Cardiovascular System Overview

The cardiovascular system transports oxygen, nutrients, hormones, and waste products throughout the body.

The part of the circulatory system that moves blood between the heart and the lungs, picking up oxygen and releasing carbon dioxide.

The part of the circulatory system that moves blood between the heart and the rest of the body, delivering oxygen and nutrients.

The heart chamber that pumps oxygen-rich blood to the body.

The heart has different chambers and valves (e.g., right atrium, left ventricle, mitral valve) to regulate the flow of blood.

The left ventricle has thicker walls than the right ventricle because it pumps blood to the entire body, requiring more force.

A unique circulatory pathway in which blood from the digestive organs travels to the liver for processing before returning to the heart.

Arteries carry blood away from the heart, while veins carry blood back to the heart.

Thicker than the right ventricle to pump blood throughout the body at high pressure.

Thinner than the left ventricle as it only pumps blood to the lungs.

Blood vessels that carry blood away from the heart.

Smaller branches of arteries.

Tiny blood vessels where gas and nutrient exchange occurs.

Blood vessels that carry blood back to the heart.

Small blood vessels that collect blood from capillaries.

Pressure in blood vessels drops as blood moves away from the heart.

Valves, skeletal muscle pump, and respiratory pump assist blood flow back to the heart.

Folds in veins that prevent blood backflow.

Muscle contractions help push blood up toward the heart.

Breathing helps blood flow towards the heart.

Thicker muscle layer for withstanding high pressure from the heart.

Allows arteries to stretch and recoil to maintain blood pressure.

Simple squamous epithelium lines capillaries for efficient gas exchange.

Part of the aorta that comes from the left ventricle.

The splenic artery supplies blood to the spleen, pancreas, and part of the stomach.

The renal artery carries oxygenated blood to the kidneys for filtration and waste removal.

The common iliac artery is a branch of the abdominal aorta that divides into two branches, the internal and external iliac arteries. The internal iliac artery supplies blood to the pelvic organs, and the external iliac artery supplies blood to the lower limbs.

The external carotid artery supplies blood to the face, scalp, neck, ears, tongue, and muscles of mastication.

The internal carotid artery provides blood to the brain, eyes, and the orbit.

The vertebral artery supplies blood to the cervical spine, brainstem, and posterior brain.

The basilar artery, formed by the fusion of the two vertebral arteries, supplies blood to the brainstem, cerebellum, and the posterior cerebral hemispheres.

The subclavian artery supplies blood to the upper limbs, neck, brain, and part of the thoracic wall.

The axillary artery is a continuation of the subclavian artery and provides blood to the shoulder, axilla, and the upper limb.

The brachial artery supplies blood to the upper arm, elbow joint, and forearm.

The brachial artery branches into the ulnar and radial arteries in the forearm.

The ulnar artery supplies the medial side of the forearm and the hand, including the flexor muscles.

The radial artery supplies blood to the lateral side of the forearm, the wrist, and the thumb and index finger.

The external iliac artery supplies blood to the lower limbs, including the anterior abdominal wall and inguinal region.

The internal iliac artery supplies blood to the pelvic organs, gluteal muscles, and hip joint.

The femoral artery supplies blood to the thigh, knee, hip joint, and branches into arteries that supply the lower leg and foot.

The vertebral artery, a major blood vessel in the neck, passes through the transverse foramina (openings) found in the cervical vertebrae (neck bones).

The celiac trunk, a major artery in the abdomen, branches into the common hepatic artery and splenic artery, supplying vital organs in the digestive system.

The common hepatic artery supplies blood to the liver, gallbladder, stomach, duodenum, and pancreas.

The splenic artery supplies blood to the spleen, pancreas, stomach, greater omentum (abdominal fat), and left colic flexure (colon bend).

Valves in peripheral veins prevent blood backflow, ensuring blood flows only towards the heart. This is essential for efficient blood circulation, especially against gravity.

Valves in veins are usually too small and thin to be easily observed in standard histology slides.

Three main mechanisms contribute to venous blood flow back to the heart: the muscle pump, valves, and the respiratory pump.

Skeletal muscle contractions compress veins, forcing blood upward towards the heart. Valves prevent backflow during relaxation.

Valves within veins act like one-way doors, preventing backflow and ensuring unidirectional blood flow towards the heart.

The blood in the hepatic portal system originates from the gastrointestinal tract (stomach, small intestine, large intestine), spleen, and pancreas.

The hepatic portal vein carries blood from the digestive organs to the liver for processing and detoxification before returning to the heart.

The foramen ovale, a hole between the right and left atria in the fetal heart, allows blood to bypass the non-functional lungs before birth.

The ductus arteriosus connects the pulmonary trunk (from the heart) directly to the aorta, allowing blood to bypass the lungs before birth.

The foramen ovale and ductus arteriosus are shunts that allow blood to bypass the lungs in the fetus because they're not functional before birth.

The lymphatic system has three main functions: fluid balance, immune defense, and nutrient absorption.

Lymph is formed from excess interstitial fluid, proteins, and waste products that leak out of blood capillaries into the surrounding tissues.

Lymphatic capillaries collect lymph and return it to the bloodstream via lymphatic vessels, which converge into larger vessels and eventually drain into veins.

Tiny, thin-walled vessels that collect fluid, proteins, and waste products from tissues.

Specialized lymphatic capillaries in the small intestine that absorb lipids and fat-soluble vitamins.

Lymph nodes are scattered throughout the body, especially in areas where lymphatic vessels converge, such as the neck, armpits, and groin.

Lymph nodes contain immune cells, such as lymphocytes and macrophages, that filter and destroy bacteria, cancer cells, and other foreign substances.

The thymus is responsible for the maturation of T lymphocytes (T cells), which play a critical role in cell-mediated immunity.

The spleen filters blood, removing old or damaged red blood cells, stores platelets, and plays a role in immune responses to bloodborne pathogens.

Lymphatic nodules are small, localized clusters of lymphatic tissue found in various mucosal areas, like the gut and respiratory tract, where they play a role in immune surveillance and pathogen removal.

Tonsils, located at the back of the mouth and nasopharynx, trap and remove pathogens to prevent infections.

The appendix, a small pouch attached to the cecum, contains lymphatic tissue and helps maintain gut flora, possibly by housing beneficial bacteria.

Bone marrow produces blood cells, including lymphocytes (T cells and B cells) that are key components of the immune system.

Different types of lymph nodes are found throughout the lymphatic system, including iliac, inguinal, intestinal, axillary, submandibular, and cervical nodes.

Edema is a swelling caused by excess fluid accumulation in tissues, which can result from impaired lymphatic drainage.

Lymph moves through lymphatic capillaries due to hydrostatic pressure from excess fluid, osmotic pressure from plasma proteins, one-way valves, and muscle contractions.

Lymph is returned to the blood at the right subclavian vein (right lymphatic duct) or the left subclavian vein (thoracic duct).

Lymphatic vessels have thinner walls, larger lumens, and more one-way valves compared to veins.

Blood cell formation starts in the yolk sac, then moves to the liver and spleen before shifting to bone marrow at birth.

Red bone marrow is the primary site of blood cell formation in adults.

Plasma is blood's liquid part with clotting factors. Serum is plasma without clotting factors. Interstitial fluid surrounds cells, similar to plasma but lacks albumin. Lymph circulates in the lymphatic system, carrying immune cells and waste.

A large vein located in the upper chest, formed by the union of the right and left brachiocephalic veins. It drains deoxygenated blood from the head, neck, arms, and thorax into the right atrium of the heart.

Located on each side of the neck, formed by the union of the internal jugular vein and the subclavian vein. It drains blood from the head, neck, and upper limbs, and empties into the superior vena cava.

Located along the side of the neck, runs alongside the carotid artery. It drains deoxygenated blood from the brain, face, neck, and parts of the throat and cranial cavity into the brachiocephalic vein.

Located superficially in the neck, drains into the subclavian vein. It drains blood from the face, scalp, and neck.

Formed by the union of the left and right common iliac veins and travels upward through the abdomen. It drains deoxygenated blood from the lower body (legs, pelvis, abdominal organs) into the right atrium of the heart.

Drains each kidney, located near the level of the L1 vertebra. It drains deoxygenated blood from the kidneys after filtration and carries it to the inferior vena cava.

Drains the spleen. It is located near the pancreas and stomach, and drains blood from the spleen, stomach, pancreas, and parts of the intestines, and empties into the hepatic portal vein.

Drains blood from the liver into the inferior vena cava. It drains deoxygenated blood from the liver after nutrient processing and detoxification.

Formed by the union of the splenic vein and superior mesenteric vein. It carries blood from the stomach, intestines, pancreas, and spleen to the liver for nutrient processing.

Located beneath the clavicle (collarbone) and is formed by the union of the axillary vein and the cephalic vein. It drains blood from the upper limb and part of the neck and chest, then empties into the brachiocephalic vein.

A continuation of the brachial vein, located in the axilla (armpit). It drains blood from the upper limb, shoulder, chest, and arm into the subclavian vein.

Superficial vein located on the lateral side of the forearm and arm, near the surface of the skin. It drains blood from the lateral forearm and hand, and empties into the subclavian vein.

Located in the upper arm, runs alongside the brachial artery. It drains blood from the upper arm, elbow, and forearm, and then empties into the axillary vein.

Located on the medial side of the forearm and arm, often used for venipuncture. It drains blood from the medial forearm, upper arm, and hand, and empties into the brachial vein.

Runs along the medial side of the forearm, parallel to the ulnar artery. It drains blood from the medial forearm, including the pinky and medial hand. It joins the radial vein to form the brachial vein.

Runs along the lateral side of the forearm, parallel to the radial artery. It drains blood from the lateral forearm, thumb, and lateral hand. It joins with the ulnar vein to form the brachial vein.

Formed by the union of the internal iliac vein and external iliac vein. Located in the lower abdomen near the pelvis, it drains blood from the pelvis, lower limbs, and abdominal organs, and empties into the inferior vena cava.

Continuation of the femoral vein as it passes into the pelvis, located anterior to the internal iliac vein. It drains deoxygenated blood from the lower limbs, anterior abdominal wall, and inguinal region. It empties into the common iliac vein.

Located within the pelvic cavity and drains blood from the pelvic organs, like the bladder, rectum, uterus, and prostate, gluteal region, and hip joint. It joins with the external iliac vein to form the common iliac vein.

Continuation of the popliteal vein, located in the thigh, medial to the femoral artery. It drains blood from the thigh, knee, hip joint, and parts of the lower leg. It becomes the external iliac vein as it enters the pelvis.

The longest vein in the body, located superficially in the leg, runs along the medial side from the foot to the groin. It drains blood from the superficial structures of the lower leg and foot, and empties into the femoral vein.

Located behind the knee in the popliteal fossa, it is the continuation of the posterior tibial vein. It drains blood from the knee joint, muscles of the knee, and lower leg, and becomes the femoral vein as it ascends into the thigh.

The left ventricle has thicker walls than the right ventricle because it pumps blood to the entire body, requiring more force.

Blood in the fetus bypasses the lungs, using the foramen ovale and ductus arteriosus, because the lungs aren't functional before birth.

The left ventricle wall is thicker than the right ventricle wall because it needs to pump blood with more force to reach the entire body.

Capillaries are the smallest blood vessels where gas exchange, nutrient delivery, and waste removal occur due to their thin walls.

Veins have valves to prevent backflow of blood, ensuring blood flows towards the heart.

Arteries have thicker muscle layers to withstand high pressure from the heart's pumping action.

A branch of the celiac trunk that supplies blood to the spleen, pancreas, and part of the stomach.

Arises from the abdominal aorta and carries oxygenated blood to each kidney for filtration and waste removal.

The terminal branch of the abdominal aorta that splits into internal and external iliac arteries, supplying blood to the lower limbs and pelvic organs.

Branches from the common carotid artery in the neck and supplies blood to the face, scalp, neck, ears, tongue, and muscles of mastication.

Branches from the common carotid artery and enters the skull through the carotid canal, supplying blood to the brain, eyes, and the orbit.

Formed by the fusion of the two vertebral arteries at the brainstem, supplying blood to the brainstem, cerebellum, and the posterior cerebral hemispheres.

Arises from the brachiocephalic trunk or the aortic arch and passes under the clavicle, supplying the upper limbs, neck, brain, and part of the thoracic wall.

Continuation of the subclavian artery after it passes the first rib, located in the axilla (armpit) region, supplying the shoulder, axilla, and the upper limb.

The vertebral artery passes through the transverse foramina of the cervical vertebrae (neck bones).

Drains deoxygenated blood from the upper body (head, neck, arms, and thorax) into the right atrium of the heart.

Drains deoxygenated blood from the lower body (legs, pelvis, abdominal organs) into the right atrium of the heart.

Carries blood from the stomach, intestines, pancreas, and spleen to the liver for nutrient processing.

Located in the upper arm, it runs alongside the brachial artery.

Located on the medial side of the forearm and arm, it is often used for venipuncture.

Continuation of the popliteal vein, located in the thigh, medial to the femoral artery.

The longest vein in the body, located superficially in the leg, runs along the medial side from the foot to the groin.

Located behind the knee in the popliteal fossa, it is the continuation of the posterior tibial vein.

Drains blood from the pelvis, lower limbs, and abdominal organs, and empties into the inferior vena cava.

Drains deoxygenated blood from the kidneys after filtration and carries it to the inferior vena cava.