Foundations of Anatomy and Physiology

Unit 3
Anatomy
 Anatomical Position
▪ Anatomical position – a common
visual reference point, it is
important to understand this
position because most medical
body terminology uses this
position as a reference point.
▪ Person stands erect with feet
together and eyes forward
▪ Palms face anteriorly with the
thumbs pointed away from
the body
Directional Terms

Enables medical personnel and

anatomists to describe
precisely where the body
structure is in relation to
another.
Directional Terms
Superior – toward the head
Inferior ---towards the feet
Anterior – toward the front
Posterior --toward the back
Medial – toward themidline
Lateral --away from the midline
Intermediate --between a more medial and lateralstructure
Proximal – near the trunk
Distal – away from the trunk
Superficial – toward the body surface
Deep – away from the bodysurface
Body
Planes
Body Planes

Sagittal – divides the body into right and left parts

Midsagittal or medial – sagittal planethat lies on the
midline
Frontal or coronal – divides the bodyinto anterior
and posteriorparts
Transverse or horizontal (cross section) – divides the
body into superior and inferior parts
Oblique section – cuts made diagonally
Body Planes
Body Cavities

Figure 1.9a
Body Cavities
Dorsal cavity protects thenervous system, and is divided
into twosubdivisions
Cranial cavity is within the skull and encases the brain
Vertebral cavity runs within the vertebral column and encases
the spinalcord
Ventral cavity houses the internal organs (viscera), and is
divided into two subdivisions: - Thoracic and
Abdominopelvic cavities
Body Cavities
Body Cavities
Thoracic cavity is subdivided into pleural
cavities, the mediastinum, and the
pericardial cavity
Pleural cavities – each houses alung
Mediastinum – contains thepericardial cavity,
and surrounds the remaining thoracic organs
Pericardial cavity – encloses the heart
Body Cavities
The abdominopelvic cavity is separated from the
superior thoracic cavity bythe dome-shaped
diaphragm.
It is composed of two subdivisions
Abdominal cavity – contains the stomach, intestines,
spleen, liver, and other organs
Pelvic cavity – lies within the pelvis and contains the
bladder, reproductive organs, and rectum
Ventral Body Cavity Membranes
Serosa (also called serous membrane) covers the walls of
the ventral body cavity and outer covering of its organs. It
is a double-layered membrane made up of two parts
called the “parietal serosa” (lines the cavity walls) and
“visceral serosa” (covers organs in the cavity). A thin layer
of fluid called “serous fluid” separates the serous
membranes.
Serous fluid is secreted by both membranes and acts as a
lubricant, allowing organs to slide in the cavity without
causing friction.
•Typically, the serous membranes are named according to
the cavity and organ they associate with. For example,
the parietal pericardium lines the pericardial cavity.
Ventral Body Cavity Membranes
 Other Body Cavities

Oral cavity – mouth, contains teeth and

gums
Nasal cavity -part of the respiratory
system
Orbital cavities – house the eyes
Middle ear cavities – carved into the skull
Synovial cavities -surround freely movable
joints and secrete a lubricating fluid like
serous membranes
Abdominal Regions and Quadrants
•Abdominal regions- divide the abdomen
into nineregions
Abdominal Quadrants

Abdominal quadrants divide the

abdomen intofour quadrants
• Right upper and left upper
quadrants
• Right lower and left lower
quadrants
Chemistry
Basic Chemistry
Matter
•Matter is anything that occupies space andhas
mass.
•Some matter is easy to see, smell andfeel.
•Matter exist in threestates, Solid, Liquid and Gas
StatesOf Matter
The three states of matter can be found in different
examples in the body.
STATE EXAMPLE SHAPE VOLUME

Solid Bones, teeth yes yes

Conformto
yes
Liquid Blood plasma, interstitial shape of
container
fluid

Gas Air Not definite Not definite

 Distinguishing Matter
Physical and chemical properties can tellthe difference between samples of matter.
Physical property: no alteration to the basic nature of the substance composition
Chemical property: alteration of the composition to the substance
When iron rusts, it must react and
At the boiling point, water is converted to
incorporate oxygen to become a new
steam, but steam is just a different form of compound.
water.
Energy
•Physical and chemical changes are accompanied by energy
changes.
•Energy: the capacity to dowork
•work: results from a force acting ona distance
Two Types of Energy
Potential energy (PE): energy due to the
position or composition of the object
Kinetic energy (KE): energy due to motion of
theobject

An object’s total energy is the sum of its PE and

KE
Potential Energy

Consider a roller coaster.

At the top, it has potential energy.

The energy is stored. It is energy

waiting to be used for motion.
Another example would be a
rubber band.
Kinetic Energy

As the roller coaster

moves toward the
bottom, kineticenergy
increases along with
the roller coaster’s
speed.
Specific Types of Energy
Electrical energy is the energy associated with the flow of electrical charge.
Nerve impulses transmitting messages from one part of the body to another
Mechanical energy is the energy associatedwith motions of matter.
Lifting of objects
Chemical energy is a form of PEassociated with positions of particles in a
chemical system. The food we eat is digested and stored as PE,fuel for our
bodies.
Radiant Energy is the energy of the electromagnetic spectrum, e.g. X-rays,
visible light, radio and ultra violet waves ( mammals radiatesheat).
Forms of Energy
Energy Conversion
In most cases, energy is easily converted. For instance, chemical energy in gasoline can
be used to power the motor of a car. By doing so, the energy is converted to
mechanical energy (the tires move). During an energy conversion, some energy is
always lost as heat. All energy conversions in the body give off heat. In turn, the heat
helps us maintain our body temperature.
Composition of Matter

Matter refers to anything that takes up space and has

mass.

All matter (living and nonliving) is composed of basic

elements.
a.Elements cannot be broken down to substances with different
chemical or physical properties
b. There are 92naturally occurring elements
c. Six elements (C, H, N, O, P, S) make up 98%of most organisms.
Composition of Matter
• Carbon, oxygen, hydrogen, and nitrogen, makes up 96% of the
human body, they are known as the four main elements of the
human body.
• Several other elements are also present in the body, in trace
amounts. The periodic table lists all known elements and explains
the properties of each.
• All elements are composed of smaller particles called atoms.
• Atoms: submicroscopic particles that are the
fundamental building blocks of allmatter.
•Every elements atoms differ from those ofother
elements giving it unique physical and chemical
properties.
Periodic Table Of Elements
Composition of Matter
•Each element is designated with an
atomic symbol.
•An atomic symbol is a one or two letter (usually the first letter/s
of an elements name) shortened name. For instance, O stands
for oxygen, C stands for carbon and Ca for calcium.
• In some cases theanatomicsymbolistaken from the Latin name for the
element. E.g. sodium is indicated by Na (from the Latin word natrium)
Composition of Matter
Atomic structure
• Atoms are indescribable small, they are clusters of even smaller (subatomic) particles.
These subatomic particles differ in mass, electrical charge and station within the atom.
Nucleus- each atom has a central nucleus. The central nucleus contains protons and
neutrons bound together. The nucleusis
surrounded by electrons (orbiting).
1. Proton– has a positive electrical charge.
2. Neutron– has a neutral charge. Because the nucleus is made
up of protons and neutrons, it has an overall positive charge.
3.Electron– has a negative charge. Electrons are very small (1/2000 the mass of a
proton).
All atoms are electrically neutral because the number of protons (+) is balanced out by the
number of electrons (-). For example, iron has 26 protons and 26 electrons (making its
electrical chargeneutral).
The number of electrons and protons is always equal in anatom.
Components of Matter
Components of Matter

Identifying Elements
•Atoms of different elements are composed of different
numbers of protons, neutrons, and electrons. For example,
hydrogen has one proton, one electron, and no neutrons.
Helium has two protons, two neutrons, and two electrons
and the list goes on. Science uses
atomic number, atomic weight, and mass number to
identify a particular element.
Components of Matter
• Atomic number– is equal to the number of protons in the nucleus of an atom.
It is written as a subscript to the left of the atomic symbol. For instance,
hydrogen’s atomic number would be 1 because it has one proton.
• Mass number– is the sum of the atoms protons and neutrons. For example,
helium has two protons and two neutrons so its mass number is 4.
Components of Matter
• Isotopes– Isotopes have the same number of protons and electrons but
differ in the number of neutrons they contain. Therefore the isotopes of an
element have the same atomic number but different atomic masses.
Earlier, we said hydrogen has a mass number of 1 (which it does) but this is
not always the case. Hydrogen has several isotopes, it’s most abundant
contains a mass number of 1, but others contain mass numbers of 2 and 3.
• Atomic weight– is an average of the relative weights (mass numbers) of all
the isotopes of an element. Generally, the atomic weight is equal to the
mass number of its most abundant isotope.
Components of Matter
• Radioisotopes-the process of atomic decay is called
radioactivity. This happens when an atom is unstable and decays
spontaneously into a more stable form. Isotopes that cause
radioactivity are called radioisotopes.

• Radioisotopes are used in microscopic amounts to tag

biological molecules so they can be monitored or traced
through the body and are valuable tools used in biology and
medicine. For example, a radioisotope of Iodine 131 is used to
decide the size and activity of the thyroid gland. It’s also used
to identify thyroid cancer, but radioisotopes can also harm the
body. For instance, inhaled particles from decaying radon can
cause lung cancer.
Molecules and
Compounds
• A molecule is a group of two or more atoms from the same element
held together by a chemical bond. For instance, when two hydrogen
atoms combine, a molecule of hydrogen gas forms.
• Compounds are formed when two (or more) different kinds of
atoms combine.
• Compounds differ from molecules because they always contain
atoms of at least two different elements.
• Since oxygen gas only contains one element, (oxygen) it’s considered a
molecule. In contrast, water (H2O) is a compound because it contains
two elements, hydrogen and oxygen. Properties of compounds are
usually very different from the atoms they contain, this is an
important concept to understand. For instance, water is very different
from the atoms it contains (hydrogen and oxygen).
Molecules and Compounds
Chemical Bonds and Chemical
Reactions
Chemical Bonds
• When atoms combine with other atoms they are held together by
chemical bonds (bonds formed between electrons of reacting atoms).
These electrons occupy regions of space orbiting the nucleus called
electron shells. Each electron contains one or more orbitals and each
electron shell represents a different energy level (a general
understanding of chemical bonds is necessary in anatomy and
physiology).
• A few key points to remember about electrons, orbitals, and
electron shells include:
1. Electrons furthest from the nucleus have the greatest potential
energy.
2.Electrons furthest from the nucleus are most likely to interact with
other atoms.
3. The only electrons important in chemical bonding are those in
the atoms outermost shell (Valance Shell).
Chemical Bonds and Chemical Reactions

• Valence shell specifies the atoms outermost electron shell or

energy level (important). Its electrons determine the chemical
behaviour of an atom
•When the valence shell is full (or has eight electrons), the
atom is considered stable and chemically inactive.
•When the outer (Valance) shell is not full, less than 8
electrons, atoms will compensate for it by gaining, losing, or
sharing electrons with other atoms to achieve stability. This is
when chemical bonds are formed.
Chemical Bonds and Chemical Reactions
Types of chemical bonds
• There are three main types of chemical bonds: ionic, covalent,
and hydrogen bonds.
• Ionic bond– is a chemical bond between atoms made by the complete
transfer of electrons from one atom to the other. The atom that gains
an electrons is called the electron acceptor. Due to the fact that
electrons are electronegative, it acquires a net negative charge and is
called an anion.
• The electron donor is the atom that loses electrons. It acquires a net
positive charge (because it loses electronegative electrons) and is
called a cation. Anions and cations are formed whenever electron
transfers between atoms occur. A good example of an ionic bond is
table salt (NaCl).
Chemical Bonds and Chemical Reactions
• Covalent bond– Electrons do not have to be completely lost or gained for atoms to attain stability.
Instead, they can be shared so each atom is able to fill it’s valence shell. When electrons occupy a
single orbital shared by both atoms, it’s called a covalent bond. For instance, in the image below
two fluorine atoms are sharing a pair of electrons on their valence shell.
• They are covalently bonded. Typically there are single, double, and triple covalent bonds (atoms
share one, two, or three pairs of electrons).
Chemical Bonds and Chemical
Reactions
• Hydrogen bonds– generally are extremely
weak bonds, they are more like attractions
than true bonds. They form when a hydrogen
atom, already covalently linked to an
electronegative atom, is attracted by an atom
looking for electrons (forming a bridge
between them). Hydrogen bonding is
responsible for the tenancy of water
molecules to cling together and form films
(referred to as surface tension). This is why
water beads up into spheres when sitting on a
flat surface. The best example of a hydrogen
bond is the bonds formed between water
molecules.
Chemical Bonds and Chemical Reactions

Patterns of Chemical Reactions

Chemical reactions happens whenever one set of chemical
substances is transformed into another. The total number of atoms
stays the same, however the atoms appear in new combinations.
There are four elementary chemical reactions which form the basis
of chemical science, also known as chemistry.
Chemical Bonds and Chemical Reactions
Synthesis Reactions
• A+B -> AB
These basic reactions occur when two or more atoms or
molecules are combined to produce a more complex product.
When this happens energy is stored in the bonds that hold the
reactants together. A good example of this occurs when iron and
sulfur combine to form iron
• (II) sulfide.
• Synthesis reaction underline all anabolic activities that occur
the body cells.
• Important for growth and repair of worn out or damaged body
tissues.
 Chemical Bonds and Chemical Reactions
Decomposition Reactions
• AB -> A+B
•Decomposition is the exact opposite of synthesis. Instead of
reactants combining, they are broken down into their more basic
components and the energy stored within their bonds is released.
•For example, digestion of food into their building blocks.
Chemical Bonds and Chemical Reactions
Exchange Reactions
• AB+CD -> AD+CB
•These reactions involve both synthesis and decomposition
reactions and occur when bonds are made and broken,
reactants exchange parts to make new compounds. These
reactions will always cause the formation to change it's original
form of a solid, gas or a weakly ionizing compound (like water).
An example of this occurs when liquid silver nitrate is combined
with liquid sodium chloride to create solid silver chloride.
• Most chemical reaction are reversible
• Reversibility is indicated by a double arrow
Biochemistry
The Chemical Composition of Living Matter
•All chemicals found in the body fall into one of two categories
of molecules, they are either inorganic or organic compounds.
•Inorganic and Organic Compounds is differentiated by the
presence or absence of carbon.
Inorganic compounds Small, simple substances Biologically
important groups include water, simple acids and bases, and
simple salts/
Organic compounds Generally large, complex carbon- containing
compounds Typically, two or more carbon atoms are bonded to
each other to form the backbone, or skeleton, of the molecule.
Biochemistry
Inorganic Compound
Water
Life evolved in water
• All living things are70-90% water
• Because water is a polar molecule,
water molecules are hydrogenbonded
to eachother
• Water is the most inorganic compound
in the body, accounting for 2/3 of body
weight
• Vital water properties are:
• High heat capacity
• Polarity/solvent properties
• Chemical reactivity
• Cushioning- protective function
Biochemistry
Salts
• Any compound that results from the chemical interaction of an acid
and a base
• Salts of many metal elements are commonly found in the body, the
most popular salts are those that contain calcium and phosphorus,
found mainly in the bone and teeth.
• Dissociate in solution tobecome ions.
Acid
molecules dissociate in water, releasing hydrogen ions (H+) ions:
• Hydrochloric acid (HCl) is a strong acid: HCl ---> H+ + Cl–
Bases
are molecules that take up hydrogen ions orrelease hydroxide
ions:
• Sodium hydroxide (NaOH) is a strong base: NaOH ---> Na+ +OH-
Biochemistry

• pH scale, which ranges from 0 to 14, is used to indicate the strength

of acids andbases
• pH = a measure of hydrogen (H+) ion concentration in a solution
• Low pH value indicates a high concentration of H+ ions (acids)
• High pH value indicates a low concentration of H+ ions (bases)
• pH value of 7 is neutral, i.e. the solution has an equal
concentration of H+ and OH-ions
• pH scale is logarithmic, i.e. a ten fold difference for each number
E.X.: pH 4 is 10times more acidic than 5, and 100 times more acidic than
6
Biochemistry
Buffers
Buffers are present in body fluids, it keeps pH steady
and within normal limits in living organisms, e.g.
human blood pH is 7.4 and must be maintained within
very narrow limits or death becomes a distinct
possibility.

• Buffers stabilize pH of a solution by taking up excess hydrogen

or hydroxide ions.

• Carbonic acid helps keep blood pH within normal limits.

Biochemistry
Organic Compounds
Carbohydrates
Include sugar and starches, contain carbon, hydrogen and oxygen
• Provide energy that cellsrequire
• Contribute to cellstructure
• Built by simple sugar molecules(monosaccharides)
Lipids
Large and diverse group of organic compounds, the most abundant lipid in the body istriglycerides
• (Fat, Phospholipids, Steroids)
• Supply energy, build cellparts

• Basic building block of fat molecules is combination of glycerol and fatty acids
Biochemistry
Protein
• Serve as structural materials, energy sources, hormones, cell surface
receptors, and enzymes, account for 50%of the organic matter in the body
• Enzymesspeed chemical reactions without being consumed
• Amino acids are building blocks of proteins
• Proteins vary in the number and types of amino acids contained and in their
sequence
• Amino acid chain of protein folds into a complex shape that is maintained by
hydrogenbonds
• Excessive heat, radiation, electricity, altered pH, or chemicals can alter
proteins
Biochemistry
Nucleic Acids
Make up genes that provide the basic blueprint of life, they determine what kind
of organism we will be and direct growth and development, by dictating protein
structure.
Nucleic Acids composed of carbon, oxygen, hydrogen, nitrogen and phosphorus
atoms.
• Nitrogen base, pentose sugar, phosphate)
• Genetic material and control cellularactivities
• Nucleic acid molecules composed of nucleotides:
• Adenine A
• Guanine G
• Cytosine C
• Uracil U
• Thymine T
• A & Gare purines (large 2 ringbases)
• C, U, & Tare pyrimidines (small single ring bases)
Biochemistry
Important Nucleic Acids
• DNA (deoxyribonucleic acid)
•Double stranded polymer (double helix)-twisted ladder
•Nucleotides building are A, G, C,andT
•Pentose sugar isdeoxyribose
•Stores information that cell parts use to construct specific
protein molecules“Blueprint”
•Nucleotides held by hydrogenbonds
• A always bonds toT
• Galways bonds toC
Biochemistry
• RNA (ribonucleic acid)
•Help synthesize protein
•Pentose sugar isribose
•Single strands of nucleotides
• A, G, C,& U (U replacesT)
• A always bonds to U
• Galways bonds toC

• Ribosomal RNA (rRNA)

•Forms ribosomes (site of protein synthesis)
•Nucleolar organizer
DID YOUGET IT?

• How doionic bonds differ from covalent bonds?

• What kind of bond forms between water molecules?
• What name is given to the type of chemical reaction in which
a larger molecule is broken down into smaller molecules or
atoms?
• How can you indicate that a chemical reaction is
reversible?
DID YOUGET IT?
• Which four elements make up the bulk of living matter?
• What is the relationship of an atom to an element?
• An atom has 5neutrons, 4 protons, and 4 electrons. What is the atomic
number. What is its atomic mass number?
• What name is given to an unstable atom that has either more or
fewer neutrons than the typicalnumber?
• What is the meaning of the term molecule?
• How does a molecule of an element differ from a molecule of a
compound?