The cell, the respiratory system, the organelles, gases, diffusion, active transport ...

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The cell is the basic unit of which they are made all living things. It is the smallest unit capable of performing all the functions that characterize a living being.

Depending on whether a body is formed by one or more cells can be:

Unicellular organisms. They consist of a single cell that performs all the functions necessary for survival. Sometimes, several single-celled organisms living together colonies. (like amoeba)

Multicellular organisms. Consist of multiple cells that lose the ability to survive alone. Each cell performs a specific task, and all work together to survive the body (such as plants and animals). Our body is composed of a large number of cells. People are multicellular beings.

The cells in our body can have different shape and size, and all of them are:

  • Cell membrane or plasma. It is a thin layer that surrounds the cell, and borders between it and the extracellular environment.
  • Cytoplasm. It is the content of the cell to delete the core. It consists of a solution of water in which they are offered a variety of structures, called organelles, which then carry out different functions.
  • Membrane. It is a structure which is spherical and is situated in the center of the cell. Contains the genetic material with the necessary information to direct and control cellular functions.


Mitochondria. They are oval-shaped organelles with a double membrane enclosing an interior space. Provides enrxia the cell for its operation.

Endoplasmic reticulum. It is a set of membranous sacs and ducts connected that extends throughout the cell cytoplasm. In lattice facrícanse various substances. There are two types:

  • Rough. With ribosomes stuck to the outside surface of the membrane.
  • Smooth. Without ribosomes stuck.

Vacuoles. Are membranous vesicles containing water with dissolved substances. Storing products reservation or debris.

Ribosomes. They are small particles that appear both free in the cytoplasm as traces membranes of the endoplasmic reticulum. It is responsible for making proteins.

Lysosome. Are membranous vesicles within which substances are transformed into other more complex task than the cell can use.

Cytoskeleton. It is a set of strings that are distributed throughout the cytoplasm, forming a network. They are the "skeleton" of the cell and involved in their movements.

Centriole. Are two hollow cylinders whose walls are formed by filaments. Directs the movement of the Cytoskeleton.

Golgi apparatus. It consists of piles of flattened membranous sacs, surrounded by small pockets in which empaquetan substances manufactured in the reticulum and often empty their contents into the extracellular environment. Its function is to secrección.

The cells of the human body, such as animals, plants, fungi and protists are eukaryotic cells. This means:

  • The nucleus is separated from the rest of the cytoplasm by a membrane that surrounds it.
  • The cytoplasm is divided into compartments, ie, consists of elements delimited by a membrane, which we call organelles.

The nucleus and the cell structure that best appreciates. Compared with other elements and large, and usually has a spherical shape and being in the center.

At the core can be distinguished:

  • Nuclear envelope. It is a double membrane pierced by pores that allow the exchange of substances between the nucleus and cytoplasm.
  • Nucleoplasm. It is the content of the core. It consists of a solution in which they are chromatin and nucleoli.
  • Chromatin. It consists of a set of very long filaments that are assembled inside the nucleus. Each strand consists of a DNA molecule that contains genetic information of the cell or inherited. Chromatin tinguese well with dyes. When a cell will divide to form two daughter cells, the chromatin strands contract and form a structure shorter and thicker called chromosomes. At the core of each cell of the human body there are 46 strands of DNA, forming 46 chromosomes, except the reproductive cells or payments which are 23
  • Nucleoli. Are the core areas in which they produce ribosomes. Its shape is spherical.

The plasma membrane has selective permeability, and is to overtake some substances and prevents the passage of others.

The smaller molecules cross the plasma membrane via two different mechanisms:

  • Dissemination. It is the mechanism by which some small molecules, such as oxygen or carbon dioxide, freely cross the plasma membrane. If these molecules have a lower concentration inside the cell than in the extracellular medium enter the cell, otherwise the molecules leave the cell and thus the concentrations on both sides of the membrane tend to igualarse.

Osmosis is a special form of diffusion. This is the diffusion of water through a membrane of a solution

diluted to a more concentrated. The concentrations for both sides tend to igualarse.

  • Active transport. Sometimes a cell needs to substances that exist in lower concentrations in the middle that extrcelular inside. In these, the membrane can transport substances through a process contrary to the disclosure, ie, from the place where their concentration and less to where it is greater. This transport represents an expenditure of energy for the cell.

The large particles can not cross the membrane to enter the cell. In the membrane sinks and includes the particle, forming a small pouch that is incorporated into the cytoplasm. This process is called endocytosis.

The opposite process, whereby the stock cell empty its contents to the outside is the exocytosis.

The set of chemical reactions that happen inside the cell metabolism constiúte

Distinguished two types of metabolic processes:
  • Catabolism. The set of reactions whose purpose is to degrade the complex molecules and transform it into simpler ones to release the energy they contain. The cellular respiration and an example catabolic.
  • Anabolism. The set of reactions whose goal is to build complex molecules from simpler ones. Use of the energy produced in catabolism. The production of proteins is one example.

The cells take care of those around them the substances necessary for metabolism and it expel the gas that is produced.

In unicellular organisms to their cell to perform these exchanges directly with the external environment. In a multicellular organism the vast majority of cells are not in direct contact with the external environment.

How to get the nutrients and expel waste?

Every cell in our body is surrounded by a liquid which carries the trade, the extracellular fluid constirue the internal environment. The different systems of our body are responsible for supplying nutrients to the internal environment and derive the waste.

In a multicellular organism, the number of cells increases by cell division. A cell divides and gives rise to two daughter cells. One aespecializase to do a special job and often loses the ability to divide. The other maintains its ability to divide and thus ensured the growth of the organism and cell renewal.

The changes in shape and within a specialized cell fana appropriate to perform a particular function.

The specialized cells of a multicellular organism are not able to live independently.

To better achieve the function of specialized cells of the same type are grouped and modern work together to form a tissue.

A tissue includes not only cells but also the substance that they themselves produce. This substance has filled the spaces between cells and intercellular substance is called.

A tissue is an aggregation of cells, usually of the same type, arranged to perform a common function.

The cells of our body are in one of four tissues: epithelial, connective, muscular and nervous. Within the connective tissue is distinguished in turn connective tissue, cartilage and bone.

The epithelial tissue or epithelium is covering both the external surface of the body, such as the inner and outer bodies. Its cells are arranged next to each other, not only with intercellular substances. There are two types of epithelia:

  • Epithelial covering. It consists of several layers of cells, such as skin, or by one, as the capillaries. The epithelium has a protective function.
  • Glandular epithelium. Forman specialized epithelial cells produce and secrete substances. These cells adoitanse cluster and form structures called glands, such as sebaceous glands, which produce fat loss.

Neural tissue forms the brain, spinal cord and nerves. Charge of gathering informaci'pon both the outside and the inside of the body and pass from one place to another body to develop appropriate responses in each case.

The main nerve cells are neurons, are star shaped with long extension. The space between neurons is occupied by glial cells, a set of cells that perform various support functions, protection and nutrition of neurons.

The connective tissues perform functions of marriage. Characterized because the cells are surrounded by abundant intercellular substance that has many fibers produced by the cells themselves.

  • Tissue. It is the material filling the body. You are in the deepest layer of skin and occupies the spaces between the organs. A special type of tissue and fat.
  • Cartilage tissue or cartilage. It is the main component of the skeleton of the embryos. In the adult is in the joints of the bones, trachea, nose, ears and intervertebral discs. Performs support functions.
  • Tissue. It is the essential component of bones of an adult. It is the strongest of the connective tissues, as the intercellular substance contains calcium salts, ie, the mineralized.

Muscle tissue is the main component of muscles and the head of the movement of different parts of the body. Their cells are elongated and are called muscle fibers. There are three types:

  • Striated muscle skeleton. Form the muscles that attach to bones and produce movement. Its contraction is voluntary.
  • Cardiac striated muscle tissue. Composes the thick walls of the heart. Unlike esqueléctico, its contraction is involuntary.
  • Smooth muscle tissue. Haine wall of the stomach, blood vessels, uterus or bladder. Its contraction is involuntary.

An organ is composed of two or more different tissues. The modern fabrics are grouped to perform a new function that each of them failed to meet separately.

A set of organs, whose activity is related closely to develop a complex function is a device, apparatus or system of organs.

In addition to the digestive system, other systems such as the circulatory, nervous, respiratory, which are in our body.

A body consists of organs and organ systems that work in a coordinated way.

Transplant is to replace a diseased organ, which endangers the life of a person (receiver) with one that works properly

It is not always necessary to replace the entire organ, sometimes enough to transplant the organ, tissue or cells.

A necetita a transplant recipient and a donor.

The donor is usually a person who is brain dead or brain death, ie a person who died but who remain artificially Day Next Day his heart for the transplant organs that are in good condition.

In some cases, the donor may be a person who remains alive after the donation. This can happen when the receiver needs to:

  • A tissue sources, such as skin, blood or bone marrow.
  • A portion of an organ that is capable of regeneration, such as the liver.
  • Prescindible an organ, such as the kidney, since a person can live with one.

It is essential that the donor and recipient are as comparable as possible, ie, they are compatible, otherwise it is the repudiation. The receiver tries to defend itself from foreign bodies and destroy it and reject may cause his own death. This defendeno our defenses

According to the relationship between the recipient and donor transplants are called:

  • Autograft or autograft. Donor and recipient are the same individual. It is used in case of tissues or parts of organs such as skin, bones, blood vessels or bone marrow.
  • Isotransplantations. Donor and recipient twins. When they are genetically identical, as in the case of autografts, do not take rejection ..
  • Tx. Donor and recipient are the same species, but are not genetically identical. This type of transplant and more common.
  • Xenotransplantation. Donor and recipient are of different species. An example of the use of pig heart valves in humans.

the alimntos q inxerimos axegan nutrients already indispnsabls q asta obtña the Mátria ennrxia ncsarias already fulfill its function and can rnovars.

the alimntos sn natural products oulavora2 q q proxcionan substances our daughter cells ncsitan already live.

types d substances composition kimica second terms:

  • inorganic: cm water and salsa minrais.
  • organic substances: the glici2 cm, oslipi2 the protina and vitamins.

second terms of their composition, the alimntos podn sr:

  • alimntos simple: Stan forma2 x 1 d so kind alimnticia substance. the acit, sugar ...
  • alimntos compounds: Stan forma2 x difrnts substances alimnticias. bread, lit.

shamans but not so typical of sn Mátria alive. sn two:

  • water. the most abundant compound in living and SRS mdio in q in qs dsnvolv the life of daughter cells.

Our body PRD water continuamnt and ncsita rpoñela with alimntacion. admais water bbmos q to2 the alimntos the contñen more or mnor mDida.

  • the salsa minrais: chlorides, carbonates, phosphates ... stan bone and the NCD Dany firmness. also ai salsa extinct in the to2 cm liki2 the body's blood, or sweat.

The organic constituents 2 alimntos sn:

  • glici2. the simplest cm glucose and maltose tñen flavor doc, so s x cm coñecn sugar. glucose and carbohydrate 1 q s not pod dscompoñer nurses more simple. the maltose sta formed by two Molecules 1ion d d glucose.

starch and clulsa q sn glici2 Complx not tñen flavor doc. its very large Molecules sn

product of many Molecules 1ion d d glucose.

  • lipi2 cm fats or colstrol. q sn substances not s disolvn nothing or very little in d source vxetal or unsaturated sn liki2 when stan tmpratura the environment and shamans acit. d the animal or saturated fats in butter cm sn soli2 and coñecns sbos cm.

1st molecule d fat pod dscompoñers into simpler substances: a glicrina and aci2 acids.

  • protina cm Emoglobina or gluten. sn macromolculas formed pala 1ion d cntnars d Molecules mils or more simply, the aminoaci2.

existn many protina difrnts. 1st protina difrncias of dmais in numri, the type and arrangement 2

aminoaci2 qa component.

  • Vitamins. sn q ncsitamos organic substances in quantities far pqnäs pro q sn imprscindibls already corrcto funcionamnto the body. cm podm fabricalas not take over the 2 alimntos q contñen.

alimntos the stan constitui2 pols msmos qo compounds our bodies as well as substances Complx 2 alimntos podn HRGC so our daughter cells and used srn s sn prviamnt transformed into simpler ones nutrients. sta transformation produces the sistma dixstivo.

the sistma dixstivo forman tube dixstivo and glands dixstivas.

tube dixstivo and 1 d brown conduct musculsas q will dnd the mouth to the anus.

part of the tube dixstivo
  • mouth. and 1st abrtura q Contner the NCD and language. NCD fit in the jaws and a sn matrial similar to bone, dntina, q eta by rcubrto Smalt. intrna its part, the pulp dntaria, Contner the trminacions nrviosas and blood vessels to nutrn q dntina. the language formed sta x potnts muscle and abundant rcptors of sntido taste.
  • pharynx. 1st joint cavity and the sistma dixstivo and rspiratorio.xla passes alimnto dnd the mouth to the Defroster and Air dnd the nose or mouth to the larynx.
  • Defroster. and conduct by qo alimnto avvanz dnd the pharynx to the stômago.
  • stômago. and 1 ensanxe tube dixstivo, shaped dune stock bent. its very brown tñen muscle potnts and when sta bleat tn numrosas folds q s to enxern dsaparcn. the entry of the dnd alimnto Defroster ACHIEVED through dua valve, the cardio. the other valve, op'ldoro communicates with intstino dlgado.
  • intstino dlgado. and 1 long tube, several prgado vcs q communicates with stômago intstino thick. part of intstino dlgado q sgue continued stômago already duodno dbid + aq and the SRS UMAN tn 1st length doc about D2.
  • intstino thick. 1 line and thicker than the intstino dlgado, to which wheel. PRT fundamntal tube du invrtido tn form and have + and Colon. in 1ion Colon with the sta intstino dlgado cgo, 1st bag which extrmo pxado LVA 1st thin extension xamada Appendix. communication with Colon Vehicles for Sale is made by rto, q rmati year.

glands dixstivas sn so organs encarga2 d produce zums dixstivos and vrtls the intrior tube dixstivo.

STS liki2 contñen 1st variety d substances between the enzyme dstacan q + sn digstivosq type 1 d q protina aclran the dscomposicion substances Complx donates alimntos in their componnts simpler nutrients.

glands dixstivas prsntans two for d +:

  • rpartidas the brown tube dixstivo. well acontceu with gastric glands of the pard and stômago intstinais of the pard intstino.
  • out of the tube dixstivo at qs xaman anxas glands. sn:

- Glands salivars. comprndn 3 pars d glands whose ducts dsmbocan in the intrior

mouth. producn saliva.

- Pancras. shaped gland d d frxa tip, located at the sqrda body of dbaixo

stômago. produces zum Pancrate and vrto to duodno.

the pancras admais d s zum ixstivos produces insulin. sta ormone VRTS dirctamnt blood

and the amount rgula q dglicosa Contner.

  • liver. gland and the larger sta drito the body next to stômago. produces bil QS ALMACN vsicula the gallbladder is the vrt duodno when traveling XL alimntos rich in fats.

the bil not Contner enzyme + digstivos pro ACHIEVED on fats 1 efcto in partial soap:

fragmntaas in pqnisi + QS drops mantñen disprsas. which facilitates the action 2 zums digstivos

on the fat.

The liver also ALMACN glici2, VEGETATION and some vitamins and helps the blood of Alimini

mdicamntos or toxic substances cm the alcohol.

digstion procs and the transformation d q exprimntan the alimntos its passage through the tube dixstivo. Mr. pod digstion mcanica or kimica.

digstion mcanica

includes 1 set d q rducn accions physical size of the particles and alimnticias fanas move along the tube. stas sn accions fundamntalmnt:

  • ground. ralizano NCDs in the mouth.
  • dgluticion. and the passage of alimnto dnd Defroster the mouth through the pharynx. the msmo tmpo the laring pxa already impdir qo alimnto pas ways rspiratorias.
  • movmnt: provoca2 Palas contracciions 2 muscle pard of the burrows dixstivo. sn:

- The mstura. put in contact with the particles d alimnto with zums digstivos.

- Pristalticos. alimnto are advancing along the tube.

dixstion kimica

is the transformation of macromolculas in pqnäs Molecules soluble nutrients. and 1 procs kimico aclrado pols enzyme + conta2 in zums digstivos. tn Time:

  • the mouth, saliva ond q Contner 1 enzyme xamado Amil, starts digstion 2 glici2.
  • the stômago, ond the alimnto s ALMACN is mstura with q producn zum gastric glands of the Pardo. st zum will Contner acid and 1 enzyme, ppsina, q indicates the digstion of protina.
  • the intstino dlgado, ond s complte the procs. the zums procdnts the pancreas and glands intstinais vrtns to duodno. STS zums contñen + cm enzyme lipase q dscompoñen fats, and other processing compltan q 2 glici2 and protina.

the alimntos convirtns nutrients during digstion. then passed into the blood and sn transxta2 until all daughter cells of the body.

The rsultado of digstion

the alimntos convirtns nutrients during digstion. then passed into the blood and sn transxta2 until all daughter cells of the body.

absorption intstinal

Step 2 nutrients dnd tube dixstivo blood sucd fundamntalmnt in RCIB intstino and the nom d absorption intstinal

  • most 2 organic nutrients absorbns in intstino dlgado. and 1 procs rlativamnt fast as its huge qa suprficie intrna facilitates contact between nutrients and pard q db across. sta great suprficie dbs to several factors:

- The great length of intstino dlgado

- The numrosas prgaduras face intrna its sta vz full infinity d pqnäs folds, the

vilsidads intstinais. stas vilsidads tnemos form d ddo and Dany 1 aspcto avludado.

  • most of the water and salsa minrais absorbns in intstino Vactra qo abitan the xamada flora intstinal, manufacture some vitamins DSpO q sn treated in Colon.

The formation of FECS

substances in alimntos existn q podm not digest and so absorbr. q aqls rstos could not Mr. dixeri2 or absorbi2 part of the FCS and sn expulsa2 the body through the years mdiant 1 mcanismo dnominado dfcacion.

the alimntos and diet

all d alimntos q we diariamnt is our diet.

diet ekilibriu eaq axega to2 types d nutrients in adequate amounts already mantra of our body in good stado and asguria 1 dsnvolvmnto corrcto.

function 2 alimntos

functions 2 alimntos sgun nutrients axegan q sn:

  • plastic function. utilñizas have been part of our own and so Mátria crcr or rpoñer the Matrio prdi2. ralizana the alimntos rich protina minrais or salsa.
  • enrxetica function. pounds enrxia and so podm ACHIEVED travay the muscle or mantra tmpratura the body, ralizana the alimntos with abundant glici2 or lipi2.
  • rguladora function. q to2 enable the procs q TNAN place in our body s dsnvolvan normally, ralizano the alimntos q proxcionan salsa minrais and vitamins.

wheel 2 alimntos

Consumers consguiron 1st ekilibriu diet, the groups distributed alimntos second terms the type d q axega nutrients and their function in the body. sta collation sctors knows cm 2 alimntos wheel.

Vrmyos groups (1 and 2) Contner alimntos rich protina qur dsmpñan functions arts.

Groups amarls, 6 (alimntos rich glici2), 7 (alimntos rich lipi2) cumprn 1st function enrgtica.

Groups VRDS (4 and 5) alimntos rich in vitamins and salsa minrais and cumprn functions rguladoras.

The orange group (3) comprnd alimntos with nutrients to2 x functions that ralizan plastic rguladoras and enrgticas.

diet mditrrana: 1st diet ekilibriu

RCIB the nom d diet mditrrana aqd traditional way in countries sgue s cm p, xtugal or Italy.

nla stan prsnts the sguints nutrients:

  • the glici2, bas dsta diet, sn axega2 x:

- The Crais cm rice and its driva2, bread and pasta.

- The lgumscm the lntyas or fixons.

- Fruits and vrduras.

  • protina procdn the more pixels q d meat.
  • the main uses and fat qs acit d olive.
  • the axega sncial d vitamins and salsa minrais PROCD also of fruits and vrduras frscas.

The factors most vnficiosos diet mditrrana sgun the exprtos sn:

  • most of enrxia axegada pols alimntos PROCD d glici2 Complx; lipi2 proxcionan so the 1st pqna quantity (prvn the obsidad).
  • between lipi2 prdominan front unsaturated fats saturated fats prvn enfrmdads diseases.
  • fruits and vrduras frscas along with lgums and Crais intgrais provides 1st adequate amount alimntaria d fiber, the prvn strinximnto.

mto2 d consrvacion 2 alimntos

  • the bleat: empaqtar the alimntos in rcipients the QS is drawn, the air q contñen.
  • dsidratacion: preliminary water from alimnto already impdir the dsnvolvmnto 2 microorganisms.
  • Heat:

- Mdiant strilizacion somts to alimntos the tmpraturas ENTR 110 and 120 c xaliminar to2


- The pastrurizacion consists qntar to 72 C for 15 sgun2 and DSpO arrfriar rapidamnt.

  • cold: the mantra alimntos at low tmpraturas, x Enriz c or d 0 x 0 c d dbaixo already imposibilitar the dsnvolvmnto 2 seed.
  • additives: impdir the d dsnvolvmnto microorganisms adding substances or additives kimicos artificiyas.

osistma rspiratorio and rsponsabl d FACR circulate air between the body and mdio extrno. ducts pols q circulates the air in sistma rspiratorio shamans way rspiratorias:

  • routes rspiratorias supriors include the nose, pharynx and larynx.
  • ways rspiratorias infriorsincluena TRAQ, the bronkios and bronkiols q rmatan in alvols.

the sistma rspiratorio sta formed by means rspiratorias and lungs, q stan aloxa2 thoracic cavity.

the prcorrido the air in sistma rspiratorio

  • nose and mouth. sn entry routes d d air. dnd there the air passes the pharynx, 1st joint cavity in sistma dixstivo. ds point from the air prcorr 1 way indpndnt to 2 alimntos.
  • laring. tn d funnel shape and their hard brown d apalpans cartilage in the antrior of pscozo. your intrior atopans the vocal cords, q vibrate to the passage of air and producn the NHS.
  • TRAQ. and 1 tube Flxible q smpr prmanc abrto pasp to the air.
  • lungs. sn situa2 two organs in the thoracic cavity and protxi2 by costlas. its shape and tapered and its bas, lixeiramnt concave support on the diaphragm.
  • bronkios and bronkiols. sn tubes like Traq QS branches.

sn inicialmnt two and donominans bronkios. the mDida q sw vz subdividn fans each thinner and

bronkiols shamans.

  • alvols lung. sn d brown balls pqnäs dlgadas located in the very final 2 bronkiols finest. Stan roda2 d d infinity blood capillaries.

xq are the Gasse?

one of the oxygen of the air contñen q avols across their brown and very fine hair 2 q the Rhone and passes into the blood. D carbon dioxide prcorr the other way around: dnd the blood passes to the intrior 2 avols.

2 avols the brown hair and 2 d intrvñen not actively crossing stds Gasse. the Gasse atravsan stas x brown spread, dnd ond place your concntracion and higher for ond place in stan mnor concntracion. x does not ai d intrcambio nitrogen, xq s obsrva equally concntracion in intrior 2 avols than in blood.

noa avols oxygen is dnd the air in the blood x simple diffusion, the carbon dioxide goes into d sntido invrso by msmo mcanismo.

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