TRANSPORT

Adaptations for Transport TRANSPORT: It is the process by which substances move into or out cells or are distributed within cells. In simple organisms no special system is needed to move materials within cells and between cells. In complex organisms many cells are far from the outside environment. These organisms need a special system called the circulatory system to transport materials to and from all parts of the organism.

Circulatory System A circulatory system is made up of three parts: 1.a fluid in which materials are transported 2.a network of tubes or body spaces through which the fluids flow 3.a means of driving the fluid through the tubes or spaces

Transport in Protists Protists are usually one-celled animals that have no circulatory systems. Diffusion and active transport are used to move materials into and out of the cell. Within the cell, the movement of the material is aided by cyclosis, the streaming of the cytoplasm.

Transport in Hydra

Hydra is a simple multicellular organism and has no circulatory system. The body wall of the hydra is composed of two layers of cells. By diffusion both cell layers can exchange dissolved oxygen, carbon dioxide, and wastes with their surroundings. Transport in Hydra

Planarian has no circulatory system. O 2 and CO 2 diffuse into and out of individual cells Transport in Planaria

Transport in Earthworm

Most of earthworm cells are not in direct contact with their surroundings. It is the circulatory system of the earthworm that makes possible the exchange of materials between its outside environment and its body cells. The blood carries dissolved nutrients, gases, wastes, water, and other substances. Transport in Earthworm

It is red because it contains the red, iron- containing pigment hemoglobin. Hemoglobin increases the amount of oxygen the blood can carry. The circulatory system of the earthworm is an example of a closed circulatory system. In closed circulatory system, the blood is always contained within tubes or vessels in the body. Transport in Earthworm

Transport in Grasshopper

The grasshopper has an open circulatory system. In an open circulatory system, the blood is not always enclosed in blood vessels. Instead it flows directly into body spaces where it bathes the tissues. The colorless blood of grasshopper (and other insects) does not contain hemoglobin and it does not transport oxygen and carbon dioxide. Transport in Grasshopper

The respiratory gases are transported through a series of tubes that are separate from the circulatory system. In the grasshopper the blood serves mainly to transport nutrients and nitrogen- containing wastes. Transport in Grasshopper

(a) open circulation e.g. mollusc, arthropods Types of Circulatory Systems

(b) closed circulation e.g. vertebrate, annelid, worms, squid Types of Circulatory Systems

OPEN CIRCULATORY SYSTEMCLOSED CIRCULATORY SYSTEM  blood moves slow  blood moves faster  blood flows in the body spaces (body sinuses), not always in vessels  blood flows always in the blood vessels  blood does not contain respiratory pigment  blood contains respiratory pigments (ex: hemoglobin)  blood does not carry O 2 and CO 2 but transports nutrients and nitrogenous – wastes  blood transports O 2, CO 2, nutrients and nitrogenous wastes  no blood capillaries  capillaries form between arterioles and venules  Ex: grasshopper  Ex: human, earthworm

Circulatory Systems in Vertebrates Vertebrates that use gills for respiration, such as fishes and larval amphibians ( e.g. tadpole ) have a single loop circulatory system. –Blood travels from the heart to the gills to the body and back to the heart. –The heart in fish is simple. It consists of two chambers: an atrium that recieves blood from the body and a ventricle that pumps the blood to the gills. –As the deoxygenated (oxygen-poor) blood passes through the gill capillaries, CO 2 diffuses out whereas O 2 diffuses into the blood. –Then the oxygenated blood (oxygen-rich blood) is directly transported to the body capillaries. The heart in fish always contains deoxygenated blood.

Vertebrates that use lungs for respiration ( frogs, reptiles, birds and mammals ) have a double-loop circulatory system. –The first loop carries the blood between the heart and the lungs. –Oxygen-poor blood from the heart is pumped to the lungs, oxygen-rich blood from the lungs returns to the heart. –The second loop carries blood between the heart and the body. Oxygen-rich blood from the heart is pumped to the body, oxygen-poor blood from the body returns to the heart. –During the course of vertebrate evolution, the heart developed chambers and partitions that help separate the blood travelling in the two loops of the circulatory system. Circulatory Systems in Vertebrates

In frog heart there are two atria and one ventricle. –This means the oxygen-rich and oxygen-poor blood cannot mix in the atria. –However, oxygen-rich and oxygen-poor blood can mix in the ventricle. –Thus, the concentration of oxygen in the blood travelling to the body is not as high as it could be. The oxygen-poor blood from the body enters the right atrium and the oxygen-rich blood from the lungs enters the left atrium. –Since there is only one ventricle, the blood mix up in the ventricle and from there the mixed blood is pumped to the body. Circulatory Systems in Vertebrates

Most reptiles have a three chambered heart consisting of 2 atria and 1 ventricle. But there is a partial partition in the ventricle. This partial partition minimises the mixing of oxygen-rich and oxygen-poor blood, but it does not completely eliminate it. In crocodiles the heart is completely partitions into four chambers: 2 atria and 2 ventricles. But in a canal, placed just at the leaving point of blood from the heart, oxygen-rich and oxygen- poor blood mix. (Türkçe’de bu kanal Panizza Kanalı olarak adlandırılır). Circulatory Systems in Vertebrates

In birds and mammals, the heart is four chambered: 2 atria and 2 ventricles. This means that the lung loop and the body loop of the circulatory system are completely separated: There is no mixing of oxygen-poor and oxygen-rich blood in the heart. The four chambered heart is sometimes described as double pump: –One pump moves blood through the lung loop. –The other pump moves blood through the body loop. Circulatory Systems in Vertebrates

THE HUMAN CIRCULATORY SYSTEM

Blood Vessels ARTERYCAPILLARIESVEIN Wall structure thickest epithelial tissue smooth muscle connective tissue thinnest epithelial tissue middle epithelial tissue smooth muscle connective tissue Direction of blood flow from heart to body between artery and vein from body to heart Velocity of blood highestslowestmiddle Blood pressure highestmiddlelowest

Blood Vessels Arteries and veins are distinguished by the direction in which they carry blood, not by the quality of the blood that they contain. Most of the arteries in human circulatory system carry oxygenated blood, whereas pulmonary artery carries deoxygenated blood. Also pulmonary vein carries oxygenated blood.

Factors Affecting the Flow of Blood in Veins  Contraction of skeletal muscles  Valves  Gravity  Pressure decrease at chest cavity  Smooth muscles on the walls of the vein  During diastole (relaxing of heart), pressure decrease in atria

Varicose Veins Varicose veins develop when one of the valves in a vein ruptures. This condition develops from poor blood flow in which blood accumulates in a vein and places so much weight on a closed valve that is ruptured. Varicose veins develop most often in surface veins, which are not surrounded by skeletal muscle in the legs, especially when a person sits or stands for long periods of time.

Varicose Veins