science

Circulatory System

Responsible for transporting oxygen, nutrients, hormones, and waste throughout the body.

Heart

Pumps blood throughout the body.

Arteries

Carry oxygen-rich blood away from the heart (except pulmonary artery).

Veins

Carry oxygen-poor blood back to the heart (except pulmonary vein).

Capillaries

Tiny blood vessels where oxygen and carbon dioxide exchange happens.

Blood

Transports gases, nutrients, and waste.

Systemic Circulation

Moves oxygenated blood from the heart to the body.

Pulmonary Circulation

Moves deoxygenated blood to the lungs for oxygenation.

Superior & Inferior Vena Cava

Carries deoxygenated blood from the body to the heart.

Right Atrium

Receives deoxygenated blood from the vena cava.

Right Ventricle

Pumps blood to the lungs.

Pulmonary Artery

Carries deoxygenated blood to the lungs.

Lungs (Alveoli)

Site where gas exchange happens (O₂ enters, CO₂ leaves).

Pulmonary Vein

Carries oxygenated blood from the lungs to the heart.

Left Atrium

Receives oxygen-rich blood from the pulmonary vein.

Left Ventricle

Pumps oxygenated blood to the entire body.

Aorta

The largest artery, distributing blood to the body.

Nose/Nasal Cavity

Filters, moistens, and warms air.

Pharynx & Larynx

Air passage & voice box.

Trachea (Windpipe)

Main airway leading to lungs.

Bronchi & Bronchioles

Branches that direct air into lungs.

Alveoli

Site of gas exchange (O₂ enters, CO₂ exits).

Diaphragm

Controls inhalation and exhalation.

Inhalation

Oxygen enters the alveoli and diffuses into the bloodstream.

Exhalation

Carbon dioxide diffuses from the blood into the alveoli and is expelled.

Gas Exchange (Alveoli)

O₂ moves from alveoli to blood; CO₂ moves from blood to alveoli.

Gene

Segment of DNA controlling traits.

Allele

Different versions of a gene (e.g., brown vs. blue eyes).

Dominant Trait (A)

Always expressed if present.

Recessive Trait (a)

Expressed only if both alleles are recessive.

Punnett Square

Tool used to predict genetic variations in offspring.

Incomplete Dominance

Blended traits, as in red (RR) and white (WW) producing pink (RW).

Codominance

Both traits are visible, as in blood type AB (A and B are expressed).

Polygenic Traits

Traits controlled by multiple genes, e.g., height.

Meiosis

Process that leads to genetic variation through the formation of gametes.

Genetic Variation

Occurs due to recombination and mutation in siblings.

Blood type AB

Can produce children with blood types A, B, or AB.

Probability of Blue-eyed Child

Determined by the genetic makeup of the parents' alleles.

Hemoglobin

A protein in red blood cells that transports oxygen.

Why is the left ventricle more muscular?

It pumps oxygenated blood to the entire body, requiring more force.

What happens if pulmonary artery is blocked?

Prevents blood from reaching lungs, causing decreased oxygenation.

Function of Diaphragm in Breathing

Contracts to create negative pressure for inhalation.

Why do capillaries have thin walls?

Allows for efficient gas exchange between blood and tissues.