Circulatory and Respiratory Systems in Vertebrates

ReViTaLise

Mnemonic for blood flow from right ventricle to lungs.

Right Ventricle

Pumps blood to lungs via pulmonary arteries.

Left Ventricle

Pumps oxygen-rich blood to body via aorta.

Unicellular Organisms

Exchange materials directly with environment via diffusion.

Diffusion

Net movement of substances across plasma membrane.

Gastrovascular Cavity

Distributes substances and aids digestion in Cnidarians.

Circulatory System Components

Includes fluid, vessels, and muscular pump (heart).

Circulatory Fluid

Fluid that circulates through the circulatory system.

Open Circulatory System

Haemolymph bathes body cells as interstitial fluid.

Closed Circulatory System

Blood confined to vessels, distinct from interstitial fluid.

Cardiovascular System

Heart and blood vessels in vertebrates.

Arteries

Carry blood away from the heart.

Arterioles

Smaller vessels branching from arteries.

Capillaries

Microscopic vessels with thin, porous walls.

Capillary Beds

Networks of capillaries infiltrating tissues.

Venules

Small vessels that converge into veins.

Veins

Carry blood back to the heart.

Single Circulation

Blood passes through two capillary beds before returning.

Double Circulation

Two circuits of blood flow in amphibians, reptiles, mammals.

Pulmonary Circuit

Right heart pumps oxygen-poor blood to gas exchange tissues.

Intermittent Breathers

Amphibians that breathe periodically, using skin for gas exchange.

Atrioventricular (AV) Valve

Valves between atria and ventricles.

Semilunar Valves

Valves at exits of heart to pulmonary artery and aorta.

Heart Murmur

Abnormal sound from blood squirting backwards through defective valve.

Sinoatrial (SA) Node

Pacemaker cells in right atrium setting heart contraction rate.

Endothelium

Single layer lining blood vessels, minimizing fluid flow resistance.

Lumen

Central cavity of blood vessels.

Capillary Diameter

Slightly greater than that of a red blood cell.

Smooth Muscle

Muscle tissue regulating vessel diameter.

Elastic Fibres

Fibres allowing vessel stretching and recoiling.

Collagen

Protein providing strength to vessel walls.

Ventricular Contraction

Heart muscle contraction generating blood pressure.

Diastole

Heart phase when ventricles relax.

Diastolic Pressure

Blood pressure during heart relaxation.

Vasoconstriction

Narrowing of arterioles increasing blood pressure.

Vasodilation

Widening of arterioles decreasing blood pressure.

Precapillary Sphincters

Muscle rings regulating blood flow to capillaries.

Erythrocytes

Red blood cells transporting oxygen.

Leucocytes

White blood cells involved in defense.

Platelets

Cell fragments aiding in blood clotting.

Sickle-Cell Disease

Condition causing abnormal hemoglobin shape.

Atherosclerosis

Hardening of arteries due to fatty deposits.

Gas Exchange

O2 uptake and CO2 discharge process.

Partial Pressure

Pressure exerted by a specific gas.

Ventilation

Movement of respiratory medium over exchange surfaces.

Atmospheric Pressure

Pressure exerted by the atmosphere at sea level.

PO2

Partial pressure of oxygen in gas mixtures.

Gill ventilation

Movement of gills or water for breathing.

Alveoli

Air sacs in lungs for gas exchange.

Parabronchi

Channels in bird lungs for air flow.

Negative pressure breathing

Air pulled into lungs by diaphragm.

Medulla oblongata

Brain region regulating breathing rhythm.

Respiratory pigments

Proteins binding O2 for transport in blood.

Isoosmotic

Two solutions with equal osmolarity.

Hyperosmotic

Solution with higher solute concentration.

Hypoosmotic

Solution with lower solute concentration.

Osmoconformer

Animal isoosmotic with its environment.

Osmoregulator

Animal controlling internal osmolarity independently.

Stenohaline

Animals intolerant to osmolarity changes.

Euryhaline

Animals surviving large osmolarity fluctuations.

Marine bony fishes

Fish losing water, balancing by drinking seawater.

Shark osmoregulation

Sharks maintain lower salt concentration than seawater.

Trimethylamine oxide (TMAO)

Organic molecule aiding shark osmoregulation.

Freshwater animals

Must be hyperosmotic to survive in water.

Dilute urine

Excretion method for freshwater animals.

Euryhaline fish examples

Salmon and long-finned eel adapt to environments.

Gas exchange surface in birds

Air flows unidirectionally over lung surfaces.

Breathing control centers

Neural circuits in medulla for rhythm regulation.

Water balance in osmoregulators

Discharge or intake water based on environment.

Osmoregulation in salmon

Changes between freshwater and saltwater environments.

Cortisol

Steroid hormone aiding in salt secretion during migration.

Osmoregulation

Maintaining water and salt balance in organisms.

Metabolic Rate

Osmoregulation accounts for 5% of fishes' resting rate.

Ammonia Excretion

Common in aquatic species needing large water access.

Urea Excretion

Less toxic nitrogenous waste, requires energy to produce.

Uric Acid Excretion

Primary waste for insects, snails, and reptiles.

Protonephridia

Excretory system in Platyhelminthes with dead-end tubules.

Aerobic Respiration

Process of using oxygen to produce energy.

Cellular Metabolism

O2 consumption in mitochondria producing ATP and CO2.

Diffusion Rate

Rate of oxygen movement expressed as Ko2 .A . ΔP/d.

Cutaneous Diffusion

Gas exchange through skin, seen in flatworms.

Circulatory System

Transport system for gases between respiratory organs.

Oxygen Content in Air

Air at 20°C contains 260 mg/L of oxygen.

Oxygen Content in Water

Freshwater at 20°C contains 9.1 mg/L of oxygen.

Surface Area to Volume Ratio

Larger animals have smaller ratios affecting respiration.

Gills

Thin outgrowths for gas exchange in aquatic animals.

External Gills

Gills ventilated externally and perfused with blood.

Internal Gills

Gills located inside the body for gas exchange.

High Altitude Adaptation

Frogs use gills and circulatory systems for oxygen.

Energy Cost of Urea

Energy required to convert ammonia into urea.

Salt-Secreting Cells

Specialized cells increased by cortisol during migration.

Passive Ventilation

Ventilation without energy expenditure, relies on natural processes.

Active Ventilation

Ventilation requiring energy to move air or water.

Lugworms

Burrowing polychaetes with afferent and efferent vessels.

Water 'Lungs'

Cavity ventilated by tidal movement of water.

Tidal Ventilation

Air enters and exits lungs through same pathway.

Energetic Cost of Ventilation

Ventilation requires significant energy expenditure.

Molluscs

Organisms with internal gills ventilated by cilia.

Crayfish Gill Bailer

Pumps water unidirectionally over enclosed gills.

Diffusion Factors in Crustaceans

Includes surface area and thin cuticle for gas exchange.