All posts by medical

Pharyngeal pouch (embryology) – Wikipedia, the free …

In the embryonic development of vertebrates, pharyngeal pouches form on the endodermal side between the pharyngeal arches. The pharyngeal grooves (or clefts) form the lateral ectodermal surface of the neck region to separate the arches.

The pouches line up with the clefts,[1] and these thin segments become gills in fish.

The endoderm lines the future auditory tube (Pharyngotympanic Eustachian tube), middle ear, mastoid antrum, and inner layer of the tympanic membrane.

Derivatives include:

The rest is here:

Pharyngeal pouch (embryology) - Wikipedia, the free ...

The Case Against Abortion: Medical Testimony

Page Summary: It is false to claim that no one knows when life begins and dishonest to argue that abortion does not kill a human being.

Every new life begins at conception. This is an irrefutable fact of biology. It is true for animals and true for humans. When considered alongside the law of biogenesisthat every species reproduces after its own kindwe can draw only one conclusion in regard to abortion. No matter what the circumstances of conception, no matter how far along in the pregnancy, abortion always ends the life of an individual human being. Every honest abortion advocate concedes this simple fact.

Faye Wattleton, the longest reigning president of the largest abortion provider in the United StatesPlanned Parenthoodargued as far back as 1997 that everyone already knows that abortion kills. She proclaims the following in an interview with Ms. Magazine:

I think we have deluded ourselves into believing that people don't know that abortion is killing. So any pretense that abortion is not killing is a signal of our ambivalence, a signal that we cannot say yes, it kills a fetus.1

On the other side of the pond, Ann Furedi, the chief executive of the largest independent abortion provider in the UK, said this in a 2008 debate:

We can accept that the embryo is a living thing in the fact that it has a beating heart, that it has its own genetic system within it.Its clearly human in the sense that its not a gerbil, and we can recognize that it is human life.2

Naomi Wolf, a prominent feminist author and abortion supporter, makes a similar concession when she writes:

Clinging to a rhetoric about abortion in which there is no life and no death, we entangle our beliefs in a series of self-delusions, fibs and evasions. And we risk becoming precisely what our critics charge us with being: callous, selfish and casually destructive men and women who share a cheapened view of human life...we need to contextualize the fight to defend abortion rights within a moral framework that admits that the death of a fetus is a real death.3

David Boonin, in his book, A Defense of Abortion, makes this startling admission:

In the top drawer of my desk, I keep [a picture of my son]. This picture was taken on September 7, 1993, 24 weeks before he was born. The sonogram image is murky, but it reveals clear enough a small head tilted back slightly, and an arm raised up and bent, with the hand pointing back toward the face and the thumb extended out toward the mouth. There is no doubt in my mind that this picture, too, shows [my son] at a very early stage in his physical development. And there is no question that the position I defend in this book entails that it would have been morally permissible to end his life at this point.4

Peter Singer, contemporary philosopher and public abortion advocate, joins the chorus in his book, Practical Ethics. He writes:

It is possible to give human being a precise meaning. We can use it as equivalent to member of the species Homo sapiens. Whether a being is a member of a given species is something that can be determined scientifically, by an examination of the nature of the chromosomes in the cells of living organisms. In this sense there is no doubt that from the first moments of its existence an embryo conceived from human sperm and eggs is a human being.5

Bernard Nathanson co-founded one of the most influential abortion advocacy groups in the world (NARAL) and once served as medical director for the largest abortion clinic in America. In 1974, he wrote an article for the New England Journal of Medicine in which he states, "There is no longer serious doubt in my mind that human life exists within the womb from the very onset of pregnancy..."6 Some years later, he would reiterate:

There is simply no doubt that even the early embryo is a human being. All its genetic coding and all its features are indisputably human. As to being, there is no doubt that it exists, is alive, is self-directed, and is not the the same being as the motherand is therefore a unified whole.7

Don't miss the significance of these acknowledgements. Prominent defenders of abortion rights publicly admit that abortion kills human beings. They are not saying that abortion is morally defensible because it doesn't kill a distinct human entity. They are admitting that abortion does kill a distinct human entity, but argue it is morally defensible anyway. We'll get to their arguments later, but the point here is this: There is simply no debate among honest, informed people that abortion kills distinctly human beings.

The problem is, Roe vs. Wade, the landmark 1973 verdict which legalized abortion in the U.S. is actually built on the claim that there's no way to say for certain whether or not abortion kills because no one can say for certain when life begins. Justice Harry Blackmun, who authored the majority opinion wrote:

The judiciary, at this point in the development of man's knowledge, is not in a position to... resolve the difficult question of when life begins... since those trained in the respective disciplines of medicine, philosophy, and theology are unable to arrive at any consensus.8

Justice Blackmun's assertion is a ridiculous one, at least as it applies to the field of medicine. Dr. Nathanson had this to say about the ruling:

Of course, I was pleased with Justice Harry Blackmun's abortion decisions, which were an unbelievably sweeping triumph for our cause, far broader than our 1970 victory in New York or the advances since then. I was pleased with Blackmun's conclusions, that is. I could not plumb the ethical or medical reasoning that had produced the conclusions. Our final victory had been propped up on a misreading of obstetrics, gynecology, and embryology, and that's a dangerous way to win.9

Dr. Nathanson would eventually abandon his support for elective abortion and note that "the basics [of prenatal development] were well-known to human embryology at the time the U.S. Supreme Court issued its 1973 rulings, even though the rulings made no use of them."9 In biological terms, life's beginning is a settled fact. Individual human life begins at fertilization, and there are all sorts of authoritative, public resources to prove this. Consider the evidence below:

"Human development begins at fertilization, the process during which a male gamete or sperm (spermatozoo developmentn) unites with a female gamete or oocyte (ovum) to form a single cell called a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual."

"A zygote is the beginning of a new human being (i.e., an embryo)."

Keith L. Moore, The Developing Human: Clinically Oriented Embryology, 7th edition. Philadelphia, PA: Saunders, 2003. pp. 16, 2.

"Development begins with fertilization, the process by which the male gamete, the sperm, and the femal gamete, the oocyte, unite to give rise to a zygote."

T.W. Sadler, Langman's Medical Embryology, 10th edition. Philadelphia, PA: Lippincott Williams & Wilkins, 2006. p. 11.

"[The zygote], formed by the union of an oocyte and a sperm, is the beginning of a new human being."

Keith L. Moore, Before We Are Born: Essentials of Embryology, 7th edition. Philadelphia, PA: Saunders, 2008. p. 2.

"Although life is a continuous process, fertilization (which, incidentally, is not a 'moment') is a critical landmark because, under ordinary circumstances, a new genetically distinct human organism is formed when the chromosomes of the male and female pronuclei blend in the oocyte."

Ronan O'Rahilly and Fabiola Mller, Human Embryology and Teratology, 3rd edition. New York: Wiley-Liss, 2001. p. 8.

"Human embryos begin development following the fusion of definitive male and female gametes during fertilization... This moment of zygote formation may be taken as the beginning or zero time point of embryonic development."

William J. Larsen, Essentials of Human Embryology. New York: Churchill Livingstone, 1998. pp. 1, 14.

"It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitues the culmination of the process of fertilization and marks the initiation of the life of a new individual."

Clark Edward Corliss, Patten's Human Embryology: Elements of Clinical Development. New York: McGraw Hill, 1976. p. 30.

"The term conception refers to the union of the male and female pronuclear elements of procreation from which a new living being develops."

"The zygote thus formed represents the beginning of a new life."

J.P. Greenhill and E.A. Friedman, Biological Principles and Modern Practice of Obstetrics. Philadelphia: W.B. Saunders, 1974. pp. 17, 23.

"Every time a sperm cell and ovum unite a new being is created which is alive and will continue to live unless its death is brought about by some specific condition."

E.L. Potter and J.M. Craig, Pathology of the Fetus and the Infant, 3rd edition. Chicago: Year Book Medical Publishers, 1975. p. vii.

"Every baby begins life within the tiny globe of the mother's egg... It is beautifully translucent and fragile and it encompasses the vital links in which life is carried from one generation to the next. Within this tiny sphere great events take place. When one of the father's sperm cells, like the ones gathered here around the egg, succeeds in penetrating the egg and becomes united with it, a new life can begin."

Geraldine Lux Flanagan, Beginning Life. New York: DK, 1996. p. 13.

"Biologically speaking, human development begins at fertilization."

The Biology of Prenatal Develpment, National Geographic, 2006.

"The two cells gradually and gracefully become one. This is the moment of conception, when an individual's unique set of DNA is created, a human signature that never existed before and will never be repeated."

In the Womb, National Geographic, 2005.

In 1981, a United States Senate judiciary subcommittee received the following testimony from a collection of medical experts (Subcommittee on Separation of Powers to Senate Judiciary Committee S-158, Report, 97th Congress, 1st Session, 1981):

"It is incorrect to say that biological data cannot be decisive...It is scientifically correct to say that an individual human life begins at conception."

Professor Micheline Matthews-Roth Harvard University Medical School

"I have learned from my earliest medical education that human life begins at the time of conception."

Dr. Alfred M. Bongioanni Professor of Pediatrics and Obstetrics, University of Pennsylvania

"After fertilization has taken place a new human being has come into being. [It] is no longer a matter of taste or opinion...it is plain experimental evidence. Each individual has a very neat beginning, at conception."

Dr. Jerome LeJeune Professor of Genetics, University of Descartes

"By all the criteria of modern molecular biology, life is present from the moment of conception."

Professor Hymie Gordon Mayo Clinic

"The beginning of a single human life is from a biological point of view a simple and straightforward matter the beginning is conception."

Dr. Watson A. Bowes University of Colorado Medical School

The official Senate report reached this conclusion:

Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human being - a being that is alive and is a member of the human species. There is overwhelming agreement on this point in countless medical, biological, and scientific writings.11

The American Medical Association (AMA) declared as far back as 1857 (referenced in the Roe. vs. Wade opinion) that "the independent and actual existence of the child before birth, as a living being is a matter of objective science. They deplored the popular ignorance...that the foetus is not alive till after the period of quickening.

Why have all the teaching texts and so many medical experts come to this same conclusion? Because there are simple ways to measure whether something is alive and whether something is human. If Faye Wattleton is correct and everyone already knows that abortion kills a human being, they have come to that knowledge in spite of the information circulated by Planned Parenthood and the rest of the abortion-rights community. The abortion section of the Planned Parenthood website explains abortion this way:

"Abortion is a safe and legal way for women to end pregnancy."12

Planned Parenthood either believes that the killing component of abortion is so obvious that it doesn't bear mentioning, or they are simply reinforcing a common and convenient misconception. Biologically speaking, abortion has nothing to do with potential human life. Every abortion at every point in the pregnancy ends the life of a genetically-distinct human being.

Footnotes

Even if an embryo is technically alive at fertilization, it's still just a clump of microscopic cells. Until the heart is beating or the brain is functioning, women should be free to have an abortion.

To learn our response, continue to the next page: Prenatal Development

Read the original:

The Case Against Abortion: Medical Testimony

The Biology Project: Cell Biology

Cell Membranes Learn that membranes are fluid, with components that move, change, and perform vital physiological roles as they allow cells to communicate with each other and their environment.

Cell Signaling Learn that living organisms constantly receive and interpret signals from their environment. Cells of multi-cellular organisms also receive signals from other cells, including signals for cell division and differentiation.

Studying Cells Introduce yourself to the cell as the fundamental unit of life and the scientific method.

The Cell Cycle & Mitosis Understand the events that occur in the cell cycle and the process of mitosis that divides the duplicated genetic material creating two identical daughter cells.

Meiosis Understand the events that occur in process of meiosis that takes place to produce our gametes.

Prokaryotes, Eukaryotes, & Viruses Learn about the cells that make up all living systems, their organelles, and the differences between living cells and viruses.

The Cytoskeleton Learn that the cytoskeleton acts both a muscle and a skeleton, and is responsible for cell movement, cytokinesis, and the organization of the organelles within the cell.

Overview of Cells including their makup and the differences between animal and plant cells (link courtesy of Carey Konarski)

CELLS Alive! is a highly visual site, where you will find movies and animated illustrations on cell processes, parasites, penicillin and more.

cell.de Online-Service for Cell Biology includes digital media in internet quality and further information for university and high school on cellular and molecular biology. The IWF - Institute for Scientific Film, Gttingen (Germany) prepares educational media about cellular and molecular biology didactically and technically for different media carriers.

C. elegans Movies A visual introduction to C. elegans and its development. This page has links to movies made by C. elegans researchers worldwide.

Biology Mad. This website is mainly aimed for students studying AQA (spec. A) Biology in the UK. It is informative, beautifully designed and easy to use.

http://www.actionbioscience.org is an education resource of the American Institute of Biological Sciences. The site provides peer-reviewed articles by scientists, science educators, and science students. In addition, the web site provides educators with original lessons and other resources to enhance bioscience teaching. Selected articles are translated into Spanish.

biochem4schools, is an online collection of biochemistry resources. With comprehensive reviews and extensive cross-referencing, this site will be an indispensable tool for teachers and students involved in biochemistry at all levels.

Continued here:

The Biology Project: Cell Biology

Cell Biology Content – CELLS alive

Cell Models- the structure of eukaryotic and prokaryotic cells

How Big is a ... ?- from dust mites to Ebola on the head of a pin

Mitosis- interactive animation of mitotic stages

Meiosis- interactive animation

The Cell Cycle- how mitosis fits into a cell's overall life cycle

Cell CAMS- see cancer cells and bacteria multiplying in real time

Pumping Myocytes- these heart cells got rhythm

Apoptosis- when a cell commits suicide

Quiz on Cell Biology- check your knowledge

Here is the original post:

Cell Biology Content - CELLS alive

Biological Cell Introduction – Biology Online

It only takes one biological cell to create an organism. In fact, there are countless species of single celled organisms, and indeed multi-cellular organisms like ourselves.

A single cell is able to keep itself functional by owning a series of 'miniature machines' known as organelles. The following list looks at some of these organelles and other characteristics typical of a fully functioning cell. The italic links for each lead to an extra description in the dictionary, as do all similar links in the tutorials;

Cells can become specialised to perform a particular function within an organism, usually as part of a larger tissue consisting of many of the same cells working in tandem, for example;

Cells combine their efforts in these tissue types to perform a common cause. The task of the specialised cell will determine in what way it is going to be specialised, because different cells are suited to different purposes, as illustrated in the above list and below example;

Many of these cells contain organelles, though after some cells are specialised, they do not possess particular characteristics as they do not require them to be there. i.e. efficiency is the key, no resources are wasted and the resources available are put to their idyllic optimum.

The cell membrane, otherwise known as the plasma membrane is a semi-permeable structure consisting mainly of phospholipid (fat) molecules and proteins. They are structured in a fluid mosaic model, where a double layer of phospholipid molecules provide a barrier accompanied by proteins.

It is present round the circumference of a cell to acts as a barrier, keeping foreign entities out the cell and its contents (like cytoplasm) firmly inside the cell.

The plasma membrane allows only selected materials to pass in and out of a cell, and is thus known as a selectively permeable membrane. There are a number of methods that allow the exchange of materials in and out the cell possible, mentioned below.

There are three methods in which ions are transported through the cell membrane into the cell,

In cells, sometimes it is required to breakdown more complex molecules into more simple molecules, which can then be 're-built' into what is needed by the body with these new raw materials.

'Pinocytosis' where to contents of a structure (such as bacteria) are drank, essentially by breaking down molecules into a drinkable form.

'Phagocytosis' where contents are 'eaten'. See cell defence for more information in regards to this.

Absorption is the uptake of materials from a cells' external environment. Secretion is the ejection of material.

This page is designed to give you an introductory overview of a single cell. The continuing cell biology tutorial elaborates on the concepts mentioned here, and will give you a fuller understanding of the biological cell at work.

Go here to read the rest:

Biological Cell Introduction - Biology Online

Biochemical Society – What is biochemistry?

Biochemistry is the branch of science that explores the chemical processes within and related to living organisms. It is a laboratory based science that brings together biology and chemistry. By using chemical knowledge and techniques, biochemists can understand and solve biological problems.

Biochemistry focuses on processes happening at a molecular level. It focuses on whats happening inside our cells, studying components like proteins, lipids and organelles. It also looks at how cells communicate with each other, for example during growth or fighting illness. Biochemists need to understand how the structure of a molecule relates to its function, allowing them to predict how molecules will interact.

Biochemistry covers a range of scientific disciplines, including genetics, microbiology, forensics, plant science and medicine. Because of its breadth, biochemistry is very important and advances in this field of science over the past 100 years have been staggering. Its a very exciting time to be part of this fascinating area of study.

What do biochemists do?

Provide new ideas and experiments to understand how life works

Support our understanding of health and disease

Contribute innovative information to the technology revolution

Work alongside chemists, physicists, healthcare professionals, policy makers, engineers and many more professionals

To find out more about careers in biochemistry read our booklets Biochemistry: the careers guide and Next Steps.

Visit link:

Biochemical Society - What is biochemistry?

Biochemistry (ACS Publications)

Your browser is currently set to not accept cookies. Please enable cookies in your web browser to continue.

For most browsers, the cookies settings are located under Preferences or Internet Options. The Help section of the toolbar may also explain how you can enable or disable cookies for all sites, or select the sites from which you will accept cookies.

This site uses cookies to improve performance by remembering that you are logged in when you go from page to page. Providing access without cookies would negatively impact the performance of this site.

Cookies are short pieces of data that are sent to your computer when you visit a website. This site only uses cookies to store automatically generated session IDs. No other information is captured.

For additional help, contact our support desk.

Continued here:

Biochemistry (ACS Publications)

biochemistry | science | Britannica.com

Alternative title: physiological chemistry

Biochemistry,study of the chemical substances and processes that occur in plants, animals, and microorganisms and of the changes they undergo during development and life. It deals with the chemistry of life, and as such it draws on the techniques of analytical, organic, and physical chemistry, as well as those of physiologists concerned with the molecular basis of vital processes. All chemical changes within the organismeither the degradation of substances, generally to gain necessary energy, or the buildup of complex molecules necessary for life processesare collectively termed metabolism. These chemical changes depend on the action of organic catalysts known as ... (100 of 5,651 words)

Read the original:

biochemistry | science | Britannica.com

Chem4Kids.com: Biochemistry

The key thing to remember is that biochemistry is the chemistry of the living world. Plants, animals, and single-celled organisms all use the same basic chemical compounds to live their lives. Biochemistry is not about the cells or the organisms. It's about the smallest parts of those organisms, the molecules. It's also about the cycles that create those biological compounds.

Every cycle has a place, and each one is just a small piece that helps an organism survive. In each cycle, molecules are used as reactants and then transformed into products. Life is one big network of activity where each piece relies on all of the others. A compound, such as an herbicide, may only break one part of one cycle in a plant. However, because everything needs to work together, the whole plant eventually dies.

We like biochemistry because we learn about things that are inside of us. We can relate to what happens when we eat and how our bodies are constructed. We can imagine how the molecules are moving around the mitochondria or chloroplasts, as opposed to chemical changes that make natural gas. If you choose a career in biology or chemistry, you will need to understand the information in both biochemistry and organic chemistry. Why? Because the movement of atoms in the bio-chem world follows the same rules you will learn in o-chem.

See the rest here:

Chem4Kids.com: Biochemistry

Gray, Henry. 1918. Anatomy of the Human Body

Select Search World Factbook Roget's Int'l Thesaurus Bartlett's Quotations Respectfully Quoted Fowler's King's English Strunk's Style Mencken's Language Cambridge History The King James Bible Oxford Shakespeare Gray's Anatomy Farmer's Cookbook Post's Etiquette Brewer's Phrase & Fable Bulfinch's Mythology Frazer's Golden Bough All Verse Anthologies Dickinson, E. Eliot, T.S. Frost, R. Hopkins, G.M. Keats, J. Lawrence, D.H. Masters, E.L. Sandburg, C. Sassoon, S. Whitman, W. Wordsworth, W. Yeats, W.B. All Nonfiction Harvard Classics American Essays Einstein's Relativity Grant, U.S. Roosevelt, T. Wells's History Presidential Inaugurals All Fiction Shelf of Fiction Ghost Stories Short Stories Shaw, G.B. Stein, G. Stevenson, R.L. Wells, H.G.

Original post:

Gray, Henry. 1918. Anatomy of the Human Body