Blood vessels Flashcards
Define Pulmonary circulation
- deoxygenated blood is carried away from the heart by the pulmonary artery
- oxygenated blood is carried to the heart by pulmonary veins
Define systemic Circulation
- oxygenated blood is carried away from the heart by the arteries
- deoxygenated blood is carried to the heart by the veins
What is the organisation of the vascular system ?
arteries, veins, arterioles, venues, capillaries
Describe Arteries
- always carry blood away from the heart
- thick, muscular walls
- except pulmonary arteries all carry oxygenated blood
What is the largest artery ?
- the aorta
Describe the aorta
- its the first artery through which blood in the systemic flows through on leaving the heart
- all other arteries branch directly or indirectly off the aorta
Define the function of the carotid artery
carries blood to the head
What’s the function of the subclavian artery ?
carries blood to the arm
Describe the abdominal aorta
- located on the left side of the body
- key artery coming off it = ciliac artery
- the ciliac artery branches into the hepatic, gastric and splenic arteries which carry blood to the liver, stomach and spleen
Describe veins
- thinner walls than arteries
- always carry blood bacteria to the heat - except for the pulmonary vein which carries deoxygenated blood
- Venae cave = largest veins in the body
Describe the Venae Cava
- Venae Cava = Plural
- Superior Vena Cava - collects blood from upper body & head - short vein
- Inferior Vena Cava - collects blood from the lower body - lower vein located in the right side of the body
Describe the distribution of blood in the body
systemic venous system = 64%
pulmonary circuit = 9%
heart = 7%
systemic arterial systems = 13%
systemic capillaries = 7%
What makes up the microvasculature of the circulatory system ?
capillaries, arterioles, venules
Describe capillaries
exchange of gases (oxygen & carbon dioxide) and chemical takes place between the blood and interstitial tissue
Describe arterioles
the narrowest type of artery and deliver oxygenated blood to the capillary bed
Describe Venules
narrowest type of vein and receive deoxygenated blood from the capillary bed
What is the role of Precapillary Sphincters ?
they control the flow of blood from the arteriole into each capillary
- when 1 pre capillary sphincter constricts blood is diverted into other branches
What are the 3 layers that make up all vessels ?
- Tunica intima
- Tunica media
- Tuncia adventitia
Describe Tunica intima
- inner layer
- endothelia line the blood vessel
Describe Tunica media
- middle layer
- vascular smooth muscle cells, collagen & elastin fibres
- often thickest layer
Describe Tunica adventitia
-outer layer
- outer protective layer
- contains fibroblasts
What are Elastic Arteries ?
- arteries close to the heart must be able expand & recoil to maintain constant BP
What are some examples of elastic arteries ?
- aorta
- carotid artery
- pulmonary artery
Describe Muscular arteries
- smaller branches off elastic arteries
- more smooth muscle & fewer elastic fibres
- coronary & femoral arteries = examples
What are the 3 types of capillaries ?
- continuous
- fenestrated
- sinusoid
Describe Continuous Capillaries
- majority of body’s capillaries
- restricted permeability
- permits exchange of water, small solutes & lipid-soluble between blood & interstitial fluid
Describe Fenestrated Capillaries
- example = kidney/intestine
- facilitate rapid exchange of water & solutes between blood and interstitial fluid
Describe Sinusoid Capillaries
- example = liver, bone marrow
- free exchange of water, solutes & large plasma proteins
Define Vasculogenesis
- refers to formation of entirely new blood vessels
- only occurs in embryonic development
Define Angiogenesis
- sprouting of new branches from pre-existing blood vessels
- occurs throughout life
What is Atherosclerosis ?
build up of fatty deposits within the walls of arteries which can trigger clot formation & become dislodges - blocking arteries
What can atherosclerosis cause ?
heart attack, stroke or kidney disease
