Unit 3 HBS Review

Cardiac Muscle

Involuntary, striated muscle found only in the heart.

Skeletal Muscle

Voluntary muscle attached to bones.

Smooth Muscle

Involuntary, non-striated muscle in walls of internal organs and blood vessels.

Left/Right Atrium

Upper chambers that receive blood.

Left/Right Ventricle

Lower chambers that pump blood out.

Valve

Prevents backflow of blood.

Artery

Carries blood away from the heart (usually oxygenated).

Vein

Carries blood toward the heart (usually deoxygenated).

Capillary

Small vessels for exchange of gases and nutrients.

Systemic Circulation

Blood flow between heart and body.

Pulmonary Circulation

Blood flow between heart and lungs.

Myocardial Infarction

Heart attack.

Arrhythmia

Irregular heartbeat.

Tachycardia

Fast heartbeat.

Bradycardia

Slow heartbeat.

Fibrillation

Uncoordinated heartbeat.

Electrocardiogram (EKG)

Records electrical activity of the heart.

Sphygmomanometer

Device to measure blood pressure.

Cardiac Output

Blood volume pumped by the heart per minute.

Stroke Volume

Amount of blood pumped per beat.

Diffusion

Gas exchange process across alveolar membrane.

Phagocyte

White blood cell that engulfs pathogens.

Antigen

Foreign substance that triggers an immune response.

Antibody

Protein that binds specifically to antigens.

Passive immunity

Short-term immunity from another source (e.g., breast milk).

Normal flora

Harmless microbes that help prevent pathogen colonization.

First degree burn

Affects epidermis only, red and painful.

Second degree burn

Affects epidermis and dermis, blistering.

Third degree burn

Destroys all skin layers, may be numb.

Fourth degree burn

Extends to muscles/bones; severe damage.

Infectious disease

Illness caused by pathogens (microorganisms).

Pathogen

A disease-causing agent.

Virus

Non-living pathogen requiring host cells to replicate.

Bacteria

Single-celled prokaryotes, some pathogenic.

Fungi

Can cause infections like athlete’s foot or ringworm.

Helminth

Parasitic worm (e.g., tapeworms).

Lymph nodes

Filter lymph and house white blood cells.

Spleen

Filters blood, recycles old RBCs, helps immune response.

Thymus

Matures T cells (shrinks with age).

Liver

Filters blood and helps immune function.

Platelets

Cell fragments that help in clotting.

Red blood cells (RBCs)

Carry oxygen with hemoglobin.

White blood cells (WBCs)

Fight infection; includes phagocytes and lymphocytes.

Retina

Light-sensitive layer with photoreceptors.

Iris

Colored part, controls pupil size.

Cornea

Clear front layer of eye; bends light.

Optic nerve

Carries visual signals to the brain.