Flashcards in Anatomy 16 - Circulatory System Deck (72)
What are the great vessels?
Thos directly connected to the heart chambers
What structures are contained within a neurovascular bundle?
What is a territory?
A body region/ organ supplied by an artery and its branches
Give an example of an artery that trifurcates?
the celiac trunk
What does the term "trunk" or "common" indicate about an artery?
That it will definitely divide again
what os the course of an artery?
The arteries journey from its origin to its termination
Why do arteries often run a tortuous course?
It helps to prevent over-stretching/ tearing
Why are arteries usually located deeper than veins?
Helps reduce the chance of a more serious haemorrhage
How can you limit blood loss from an artery?
By pressing on a pulse point proximal to the injury
What do the elastic fibres found in the walls of the largest, most proximal arteries do?
Permit expansion of the aorta to accommodate the blood forced into it during systoleeHelp to maintain blood pressure during diastole via elastic recoil
Which arterial blood vessels contain smooth muscle?
ArteriolesSome arteries called "muscular arteries"
What happens when smooth muscle in walls of arterioles and muscular arteries contracts?
Vasoconstriction occurs which reduces blood flow to the organ/ tissue supplied
What is the opposite of vasoconstriction?What causes this?What does it do?
VasodilationWidens the lumen increasing the blood flow to the organ/ tissue suppliedRelaxation of smooth muscle
What does the arterioles and muscular arteries go into to to help reduce blood loss following an injury?
Spasm (smooth muscle contracts)
In terms of smooth muscle, what always exists in arteriolar smooth muscle?What does this mean?Called?
There is always a background low level of contraction of arteriolar smooth muscleArterioles are most often slightly narrowed compared to their maximum internal diameterSympathetic tone
What causes the sympathetic tone of arteriolar smooth muscle?
Tonic conduction of action potentials to arterioles by sympathetic nerves
What segments of the spinal cords have lateral horns?
T1 to L2 segments
How long is the sympathetic trunk?
Full length of the vertebral column
In the body wall what does the sympathetic fibres supply? (3)
Skin sweat glandsSkin arrestor musclesALL arterioles (sympathetic tone)
Via which nerves are the organs supplied with sympathetics?
What is the territory of the aorta?
The whole body
What are the 2 branches from the ascending aorta?
The right and left coronary arteries
What are the 3 branches from the arch of the aorta?
Brachiocephalic trunkLeft common carotid arteryLeft subclavian artery
What does the brachiocephalic trunk bifurcate into?
the right common carotid and right subclavian arteries
What branches from the subclavian arteries which passes to the cranial cavity?How does it travel to the cranial cavity?
The right vertebral artery Passes through transverse foramina in cervical vertebrae then through foramen magnum
What does the common carotid arteries bifurcate into?
The external carotid arteries and the internal carotid arteries (one of each in each side e.g. right internal carotid artery)
Where does the external carotid arteries pass and to supply what?
Remains external to the cranial cavity to supply the face and scalp
Where does the internal carotid arteries pass and to supply what?
Becomes internal to the cranial cavity via the carotid canal to supply the brain
What is the circle of arteries called on the inferior aspect of the brain?
The circle of Willis