Science Revision: Circulatory, Respiratory, Excretory, Digestive, Endocrine, Reproductive, and Immune Systems

Flashcards for reviewing the circulatory, respiratory, excretory, digestive, endocrine, reproductive, and immune systems.

Circulatory System

The body's transport system, consisting of blood, the heart, blood vessels, and the lymphatic system.

Heart

A muscular organ, about the size of your fist, located in the center of your chest, responsible for pumping blood throughout the body.

Right Atrium

Receives deoxygenated blood from the body.

Right Ventricle

Pumps deoxygenated blood to the lungs.

Left Atrium

Receives oxygenated blood from the lungs.

Left Ventricle

Pumps oxygenated blood to the body.

Valves

Separate the atria from the ventricles and keep blood flowing in one direction.

Pacemaker (Sinoatrial Node)

A group of cells in the right atrium that send out signals to the heart muscle to contract.

Deoxygenated Blood Loop

The flow of blood from the heart to the lungs and back to the heart.

Oxygenated Blood Loop

The flow of blood from the heart to the body and back to the heart.

Arteries

Strong, thick-walled blood vessels that carry oxygen-rich blood away from the heart.

Capillaries

Microscopic blood vessels where the exchange of substances and waste occurs.

Veins

Blood vessels that carry deoxygenated blood back to the heart.

Plasma

The fluid portion of blood, carrying digested food products, vitamins, minerals, and waste.

Red Blood Cells (RBCs)

Blood cells that carry oxygen to the body's cells, containing hemoglobin.

White Blood Cells (WBCs)

Blood cells that act as the body's disease fighters.

Platelets

Cell fragments important in forming blood clots by releasing chemicals to produce fibrin.

Blood Groups

Marker molecules attached to RBCs that determine blood type.

Heart Attack

Occurs when blood does not reach the heart muscle, damaging the heart.

Stroke

Occurs when a clot forms in blood vessels supplying oxygen to the brain, leading to brain cell death.

Pulse

Alternating expansion and relaxation of the artery wall due to left ventricle contractions.

Blood Pressure

The measure of pressure exerted against blood vessels.

Hypertension

Elevated blood pressure.

Hypotension

Low blood pressure.

Pharynx

The upper throat.

Epiglottis

A flap of tissue that covers the larynx to prevent food from entering.

Larynx

The voice box.

Trachea

A long tube connecting the outer and inner respiratory systems.

Bronchi

Branches of the trachea in the lungs.

Bronchioles

Smaller branches from each bronchus inside each lung.

Alveoli

Air sacs at the end of each bronchiole where gas exchange happens.

Lungs

Where gas exchange takes place.

Cilia

Lines the nose and air passages, trapping and sweeping away foreign materials.

Cellular Respiration

Process by which cells use oxygen and glucose to produce ATP.

Breathing

Mechanical movement of air into and out of the lungs.

Respiration

Process of gas exchange in the body.

Feedback Mechanism

Maintains homeostasis through an internal feedback system controlled by the nervous and endocrine systems.

Hormones

Substances that act on target cells to produce an action.

Gland

An organ that secretes hormones.

Endocrine Gland

Secretes hormones into the bloodstream.

Exocrine Gland

Secretes out of the bloodstream.

Steroid Hormone

Hormone made from lipids that easily pass through the plasma membrane.

Amino Hormone

Hormone made from protein.

Human Growth Hormone

Regulates body functions and helps cells grow.

Thyroxine

Regulates metabolism.

Calcitonin and Parathyroid Hormone

Regulates calcium.

Insulin

Lowers blood sugar.

Glucagon

Increases blood sugar.

Aldosterone

Reabsorbs sodium.

Cortisol

Raises blood glucose and treats inflammation.

Epinephrine (Adrenaline) and Norepinephrine

Increases heart rate, blood pressure, breathing rate, and blood sugar levels during stress.

Reproduction

Ensures the continuation of a species.

Gametes

Sex cells (sperm and egg).

Fertilization

The union of sperm and egg, creating a zygote.

Testes

Glands outside the body where sperm are produced.

Scrotum

The pouch containing the testes.

Sperm Cell

Male sex cell.

Epididymis

Structure on top of each testis where sperm mature and are stored.

Vas Deferens

Duct leading away from the testis.

Urethra

Tube that carries semen and urine outside the body.

Semen

Fluid containing sperm, nourishment, and other fluids.

Prostate

Gland contributing to semen.

Seminal Vesicles

Secrete sugar needed for energy and other nutrients for sperm.

Testosterone

Hormone necessary for sperm production.

Hypothalamus

Releases GnRH, which increases FSH & LH production.

Anterior Pituitary

Releases FSH and LH.

Puberty

Age at which secondary sex characteristics appear and sexual maturity is reached.

Oocyte

Immature eggs females are born with.

Ovum

Mature oocyte.

Ovaries

Secrete estrogen.

Fallopian Tubes (Oviduct)

Tubes connecting ovaries to uterus.

Uterus

Hollow muscular organ where embryos develop.

Cervix

The narrower opening of the uterus.

Vagina

Tube leading to the outside of the body.

Menstrual Cycle

Events preparing a female for pregnancy.

Flow Phase (Menstruation/Period)

Days 1-6 of the cycle, characterized by low estrogen levels and shedding of the endometrium.

Follicular Phase

Days 6-14 of the cycle, characterized by maturing follicles and a surge of LH.

Ovulation

Release of an ovum, typically around the 14th day.

Luteal Phase

Days 15-28 of the cycle, characterized by the corpus luteum and secretion of progestogen and estrogen.

Infectious Disease

A disease caused by a pathogen passed from one organism to another.

Pathogen

Agents that cause infectious diseases.

Germ Theory

States that some microorganisms are pathogens.

Koch's Postulates

Rules for demonstrating that an organism causes a disease.

Reservoir

A source of the pathogen in the environment.

Human Reservoir

Passing a pathogen from an infected person to another.

Asymptomatic

Someone who is a carrier but does not show any physical symptoms.

Animal Reservoirs

Pathogens from animals infect humans or other animals.

Other Reservoirs

Inanimate objects spreading disease.

Disease Patterns

CDC and WHO monitor these to help control spread.

Endemic

Small numbers of incidents continually found in a population.

Epidemic

A large outbreak in an area.

Pandemic

A widespread epidemic throughout a large region, country, continent or globe.

Antibiotic

Prescription drug that can kill or inhibit the growth of microorganisms.

Antivirals

Used to treat viral infections.

Antibiotic Resistance

Bacteria becoming resistant to drugs.