Circulatory System (Good copy)

Circulation

The movement of blood that transports materials throughout the body

Circulatory system

The body system that transports nutrients, gases, wastes, hormones, and immune cells

Relationship between digestive and circulatory systems

The digestive system breaks food into small molecules that diffuse into the blood, and the circulatory system delivers them to cells

Nutrients

Molecules from digested food used by cells for energy and growth

Respiratory gases

Oxygen and carbon dioxide that must be transported in the blood

Cellular waste

Waste products produced by cells that must be removed

Protective agents

Immune defenses such as white blood cells and antibodies

Regulatory molecules

Hormones that control body processes

Heart

Muscular organ that pumps blood throughout the body

Blood

Fluid tissue that transports materials

Blood vessels

Network of tubes that carry blood

Function of blood

Transports nutrients, regulates body temperature, and protects the body

Homeostasis

The maintenance of stable internal conditions

Blood tissue

A tissue made of plasma and cells

Plasma

Liquid part of blood that makes up about 55% of blood

Plasma components

Water, salts, sugars, proteins, wastes, hormones, antibodies, and enzymes

Red blood cells (erythrocytes)

Blood cells that carry oxygen and carbon dioxide

Hemoglobin

Iron

Biconcave shape

Shape of red blood cells that increases surface area for gas exchange

Red blood cell nucleus

Absent; RBCs do not have a nucleus

Red blood cell lifespan

About 90–120 days

Red blood cell recycling

Old RBCs are broken down in the liver and spleen

White blood cells (leukocytes)

Blood cells that fight infection

White blood cell nucleus

Present

White blood cell count

Lower than RBCs but increases during infection

Phagocytes

White blood cells that engulf and destroy bacteria and old cells

Phagocytosis

Process of engulfing and digesting pathogens

Lymphocytes

White blood cells involved in immune responses

B

lymphocytes

Platelets

Small cell fragments involved in blood clotting

Platelet nucleus

Absent

Blood clotting

Process that prevents blood loss

Fibrinogen

Plasma protein involved in clotting

Fibrin

Protein threads that form a mesh to trap blood cells

Scab

Hardened clot that seals a wound

Antigens

Proteins on the surface of red blood cells used in blood typing

Blood typing

Classification of blood based on antigens on RBCs

Universal donor

Type O blood because it has no antigens

Universal recipient

Type AB blood because it has all antigens

Anemia

Condition where too few RBCs or hemoglobin causes low oxygen delivery

Sickle cell anemia

Genetic disorder where misshaped RBCs carry less oxygen

Leukemia

Cancer where abnormal white blood cells crowd out normal blood cells

Hemophilia

Genetic disorder where blood does not clot properly

Arteries

Blood vessels that carry blood away from the heart

Pulmonary artery

Carries deoxygenated blood from the heart to the lungs

Veins

Blood vessels that carry blood toward the heart

Pulmonary vein

Carries oxygenated blood from lungs to heart

Capillaries

Tiny vessels where exchange occurs

Artery structure

Thick, elastic walls made of smooth muscle

Artery pressure

High pressure

Arterioles

Small arteries leading to capillaries

Vein structure

Thin walls, wide diameter, low pressure

Vein valves

One

Skeletal muscle pump

Muscle contractions that help move blood through veins

Capillary structure

One cell thick

Capillary function

Diffusion of oxygen, nutrients, and wastes

Pulse rate

Heartbeats per minute

Normal pulse rate

60–100 beats per minute

Pulse cause

Expansion and contraction of arteries

Blood pressure

Force of blood against artery walls

Systolic pressure

Pressure during heart contraction

Diastolic pressure

Pressure during heart relaxation

Normal blood pressure

120/80 mmHg

Heart

Fist

Heart muscle

Striated and involuntary muscle

Pericardium

Fluid

Septum

Muscular wall separating left and right sides of heart

Atria

Upper chambers of the heart

Ventricles

Lower chambers of the heart

Heart valves

Structures that prevent backflow of blood

Superior vena cava

Returns deoxygenated blood from upper body

Inferior vena cava

Returns deoxygenated blood from lower body

Aorta

Largest artery that carries oxygenated blood to the body

Coronary arteries

Supply oxygenated blood to the heart muscle

Right atrium

Receives deoxygenated blood from the body

Right ventricle

Pumps blood to the lungs

Left atrium

Receives oxygenated blood from lungs

Left ventricle

Pumps oxygenated blood to the body