Lecture 11: Circulatory System Flashcards Preview

CHI 280: Human Anatomy I > Lecture 11: Circulatory System > Flashcards

Flashcards in Lecture 11: Circulatory System Deck (25):

What are the components of the blood?

Plasma: water, protein, electrolytes, gases, by products (non living) 55%
Buffy coat: Leukocytes and platelets 1%
Erythrocytes: red blood cells (45%)


What is hematocrit?

-Defined as the measure of the fractional volume of erythrocytes
-representation of the oxygen carrying capacity of blood (1 molecule hemoglobin can transport 4 molecules of oxygen)
-normal values: men-40-45
Women: 36-45
Hematocrit reduced by over-hydration, blood loss, anaemia
Increased by dehydration, increased production of red blood cells


Be able to label the main blood vessels on pg 6

Big one bebe


Why is there 80% in venous circulation most of the time?

Because of the size of the lumen, they can expand further and carry more blood


Types of arteries.

Large elastic arteries: tunica media has bulk elastic fibres➡ allows expansion eg aorta
Medium muscular arteries: tunica media mostly smooth muscle fibres➡ regulation of vascular tone by para and Symp fibres eg coronary arteries, axillary arteries, intercostal arteries

Small arteries and arterioles

End arteries: end terminal artery➡ ie don't anastomoses with adjacent arteries = only supply of oxygenated blood eg central artery of retina. If they get occluded blood supply gone forever

Functional end arteries: form INEFFECTIVE anastomoses. So if they were occluded wouldn't keep tissue Alice eg coronary artery = myocardial infarction


Anastomoses. Why are they important?

In vital tissues vulnerable to ischemia. Collateral arteries will provide an alternative supply of blood
Eg brain or crucial joints in body like hip, knew, ankle, knee etc otherwise we would loose ability to run from lions


What are the 3 branches of the aortic arch?

Brachiocephalic artery -right subclavian, and right common carotid
Left common carotid artery
Left subclavian artery
Slide 17


Tell some stuff about the brachiocephalic trunk.

-Originates behind the manubrium for protection
-at superior edge of right sternoclavicular joint it divides into right common carotid and (supplied right side of head and neck) and right subclavian artery (supplied limb)


Tell me about the left common carotid

-slightly posterior to brachiocephalic trunk
-ascends through superior mediastinum along left side of trachea
-supplies left side of head and neck


Left subclavian

-ascends through superior mediastinum along left side of trachea
-major blood supply to left upper limb


As the aorta goes down through the thorax, what arteries branch of it?

Posterior intercostal arteries
Superior phrenic armies
Subcostal arteries
Slide 21


Thoracic arteries
Label slide 22

Comes of subclavian arteries➡ internal thoracic artery➡ superior epigastric artery.
Anterior perforating branches come of it.
Anterior intercostal arteries come from it also


Tell me about the intercostal arteries

Posterior intercostals: They arise from the descending thoracic aorta ➡ posterior intercostal arteries (except 1st and 2nd space)

Anterior internal thoracic arteries come from internal thoracic arteries (1st-6th space)
Slide 23


Tell me about the internal thoracic arteries

They arise from subclavian
-deep to ribs
-1cm lateral to sternum
-supplies anterior chest wall and breasts
-birficates into the superior epigastric and musculophrenic artery at 6th intercostal space


Perfusion (delivery of blood to a capillary bed) of anterior thoracic and abdominal wall.
Slide 26

There is anastomosis formed between descending superior epigastric and musculophrenic arteries (from the internal thoracic artery) and ascending inferior epigastric artery from the external iliac artery.


Label the slide of the pulmonary vessels on slide 30, 31, 32



How is the abdominal viscera supplied by blood?
Slide 34

Coeliac trunk: branches of descending aorta. supplies liver, stomach, pancreas, spleen, proximal part of duodenum.

Superior mesenteric artery:
-supplies distal end of duodenum, jejumn, ilieum, ascending and transverse colon.

Inferior mesenteric artery: supplies descending and sigmoid colon, rectum


Axillary arteries
What does it branch to?

Branch of the subclavian.
-its axillary artery at lateral border of first rib

Axillary artery branches:
-superior thoracic artery
-thoracoacromial and lateral thoracic artery
-subscapular and anterior/ posterior circumflex numeral artery
Slide 37


We're does the carotid pulse lie in relation to?

Groove between the trachea and infra-hyoid muscles


We're to palpate brachial pulse

Palpate medial to bicep brachii muscle
-brachial passes deep to the tendon if biceps brachi and splits into radial and ulna arteries
Slide 40
There are more pulses to find but cbf


Thorax veins. Label slide 44

If we have a collusion of IVC AND SVC- azygos can still bring blood back.
Azygos drains posterior intercostals
Hemiazygos drains anterior intercostals


Tell me sumfin cool about the SVC and IVC

Receives L and R brachiocephalic veins and azygos vein immediately before entering pericardial sac


Brachiocephalic veins receives from which other veins?

Subclavian, intercostal, internal thoracic veins


Label diagram axillary veins on slide 49



Venous drainage.
What drains the:
Posterior thoracic wall
Anterior thoracic wall

Face: ➡external jugular ➡ subclavian ➡ brachiocephalic ➡ superior vena cava
Brain: ➡internal jugular ➡ subclavian ➡ brachiocephalic ➡superior vena cava
Posterior thoracic wall: ➡posterior intercostal veins ➡ azygos system of veins ➡ superior vena cava or inferior vena cava
Anterior thoracic wall: ➡musculophrenic/ superior epigastric➡ internal thoracic ➡ brachiocephalic ➡ SVC