Anatomy of the Systemic Arteries: Structure, Function, and Clinical Relevance

Anatomy of the Systemic Arteries

Overview of Systemic Arteries

The systemic arteries are responsible for transporting oxygenated blood from the heart to all tissues of the body. The largest artery is the aorta, which originates from the left ventricle and branches extensively to supply every organ system.

• Aorta: Divided into ascending aorta, aortic arch, descending thoracic aorta, and descending abdominal aorta.

• Major branches: Brachiocephalic trunk, left common carotid artery, left subclavian artery.

• Terminal branches: Common iliac arteries, which further divide into internal and external iliac arteries.

Aortic Arch and Its Branches

The aortic arch gives rise to three main arteries that supply the head, neck, upper limbs, and thorax.

• Brachiocephalic artery: Divides into right common carotid and right subclavian arteries.

• Left common carotid artery: Supplies left side of head and neck.

• Left subclavian artery: Supplies left upper limb and thorax.

Arteries of the Head and Neck

Carotid and Subclavian Arteries

The head and neck receive blood primarily from the right and left common carotid arteries, with additional supply from the subclavian arteries.

• Common carotid arteries: Split into external and internal carotid arteries at the level of the fourth cervical vertebra.

• External carotid artery: Supplies superficial structures of the head and face.

• Internal carotid artery: Supplies the brain.

• Carotid sinus: Located at the bifurcation, important for blood pressure regulation.

Branches of the External Carotid Artery

The external carotid artery divides into several branches serving the neck, face, and scalp.

• Superior thyroid artery: Supplies thyroid gland and anterior neck.

• Lingual artery: Supplies tongue.

• Facial artery: Supplies face.

• Occipital artery: Supplies posterior scalp.

• Maxillary artery: Supplies deeper facial structures. (including the teeth, the gums, and the nasal cavity)

• Superficial temporal artery: Supplies lateral head and scalp. (Also supplies the parotid salivary gland in the lateral cheek).

Arterial Supply to the Brain

The brain receives blood from the internal carotid and vertebral arteries, which form an important anastomosis called the cerebral arterial circle (circle of Willis).

• Internal carotid arteries: Branch into anterior cerebral, middle cerebral (both supply to the lobes of the cerebrum) and ophthalmic arteries (eyes).

• Vertebral arteries: ( branches of the right and left subclavian arteries) Fuse to form basilar artery ( enter the skull by passing through the foramen magnum) , which splits into posterior cerebral arteries.

• Circle of Willis: Includes anterior and posterior communicating arteries, anterior and posterior cerebral arteries, and internal carotid arteries.

  • It helps to equalize pressure in the arteries of the brain and minimize changes in systemic arterial pressure

  • It provides collateral circulation that allows blood to continue flowing to the brain even if blood flow through one of the brain’s major arteries is disrupted

Cerebrovascular Accident (Stroke)

A cerebrovascular accident (CVA), or stroke, is caused by disruption of blood flow to the brain, resulting in tissue damage.

• Causes: Blockage (ischemic stroke) or hemorrhage (ruptured artery).

• Symptoms: Sudden paralysis, vision loss, speech difficulties, headache.

• Risk factors: Hypertension, atherosclerosis, diabetes, smoking, hypercholesterolemia, atrial fibrillation, age, and female sex.

• Treatment: Clot-dissolving medications for ischemic stroke; surgery for hemorrhagic stroke. Prompt intervention is critical.

Arteries of the Thorax

Thoracic Wall and Organs

The thoracic wall and organs are supplied by branches of the subclavian arteries and the descending thoracic aorta.

• Anterior thoracic wall: Supplied by anterior and posterior internal thoracic arteries (internal mammary arteries).

  • The left internal thoracic artery is important clinically, as it’s often used to bypass a blocked coronary artery and restore blood flow to the myocardium.

• Intercostal arteries: Anterior and posterior branches form anastomoses in intercostal spaces.

• Thoracic organs: Bronchial arteries (lungs), esophageal arteries (esophagus), superior phrenic arteries (diaphragm).

Arteries of the Abdominal Organs

Abdominal Wall and Major Branches

The abdominal wall and organs are supplied by branches of the descending abdominal aorta and its terminal branches.

• Superior epigastric artery: Supplies superior anterior abdominal wall.

• Inferior epigastric artery: Supplies inferior abdominal wall.

• Lumbar arteries: Supply posterior abdominal wall. (5 pairs)

Celiac Trunk and Its Branches

The celiac trunk is a major branch of the abdominal aorta, supplying the upper abdominal organs.

Celiac Trunk is broken into 3 Arteries:

• Common hepatic artery: Branches into right gastric and gastroduodenal arteries, (stomach, pancreas, and duodenum) then becomes hepatic artery proper. (supplies liver and gallbladder)

• Splenic artery: Supplies spleen (stomach and pancreas)

• Left gastric artery: Supplies stomach; forms anastomosis with right gastric artery. (Smallest branch of Celiac trunk)

Mesenteric Arteries

The mesenteric arteries supply the intestines and adrenal glands.

• Middle suprarenal arteries: Supply adrenal glands.

• Superior mesenteric artery: Supplies small intestine and much of large intestine via ileocolic, middle colic, and right colic arteries.

  • Large intestine via its branches the ileocolic , the middle colic, and the right colic arteries

Acute Mesenteric Ischemia

Occlusion of the superior mesenteric artery can cause acute mesenteric ischemia, leading to bowel infarction and high mortality if not treated promptly.

• Symptoms: Nausea, vomiting, abdominal pain, rectal bleeding.

• Treatment: Restoration of blood flow by removing obstruction or affected bowel segment.

Renal, Gonadal, and Inferior Mesenteric Arteries

Other major branches of the abdominal aorta include the renal, gonadal, and inferior mesenteric arteries.

• Renal arteries: Supply kidneys.

• Gonadal arteries: Supply testes or ovaries.

• Inferior mesenteric artery: Supplies remainder of large intestine via inferior colic, sigmoidal, and superior rectal arteries.

Internal Iliac Arteries

The internal iliac arteries supply pelvic structures and musculature.

• Superior and inferior gluteal arteries: Supply gluteal muscles.

• Internal pudendal arteries: Supply perineum and external genitalia.

Arteries of the Upper Limb

Major Arteries of the Upper Limb

The upper limb is supplied by the subclavian artery, which becomes the axillary and then the brachial artery.

• Axillary artery: Supplies shoulder region.

  • Anterior and posterior humeral circumflex arteries, which surround the head of the humerus and supply the bone and the shoulder joint.

• Brachial artery: Supplies arm; branches into deep brachial, radial, and ulnar arteries.

  • Posterior deep brachial artery, supply the muscles and other structures of the arm

• Radial and ulnar arteries: Supply forearm and terminate in palmar arches.

  • The superficial and deep palmar arches.

Arteries of the Lower Limb

Major Arteries of the Lower Limb

The lower limb is supplied by the femoral artery, which continues as the popliteal artery and branches further.

• Femoral artery: Main artery of the thigh.

• Deep femoral artery: Supplies hip joint, femur, and thigh muscles.

• Popliteal artery: Supplies knee; branches into anterior and posterior tibial arteries.

• Anterior tibial artery: Supplies anterior leg and foot. (Splits from popliteal artery)

• Posterior tibial artery: Supplies posterior and lateral leg; forms plantar arch in foot. (Splits from popliteal artery)

• Dorsalis pedis artery: crosses the ankle joint and enters the foot.

Pulse Points

Pulse Points and Clinical Assessment

Pulse points are locations where superficial arteries can be palpated to assess heart rate and blood flow. The pulse is caused by pressure changes during ventricular systole and diastole.

• Pulse points: Temporal, carotid, brachial, radial, ulnar, femoral, popliteal, dorsalis pedis, posterior tibial.

  • Pulses may also be palpated in the ulnar, superficial temporal, and popliteal arteries (Lesson common)

• Clinical use: Used to monitor cardiovascular health and detect abnormalities.

Major Systemic Arteries Table

Classification and Properties of Major Systemic Arteries

The following table summarizes the main systemic arteries, their descriptions, locations, and the regions they supply.

Artery	Description	Location	Structures Supplied
Aorta	Largest artery in the body	Originates from left ventricle	Entire systemic circulation
Brachiocephalic	First branch of aortic arch	Right side of neck and upper limb	Right head, neck, upper limb
Common carotid	Main artery of head and neck	Neck	Head, neck
Subclavian	Supplies upper limb	Below clavicle	Upper limb, thorax
External carotid	Supplies superficial head and face	Neck	Face, scalp
Internal carotid	Supplies brain	Neck	Brain
Vertebral	Supplies brainstem	Neck	Brainstem
Axillary	Supplies shoulder	Axilla	Shoulder
Brachial	Supplies arm	Arm	Arm
Radial	Supplies lateral forearm	Forearm	Lateral forearm
Ulnar	Supplies medial forearm	Forearm	Medial forearm
Femoral	Main artery of thigh	Thigh	Thigh
Popliteal	Supplies knee	Knee	Knee
Anterior tibial	Supplies anterior leg	Leg	Anterior leg
Posterior tibial	Supplies posterior leg	Leg	Posterior leg
Dorsalis pedis	Supplies foot	Foot	Foot
Plantar arch	Supplies sole of foot	Foot	Sole of foot
Renal	Supplies kidneys	Abdomen	Kidneys
Gonadal	Supplies gonads	Abdomen	Testes/ovaries
Superior mesenteric	Supplies small intestine	Abdomen	Small intestine
Inferior mesenteric	Supplies large intestine	Abdomen	Large intestine