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50 terms

Cardiolvascular Part A

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Blood Vessels to Vein journey
Start from base of Heart (Left Ventricle)
Ends at Right Atrium of Heart
Three walls of blood vessel
Tunica Intima (inner)
Tunica Media (middle)
Tunica adventitia (outer)
What does the thickness of a vessels wall indicate?
It depicts the amount of pressure the vessel is designed to withstand.
Tunica Intima
Simple Squamous epithelium
Elastic Layer
Tunica Media
Smooth muscles
Elastic CT
Thickest layer in Arteries
Tunica Adventitia
Thin
CT of elastin and collagen fibers
Tunica Media - Elastic Arteries
closest to the heart
Has more elastic tissue
Tunica Media - muscular arteries
Predominantly smooth muscle with less elastic tissue
Tunica media smooth muscle is innervated by
Sympathetic nervous system
What does the sympathetic stimulation cause in a blood vesssel?
Contractions, known as vasoconstriction
Lack of stimuli from PARA, leads to vasodialation (widening of lumen)
System communication Nervous
Sympathetic
Fight of Flight
-increases heart rate
-breathe faster
-pupils dilate
-slow digestion
-cold, sweaty
-liver releases sugars into blood
Parasympathetic
Rest and Digest
-heart slows
-breathe slows
-blood flow to GI increases
-pupils constrict
Arteries
-Carry blood away from heart
-Elastic to handle high pressure
-Branch into arterioles
Arterioles
-Smaller than arteries
-Composed mostly of smooth muscle
-fewer than 5 layers of sm. muscle
-control blood distribution to various regions of body by contracting and relaxing of their smooth muscle
Capillaries
-Single Layer of squamous epithelial cells
-semipermeable
-lot of cap. in muscle and nervous tissue
- few in cornea & cartiladge
- Form capillary beds.
Capillary beds
Branched networks within tissues and organs
Precapillary Sphincters
-Regulate flow into capillary bed
-solutes cross capillary wall by diffusion
-plasma proteins stay (too big) so they help with osmotic pressure.
Capillaries filtration
The filtration forces the formation of fluid in the interstitial space and results in hydrostatic pressure
Capillaries (2 types)
-Continuous
-Fenestrated
Continuous capillaries
endothelial cells form a complete tube type
Fenestrated Capillaries
Increased pores for
fenestrated, the endothelial cells have large gaps (fenestrae) in them....thereby increasing the 'leakiness' of the capillary
Which arterial wall exhibits greatest variation?
Tunica media
What is the composition of a capillary?
a single layer of squamous epithelium and a basement membrane
Which vessels of the vascular system exhibit valves?
Veins
Venules
(come after capillaries in bed in flow)
-Merge to form veins
-tunica media and adventitia composed of LCT
Veins
-Carry blood towards the heart
-path of veins parrallels that of arteries
-Same 3 layers as arteries (much smaller TUNICA MEDIA)
-possess valves
-blood pressure is lower than in arteries
-blood may pool as reservoir
-tunica adventitia exhibits smooth muscle
-have valves
What is the function of valves in the vascular system?
permit unidirectional flow (prevent backflow)
What is the purpose of having smooth muscle in tunica adventitia in veins?
TO massage blood back to the heart
Circulatory System- Four divisions
-coronary
-pulmonary
-systemic
-portal
Blood distribution
Systemic majority 70%
(Arteries, veins, Capillaries)
Pulmonary 18%
Heart 12%
Coronary Circulation
Right coronary Artery(green)
Left Coronary artery (purple)
-provides oxygenated blood to the heart muscle
Right coronary artery
-marginal artery(yellow)
posterior interventricular artery
Left Coronary Artery
Ciumflex coronary artery (gray)
Anterior interventricular artery (brown)
There are two types of coronary circulations
-On posterior surface of heart
-within the interventricular septum
Posterior surface of the heart....
Between circumflex coronary and Terminal branch of RCorArt
Within interventricular septum...
branch of the anterior
interventricular
and posterior interventricular
Coronary sinus
provides oxygenated blood to the heart muscle
portal: takes venous blood from the digestive tract to the liver for processing 3. pulmonary: 4. systemic:
...
Pulmonary Circulation
oxygenates systemic blood returned to the heart
Pathway of pulmonary circulation
O2 starved bllod from body goes to Right atrium then to right ventricle and out to the lungs
From lungs to heart...
Once oxygenated (the blood) by the lungs, the blood enters the Left Atrium, through the left ventricle and back to the body.
Pulmonary Systemic circuits
Systemic Circulation
delivers oxygenated blood to all of the organs of the body
Portal Circulation
takes venous blood from the digestive tract to the liver for processing
Why is the venous blood from the GI filtered through liver via portal circulatory circuit?
-to remove wastes absorbed by the gut
-store nutrients in liver (glucose, glycogen)
Portal Veins is formed when ....
the 3 veins that drain the intestinal tract join together
-splenic vein
-inferior mesenteric
-superior mesenteric
Where does the portal vein deliver blood to?
It delivers blood to liver for filtration before it is returned to vena cava.
Systemic circulation Arteries
Descending aorta intercostal (thoracic)
Aortic Arch (Heart)
Common iliac (Iliium)
Internal Iliac(Iliium)
External Iliac (Iliium)
Systemic Circulation Veins
-Superior Cava (heart)
- Inferior cava (cardiothoracic)
-Internal Iliac (Iliium)
-External iliac (Iliium)