FUNCTIONS OF THE BLOOD

Blood circulation in human beings is double and complete. It is double because it has two circuits (general and pulmonary) and complete because the blood in the veins never mixes with the blood in the arteries. There are three kinds of blood vessels: arteries which go from the heart to the tissues, capillaries, minute vessels which are responsible for transporting the blood in the tissues, and veins that return the blood to the heart.

FUNCIONS:
1.Transports oxygen from the lungs to body tissues and transports the waste products of cellular metabolism and nutrients, hormones and enzymes.
2.Regulates blood clotting, body temperature, acid-base balance, water and electrolytes.
3.Protects against harmful organisms through white cells and antibodies.

RESPIRATORY SYSTEM

-- THE RESPIRATORI SYSTEM--

A respiratory system's function is to let gas exchange. The space between the alveoli and the capillaries, the anatomy or structure of the exchange system, and the precise physiological uses of the exchanged gases vary depending on the organism. In humans and other mammals, for example, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles. Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood.

TISSUES.

A tissue are a group of cells with a similar structure that do the same type of activity. Tissues are present in complex animal and plants. Sponges, jellyfish, algae, fungi do not have tissues.

ANIMAL TISSUES.
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covering>>Epithelial >>Protection>> Skin, blood vessels,interior of organs.
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Glandular>> Secretion>> Glands, glandular epithelium of the intestine.
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connectings>> Conjunctive>> Union>> All the body
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Adipose>>Reserve/insulation>> All the body
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Cartilaginous>> Skeleton >>ears, inter-vertebrate disc, tracheal rings...
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Bone Skeleton Skeleton
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Blood>> Transport>> All the body
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Muscular >>Smooth>>Movement>>Internal organs
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Striated>> Movement>> Skeletal Muscles
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Cardiac>> Movement>> Heart
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Nerve>> Information/responses>> Nervous system
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-Les cèl·lules, com altres éssers vius, fan activitat constant, el que els permet produir descendents. Duen a terme 3 funcions: nutrició, interacció i reproducció.

A traves de la nutrició les cèl·lules obtenen el material i energia que necessiten per formar la materia cel·lular i fer les activitats.

ANOTHER DIFFERENCE

·1.5 billion ago eucaryotic cells arose
·0.5 billion ago the cambrian explosion>> multi-celled eucaryotic arose
·3 million years ago our earliest ancestors, the hominids, appeared

There is strong data to suggest that eucaryotic cells actually evolved from groups of procaryotic cells that became interdependent on each other. You'll be learning more about this theory later.

PROCARYOTIC CELL & EUCARYOTIC CELL have in common:
·Both have DNA as their genetic material.
·Both are covered by a cell membrane.
·Both contain RNA.
·Both are made from the same basical chemicals (carbohydrates, proteins, nucleic acid, minerals, fats and vitamins.
·Both have ribosomes.
·Both regulate the flow on the nutrients and wastes that enter and leave them.
·Both have similar basic metabolism (life processes) like photosyntesis and reproduction.
·Both require a supply of energy.
·Both are highly regulated by elaborate sensing systems ('chemical noses') that make them aware of the reactions within them and the enviroment around them.

ANOTHER DIFFERENCES.
Scientists belive that procaryotic cells (in the form of bacteria) were the first life forms on earth. They are considered 'primitive' and originated about 3.5 billion years ago. That's 2 billion years earlier than eucaryotic cells and billion of years before our earliest ancestors, the hominids.
·4.6 billion years ago the Earth was formed.
·3.5 billion years ago the first life arose: procaryotic bacteria

Procaryotic & Eucaryotic cell

Procaryotic cell are a group of organisms that lack a cell nucleus, or any other membrane-bound organelles. The difference from the eucaryotic cell, which have a cell nucleus. Most are unicellular.

Eucaryotic cell are an organisms whose cells are organized into complex structures enclosed whitin membranes. The difference from the procaryotic cells is the nucleus.