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Introduction; Directional Terms; Body Cavities
Human anatomy is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross anatomy is the study of anatomical structures that can be seen by unaided vision. Microscopic anatomy is the study of minute anatomical structures assisted with microscopes, which includes histology (the study of the organization of tissues), and cytology (the study of cells). Anatomy, physiology (the study of function) and biochemistry (the study of the chemistry of living structures) are complementary basic medical sciences when applied to the human body. As such, these subjects are usually taught together (or in tandem) to students in the medical sciences. In some of its facets human anatomy is closely related to embryology, comparative anatomy and comparative embryology, through common roots in evolution; for example, much of the human body maintains the ancient segmental pattern that is present in all vertebrates with basic units being repeated, which is particularly obvious in the vertebral column and in the ribcage, and can be traced from very early embryos. The human body consists of biological systems, that consist of organs, that consist of tissues, that consist of cells and connective tissue.
Click here for the Levels of Body Organization: http://members.cox.net/tmccabe_2/SEASAND/bodysystemsorganization.ppt
What you will be learning in this human anatomy course is the names of locations and structures of the human body. It will be presented by organ systems. It will require a lot of memorization, visualization, imagination and time.
Anatomical Position
As a standard point or frame of reference, the human body is described as being in the anatomical position when it is standing erect, facing you, feet together flat on the floor, the arms slightly raised from the sides with the palms facing forward. Here is a list of useful directional terms. Know not only what they mean, but how to correctly use them.
Planes of Sectioning We will spend time studying not only the surface anatomy of many organs, but we will also have to look at the interior anatomy of many organs. For example, the brain has a lot of interesting internal anatomy. In order to see these internal structures we will have to cut, or section, the various organs or parts of the body. Now three dimensionally there would have to be three different directions, or planes, that we can cut something.
1:Coronal Section; 2:Transverse (Horizontal) Section; 3:Ventral (Anterior); 4:Dorsal (Posterior); 5:Midsagittal; 6:Proximal; 7:Distal; 8:Superior; 9:Inferior; 10:Medial; 11:Lateral
The first direction, or sectional plane, that we may use to cut a specimen could be to cut it in a horizontal plane. This type of cut would leave you with a top piece and a bottom piece. This type of section is called a transverse section or plane.
A different type of cut would be to cut, or section, a specimen in a vertical direction so that you are left with a front piece and a back piece. This type of section is called a coronal section or plane. For example, if you wanted to look at the interior structures of the brain and how their shapes vary as you move from front to back inside the brain, you would need to make a series of coronal sections to follow the changes in the shape of the internal structures.
The third direction that you may wish to cut a specimen, or the entire body, is to cut it into a right piece and a left piece. This type of section is called a sagittal section or plane. Now be careful, I think we all automatically think to cut something equally in half right down the middle, but a sagittal section does not always have to be right down the middle. To cut a specimen right down the middle producing equal right and left halves is called a midsagittal section. To section a specimen into right and left pieces that are not necessarily equal (on off-center cut in the sagittal plane) is to make a parasagittal section.
(a) Transverse Section
Remember, we are cutting up a organ or part of the body in order to better visualize the internal structures of that organ or area of the body. You will have to then use your imagination to visualize in your mind how it looks uncut.
1:Cranial; 2:Vertebral Canal; 3:Thoracic; 4:Abdominal; 5:Pelvic
Before we start in detail naming many of the parts and structures of the human body, we must first step back and view the body as a series of hollow cavities or compartments that hold different organ systems. For example, we have a hollow skull for the brain. We also have a hollow chest, or thoracic cavity for the heart and lungs. We have a hollow abdominal cavity for the intestines and digestive organs. There is also the pelvic cavity housing primarily the reproductive organs in the female. So hopefully you can agree that we do consist of many hollow compartments. Speaking of the abdominal and pelvic cavities, as you well know, the two cavities are right next to each other. The pelvic cavity below outlined by the pelvic bones while the abdominal cavity is directly above outlined by the muscles of the abdominal wall. Since there is not natural boundary between the pelvic cavity and the abdominal cavity (they are continuous), they are commonly referred to together as the abdominopelvic cavity.
So how do we place organs into these cavities and have them stay in place? Even trickier, how to we place an organ that is always moving, say the heart or the lungs or even your intestines, into one of these hollow cavities and keep it in place without firmly attaching it to the inside walls of the cavity since the organ needs to be able to move freely? Let's start with the heart as an example. If you imagine my closed fist as my heart, picture then a balloon right next to my 'fist/heart'. As I push my 'fist/heart' up against the balloon, one side of the balloon is in direct contact with my 'fist/heart' while the opposite side of the balloon is not touching my 'fist/heart'. As I continue to push my 'fist/heart' into the balloon, by 'fist/heart' will become completely surrounded by the balloon.
Yet the other side of the balloon is not touching my 'fist/heart', but is separated from it by the air in the balloon. Assume that the balloon is stick on the outside so that when I push my 'fist/heart' up against it farther and farther, the balloon sticks to my 'fist/heart'. If I hold the other side of the balloon with my other hand, my 'fist/heart' will not fall to the ground since it is stuck to the sticky surface of the balloon (remember, my 'fist/heart' is not suppost to be attached at the wrist). So now all I need to do is place this side of the balloon that is not in contact with the 'fist/heart' up inside my ribs and it will also stick. I've done it. My heart is free to beat and move, yet it won't fall down or wiggle loose since the other side of the balloon is attached to the insides of my ribs. Why this works so well is that it is just one single balloon. But one single balloon with two surfaces. One surface attached to the 'fist/heart' and the other surface attached to the insides of my ribs. This balloon is called the pericardium. Instead of the balloon being filled with air, it is filled with fluid, the pericardial fluid. Now the pericaridium can be named according to what surface you are talking about, the surface stuck to the heart or the surface stuck to the insides of the ribs. This is anatomy, so we give a name to each surface of the pericardium. The part of the pericardium that is stuck to the heart itself is called the visceral pericaridum while the other surface of the pericardium that is attached to the insides of the ribs is called the parietal pericardium. The pericardium has both the visceral portion and the parietal portion, but it is still one continuous balloon, one continuous membrane called the pericardium.
The four most abundant atoms in you and I are: carbon; nitrogen; oxygen and hydrogen. Carbon will always form 4 colavent bonds and so will always be drawn with four lines connected to it. Nitrogen will form three covalent bonds and so have three lines connected to it. Oxygen will form two covalent bonds and so have two lines drawn to it. And hydrogen forms one covalent bond so it will have one line connected to it. For example: water, H 2 O, H-O-H.
Stringing together atoms is how you form molecules. The four most abundant molecules in you and I are: proteins (strings of amino acids); carbohydrates = sugars = polysaccharides; triglycerides = fats = lipids; and nucleic acids (DNA and RNA).
Where we came from: Embryology: Day 1 Lecture The following diagrams on embryonic development supplement the brief lecture material on development. You do not need to memorize everything in these diagrams. You are only responsible for whatever is discussed in class and so only need to know the terms appearing in these diagrams that you have in your class notes from lecture.
medium sized charged substances (including ions) that cannot cross the lipid bilayer without help. Macromolecules, such as proteins, cannot pass through the plasma membrane except by endocytosis and exocytosis.
Intracellular fluid = fluid within cells; or another more common term for this fluid is the cytosol. Extracellular fluid = fluid outside cells. -Interstitial fluid: the extracellular fluid in between cells -Plasma: the extracellular fluid found in the blood vessels
Passive movement across a plasma membrane (a phospholipid bilayer) required no ATP and involves diffusion, the movement of molecules from areas of high concentration to areas of low concentration. The three types of passive movement were discussed in class. They were Simple Diffusion; Facilitated Diffusion; and Osmosis.
Active transport mechanisms require ATP energy, generally to move molecules against their concentration gradient (to move molecules from areas of low concentration to areas of high concentration).
Endocytosis is the uptake by a cell of material from the environment by invagination of its plasma membrane; it includes both phagocytosis and pinocytosis. It is a process by which substances are taken into the cell. When the cell membrane comes into contact with a suitable food, a portion of the cell cytoplasm surges forward to meet and surround the material and a depression forms within the cell wall. The depression deepens and the movement of the cytoplasm continues until the food is completely engulfed in a pocket called a vesicle. The vesicle then drifts further into the body of the cell where it meets and fuses with a lysosome, a vesicle normally found in the cell that contains digestive enzymes. The food is then broken down into molecules and ions that are suitable for the cell's use. There are two types of endocytosis: pinocytosis, the engulfing and digestion of dissolved substances, and phagocytosis, the engulfing and digestion of microscopically visible particles.
Exocytosis is a process in which an intracellular vesicle (membrane bounded sphere) moves to the plasma membrane and subsequent fusion of the vesicular membrane and plasma membrane ensues.
exocytosis Transport of substances out of a cell in vesicles
facilitated
diffusion
Diffusion in which carrier molecules transport substances across membranes from a region of higher concentration to an area of lower concentration
Golgi apparatus An organelle that prepares cellular products for secretion
lysosome organelle that contains digestive enzymes
mitochondrion Organelle housing enzymes that catalyze the reactions of aerobic respiration.
mitosis Division of a somatic cell to form two genetically identical cells
nucleolus Small structure within cell nucleus that contains RNA and proteins
nucleus
Cellular organelle enclosed by double layered membrane and containing DNA; dense core of atom composed of protons and neutrons
organelle Part of a cell that performs a specific function
osmosis
Diffusion of water through a selectively permeable membrane in response to a concentration gradient
phagocytosis Process by which a cell engulfs and digests solid substances; cell eating
pinocytosis Process by which cell engulfs droplets from its surroundings; cell drinking
ribosome Organelle composed of RNA and protein that is a structural support for protein synthesis
selectively permeable Describes membrane that allows some molecules through but not others; semipermeable
vesicle Membranous cytoplasmic sac formed by infolding of the cell membrane
http://publications.nigms.nih.gov/insidethecell/
An Owner's Guide to the Cell By Alisa Zapp
Machalek
A typical animal cell, sliced open to reveal cross-sections of organelles.
