BLOOD VESSEL AND CIRCULATION Flashcards
- carry blood to within two or three cell diameters of nearly all the trillions of cells that make up the body.
BLOOD VESSEL AND CIRCULATION
transport blood from the right ventricle of the heart through the lungs and back to the left atrium.
Pulmonary vessels-
transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium.
Systemic vessels
carry blood away from the heart; usually, the blood is oxygenated.
Arteries
- the largest-diameter arteries and have the thickest wall.
- Stretch when the ventricles of the heart pump blood into them.
- The elastic recoil of these arteries prevents blood pressure from falling rapidly and maintains blood flow while the ventricles are relaxed.
Ex. aorta and pulmonary trunk.
Elastic arteries
include medium-sized (distributing arteries) and small arteries; relatively thick compared to their diameter.
Muscular arteries
contraction of the smooth muscle in the blood vessel; decrease blood vessel diameter and blood flow.
Vasoconstriction
Relaxation of the smooth muscle in blood vessel; increases blood vessel diameter and blood flow.
Vasodilation
where exchange of substances such as oxygen nutrients, Carbon dioxide and other waste products occurs between the blood and the tissue fluid.
Capillaries
a smooth muscle where the blood flow through capillary networks is regulated.
Precapillary sphincters
very thin and consists only of endothelium; Thin walls of capillaries- facilitate diffusion between the capillaries and surrounding cells
Capillary walls
carry blood toward the heart; usually, blood is deoxygenated.
Veins
have a diameter slightly larger than that of capillaries and are composed of endothelium resting on delicate connective tissue layer.
Venules
slightly larger in diameter than venules.
Small veins
collect blood from small veins and deliver it to large veins.
Medium-sized veins
3 layers of Blood Vessel Walls
- Tunics Intima
- Tunica Media
- Tunica adventitia/ tunica externa
- innermost layer.
- Endothelium- composed of simple squamous epithelial cells, a basement membrane, and a small amount of connective tissues.
- Contains a layer of thin elastic connective tissue.
Tunica Intima
- middle layer.
- Consists of smooth muscle cells arranged circularly around the blood vessel.
- Contains variable amounts of elastic and collagen fibers.
- A layer of elastic connective tissue forms the outer margin of the tunica media.
Tunica media
- Composed of dense connective tissue adjacent to the tunica media.
- The tissue becomes loose connective tissue toward the outer portion of the blood vessel wall.
Tunica adventitia/tunica externa
The system of the blood vessels that carries blood from the right ventricle of the heart to the lungs and back to the left atrium of the heart.
BLOOD VESSELS OF THE PULMONARY CIRCULATION
Where blood from the right ventricle is pumped into a short vessel.
Pulmonary trunk
exit the lungs and carry the oxygenated blood to the left atrium.
Pulmonary veins
System of the blood vessels that carries blood from the left-ventricle of the heart to the tissues of the body and back to the right atrium.
BLOOD VESSELS OF THE SYSTEMIC CIRCULATION: ARTERIES
where all arteries of the systemic circulation branch directly or indirectly.
AORTA
part of the aorta that passes superiorly from the left ventricle.
Ascending aorta
where the aorta arches posteriorly and to the left.
Aortic arch
longest part of the aorta.
Descending aorta
localized dilation of an artery that usually develops in response to trauma or congenital weakness of the artery wall.
Arterial aneurysm
extends a short distance and then branches at the level of the clavicle to form right common carotid.
Brachiocephalic artery
transports blood to the right side of the head and neck.
Right common carotid artery
transports blood to the right upper limb.
Right subclavian artery
transports blood to the left side of the head and neck.
Left common carotid
transports blood to the left upper limb.
Left subclavian artery
the base of each internal carotid artery that is slightly dilated.
Carotid sinus
where the internal carotid contribute passes through the carotid canals.
Cerebral arterial circle (circle of wilis)
branch from the subclavian arteries and pass to the head through the transverse fom=ramina of the cervical vertebrae.
Vertebral arteries
- vertebral arteries united.
- Located along the anterior, inferior surface of the brainstem.
- Gives off branches that supply blood to the pons, cerebellum and midbrain.
Basilar artery
returns blood from the head, neck, thorax, and upper limbs to the right atrium of the heart.
Superior Vena Cava
returns blood from the abdomen, pelvis, and lower limbs to the right atrium.
Inferior Vena Cava-
- he more superficial of the two sets.
- Carry blood from the posterioir head and neck, emptying primarily into the subclavian veins.
External Jugular Veins
- much larger and deeper.
- Carry blood from the brain and the anterior head, face and neck.
- Joins the subclavian veins on each side of the body to form brachiocephalic veins.
Internal jugular veins
carry blood from the deep structures of the upper limbs.
DEEP VEINS
accompany the brachial artery and empty into the axillary vein.
Brachial veins
Carry blood from the superficial structures of the upper limbs and then into the deep veins.
SUPERFICIAL VEIN
empties into the axillary vein and basilic vein.
Cephalic vein (toward the head)
- usually connects the cephalic vein or its tributes with the basilic vein.
- Quite prominent on the anterior surface of the upper limb at the level of the elbow.
Median Cubital vein
often used as a site in drawing blood.
Cubital fossa-
3 MAJOR VEINS RETURN BLOOD FROM THE THORAX TO THE SUPERIOR VENA CAVA
Right brachiocephalic vein
Left brachiocephalic vein
Azygos vein
where blood returns from the anterior thoracic wall.
Anterior intercostal veins
- where blood from the posterior thoracic wall is collected.
- Empty into the azygos vein on the right.
Posterior intercostal veins-
empty into the azygos veins, which empties into the superior vena cava.
Hemiazygos and accessory hemiazygos
- where blood from the posterior abdominal wall returns toward the heart.
- The gonads, kidneys, adrenal glands, and liver are the only abdominal organs outside pelvis from which blood empties directly into the inferioir vena cava,
Ascending lumbar veins
return blood from the pelvis and join the external iliac veins to form the common iliac veins.
Internal iliac veins-
a system of blood vessels that begins and ends with capillary beds and has no pumping mechanism, such as heart, in between.
Portal system
combine to form the inferior vena cava.
common iliac veins
begins with capillaries in the viscera and ends with capillaries in the liver.
Hepatic Portal system
Major vessels of Hepatic Portal System
Splenic Vein
Superior mesenteric vein
empties into the splenic vein.
Inferior mesenteric vein
formed by splenic vein and superior mesenteric vein.
Hepatic portal vein
where blood from the liver flows in.
Hepatic veins
carry blood from the kidneys.
Renal Veins-
drain the adrenal glands.
Suprarenal veins
drain blood from reproductive organs.
Gonadal Veins
drain testes in males.
Testicular veins
drain the ovaries in the females.
Ovarian veins
follow the same path as the arteries and are named for the arteries they company.
DEEP VEINS
originates over the dorsal and medial side of the foot and ascends along the medial side of the leg and thigh to empty into the femoral veiin.
Great saphenous vein
begins over the lateral sid of the foot and joins the popliteal vein, which becomes the femoral vein.
Small saphenous vein
veins of the lower limbs that become dilated that the cusps at the valves no longer overlap to prevent the backflow of the blood.
Varicose Veins
The clot in the varicose veins
thromboses
a condition that lack of blood flow; can also lead to tissue death and infection with anaerobic bacteria
gangrene
achieved by periodic relaxation and contraction of the precapillary sphincters
local control
carried out primarily through the sympathetic division of the autonomic nervous system.
nervous and hormonal control
- an area of the lower pons and upper medulla oblongata.
- continually transmit a low frequency of action potentials to the sympathetic nerve fibers that innervate the blood vessel of the body.
vasomotor center
a condition when the peripheral blood vessel are continually in a partially constricted area.
vasomotor tone
slightly less than average of the systolic and diastolic pressures in the aorta because diastole lasts longer than systole.
mean atrial blood pressure (MAP)
an inadequate blood flow throughout the body that causes tissue damage due to lack of oxygen,
circulatory shock
result of reduced blood volume.
hypovolemic shock
caused by internal and external bleeding, is one type of hypovolemic shock.
hemorrhagic shock
results from loss of plasma, as may occur in severely burned areas of the body.
plasma loss shock
reduced blood volume resulting from the loss of interstitial fluid, as may occur as a result of diarrhea, vomiting, or dehydration.
interstitial fluid loss shock
caused by vasodilation in response to emotional upset or anesthesia.
neurogenic shock
caused by an allergic response.
anaphylactic shock
caused by infections that release toxic substances into the circulatory system (blood poisoning).
septic shock
results from a decrease in cardiac output caused by events that decrease the heart’s ability to function.
cardiogenic shock
