Biology Midterm Review: Blood and Plasma Functions

Blood is composed of approximately 55% plasma, which consists of 91% water and 7% proteins. The other 45% of blood consists of formed elements, including red blood cells, white blood cells, and platelets.

Plasma is the liquid part of blood that makes up about 55% of blood volume and consists of various components essential for bodily functions. It is not related to matter in the sun, the states of matter, or the layers of Earth's atmosphere.

Proteins in plasma play various roles such as maintaining viscosity, osmotic pressure, acting as buffers, and transporting different substances. Albumins are responsible for transporting fatty acids, free bilirubin, and thyroid hormones. Globulins transport lipids, carbohydrates, hormones, ions, and antibodies. Fibrinogen is involved in blood clotting.

Red Blood Cells contain hemoglobin which allows them to transport oxygen and carbon dioxide throughout the body. They have a lifespan of approximately 120 days in circulation before being removed by the body.

White Blood Cells, or leukocytes, play a vital role in protecting the body against microorganisms and removing dead cells and debris. They are also responsible for immune responses. Granulocytes are a type of white blood cell with distinctive characteristics.

Platelets are primarily responsible for forming platelet plugs at the site of injury and releasing chemicals necessary for the blood clotting process, not for carrying oxygen, regulating blood pressure, or producing insulin.

Hematopoiesis is the process through which the body produces blood cells, including red blood cells, white blood cells, and platelets.

The correct answer explains the various mechanisms through which Carbon Dioxide is transported from tissues to lungs, highlighting the crucial role of bicarbonate ions in the process.

Erythropoietin is a hormone produced by the kidneys to stimulate the production of red blood cells in response to low oxygen levels in the blood. It does not break down red blood cells, is not a type of white blood cell, and is not involved in regulating blood glucose levels.

Hemoglobin breakdown is a complex process involving macrophages breaking down heme and globin chains, with globin chains further metabolized into amino acids for various uses.

White Blood Cells exhibit chemotaxis, which is the process of attraction to and movement toward foreign materials or damaged cells. This allows them to actively move towards areas of infection or injury to initiate an immune response.

Neutrophils are a type of white blood cell that primarily function in the immune system's defense against infection and disease. They secrete lysozyme, an enzyme that helps break down bacterial cell walls. Neutrophils typically account for 60-70% of white blood cells in the body.

Eosinophils are a type of white blood cell that play a key role in the immune response, particularly in allergic reactions and combating parasitic infections. They are not involved in transporting oxygen, blood clotting, or regulating blood sugar levels.

Basophils are a type of white blood cell that play a key role in inflammatory and allergic reactions by releasing histamine and heparin. They make up less than 1% of the total white blood cell population.

Lymphocytes are a type of white blood cell that plays a key role in the immune system by recognizing and responding to foreign invaders such as bacteria and viruses. They migrate to lymphatic tissues, where they multiply and produce antibodies to fight off these invaders. Lymphocytes do not carry oxygen, break down food, or regulate body temperature.

Monocytes play a crucial role in the immune system by presenting antigens to lymphocytes for recognition, triggering an immune response.

The heart's main functions include generating blood pressure to allow blood to circulate throughout the body, routing blood to the lungs and the rest of the body, ensuring one-way blood flow with the help of valves, and regulating the blood supply to meet the body's needs.

The fibrous pericardium is a tough fibrous outer layer that prevents over distention of the heart by providing structural support.

The Serous Pericardium is a thin, transparent, inner layer that surrounds the heart.

The Visceral Pericardium specifically covers the surface of the heart, protecting it and reducing friction during heartbeats.

The heart wall is composed of three main layers: The epicardium, which is a serous membrane that covers the outer surface of the heart. The myocardium, the middle layer made up of cardiac muscle cells responsible for the heart's pumping action. And the endocardium, which is the smooth inner surface of the heart chambers.

The Coronary Arteries exit the aorta just where the aorta exits the heart, providing oxygenated blood to the heart muscle itself.

The heart skeleton is primarily responsible for providing structural support and electrical insulation within the heart, ensuring coordinated pumping action.

Intercalated disks are structures found in cardiac muscle where the membranes of adjacent cells are tightly joined to allow for synchronized contraction. They are specialized for maintaining close cell-cell contact.

The SA Node is responsible for initiating the electrical impulses that regulate the heart's rhythm, making it the pacemaker of the heart.

The AV Node is located near the right AV valve and is responsible for conducting action potentials more slowly to allow for coordination of atrial and ventricular contractions.

Purkinje Fibers are specialized large diameter cardiac muscles that conduct action potential to ventricular muscle cells, allowing for coordinated contraction of the ventricles.

The Absolute Refractory Period in cardiac muscle cells refers to the phase when the cell is completely insensitive to further stimulation, which ensures proper cardiac muscle contraction and prevents tetanic contractions.