Human Circulatory System

Right atrium receives oxygen depleted blood from the body from two major veins, the superior vena cava and the inferior vena cava. Right ventricle receives oxygen depleted blood from the right atrium.

Open vascular bundles contain cambium between xylem and phloem, allowing secondary growth. Closed bundles lack cambium and cannot undergo secondary thickening. Exarch and endarch refer to xylem maturation patterns, not cambium presence.

In rabbits, the azygous vein (unpaired midline vein), hemizygous vein (half/unpaired), and caudal vein are all single/unpaired structures - they exist as single vessels rather than paired left/right structures. 'All of these' is correct because all three veins are unpaired in rabbit anatomy.

Arteries are blood vessels that carry blood away from heart. Arteries carry blood from capillaries to the heart.

The left renal vein courses anteriorly across the aorta, passing below the superior mesenteric artery before joining the inferior vena cava. This anatomical relationship is clinically relevant during surgical procedures and imaging.

When the circumflex artery (branch of left coronary) supplies the posterior interventricular artery, it is called left dominance. Normally, the right coronary artery supplies this vessel (right dominance, seen in 70-80% of people).

At the left lung hilum, structures are arranged from superior to inferior: pulmonary artery (most superior), bronchus, and pulmonary vein (inferior). This anatomical relationship is consistent on the left side, though slightly different on the right where the eparterial bronchus is superior to the pulmonary artery.

As blood flows through systemic capillaries, CO2 is released from tissues, which causes the oxyhemoglobin dissociation curve to shift RIGHT (Bohr effect) - facilitating oxygen unloading. This is the exception among the listed changes. The other changes DO occur: water leaves capillaries increasing hematocrit, plasma protein concentration increases slightly, and pH decreases due to acidic metabolites.

The spleen functions as the body's blood bank by storing platelets and red blood cells, filtering damaged blood cells, and releasing stored blood during emergencies. It also plays important roles in immune function and recycling iron from old red blood cells.

Arteriosclerosis is the thickening and hardening of arterial walls due to loss of elasticity. An aneurysm is a weakened bulging area, not thickening, and arthritis is joint inflammation unrelated to arteries.

Pulmonary circulation specifically describes the pathway where deoxygenated blood travels from heart to lungs for oxygenation, then returns oxygenated blood to the heart. Systemic circulation serves the body, while coronary circulation serves heart muscle.

The aorta is the largest artery in human body. It originates from the left ventricle of the heart and extends down to the abdomen.

Coronary arteries supply oxygenated blood to the heart muscle itself. Carotid arteries supply the brain and head, hepatic arteries serve the liver, and pulmonary arteries carry deoxygenated blood from heart to lungs.

This is the correct answer as humans, frogs and lizards have a double circulation system.

This is the correct answer as the heart pumps blood to the gills in fishes (pisces) and not to different parts of the body. Fishes have a two-chambered heart.