2. Introduction to Vascular Systems Flashcards
Vascular Systems
̈____ carry blood at relatively higher pressures ____ from the heart
̈Large arteries ramify or ____ into smaller ones
̈____ carry blood ____ the heart at relatively lower pressures
̈Small veins become ____ of larger ones
____ are very small vessels distributed through the tissues of the body which bring blood into close contact
with the cells of the tissues and connect arteries to veins
arteries
away
branch
veins
toward
tributaries
capillaries
The Cardiovascular System
The cardiovascular system consists of the heart and all blood vessels forming two pump-driven, closed vascular loops
The systemic circulation pumps blood through the following series of vessels:
Left ventricle > Aorta > Arteries > Arterioles
> Capillaries > Venules > Veins > ____
The pulmonary circulation pumps blood through the following series of vessels: Right ventricle > Pulmonary trunk > Pulmonary arteries > Alveolar capillary plexus of lungs > Pulmonary veins > \_\_\_\_ (\_\_\_\_)
right atrium
left atrium
lower pressure
The lumen
of each artery
is surrounded by three distinct layers of tissue
____
Loose connective tissue
____
Smooth muscle and
elastic tissue PROPORTIONS VARY
____
Endothelium plus its supporting connective tissue
tunica adventitia
tunica media
tunica intima
ELASTIC (conducting) ARTERIES
• Distend and recoil with the sudden thrust of blood
from the heart, helping to move the blood with no initiation of energy by the vessel.
• Elastic tissue is most common in the large arteries near the heart (e.g. ____ and ____) where pressure is the greatest.
• While ____ cushions the sudden rise of pressure induced by ventricular contraction or ____, ____ smooths what would otherwise be a sudden drop in pressure as ventricular pressure falls to zero in ____.
aorta pulmonary trunk elastic expansion systole elastic recoil diastole
MUSCULAR (distributing) ARTERIES
• More peripheral vessels feature less elastic tissue and more ____ in the tunica media
• The caliber of such vessels is controlled by ____ (contraction) and ____ (relaxation) of vascular smooth muscle in response to physiologic need
• The ____ - comprised almost entirely of smooth muscle - are the most important governors of ____ to blood flow
Vasoconstriction/vasodilation is under control of the ____ of the ANS as well as various ____
smooth muscles vasoconstriction vasodilation arterioles peripheral resistance
sympathetic division
circulating hormones
Vasculopathy I
• Atherosclerosis
Deposition and eventual calcification of ____ or ____ in the ____ of elastic vessels produces abnormal fluctuations in pressure with each cardiac cycle
• Plaques in turn predispose the vessels to ____ (blood clot) formation and occlusion (____)
• Turbulent flow occurring where large arteries ____, or where vessels make sharp ____, may amplify the local impact of atherosclerosis and lead to…
• Aneurysm
Weakening of all three ____ resulting from ____, ____ or ____ may lead to a bulging of the wall and widening of the arterial lumen to form a balloon-like dilation
fatty plaques atheromas thrombus stenosis branch bends
tunicae
atherosclerosis
syphilis
congential disorders
Rupture of ____ or ____ aneurysms may be life- threatening!
saccular
fusiform
Anastomosis and Collateral Circulation
• The survival of tissues and organs distal to arterial occlusions depends upon the adequacy of the ____ to those tissues.
• Collateral circulation is dependent upon the presence of ____, or ____ between branches given off at more proximal levels of the arterial system and branches arising more distally.
• Anastomoses between multiple branches of an artery provide numerous potential detours for blood flow in case the “usual” pathway is obstructed.
• But… ____ arteries lack peripheral anastomoses with neighboring arteries; occlusion of such vessels may lead to tissue ____
Examples include ____, ____ and ____ arteries
collateral circulation anastomoses free communications true terminal (end) arteries necrosis cerebral retinal renal
VEINS
• Veins are more abundant than arteries; many arteries
are accompanied by multiple ____.
– As a result, 80% of blood volume occupies the veins at any one
time. (20% found within the ____)
• Venules consist of an ____ and ____ only; while most larger veins feature varying degrees of ____ smooth muscle, (though veins, as a rule, do not ____ and do not spurt when severed)
• ____ have extremely thin walls, limited to epithelium; support is provided by stronger connective tissue (i.e. ____ in the cranial cavity)
venae comitante arteries intima adventitia longitudinal pulsate venous sinuses dura mater
VEINS
• Venous return toward the right side of the heart is facilitated by two major factors:
– Respiratory-related changes in thoracic pressure (specifically decreases in ____ and ____ pressures)
– The massaging action of ____ on deep veins, particularly in the extremities
• ____, infoldings of the intima, are arranged to allow free movement of blood toward the heart but prevent or impede passage of blood in the reverse direction
right atrial
thoracic vena cava
skeletal muscles
valves
VASCULOPATHY II
While venous return from the head and neck is eased by gravity thanks to our orthograde posture, drainage of the body and extremities is more challenging…
Chronic Venous Insufficiency (CVI) –
impaired venous return, often causing lower ____, ____, and ____ changes.
____ (inflammation of a vein) or ____ (DVT’s) may lead to CVI as the result of venous obstruction, usually through venous damage and valvular incompetence
____ – as when decreased contraction of muscles surrounding deep veins (e.g. due to immobility) decreases forward venous flow
Prolonged venous hypertension causes tissue ____, inflammation, and ____, leading to symptoms such as aching, ____, pain, tiredness, and ____
extremity discomfort
edema
skin
phlebitis
deep vein thrombosis
venous hypertension
edema
hypoxia
cramps
parasthesias
Increased pressure in deep veins may be transmitted to superficial veins if valves in ____, which connect both deep and superficial veins, are ineffective…
• ____ veins are dilated, superficial veins, usually found in the lower extremities
• Typically asymptomatic, they may cause a sense of fullness, pressure, and either ____ or ____ in the legs.
• They may also result from either ____ in the absence of surrounding skeletal muscle in the superficial veins themselves, or from primary dilation of the vein wall due to ____
perforating veins varicose veins pain hypesthesia primary venous valvular insufficiency with reflux structural weakness
Additional circulatory systems I
Portal systems
•Occur when a capillary bed drains into another capillary bed through veins, without first going through the ____. Both ____ and the ____ that connect them are considered part of the portal venous system
heart
capillary beds
vessels
Hepatic portal system receiving blood draining from the \_\_\_\_
abdominal gut
Hypophyseal portal system between the \_\_\_\_ and the \_\_\_\_
hypothalmus
anterior pituitary
Additional circulatory systems II
Lymphatic System
•Arises from a network of highly ____ capillaries arising blindly in tissues
•With muscle contraction, fine filaments anchoring vessels to surrounding CT transfer tensional forces to endothelial cells, opening spaces between cells allowing proteins and large particles present in the interstitial fluid to enter the ____.
• Conveys its contents via ____ and a network of nodes and ducts into the ____ system in the ____
permeable lymphatic capillaries vasa lymphatica venous deep neck
Superficial, deep or organ-specific lymphatic capillaries are the ____…
…draining to ____
and ultimately to a series of ____
initial lymphatics
collectors
lymphatic trunks
Lymphatic Circulation II
…in fact the lymphatic circulation of a 3/4 of the body will be directed here to the root of the neck.
On the LEFT side will be where the ____ will introduce into the venous system lymph and metabolic products derived from the entire ____ and ____ of the body.
The upper right quadrant will be drained by ____. This drains into the venous system at the neck area as well.
thoracic duct
lower half
upper left quadrant
right lymphatic duct
The thorax contains two
____
and a midline partition called the
____
pulmonary cavities
mediastinum
A fibrous pericardial sac containing the heart and the roots of the great vessels lies in the
____
middle mediastinum
STERNOCOSTAL surface of the heart RIGHT BORDER: \_\_\_\_ INFERIOR BORDER: \_\_\_\_, \_\_\_\_, \_\_\_\_ LEFT BORDER: \_\_\_\_, auricle of \_\_\_\_
right atrium
right atrium
right ventricle
left ventricle
left ventricle
left atrium
Deoxygenated blood enters the right atrium from three sources:
____
(receives venous drainage form the head, neck, and the upper extremities)
____
(receives venous drainage from all body parts that lies below the diaphragm)
____ (thin large vessel that lies on the surface of
the heart that return most of the deoxygenated blood that was utilized by the myocardium
superior vena cava
inferior vena cava
coronary sinus
CARDIOPULMONARY CIRCULATION
The ____ ejects the blood through the ____ which gives rise to the ____ and ____, whose further branching reflects the functional segmentation of each lung
right ventricle
pulmonary trunk
left
right pulmonary arteries
Pulmonary arterioles are continuous with a \_\_\_\_ in intimate contact with the \_\_\_\_, the terminal elements of the respiratory tree within each lung, which is in turn drained by tributaries of the \_\_\_\_
capillary network
alveoli
pulmonary veins
____
provide an oxygenated blood supply to the parenchymal tissues of each lung, ramifying along the bronchial tree
bronchial arteries
