Chapter 20: The Cardiovascular System: Blood Vessels and Circulation

**umbilical vein**

which carries oxygen-rich blood from the mother to the fetal inferior vena cava via the ductus venosus to the heart that pumps it into fetal circulation.

**angiogenesis**

the creation of new blood vessels from existing ones continues as needed throughout life as we grow and develop.

**Vascular tubes**

also develop on the blood islands, and they eventually connect to one another as well as to the developing, tubular heart.

**hemangioblasts**

During those first few weeks, blood vessels begin to form from the embryonic mesoderm. The precursor cells are known as

**small saphenous vein**

located on the lateral surface of the leg drains blood from the superficial regions of the lower leg and foot, and flows into to the **popliteal vein**.

**fibular vein**

drains the muscles and integument in proximity to the fibula and also joins the popliteal vein

**posterior tibial vein**

drains the posterior surface of the tibia and joins the popliteal vein.

**anterior tibial vein**

drains the area near the tibialis anterior muscle and combines with the posterior tibial vein and the fibular vein to form the popliteal vein.

**Veins Draining the Lower Limbs**

The superior surface of the foot drains into the digital veins, and the inferior surface drains into the **plantar veins**, which flow into a complex series of anastomoses in the feet and ankles,  including the **dorsal venous arch** and the **plantar venous arch.** 

**subscapular vein**

drains blood from the subscapular region and joins the cephalic vein to form the **axillary vein.**

**cephalic vein**

begins in the antebrachium and drains blood from the superficial surface of the arm into the axillary vein.

**median cubital vein**

As the basilic vein reaches the antecubital region, it gives off a branch

**median antebrachial vein**

parallels the ulnar vein, is more medial in location, and joins the **basilic vein** in the forearm.

**radial vein** and the **ulnar vein**

parallel the bones of the forearm and join together at the antebrachium

 **brachial vein**

a deep vein that flows into the axillary vein in the brachium.

**digital veins**

in the fingers come together in the hand to form the **palmar venous arches.**

**internal jugular vein**

Blood from the brain and the superficial facial vein flow into each

 **internal thoracic vein**

also known as an internal mammary vein, drains the anterior surface of the chest wall and flows into the brachiocephalic vein.

**vertebral vein**

also flows into the brachiocephalic vein close to this fusion

**The Superior Vena Cava**

drains most of the body superior to the diaphragm.

**subclavian vein**

forms when the axillary vein passes through the body wall from the axillary region.

**plantar arch**

which provide blood to the remainder of the foot and toes.

 **dorsal arch** 

There is an anastomosis with the dorsalis pedis artery, and the medial and lateral plantar arteries form two arches

**posterior tibial artery**

provides blood to the muscles and integument on the posterior surface of the tibial region.

**dorsalis pedis artery**

which branches repeatedly and provides blood to the tarsal and dorsal regions of the foot.

**anterior tibial artery**

is located between the tibia and fibula, and supplies blood to the muscles and integument of the anterior tibial region.

 **popliteal artery**

branches into the anterior and posterior tibial arteries..

**genicular artery**

which provides blood to the region of the knee

**femoral artery**

\n As it passes through the body wall, it is renamed the

 **radial arter**y and **ulnar artery**

parallel their namesake bones, giving off smaller branches until they reach the wrist, or carpal region.

**brachial artery**

supplies blood to much of the brachial region and divides at the elbow into several smaller branches, including the deep brachial arteries, which provide blood to the posterior surface of the arm, and the ulnar collateral arteries, which supply blood to the region of the elbow.

**axillary artery**

As the subclavian artery exits the thorax into the axillary region

**ovarian artery**

supplies blood to an ovary, uterine (Fallopian) tube, and the uterus, and is located within the suspensory ligament of the uterus.

**Gonadal artery**

supplies blood to the gonads, or reproductive organs, and is also described as either an ovarian artery or a testicular artery (internal spermatic), depending upon the sex of the individual.

**renal artery**

branches approximately 2.5 cm inferior to the superior mesenteric arteries and supplies a kidney.

**adrenal artery**

supplies blood to the adrenal (suprarenal) glands and arises near the superior mesenteric artery.

**inferior phrenic artery**

is a counterpart of a superior phrenic artery and supplies blood to the inferior surface of the diaphragm.

 **inferior mesenteric artery**

supplies blood to the distal segment of the large intestine, including the rectum.

**superior mesenteric artery**

arises approximately 2.5 cm after the celiac trunk and branches into several major vessels that supply blood to the small intestine (duodenum, jejunum, and ileum), the pancreas, and a majority of the large intestine.

**celiac trunk**

emerges and divides into the **left gastric artery** to supply blood to the stomach and esophagus, the **splenic artery** to supply blood to the spleen, and the **common hepatic artery**, which in turn gives rise to the **hepatic artery** **proper** to supply blood to the liver, the **right gastric artery** to supply blood to the stomach, the **cystic artery** to supply blood to the gall bladder, and several branches, one to supply blood to the duodenum and another to supply blood to the pancreas.

**superior phrenic artery**

provides blood to the superior surface of the diaphragm

**intercostal artery**

provides blood to the muscles of the thoracic cavity and vertebral column.

**mediastinal artery**

provides blood to the mediastinum.

 **esophageal artery**

provides blood to the esophagu

**pericardial artery**

supplies blood to the pericardium

**bronchial artery**

(typically two on the left and one on the right) supplies systemic blood to the lungs and visceral pleura, in addition to the blood pumped to the lungs for oxygenation via the pulmonary circuit.

**visceral branches**

Those branches that supply blood primarily to visceral organs

 **basilar artery**

is an anastomosis that begins at the junction of the two vertebral arteries and sends branches to the cerebellum and brain stem.

**posterior cerebral artery**

arises from the basilar artery.

 **posterior communicating artery**

The posterior portion of the arterial circle is formed by a left and a right

 **anterior communicating artery**

The right and left anterior cerebral arteries join together to form an anastomosis

**ophthalmic artery**

the third major branch, provides blood to the eyes

**middle cerebral artery**

supplies blood to the temporal and parietal lobes, which are the most common sites of CVAs.

 **anterior cerebral artery**

supplies blood to the frontal lobe of the cerebrum.

 **cerebrovascular accident**

Loss of blood flow for longer periods, typically between 3 and 4 minutes, will likely produce irreversible brain damage or a stroke

 **internal carotid artery**

initially forms an expansion known as the carotid sinus, containing the carotid baroreceptors and chemoreceptors.

 **external carotid artery**

supplies blood to numerous structures within the face, lower jaw, neck, esophagus, and larynx.

**common carotid artery**

divides into internal and external carotid arteries.

**thyrocervical artery**

provides blood to the thyroid, the cervical region of the neck, and the upper back and shoulder.

**vertebral artery**

passes through the vertebral foramen in the cervical vertebrae and then through the foramen magnum into the cranial cavity to supply blood to the brain and spinal cord.

**internal thoracic artery**

or mammary artery, supplies blood to the thymus, the pericardium of the heart, and the anterior chest wall.

**subclavian artery**

supplies blood to the arms, chest, shoulders, back, and central nervous system.

**abdominal aorta**

inferior to the diaphragm

 **thoracic aorta**

Superior to the diaphragm

**descending aorta**

continues close to the bodies of the vertebrae and passes through an opening in the diaphragm known as the **aortic hiatus**.

**aortic arch**

Following this ascent, it reverses direction, forming a graceful arc to the left

**ascending aorta**

moves in a superior direction for approximately 5 cm and ends at the sternal angle.

**Aorta**

 is the largest artery in the body. 

**pulmonary veins**

Once gas exchange is completed, oxygenated blood flows from the pulmonary capillaries into a series of pulmonary venules that eventually lead to a series of larger **__**

**pulmonary artery**

As the pulmonary trunk reaches the superior surface of the heart, it curves posteriorly and rapidly bifurcates (divides) into two branches, a left and a right

**pulmonary trunk**

The single vessel exiting the right ventricle is the

**pulmonary circuit**

From the right atrium, blood moves into the right ventricle, which pumps it to the lungs for gas exchange.

**Obstructive shock**,

as the name would suggest, occurs when a significant portion of the vascular system is blocked.

**Anaphylactic shock**

is a severe allergic response that causes the widespread release of histamines, triggering vasodilation throughout the body.

 **sepsis**

also called “blood poisoning,” which is a widespread bacterial infection that results in an organismal-level inflammatory response known as **septic shock**.

**Vascular shock**

occurs when arterioles lose their normal muscular tone and dilate dramatically.

**Cardiogenic shock**

results from the inability of the heart to maintain cardiac output.

**Hypovolemic shock**

in adults is typically caused by hemorrhage, although in children it may be caused by fluid losses related to severe vomiting or diarrhea

**Hemorrhage**

 is a loss of blood that cannot be controlled by hemostatic mechanisms.

**Circulatory Shock**

The loss of too much blood may lead to circulatory shock, a life-threatening condition in which the circulatory system is unable to maintain blood flow to adequately supply sufficient oxygen and other nutrients to the tissues to maintain cellular metabolism.

**Hypertension**

Chronically elevated blood pressure

**The Myogenic Response**

 is a reaction to the stretching of the smooth muscle in the walls of arterioles as changes in blood flow occur through the vessel.

**Atrial Natriuretic Hormone**

is secreted when blood volume is high enough to cause extreme stretching of the cardiac cells.

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**Erythropoietin**

is released by the kidneys when blood flow and/or oxygen levels decrease. EPO stimulates the production of erythrocytes within the bone marrow.

**Antidiuretic Hormone**

also known as vasopressin, is secreted by the cells in the hypothalamus and transported via the hypothalamic-hypophyseal tracts to the posterior pituitary where it is stored until released upon nervous stimulation.

**Chemoreceptor Reflexes**

Endocrine control over the cardiovascular system involves the catecholamines, epinephrine and norepinephrine, as well as several hormones that interact with the kidneys in the regulation of blood volume.

**Baroreceptor Reflexes**

are specialized stretch receptors located within thin areas of blood vessels and heart chambers that respond to the degree of stretch caused by the presence of blood.

 **net filtration pressure (NFP)**

 represents the interaction of the hydrostatic and osmotic pressures, driving fluid out of the capillary.

**Osmotic Pressure**

The pressure created by the concentration of colloidal proteins in the blood

**capillary hydrostatic pressure (CHP)**

Even more specifically, the pressure exerted by blood against the wall of a capillary

**capillary hydrostatic pressure (CHP)**

Even more specifically, the pressure exerted by blood against the wall of a capillary

**Hydrostatic Pressure**

is the force exerted by the blood confined within blood vessels or heart chambers.

**Bulk Flow**

\n

This movement, often referred to as__, involves two pressure-driven mechanisms: Volumes of fluid move from an area of higher pressure in a capillary bed to an area of lower pressure in the tissues via **filtration**.

**Respiratory Pump**

aids blood flow through the veins of the thorax and abdomen.

**Skeletal Muscle Pump**

In many body regions, the pressure within the veins can be increased by the contraction of the surrounding skeletal muscle.

**Compliance**

is the ability of any compartment to expand to accommodate increased content.

**sphygmomanometer and  stethoscope**

The technique of measuring blood pressure requires the use of a

**Korotkoff sounds**

Turbulent blood flow through the vessels can be heard as a soft ticking while measuring blood pressure

**Pulse**

\n

After blood is ejected from the heart, elastic fibers in the arteries help maintain a high-pressure gradient as they expand to accommodate the blood, then recoil.

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**Mean Arterial Pressure**

* represents the “average” pressure of blood in the arteries, that is, the average force driving blood into vessels that serve the tissues.