Cardiovascular System – Arterial System

Cardiovascular System

Arterial System

Learning Objectives

  • Identify major systemic arteries.

  • Recognize the parts of the aorta.

  • Name the major branches of the aorta, including:

    • Brachiocephalic trunk

    • Common carotid arteries

    • Subclavian arteries

    • Common iliac arteries

  • Identify the regions supplied by these arteries.

  • Recognize main arteries in various body regions, such as:

    • Carotid arteries (head/neck)

    • Subclavian and brachial arteries (upper limbs)

    • Femoral and popliteal arteries (lower limbs)

Arterial System Overview

  • The arterial system is a crucial component of the circulatory system, responsible for transporting oxygen-rich blood away from the heart to the body's tissues and organs.

  • It begins with the aorta, the largest artery, which branches from the left ventricle of the heart.

  • The aorta divides into progressively smaller arteries, arterioles, and capillaries, facilitating gas and nutrient exchange.

Major Vessels Associated With the Heart - Aorta & Its Branches

  • Aorta

    • The largest artery in the body known for its elasticity.

    • Cane-shaped structure.

    • Originates from the left ventricle, supplying oxygenated blood to all systemic arteries.

    • Terminates at the L4 level, branching into the right and left common iliac arteries.

  • Parts of the Aorta:

    • Ascending Aorta

    • Aortic Arch

    • Descending Aorta:

    • Thoracic Aorta

    • Abdominal Aorta

Detailed Structure of the Aorta

Ascending Aorta

  • Derived from the left ventricle of the heart.

  • Coronary arteries:

    • Right and left coronary arteries branch off to supply the myocardium (heart muscle) with oxygenated blood.

Aortic Arch

  • Curves over the heart and gives off three major branches in order:

    • Brachiocephalic trunk:

    • Divides into right subclavian and right common carotid arteries.

    • Left common carotid artery:

    • Supplies oxygen-rich blood to the left side of the head and neck.

    • Left subclavian artery:

    • Supplies oxygen-rich blood to the left upper extremity.

  • Supplies blood to head, neck, and upper limbs.

Arteries to the Brain, Head, and Neck

  • Branches of the subclavian and common carotid arteries supply blood to the brain, head, and neck.

  • Common carotid arteries:

    • Divides into internal carotid artery (ICA) and external carotid artery (ECA).

    • External Carotid Artery (ECA): Supplies the neck and face.

    • Internal Carotid Artery (ICA): Supplies blood to the brain, eyes, and forehead.

  • Carotid artery disease:

    • A significant risk factor, causing up to one-third of all strokes.

Descending Aorta

  • Thoracic Aorta:

    • Continues from the aortic arch downward through the chest.

    • Supplies blood to organs and walls within the thoracic cavity (e.g., lungs, esophagus).

  • Abdominal Aorta:

    • Begins at the diaphragm where the thoracic aorta transitions to the abdominal cavity.

    • Supplies blood to abdominal organs through multiple branches:

    • Celiac trunk

    • Superior mesenteric artery

    • Renal arteries

  • Bifurcation into Common Iliac Arteries:

    • Occurs at L4, dividing into right and left common iliac arteries, supplying the pelvis and lower limbs.

Branches of Thoracic Aorta

  • Bronchial artery: Supplies oxygenated blood to the lungs, bronchi, and pleura.

  • Pericardial artery: Supplies blood to the pericardium.

  • Esophageal artery: Supplies the esophagus.

  • Mediastinal artery: Supplies lymph nodes and connective tissue in the posterior mediastinum.

  • Posterior intercostal artery: Supplies intercostal muscles, spine, skin, and parietal pleura.

Major Branches of the Abdominal Aorta

  • Celiac Trunk/Artery:

    • Left gastric artery: Supplies the stomach.

    • Common hepatic artery: Supplies the liver.

    • Splenic artery: Supplies the spleen.

  • Phrenic Artery: Supplies the diaphragm.

  • Superior Mesenteric Artery: Supplies from the duodenum to the splenic flexure of the large intestine.

  • Suprarenal arteries: Supply blood to adrenal glands.

  • Renal arteries: Supply blood to kidneys.

  • Gonadal arteries: Supply blood to the ovaries or testes.

  • Inferior Mesenteric Artery: Supplies distal 1/3 of transverse colon, splenic flexure, descending colon, sigmoid colon, and rectum.

  • Lumbar Arteries: Supply blood to lumbar vertebrae.

  • Middle Sacral Artery: Supplies blood to the sacrum.

  • Common Iliac Arteries: Supply blood to pelvic cavity and lower extremities.

Summary - Major Branches of the Aorta

  • Portion of Aorta:

    • Branch and General Regions or Organs Supplied:

    • Ascending aorta: Right/left coronary arteries -> Heart

    • Abdominal aorta: Celiac artery -> Organs of the upper digestive tract

    • Arch of aorta: Brachiocephalic trunk -> Right upper limb, right side of the head

    • Left common carotid artery -> Left side of the head

    • Left subclavian artery -> Left upper limb

    • Descending aorta: Renal artery -> Kidney

    • Thoracic aorta: Bronchial artery -> Bronchi

    • Inferior mesenteric artery -> Lower portions of large intestine

    • Posterior intercostal artery -> Thoracic wall

    • Common iliac artery -> Lower abdominal wall, pelvic organs, and lower limb.

Arteries to the Brain, Head, and Neck

  • Cerebral arterial circle (circle of Willis):

    • Connects the carotid and vertebral artery systems, supplying blood to the brain and providing alternative pathways for blood flow.

Arteries to the Shoulder and Upper Limb

  • Subclavian arteries:

    • Give off branches (e.g., vertebral arteries) and continues into the arm.

  • Terminal branches include:

    • Axillary artery

    • Brachial artery

    • Radial artery

    • Ulnar artery

    • Deep and Superficial palmar arches

    • Digital arteries

Clinical Relevance - Pulse Points in the Upper Limbs

  • Main pulse points in the upper limb:

    • Brachial artery:

    • Located in the inner upper arm near the elbow crease; often checked in infants and for blood pressure.

    • Radial artery:

    • Located on the thumb-side of the wrist; most commonly used for routine heart rate checks due to accessibility.

Arteries to the Pelvis

  • Abdominal aorta divides into right and left common iliac arteries, supplying blood to:

    • Pelvic organs

    • Gluteal region

    • Lower limbs

  • The common iliac arteries further divide into:

    • Right/left internal iliac arteries (supply pelvic and gluteal areas)

    • Right/left external iliac arteries.

Arteries to the Lower Limb

  • External iliac arteries: Fund the primary supply to the lower limb.

  • They become:

    • Femoral arteries as they cross under the inguinal ligament.

    • Transition to popliteal arteries behind the knee (in the popliteal fossa).

    • Further divide into:

    • Anterior tibial arteries

    • Fibular arteries

    • Posterior tibial arteries

    • Dorsalis pedis

    • Medial and lateral plantar arteries

    • Digital arteries

  • Anterior tibial artery:

    • Passes anteriorly between the tibia and fibula through a gap in the interosseous membrane and runs down the leg into the foot as the dorsalis pedis artery.

Clinical Relevance - Pulse Points in the Lower Limb

  • Four main pulse points:

    • Femoral Pulse: Located entering the femoral triangle, midway between the anterior superior iliac spine and the pubic symphysis (mid-inguinal point).

    • Popliteal Pulse: Difficult to find due to deep location in the popliteal fossa; easier to locate with leg slightly flexed.

    • Dorsalis Pedis Pulse: Found on the dorsum of the foot, just lateral to the extensor hallucis longus tendon.

    • Posterior Tibial Pulse: Palpated inferoposteriorly to the medial malleolus, where the artery turns to enter the foot.