries & contains elastic tissue
Where is the tunica media thin?
in veins & contains collagenous fibers
What are the characteristics of the tunica externa?
- composed of collagenous fibers
- holds vessels in place & prevents flow disruption
What vessel should have the thickest, most elastic walls?
aorta
What are the branches of the aorta?
- brachiocephalic
- left subclavian artery
- left carotid artery
What are arterioles?
- allows body to survive on lower blood volume
- have sphincters to shunt blood
What occurs if all the sphincters in the body open?
decrease in blood pressure
What is the primary site of exchange in the circulatory system?
capillaries
What are the 3 types of capillaries?
- continuous -> tight junctions
- fenestrated -> pores
- sinusoidal ->large gaps b/w cells
What are the characteristics of continuous capillaries?
- limit flow of materials out of capillaries
- common in fat, muscle, nervous tissue
What are the characteristics of fenestrated capillaries?
- permit movement of larger molecules out of capillaries
- common in intestines, kidneys, endocrine glands
What are the characteristics of sinusoidal capillaries?
- allows cells to move in/out of blood
- found in lymph nodes, spleen, liver, & bone marrow
Venules coalesce to form what?
veins
What are the characteristics of venules?
- have large lumen to collect blood
- possess valbes to accomodate low pressure
- collagenic tunica media
What is the hepatic portal system?
- routes blood through liver
- permits absorption/ modification of nutrients
- has nutrient dense blood from digestive tract
- permits cleaning & modification of spleen blood
All blood leaves the liver through what type of vein?
hepatic vein
What enters and what leaves through the placenta?
- enters -> O2 & nutrients from mother
- leaves -> waste
What moves the blood from the right the left atrium?
foramen ovale
What connects the pulmonary artery to the aorta?
ductus arteriosus
