Multicellular systems[1]

The Human Body

Digestion[2]-a one way track-food enters the mouth where it is chewed (teeth) and moved down the “pipe” with the help of the tongue. It then enters the esophagus and pushed down it by muscular contractions (called peristalsis). From there it enters the stomach-broken down there by chemicals and then pushed into the small intestines where it is absorbed into the walls of the small intestine by the way of tiny villi which line the wall of the small intestine. It is then transported to the body and all wastes are collected in the large intestine and pushed out in excretion.

Respiration[3]-a process which supplies oxygen needed for the cells to produce energy from the nutrients (called cell respiration) it’s absorbed and then gets rid of the bad carbon dioxide of the body which is a by-product of the cell respiration. The air enters the mouth and nose and heads down to the lungs which transfer the air and carbon dioxide from the body.

Circulation[4]-carries digested food, oxygen, and water to body through the blood stream (ki hadam ho hanefesh). It also carries wastes and carbon dioxide out of the body. It also carries hormones (chemical messengers) and (antibodies) to protect the body from attack. The human circulatory system includes the heart blood vessels and blood.

Excretion[5]-removal of wastes from the body. This includes sweating as well. The parts of this system are the lungs, kidneys, sweat glands in the skin.

Movement-involves both muscular and skeletal which provide movement and support for the body.

Coordination[6]-the nervous system and the endocrine system coordinate all the various systems of the body. They do this by either sending electrical pulses throughout the body or by sending chemical messages to the cells to start or stop a process. The Brain and the nerves are part of the nervous system while the glands such as the pancreas, testes and ovaries are part of the endocrine system.

Immunity[7]-allows the body to protect itself against disease. This system includes white blood cells and antibodies which protect against attack

Reproduction-allows the continuation of the species through the mingling of the two parents genes. This process is called Reproduction.

Interactions between various systems[8]-

For ex.-the nutrients from the digestive system and oxygen from the repository system are transported through the circulatory system, the reproductive system is regulated by the hormones of the endocrine system.

Body systems maintain homeostasis[9]-when cold the body shivers which is controlled by the nervous system, hormones are released when blood sugar levels fall to low.

Humans and other organisms-comparisons and contrasts[10]-

Comparisons-are generally made up of the four main elements mentioned in lesson one, have similar cells-blood, nerves muscle etc. organ systems are very similar-digestive systems and circulatory systems of pigs very similar to humans, reproduction similar and finally similar in that we all have DNA.


[1] See the Shulchan Aruch-OC 6:1 where it begins-the body is an unbelievably complex creation! See the Aruch Hashulchan (OC 6:1) that the Beracha of Asher Yatzar is a Beracha on the wonderful science of the body which the Ribono Shel Olam created and see how he taichis the Rama in siman 5 who says that one can make asher yatzar even if he didn’t make-because the beracha is going on the etzem briah.

[2] see the many gemaros in traifos about the esophagus (veshet see the Gemara in berachos 61a that the esophagus is machnis and motzi food-digestion!), the stomach (keres-see Rash”I on Keres in Berachos 61b that says that the kurkivan is the same thing as the hemsis in a behama and that job is to grind up the food), peristalsis-see the levush (OC 6:1) that says the pshat in bichaochma of asher yatzar is going on the koach hamoshaich-peristalsis of the food, the small intestines (bnai mayim-or dakin-see the levush previously who also says so-koach hamiachel-taking the good from the food see Aruch hashulchan 6:3 who says so bifarush) and the large intestines (Chalcholis-see YD 46:5 where it says that it’s the source of feces and that the body processes the good and lets the body go-see OC 6:1 which the Mechaber says so bifarush at the end, also see Aruch hashulchan (6:4) also specifically) which shows that they clearly understood the differences between them and the way the system works.

See the Aruch Hashulchan (OC 6:5) where he quotes and interprets the Magen Avraham who explains the Rama that mafli lassos is going on food which provides Ruchniyus and Gashmiyus nourishment for the body and without food-no life.

[3] see the Gemara in Berachos daf 61b where it says that the lungs absorb all types of liquids-this could mean that the lungs gather all the blood in the body and take out the bad and put in the good. The nose and mouth are the source of life as the pasuk says in Biraishis –vaypach biapuv nishmas chaim which means the nishama is in the breath.

See the Halacha in OC 329:4 where it says that one checks if a person is alive by his breathing-that means Chaza”l understood that the body needs Oxygen and if a person is not breathing he’s dead. Also see the Gemara in Chullin 32b that says that the life of the lungs is talui in the windpipe-clearly showing they understood the function of the lungs

[4] see the pasuk-ki hadam ho hanefesh-which means that the Torah understood the idea that the life of a person is in his blood-food, oxygen waste and therefore one cannot eat it since it represents the chmriyos of a person and a person should not indulge in chumriyos-Rav Hirsch ()

Hormones are the Yetzer hara since they are found in the blood and that’s why Chaza”l say that the yetzer hara is in the laiv-since the heart pumps the hormones which push people to do averos. That’s why Chaza”l say that when a person is young they say his blood is hot-meaning his blood which is pumped with all types of hormones can cause him to do averos.

[5] see digestion and the Yerushalmi in trumos (8:3) says all sweat except for the face is poison-meaning that it contains ureic acids which are dangerous to the body (why face not-I don’t know).

See OC 6:1 a detailed description of the niflaos of the excretory system and that Chaza”l made a beracha to say which details the genius of the excretaory system and its need.

[6] see YD 32 which says that if the spinal chord is broken then it’s a traifa.

Endocrine system-see circulation and hormones

[7] see YD 57 where there is a discussion of the source of drusa which means an infection that can potentially kill-which means they had an idea of infection and disease.  See the MB in 576:9 where he qoutes the Gemara that diseases travel with humans and see that siman which documents the idea of a machla hamisdabekes-a contagious disease.

See the MB in 576:14 where he qoutes the Shla”h that when there is Smallpox breaking out in kids or Measels or mumps one should run away with his kids because the disease is contagious. (also see the Rama in YD 116: 5) which also says so and see there the Shac”h SK 5) We see that Chaza”l and the Gedolim had an understanding of the bodily system. Also see the Shulchan aruch YD 116:4 about not putting money into ones mouth because of germs on the money (also see the Shac”h there (SK 3) in the name of the Ran who also says something similar)

[8] see the Rama 6:1 that taichis-mafli laasos-that the Ribono Shel Olam connects the Ruchniyus and Gashmiyus in one body-the brain and the body-the nervous system and the body.

See the Gemara in Zevachim 26a where the Gemara says that if animal sticks a leg out of the azara bishas shechita the animal is pasul for a Korban. The Gemara in the maskana asks why? The Gemara answers because there is shamnunis that went out of the Bais Hamikdash. Asks the Chofetz Chaim in Likutai halachos their in the Zevach Toda-why is it a problem-why don’t we say that the little shamnunis is batul to the majority of blood. He leaves the question unanswered. The Chazon Yechezkel on Zevachim answers that since the blood and fats interact in the blood, and they flow together which influence’s each others characteristic’s that’s why the Gemara says that the Shamnunis pasul’s with Yotzai. We see that Chazal understood a deep level of interactions between fats-lipids and blood –that the fats in the legs are constantly passing the fats in and out of the bloodstream that’s why it’s a problem and not batul!

[9] See the gemara in Berachos (57b) that sweating is a good sign for a Choleh-that is so since the body is getting rid of the excess heat produced by the inflamed immune system getting back to normal

[10] See the gemara in Berachos (57b) that sweating is a good sign for a Choleh-that is so since the body is getting rid of the excess heat produced by the inflamed immune system getting back to normal