Vascular System Anatomy Flashcards
Vascular System - Components
- Blood
- Systemic circulation
- Pulmonary circulation
- Lymphocytes
- Lymphatic circulation
Blood in the Systemic Circulation
Arterial blood: leaving the heart, bright red, high oxygenated.
Venous blood: returning to the heart, dark red, low oxygenated.
Composition of Blood
Plasma: around 55%
Red Blood cells: around 45%
Platelets: less than 1%
White Blood cells: less than 1%
Developed from stem cells in bone marrow
Plasma
90% water. Ions Proteins Gases (oxygen, carbon dioxide) Nutrients Wastes Hormones
Red Blood Cells
Erythrocytes
Hemoglobin (HB): contains iron
O2 binds to the iron, each Hb can carry 4 O2.
Pick up O2 from lungs, deliver O2 to all cells of the body - red color.
Pick up CO2 from cells and deliver it back to lungs - blue color.
White Blood Cells
Leucocytes Several types: - Monocytes - Lymphocytes - Neutrophil - Basophil - Eosinophil Part of immune system
Platelets
Thrombocytes
Stop bleeding vessel injury, blood clotting.
Part of cytoplasm
No nucleus
Arterioles
Transport blood away from arteries to capillaries.
Capillaries
Exchange of gases and nutrients.
connects arterioles and venules
Venules
Transport blood from capillaries to veins.
Arteries
Transport blood away from the heart.
Thick and strong walls, very important layer of smooth muscle.
Keeps its shape always.
Veins
Transport low-oxygenated blood from venules to heart.
Thin, deformable.
Muscle pump.
Valves prevent backflow.
Vascular Resistance
The resistance that blood may overcome.
Different in arterial and venous system:
- Cardiac output: High pressure (Pa), high resistance, low capacity.
- Venous return: Low pressure (Pv), low resistance, high capacity.
Vascular System
Blood circulation and transportation of nutrients.
Systemic circulation
Pulmonary circulation
Lymphatic circulation
Systemic Circulation
Artery: high oxygenated blood
Veins: low oxygenated blood
Closed system
Taking blood to all muscles, organs, tissues except lungs and back to the heart.
High pressure system: 100 mmHg in major arteries.
Overcome the force of gravity.
One pump: left half of heart.
Pulmonary Circulation
Artery: low oxygenated blood Veins: high oxygenated blood Closed system Heart - lungs - heart Pulmonary blood pressure lower than systemic. Artery pressure 8-20 mm Hg at rest.
Ascending Aorta - Location and Vessels
Middle mediastinum
Coronary arteries
Aortic Arch - Location and Vessels
Superior mediastinum - lower border of T4
Common brachiocephalic trunk: right common carotid artery, right subclavian artery.
Left common carotid artery
Left subclavian artery
Descending Aorta - Location and Vessels
Inferior posterior mediastinum - lower border of T12.
Thoracic aorta: intercostal, subcostal, phrenic arteries.
Abdominal aorta:
- Inferior phrenic arteries
- Superior and inferior mesenteric arteries
- Celiac trunk
- Renal and Gonadal arteries
- Lumbar arteries
- Common iliac arteries
Superior Vena Cava - Connecting veins
Axillary and cephalic veins join to form the subclavian veins (left and right) that become the brachiocephalic veins (left and right) that merge into the superior vena cava.
Inferior Vena Cava - Connecting Veins
right common iliac vein ( right external and internal iliac veins).
left common iliac vein (median sacral vein, left external and internal iliac veins).
Right and left common iliac veins merge to form the Inferior vena cava.
Left and right renal veins merge with the inferior vena cava.
Lymphatic System
Supports cardiovascular system by collecting, filtering and returning interstitial fluid back to the blood stream via lymphatic vessels and filters pathogens from the blood (immune system).
Lymphatic Pathway
Lymph capillaries → Lymph vessels
→ Thoracic duct → Left subclavian vein
→ Right lymphatic duct → Right subclavian vein
→ Superior vena cava
Right Lymphatic Duct
Right side of head, chest and right upper limb is drained by the right lymphatic duct.
Thoracic Duct
Lower limbs, abdominal area, left side of chest, head and left upper limb is drained by the thoracic duct.
