Transport in Animals May 2012

The Importance of a Transport System Exchange materials with external environment Materials are  taken in  distributed around the body  waste produced removed  products are moved to various sites for use

The Importance of a Transport System Diffusion and Osmosis Surface area to volume ratio  large enough for small organisms E.g. protozoa, algae, flatworm  larger organisms have smaller sa-vr Distance between cells and external environment increases Diffusion therefore inefficient

The Importance of a Transport System Special absorptive surfaces  E.g. gills, lungs, alimentary canal, leaves and roots Distribution of materials rapidly through transport systems  Between cells and special absorptive structures  Between different parts of the body

The Importance of a Transport System Fluid medium Conducting structures Mechanisms for maintaining flow List the fluids that transport substances in  Plants  Animals List the conducting structures found in  Plants  Animals Describe the mechanisms for maintaining the flow of substances in  Plants  Animals

Substances transport systems carry Useful materials  Gases Respiratory surfaces to cells Plants – CO 2 from leaves and stems to photosynthesizing tissues  Nutrients Carbohydrates, amino acids, etc. from gut in animals and leaves in plants to the rest of the cells used for  respiration, growth and other metabolic processes  Hormones Produced in a particular site but used at another site They control processes such as growth, reproduction and the functioning of other systems  Other Substances Antibodies, blood proteins in animals

Substances transport systems carry Wastes  Products made during metabolic reactions in the organism that cannot be allowed to accumulate Carbon dioxide Nitrogenous materials  Plants produce insignificant amounts of nitrogenous waste Calcium oxalate and other substances Where are these products produced? What are the processes that produce them? Where do they go to to be eliminated?

Substances transport systems carry Harmful materials  Toxins  (Waste materials can also be classified as harmful) Heat  Active tissues Muscle cells, liver cells  Respiration by-product and other reactions  Enzyme activity effects  Temperature control

Small Organisms vs Larger Ones Small organisms exchange materials efficiently by diffusion. Why is this method not suitable for larger organisms? Small organisms have large SA/V ratios The diffusion distances involved are small Larger organisms have smaller SA/V ratio Greater diffusion distances are involved Diffusion is a slow process

Features of Absorptive Structures Gills, Lungs, Alimentary canal, etc. Have high SA/V ratio Are permeable to the substances which pass through them Are kept moist Have rich supplies of transport tissues (blood, etc.)

Transportation Medium In Plants  Cell sap  Water and mineral ions In Man  Blood

Transport system – tubes In Plants  Xylem  Phloem In Man  Veins  Arteries  Capillaries Draw diagrams to illustrate the structure of each tube listed above.

Transport Mechanisms In Plants  Transpiration Capillarity Root Pressure In Man  Heart

Circulatory System in Man Blood – transporting fluid  Components of Blood Cells  Red blood cells  White blood cells Platelets Plasma  Blood proteins  Water  Nutrients  Gases  Hormones  Waste

Circulatory System in Man Blood vessels – tubes carrying blood around the body  Arteries Carry blood FROM the heart to the tissues They branch into smaller arteries or arterioles  Capillaries Branch from the arterioles and penetrate tissues where they form a network  Veins Carry blood TO the heart from tissues around the body. Capillaries lead to small veins or venules which join to form larger veins

Differences in Structure and Function of Different Types of Blood Vessels ArteriesCapillariesVeins Blood carriedFrom the heart to the tissues To the tissues (between arteries and veins) To the heart from the tissues Pressure high Medium (decreasing) low Blood flow Rapid and smooth slow Gases Oxygenated Becoming deoxygenated (containing Carbon dioxide) Deoxygenated (contains Carbon Dioxide) Valves none present Position of vessels Deep within the body In the tissuesClose the surface

ArteriesCapillariesVeins Blood carriedAway from the heart To all the tissue (link arteries to veins) Towards the heart Pressurehighdecreasinglow Blood flowMoves in pulses and is rapid Movement is smooth and is slowing Moves slowly and smoothly GasesOxygenated blood (little carbon dioxide) Becoming deoxygenated (carbon dioxide level increasing) Deoxygenated (much carbon dioxide) ValvesNone present Valves present (stops back flow) Position of vessels Deep within the body To all tissuesClose to the body surface

Circulatory System in Man The Heart – a muscular pumping organ that keeps blood circulating throughout the body

Structure of the Mammalian Heart

The Chambers  4 chambers  Left side completely separate from Right side  No mixing of oxygenated and deoxygenated blood  Left side – oxygenated blood  Right side – deoxygenated blood  What are the names of the 4 chambers in the heart?

Structure of the Mammalian Heart The Valves  Valves separate the atriums (upper chambers) from their corresponding ventricles (lower chambers)  Maintain the flow of blood in a particular direction  Also found in veins

Structure of the Mammalian Heart Muscles  Cardiac muscle  Constantly contracting and relaxing  Without fatigue  Not like muscles in other parts of the body E.g. arms, legs  Contracts approx. 70 per min. Heart rate affected by a number of factors  List some factors that affect an individual’s heart rate  Infants and children have higher heart rates than adults. Explain why this occurs.  Men have higher heart rates than women. Explain.

Structure of the Mammalian Heart The walls of the atria (pl.) are less muscular than those of the ventricles. Explain The walls of the left ventricle are the most muscular. Explain (hint: Where does the blood go to from the left ventricle? Where does the blood go to from the right ventricle?)