Anatomy Lecture Notes - May 28

Cardiovascular System: Valves and Pulmonary Drainage

  • Pulmonary drainage returns oxygenated blood from the lungs to the left atrium. This process is critical for delivering oxygen-rich blood to the systemic circulation.

  • Pulmonary veins are red because they carry oxygen-rich blood. This is a key visual indicator that distinguishes pulmonary veins from other veins.

  • In the class, red and blue colors indicate oxygen-rich and oxygen-poor blood, respectively. This color-coding system is used consistently to differentiate between oxygenated and deoxygenated blood.

  • The right side of the heart pumps blood to the lungs, and the left side receives it back. This division of labor ensures efficient oxygenation of blood.

Coronary Arteries and Cardiac Veins

  • The first arteries off the aorta are the coronary arteries, located in the coronary region (corona = crown). These arteries are vital for supplying blood to the heart muscle itself.

  • Coronary arteries supply blood to the myocardium. The myocardium's function depends on the continuous supply of oxygen and nutrients from these arteries.

  • A latex-injected heart showed the density of vasculature in the myocardium. This demonstrates the extensive network of blood vessels required to sustain the heart muscle.

  • Cardiac veins collect waste products and drain into the coronary sinus. This process removes metabolic byproducts from the heart tissue.

  • The coronary sinus opens into the right atrium. This is where deoxygenated blood from the heart muscle returns to the heart's circulation.

  • Blood flows from coronary arteries to capillaries, then to cardiac veins, coronary sinus, and back to the right atrium – a continuous circulatory loop. This uninterrupted flow is essential for maintaining cardiac function.

  • Blood flow blockage in the coronary artery deprives the heart of oxygen, leading to potential damage within minutes. This highlights the critical importance of unobstructed coronary circulation.

  • The heart is essential for delivering oxygen and nutrients to the entire body. The body's tissues and organs depend on the heart's pumping action.

  • The brain is in charge, but it relies on the heart to function. The brain's regulatory role depends on the heart's ability to provide oxygenated blood.

Systemic Drainage: Superior Vena Cava

  • The superior vena cava drains blood from the head, upper limbs, and thorax above the abdomen. This vessel collects deoxygenated blood from the upper part of the body.

  • The internal jugular vein is the main vessel draining blood from the head, running alongside the carotid artery. This major vein ensures efficient drainage from the brain and facial structures.

  • There are other jugular veins, including a superficial one along the sternocleidomastoid muscle. These additional veins provide alternative drainage routes.

  • Multiple venous pathways exist, providing redundancy. This redundancy ensures that blood can still drain even if one pathway is blocked.

  • Internal jugular veins drain into brachiocephalic veins. These veins are a major confluence point for blood returning from the head and neck.

  • The left brachiocephalic vein is longer than the right due to the superior vena cava's position. This anatomical difference is due to the heart's position in the chest.

  • Brachiocephalic veins drain into the superior vena cava. These veins are the final common pathway for blood returning to the heart from the upper body.

  • Circulatory Loop Example: Aorta → common carotid artery → head capillaries → internal jugular vein → brachiocephalic vein → superior vena cava → right atrium.

Upper Limb Drainage

  • Arteries and veins run together in a neurovascular bundle. This close proximity ensures efficient blood supply and drainage.

  • Most veins running along an artery are paired with interconnections. These paired veins provide additional drainage capacity.

  • Deep veins run with arteries, while a superficial network of interconnected veins also exists. This dual system ensures comprehensive drainage of the upper limbs.

  • Ulnar and radial veins drain blood from the hand. These veins collect blood from the hand's intricate capillary network.

  • Arteries and veins are regionally named: arteries change names when they branch, veins when they converge. This naming convention aids in anatomical identification.

  • Ulnar and radial veins merge to form the brachial vein. This confluence marks a transition in the venous drainage pathway.

  • The brachial vein becomes the axillary vein in the armpit. This change in name reflects the vein's location in the axilla.

  • The axillary vein becomes the subclavian vein past the clavicle. This landmark denotes the vein's entry into the upper chest.

  • Subclavian veins drain into their respective brachiocephalic veins, then to the superior vena cava. This pathway completes the drainage route from the upper limbs to the heart.

  • Circulatory Loop Example: Brachiocephalic artery → subclavian artery → axillary artery → brachial artery → capillaries in brachium → brachial vein → axillary vein → subclavian vein → brachiocephalic vein.

Venous Collateral Circuits

  • Alternate routes exist in case of vein blockage due to interconnections. These collateral circuits ensure continuous drainage despite obstructions.

  • Collateral circuits occur when there's a block; tremendous venous collateral circuits exist. The body's capacity for rerouting blood flow is substantial.

Thoracic Drainage

  • Thoracic drainage will be covered later, noting accessory drainage systems tie into the superior vena cava.

Lower Body Drainage: Inferior Vena Cava

  • Veins are identical to arteries and drain into the inferior vena cava. These veins mirror the arterial pathways and return blood to the heart.

  • The inferior vena cava drains the abdomen, pelvis, and lower limbs, leading directly to the right atrium. This vessel is the primary drainage route for the lower body.

Pelvic Drainage

  • The Internal iliac veins drain the pelvic structures, including the ureteral structures and the rectum

  • Internal iliac veins join the external iliac vein to form the common iliac vein.

  • The Common iliac vein flows to the inferior vena cava and then the Right Atrium.

Lower Limb Drainage

  • Anterior tibial and posterior tibial veins drain the lower limb, with the fibular vein joining the posterior tibial. These veins collect blood from the lower leg.

  • These veins form the popliteal vein behind the knee. This confluence marks a transition in the venous drainage pathway.

  • Femoral veins ascend through the thigh. These veins carry blood up the leg towards the pelvis.

  • Femoral veins become external iliac veins as they pass over the superior pubic ramus. This landmark denotes the vein's entry into the pelvis.

  • External iliac veins join common iliac veins, which drain into the inferior vena cava and right atrium. This pathway completes the drainage route from the lower limbs to the heart.

  • Blood flow to and from the foot follows the same veins in reverse order, with capillaries as the turnaround point.

  • Artery → arteriole → capillary → venule → vein.

Practice Traces

  • Circulatory pathways = are loops. Once you reach a destination, you must return to the heart before going elsewhere.

  • Practice tracing red blood cells, creating varied scenarios.

Macro Circulatory Pattern

  • Blood enters the heart at the right atrium and goes to the lungs.

  • The right side of the heart pumps oxygen-poor blood to the lungs.

  • Gas exchange occurs in the lungs, and oxygenated blood returns to the heart.

  • The Aorta distributes Blood out to the heart, head, upper limbs, thorax, abdomen, pelvis, etc.

  • The Aorta splits into two common iliac arteries

  • Decreased Blood flow, due to the transition into two medium sized arteries, and ultimately slows blood flow enabling maximal exchange.

  • Some fluid goes out of capillaries some fluid comes back in.

  • Capillaries form to venules from the capillaries, The fluid goes from high diameter to smaller and smaller thus constricting blood.

  • That Smaller diameter ultimately reaches small veins, medium veins, and the cable veins (superior and inferior vena cava), and then returns Blood to the Heart.

  • Veins are bigger than arteries

Importance of Capillaries

  • The arteries have small muscled to regulate flow to the capillaries.

  • After pressure lowers after capillaries, pressure is key in bringing blood back after that.

  • Those valves can fail and pooling can occur in varicosities, possibly leading to blood clot.

Lymphatic System Overview

  • Three parts of fluid come from the arterial side, while two return venous, causing a one unit every time fluid moves, ultimately causing an increase in tissue fluid pressure and leading to pressure.

  • Without the lymphatic system, that would decrease blood plasma, and in turn reduce the blood volume.

  • Ultimately The Lymphatic capillary drains into the Brachiocephalic Vein (superior).

  • The Brachiocephalic Vein gets drained from lymphs of the digestive system so it never enters to the digest system.

Lymphatic System Specifics

  • Tissue is increased and extra plasma opens passageways for these tubes and fluid equilibrates.

  • The extra plasma from the system goes towards lymphs for immune system protection.

  • Dogs were used to show that massaged increases fluid to that area which increases the fat flow volumes.

  • Pressure causes those fluids from that area to go to the the lymph node, the vessels, that ultimate connects to a right lymphatic duct.

Right Lymphatic vs Thoracic Lymphatic Duct

  • The RIGHT lymphatic duct are the RIGHT upper limb right side, of the side and right side of the THORAX that turns into the Brachiocephalic ducts.

  • The THORACIC lymphatic duct is the drainage drainage from EVERYWHERE else.

  • Lymph is a watery solution EXCEPT after a meal when it is very MILK, and it is in a constant state of transportation of water to blood volume is maintained.

Lymphocyte and Cancer Detection

  • The lymphocytes in lymph channel acts as a immune response if it detects anything passes through that is foreign.

  • Cancer can be detected in the lymph, due to rapidly diving cells being picked up in transit

  • Bacteria doesn't not always go DIRECTYLY into capillary.

  • Bacteria gets into your Lymph with Lymph nodes taking samples.

  • Sepsis and high blood count are linked blood bond infections, but it increases even in non blood borne infections to prepare and defend.

Anatommical Information

  • Superior vena cava is this left vs right is right.

  • The Blue represents internal jurggular

Urinary System Overview

  • Filtration using urea, where this is in your blood

  • The vascular and urinary system has an interface.

  • Arties Blood goes into this Arties Kidney cleans blood tubes to drain waste. So blood come in, blood going out, but tubes to take the waste products and blood flow.

  • Blood is circulation consistently, thus waist production is constant.

  • Blood arterial, venius and urinary tubes

  • When evolutionary period created open cavity that was drained that was constantly eliminated.

  • Kidneys goes through the urethra to the structure called Blatter.

  • In that system those those structures have constant flow, thus blatter had developed as it acts as a timer (storage container) that lets the individual do activities.

  • You can force out urine by squeezing and abdomal. That can be dangerous women that are pregant so that why they urine themselves.

Incontinence and Blood volume

  • Incontinence of those elderly folks, can happens as