Blood and Cardiovascular System

These flashcards cover key concepts related to blood and the cardiovascular system to facilitate exam preparation.

What is the average amount of blood contained in an adult human body?

~5 liters.

What are the main components of blood?

Plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

What is hematocrit (HCT)?

The ratio of red blood cells to the total blood volume, usually about 45%.

What is the primary function of erythrocytes?

To carry oxygen through hemoglobin.

How long do erythrocytes typically survive?

~120 days.

What substances are required for the DNA synthesis of erythrocytes?

Vitamin B12 and folic acid.

What condition is caused by low oxygen levels in the body?

Hypoxia.

What is jaundice caused by?

The buildup of bilirubin from the breakdown of heme in red blood cells.

What do white blood cells (leukocytes) primarily do?

Help maintain the immune system and fight infections.

What are the two main categories of leukocytes?

Granulocytes and agranulocytes.

What is the main function of platelets (thrombocytes)?

To aid in blood clotting during hemostasis.

What is the role of the medulla oblongata in heart regulation?

It controls heart activity through the autonomic nervous system.

What factors affect blood pressure?

Blood volume, stroke volume, heart rate, viscosity, and peripheral resistance.

What are HDL and LDL in the context of cholesterol?

HDL (high-density lipoprotein) is good cholesterol that carries cholesterol away from arteries, while LDL (low-density lipoprotein) is bad cholesterol that can lead to plaque buildup.

What is the primary function of the cardiovascular system?

To transport oxygen and nutrients to tissues and remove waste products.

What is the pathway of blood circulation through the heart?

Blood returns to the right atrium, goes to the right ventricle, out to the lungs, returns to the left atrium, goes to the left ventricle, and is then pumped to the body.

What is the sinoatrial (SA) node?

The pacemaker of the heart that initiates the heartbeat.

What is the function of the atrioventricular (AV) node?

It delays the impulse from the SA node to allow the atria to contract before the ventricles.

What conditions can result from arrhythmias?

Premature contractions, atrial fibrillation, and ventricular tachycardia.

What is the significance of the fossa ovalis?

It is a remnant of the foramen ovale, which allows fetal blood to bypass the lungs.

What is the process of hemostasis?

The process that prevents and stops bleeding, involving vasospasm, platelet plug formation, and coagulation.

What are the components of blood plasma?

90% water, 10% gases, salts, nutrients, hormones, and proteins.

What is the function of the pericardium?

To protect the heart and provide it with lubrication.