Week 2: Cardiovascular system

State the major functions of blood

transport, regulation, protection

Blood function: Transport

carries oxygen, nutrients, hormones, and wastes

Blood function: Regulation

helps regulate body temperature, pH, and fluid balance

Blood function: Protection

fights infections and prevents blood loss through clotting

Describe the composition of plasma

water, proteins, dissolved solutes

Name the three formed elements of blood

red blood cells, white blood cells, platelets

Give the approximate percentage of blood that is plasma

55%

Give the approximate percentage of blood that is formed elements

45%

Describe the structure of a red blood cell and relate it to its function

biconcave, no nucleus, packed with hemoglobin

Name the five types of white blood cells: neutrophil

white blood cell that fights infections by engulfing and destroying bacteria

Name the five types of white blood cell: lymphocyte

white blood cell that helps defend the body against infections

Name the five types of white blood cells: monocyte

white blood cell that fights infection by engulfing germs and dead or damaged cells

Name the five types of white blood cells: eosinophil

white blood cell that helps fight parasitic infections

Name the five types of white blood cells: basophil

white blood cell that releases histamine during allergic reactions, causing inflammation

Where are formed elements produced, and what is this process called?

formed elements are produced in red bone marrow through a process called hematopoiesis

Define antibodies

proteins that recognize and bind to specific antigens to help protect the body

Define antigen

markers on cells that the immune system recognizes

What is ABO?

a blood group system that classifies blood into four types A, B, AB, and O

What determines a person's ABO blood type?

by antigens on the red blood cell surface (A, B, AB, O)

Which antibodies are present in each ABO blood type: Type A

Anti-B antibodies

Which antibodies are present in each ABO blood type: Type B

Anti-A antibodies

Which antibodies are present in each ABO blood type: Type AB

neither anti-A or anti-B antibodies

Which antibodies are present in each ABO blood type: Type O

both anti-A and anti-B antibodies

What is the Rh factor

a antigen on the surface of red blood cells that determines whether blood is Rh-positive or Rh-negative

What does positive mean in Rh factor?

the Rh antigen is present

What does negative mean in Rh factor?

the Rh antigen is absent

Define hemostasis

the process of stopping bleeding after a blood vessel is damaged

Outline the three steps of hemostasis in order

vascular spasm, platelet plug, coagulation

Define vascular spasm

when the injured blood vessel tightens to reduce blood loss

Define platelet plug

platelets stick to the damaged area and clump together to temporarily stop bleeding

Define coagulation

a process in which fibrin forms a mesh that strengthens the platelet plug, creating a more stable blood clot

State the end result of the coagulation process

a fibrin blood clot

Label the four chambers of the heart

right, left atrium, right, left ventricle

Label the four valves of the heart

tricuspid valve, pulmonary valve, mitral (bicuspid) valve, aortic valve

Trace a drop of blood through the heart, lungs, and body (pulmonary and systemic circuits)

Trace the pathway of blood through the pulmonary and systemic circuits.

Pulmonary circuit: Right ventricle → pulmonary valve → pulmonary arteries → lungs (releases CO₂ and picks up O₂) → pulmonary veins → left atrium.

Systemic circuit: Left ventricle → aortic valve → aorta → body tissues (delivers O₂ and picks up CO₂) → veins → superior and inferior vena cava → right atrium.

Define pulmonary circuit

the pathway that carries blood between the heart and lungs for gas exchange

Define systemic circuit

the pathway that carries blood between the heart and the rest of the body to deliver oxygen and nutrients

Define the cardiac cycle

the sequence of heart contraction and relaxation that fills the chambers with blood and pumps blood out

Define conduction system

makes the heart contract without external nerve signals

The heart can generate its own electrical signals without needing signals from the nervous system to start each heartbeat.

Name the components of the conduction system in order

SA node, AV node, bundle of His, Purkinje fibers

Identify the SA node

the pacemaker that sets heart rate

Identify the AV node

delays the electrical signal so the ventricles can fill with blood

Identify the bundle of His

Carries electrical signals from the AV node to the ventricles

Identify the Purkinje fibers

spread electrical signals through the ventricles, causing them to contract

Explain how the electrical conduction system drives the cardiac cycle

the electrical conduction system sends signals that cause the atria to contract first, followed by the ventricles, allowing the heart to fill with blood and pump it to the lungs and body

Define autorhythmicity

the heart’s ability to generate its own electrical signals

Define systole

the phase when the heart contracts and pumps blood out

Define diastole

the phase when the heart relaxes and fills with blood

Explain the events of the cardiac cycle and the origin of the heart sounds

lecture

Describe what happens in the atria and ventricles during one cardiac cycle

contract to push blood into the ventricles, then relax and fill with blood

Describe what happens in the atria and ventricles during one cardiac cycle

relax to fill with blood, then contract to pump blood to the lungs and body

What causes the two heart sounds: Lub

the tricuspid and mitral valves close when the ventricles begin to contract

What causes the two heart sounds: Dub

the pulmonary and aortic valves close when the ventricles begin to relax

What causes the two heart sounds: lub-dub

lub-dup = valves closing

Describe the structural differences of capillaries

walls only one cell thick; small inner opening

Describe the structural differences of arteries

thick, muscular walls; smaller inner opening

Describe the structural differences of veins

thinner walls, large inner opening, and valves to prevent backflow (stopping blood from flowing backward)

State the function of each vessel type: arteries

carry blood away (from the heart)

State the function of each vessel type: capillaries

exchange (oxygen, nutrients)

State the function of each vessel type: veins

return blood (back to the heart)

Explain why capillaries are ideal sites for exchange

thin walls, large total area

Define cardiac output

the amount of blood the heart pumps in one minute

Define stroke volume

the amount of blood pumped out by one ventricle with each heartbeat

Give the cardiac output formula

heart rate × stroke volume

List factors that change heart rate

autonomic input, hormones

List factors that change stroke volume

venous return / preload, contractility

Define blood pressure

the force of blood pushing against the walls of blood vessels

Define systolic pressure

the pressure in the arteries when the ventricles contract

Define diastolic pressure

the pressure in the arteries when the ventricles relax

Identify the factors that determine blood pressure

cardiac output and resistance

Define baroreceptor

a sensor that detects changes in blood pressure

Explain how the baroreceptor reflex makes rapid blood-pressure adjustments

the baroreceptor reflex detects changes in blood pressure and quickly adjusts heart rate and blood vessel diameter to bring blood pressure back toward normal