Anatomy

Anatomy- the structure of body parts and their relationships to one another

Subdivisions of Anatomy
1) Gross(macroscopic) anatomy- study of large body structures visible to the naked eye. Can be broken up the following ways:
regional anatomy- all the structures in a particular region of the body
Systematic anatomy- broken up by each body system
Surface anatomy- internal structures as they relate to the skin surface
2) microscopic anatomy- study of structures too small to be seen with the naked eye. Subdivisions include:
Cytology- study of the cells in the body
Histology- study of the tissues in the body
3) developmental anatomy- traces structural changes that occur in the body throughout the life span. Subdivisions include:
Embryology- developmental changes that occur before birth

Physiology

Physiology- studies the function of the body and how all body parts work together to carry out life sustaining activities

Examples of Subdivisions of Physiology
1) Renal physiology- concerns kidney function and urine production
2) neuro-physiology- explains the workings f the nervous system
3) cardiovascular physiology- examines the operation of the heart and blood vessels

Levels of Structural Organization

1) Chemical level- atoms form molecules such as water and proteins. Molecules then form organelles which compose cells
2) Cellular level- cells are the smallest units of living things. All cells have common functions but vary in size and shape to reflect their unique function
3) Tissue level- groups of similar cells that have common functions. Four basic types of tissue in the human are epithelium, muscle, connective tissue and nervous tissue.
4) Organ level- an organ is a structure compose of two of more types of tissue. On this level extremely complex functions become possible.
5) Organ system- organs that work together to achieve a common purpose
6) Organismal level- the sum total of all structural levels working together to promote life

Organ Systems

1) Integumentary system- forms the external body covering, protects deeper tissue from injury, synthesizes vitamin D, site of cutaneous recotors and sweat and oil glands
2) Skeletal System- protects and supports body organs, provides a framework for the muscles to cause movement, blood cells are formed in bones, bones store minerals
3) Muscular system- allows manipulation of the environment, movement, and facial expression, maintains posture, produces heat
4) Nervous system- fast acting control system of the body, responds to internal and external changes by activating appropriate muscles and gland
5) Endocrine system- glands secrete hormones that regulate processes such as growth, reproduction and metabolism by body cells
6) Cardiovascular system- blood vessels transport blood which carries oxygen, carbon dioxide, nutrients and wastes, the heart pumps blood.

Organ Systems cont.

7) Lymphatic System- picks up fluid leaked from blood vessels and returns it to the blood, disposed of debris in the lymphatic stream, houses white blood cells involved in immunity, the immune response mounts the attack against foreign substances within the body.
8) Respiratory system- keeps blood supplied with oxygen and removes carbon dioxide, gas exchanges occur in the walls of the air sacs of the lungs
9) Digestive system- breaks down food ink absorbable units that enter the blood for distribution to body cells, in digestive food parts are eliminated as feces
10) Urinary system- eliminates nitrogenous wastes from the body, regulates water, electrolyte, and acid base balance of the blood.
11) Reproductive System- overall function is production of offering. Testes produce sperm and male sex hormones, ducts and gland aid in delivery of sperm to the female reproductive tract. Ovaries produce eggs and female sex hormones. Remaining structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn.

Necessary life functions

1) Maintaining boundaries
2) Movement
3) Responsiveness
4) Digestion
5) Metabolism
6) Excretion
7) Reproduction
8) Growth

Homeostasis

Homeostasis is the ability to maintain relatively stable internal conditions even though the outside world changes continuously.

Homeostasis is necessary to keep the body functioning smoothly. It allows humans to live in a world with a constantly changing external environment. Every organ plays a role in helping to maintain homeostasis. A wide variety of chemical, thermal and neural factors interact in complex ways to remain in this state.

Feedback Mechanisms

Negative Feedback- the output shuts off the original stimulus or reduces its intensity. These mechanisms cause the variable to change in a direction opposite of the initial change in order to return it to its ideal value. They help to maintain a physiological function.

Positive feedback- the response enhances the original stimulus so that the activity is accelerated. The change that occurs proceeds the same direction as the initial change to deviate further from the original value. These mechanisms control unusual events that do not require continuous adjustments.

Anatomical Position

Anatomical position- the body is erect with the feet only slightly apart

Anatomical terms:
Superior- toward the head or upper part of a structure or the body, above
Inferior- away from the head or toward the lower part of a structure or body, below
Anterior (ventral)- toward the front of the body, in front of
Posterior (dorsal)- toward the back of the body, behind
Medial- toward or at the midline of the body, on the inner side of
Lateral- away from the midline of the body, on the outer side of
Intermediate- between a medial and a lateral structure
Proximal- closer to the origin of a body part or the point of attachment or a limb to the body trunk
Distal- farther from the the origin of a body part or the point of attachment or a limb to the body trunk
Superficial (external)- toward or at the body surface
Deep(internal)- away from the body surface, more internal

Body Cavities

Dorsal body cavity- protects the fragile nervous system
Subdivisions: cranial cavity- in the skull and encases the brain, vertebral/spinal cavity- runs within the bony vertebral column and encloses the delicate spinal cord

Ventral body cavity- more anterior and larger, houses internal organs called the viscera
Subdivisions: thoracic cavity- surrounded by the ribs and muscles of the chest. It is further divided into pleural cavities- each house a lung and the pericardial cavity- encloses the heart and thoracic organs. The diaphragm separates this from the abdominopelvic cavity. Abdominal cavity- stomach, intestines, spleen, liver. Pelvic cavity- bladder, reproductive organs, rectum.

Chapter 1 Questions

1) The serous membranes are inflamed. They typically line the organs and produce a lubricating fluid, but when they are inflamed it causes organs to stick and rub against one another causing severe pain.

4) The thirst sensation is part of a negative feedback reaction. This is because drinking water helps to to reduce the original problem of dehydration.

Energy Forms

Kinetic energy- energy in action

Potential energy- stored energy, energy that has potential to do work but is not presently doing so

Chemical energy- stored in the bonds of chemical substances. When chemical reactions occur, the potential energy is unleashed and becomes kinetic energy.

Electrical energy- results from the movement of charged particles.

Mechanical energy- directly involved in moving matter

Radiant energy- energy that travels in waves.(light waves, x rays)

Elements

All matter is composed of elements which are unique substances that cannot be broken down into simpler substances.

Carbon, oxygen, hydrogen and nitrogen make up 96% of body weight

Solutions-
homogeneous mixtures of components that may be gases liquids or solids. Solute does not settle out from the solvent.

Colloids-
heterogeneous mixtures that often appear translucent or milky. Some have the ability to undergo sol-gel transformations which is when they change reversibly from a fluid to a solid state.

Suspensions-
heterogeneous mixtures with large and visible solutes that settle out.

Solutions, Colloids, and Suspensions

Polar and Nonpolar molecules

Nonpolar molecules-have a covalent bond in which the electrons are shared equally between the atoms of the molecule so that there are no + or - poles of charge

Polar molecules- also have a covalent bond only the electrons are not shared equally between the atoms of the molecule so it results in + and - poles of charge.

Chemical Reactions

Synthesis reaction- when atoms or molecules combine to form a larger or more complex molecule. These reactions are the basis of constructive activities in body cells.

Decomposition reaction- when a molecule is broken down into smaller molecules or atoms. These are the reverse of synthesis reactions and bonds are broken instead of created.

Exchange reaction- involves both synthesis and decomposition reactions. Bonds are both created and broken. Parts of the reactant molecules change partners to produce different product molecules.

Oxidation reduction reactions- decomposition reactions that are the basis of all reactions in which foods are catabolized for energy. In this reaction electrons are exchanged between the reactants. The reactant that loses the electron is the donor and becomes oxidized; the reactant receiving the electron is known as the acceptor and is reduced.

Chemical Reactions Cont.

All chemical reactions are reversible however, there is little tendency for them to actually do so. This is because chemical reactions that release energy going in one direction will not go back in the other direction unless energy is added to the system. Also, if a product of one reaction is continuously removed it is unavailable to be reused to reverse the reaction.

Importance of inorganic compounds

Both water and salt are crucial in order to maintain homeostasis in the human body. Water has 5 properties that make it so vital-
high heat capacity prevents sudden changes of temperature caused by outside forces; high heat of vaporization allows large amounts of heat to be removed when we sweat, making it a powerful cooling mechanism; polar solvent properties helps to shield large molecules such as proteins as well as allowing for many chemical reactions to occur; reactivity of water helps to build and breakdown bonds between molecules; and cushioning helps to protect organs from physical trauma.

Salts in their ionized form also have an important homeostatic function. The electrolyte properties are essential in nerve impulse transmission and muscle contraction. They also help to transport oxygen within red blood cells.

Chapter 2 Questions

2) When the antibiotic binds to the enzyme in the bacteria it would prohibit usual function of the enzyme. If this enzyme is essential to the chemical reactions of the bacteria it would thus stop the bacteria from continuing to grow and eventually cause the bacteria to die off.
3)
a. PH measures the relative concentration of hydrogen ions in various body fluids. The more hydrogen ions in a solution the more acidic the solution is. The greater the amount of hydroxyl ions the more basic the solution is. PH is measured on a 0-14 scale. 0 being very basic, 7 being neutral, and 14 being very acidic. The normal PH for blood is 7.
b. This is problematic because it wakend the body systems as we need a homeostatic environment to work properly and resist disease

Membrane Junctions

Tight junctions- a series of integral proteins in the plasma membrane fuse together to form an impermeable junction that encircles the cell. This helps to prevent molecules from passing through the extracellular space between adjacent cells.

Desmosomes- bind neighboring cells together by thin linker filaments that extend from the plaques and interdigitate like a zipper in the intercellular space. These are abundant in tissues subjected to great mechanical stress as this arrangement distributes tension throughout a cellular sheet and reduces chance of tearing.

Gap junctions- a communicating junction that allows chemical substances to pass between adjacent cells. The cells are connected by hollow cylinders composed of transmembrane proteins

Membrane Transport

Substances can be transported through the plasma membrane either passively or actively.

passive processes- substances cross the membrane without any energy input from the cell.
Processes: simple diffusion, facilitated diffusion, osmosis, filtration
energy source: kinetic energy or hydrostatic pressure
direction: particles move from an area of higher concentration/ pressure to an area of lesser concentration/ pressure

active processes- the cell provides metabolic energy needed to move substances across the membrane
processes: primary active transport, secondary active transport, exocytosis, endocytosis, pinocytosis, receptor mediated endocytosis.
Energy source: ATP
Direction: in active transport substances are moved against the gradient and in vesicular transport substances are engulfed by the cell membrane and are brought to the opposite side

Glycocalyx

The Glycocalyx is a layer of outward facing glycoproteins that lay on the surface of the plasma membrane. They are important in cell interactions as they function as cell adhesion molecules and plasma membrane receptors. They can be used as "velcro" to stick themselves to molecules in the extracellular space, as "arms" used to move past other cells, as signals to protect injured areas, or as sensors to respond to tension at the cell surface.

Mitochondria

Structure:








Function: power plants of the cell, break down food fuels to form ATP from ADP

Ribosomes, E.R., and Golgi apparatus

Ribosomes:
Structure- small granules composed of protein and RNA. Made from 2 subunits that fit together
Function- free ribosomes make proteins that function in the cytosol, whereas
attached ribosomes make proteins that incorporate into the cell membrane or are to be exported outside of the cell.
Endoplasmic Reticulum:
Structure- system of interconnected tubes and parallel membranes enclosing fluid filled cavities thats coils through the cytosol
Function- rough: proteins are bound in vesicles for transport to the Golgi body. synthesizes phospholipids and cholesterol.
Smooth: lipid and steroid synthesis, lipid metabolism and drug detoxification.
Golgi apparatus-
structure:stack of smooth membrane sacs and vesicles close to the nucleus
Function: packages, modifies and separates proteins to be secreted from the cell

Lysosomes and Peroxisomes

Lysosomes- used for intracellular digestion.
Peroxisomes- detoxify a number of toxic substances in the cell, the most impotant being hydrogen peroxide.

They have similar functions as they are both used to keep the cell clean of wastes and toxins and in turn keep the organism healthy.

DNA Replication

1) DNA helice begin unwinding. A helicase enzyme untwists the double helix and separates the DNA into two complementary strands.

2) Each strand serves as a template for a new strand of DNA.

3) proteins and enzymes come together in a complex called a replisome- includes
RNA primers

4) DNA polyermase III positions complementary base pairs along the template strand and bonds them together.

5) short segments of DNA are spliced together by DNA ligase and two new identical strands are formed.

6) When replication is complete histones complete the formation of two new chromatin strands. These strands are united by a centromere and condense to form chromatids.

Protein Synthesis

Transcription- the transfer of information from a DNA gene's base sequence to the complementary base sequence of an mRNA molecule. Occurs in three stages-

RNA polymerase binds to a DNA promoter -> initiation of transcription on the template DNA strand -> elongation of the mRNA chain and termination of transcription and the release of completed mRNA.

Once the mRNA molecule is made it detaches and leaves the nucleus through the nuclear pore.

Translation- the language of nucleic acids into the langauge of protiens. This occurs in the cytoplasm.

The mRNA molecule carries the instructions and binds to a ribosomal subunit, rRNA -> tRNA transfers amino acids that were disolved into the cytosol to the ribosome-> Anticodons (end of a tRNA strand) bond with complementary codons and translate information into that of proteins

Chapter 3 Questions

4) The first gene prevents the cell from progessing into the synthesis phase and the second gene prevents the cell from begining mitosis which therefore stops the cell from being able to replicate the damaged DNA

5) the smooth endoplasmic reticulum is responsible for breaking down toxins.

Epithelial Tissue

Characteristics of Epithelial Tissue:
Cellularity- composed almost entirely of closely packed cells so that there is little extracellular material between them

Specialized contacts- cells fit close together to form sheets and adjacent cells are bound together at many points

Polarity- epithelial cells have an apical surface at the top and a basal surface in the lower region that differ from those at the top causing them to be polar.

Supported by connective tissue- they rest upon connective tissue that helps them resist stretching and tearing.

Avascular but innervated- they are supported by nerve fibers but contain no blood vessels.

Regeneration- as long as they receive adequate nourishment they can rapidly replace lost cells through cell division

Types of Epithelia

Simple Epithelia:
simple squamous epithelium- cells are flattened laterally and the cytoplasm is sparse
Function- allows a passage of materials by diffusion and filtration in sites where protection is not important, secretes lubricating substances
Location- kidneys, air sacs of lungs, lining of heart, blood vessels, lymphatic vessels
simple cuboidal epithelium- single layer of cube like cells with large, spherical central nuclei
Function- secretion and absorption
Location- kidney tubules, ducts and secretory portions of glands, ovary surface
Simple columnar epithelium- single layer of tall cells with round nuclei, some bear cilia
function- absorption, secretion of mucus, enzymes and other substances
Location- most of digestive tract, gallbladder, excretory ducts if some glands, small bronchi, uterine tubes, uterus

Glands

gland- consists of one or more cells that make and secrete a particular product

endocrine gland- produce hormores that are secreted into the extracellular place and then the blood stream to a specific target

exocrine gland- secrete their products onto body surfaces or cavities directly. include mucous, sweat, oil and salivary glands

unicellular glands- goblet cells; produce mucin that disolves to form mucus which helps to lubricate and protect surfaces

multicellular glands- more complex, composed of two parts- a duct and a secretory unit

Connective Tissue

Messenchyme- embryonic connective tissue, gel like ground substance containging fibers, star shaped cells
function- give rise to all other connective tussue
loctation- in embryo

loose connective tissue-
aerolar- fibroblasts, macrophages, mast cells, some white blood cells
Function- wraps and cushions organs, plays important role in inflammation, holds and conveys tissue fluid
Location- under Epithelia of body, forms mucus membranes, packages organs, surrounds capillaries

adipose- fat cells, nucleus pushed to side but fat droplet
Function- reserve food fuel, insulates against heat loss, supports and protects organs
Location- under skin, around kidneys and eyeballs, within abdomen, in breasts

Reticular- network of reticular fibers in a typical loose ground substance
Function- form a soft internal skeleton that supports other types
Location- lymphoid organs- lymph nodes, bone marrow, spleen

Dense connective tissue
Dense regular- parallel collagen fibers, few elastin fibers
Function- attaches muscle to bone or other muscle, attaches bones to bones, withstands great stress coming from one direction
Location- tendons, most ligaments

Dense irregular- irregularly arranged collagen fibers, some elastic fibers
Function- able to withstand tension exerted from many directions, provides strength
Location- dermis of skin, submucosa of digestive tracts, fibrous capsules of organs and joints

Connective Tissue Cont.

Hyaline cartilage- fibers form an imperceptible network, most abundant cartilage type in the body
Function- supports and reinforces and has resilient cushioning properties, resists compressive stress
Location- covers end of long bones in joint cavities, forms costal cartilage of the ribs, cartilage of nose, trachea and larynx

Elastic cartilage- similar to hyaline cartilage but more elastic fibers in matrix
Function- maintains the shape of a structure while allowing flexibility
Location- supports the external ear

Fibrocartilage- similar but less firm than hyaline cartilage, thick collagen fibers
function- tensile strength with the abikity ti absorb compressive shock
location- vertebreal discs, pubic symphysis, discs of knee joint

bone- hard, calcified matix containing many collagen fibers
function- supports and protects, provides cavities fir fat storag and synthesis if blood cells
location- bones

blood- red nd white blood cells in a fluid matrix
function- transport of gasses, nutrients wastes and ither substances
loctaion- in blood vessels

Covering and Lining Membranes

cutaneous membrane- skin; an organ consisting of a layer of epithelium attached to a thick lyer of dense irregular connective tissue. It is exposed to the air and is a dry membrane.

Mucous membrane- lines body cavities that open to the exterior such as the organs of the digestive, respitory, and urogenital tracts. they are moist membranes thatare often adapted for absoption and secretion

serous membrane- moist membranes found in closed ventral body cavities. consists of epithelium resting on loose connective tissue

Tissue Repair

1) The severed blood vessels bleed out and inflamatory chemicals are released. This causes the blood vessels to dilate and become more permeable so white blood cells, clotting proteins, etc can get to the injury faster. Clotting is initiated and scab forms

2) Granulation tissue(delicate pink tissue) forms and capilary buds restore vascular supply. Collagen fibers bridge the gap and macrophages destroy dead tissue. Surface epithelial cells begin to migrate over granulation tissue

3) Scab detaches and epitheulim thickens until it fully resembles that of the surrounding skin.

Origin of Tissue Classes

Three primary germ layers are formed in embryonic development. the outermost being the ectoderm, then the mesoderm and the innermost is the endoderm. These them specialize into four different types of tissue.

epithelial tissues form from all three layers.

muscle and connective tissues form from the mesoderm.

nervous tissue develop arises from the ectoderm.

Chapter 4 Questions

1) John cannot expect a quick and uneventful recovery from his torn knee cartilage. In comparison with other tissues cartilage has a weak regenerative capacity. Because catprtilage is avascular and aging, the cells can lose their ability to divide which makes the healing process much harder.

2) Keratinized stratified squamous epithelium is better suited to protect the body's external surface than a simple columnar epithelium because it is composed of several layers instead of just a single layer and the cells are constantly being replaced, helping to protect against injury.

Sources

Marieb, Elaine Nicpon. Human anatomy and physiology. 6th ed. San Francisco, Calif.: Benjamin/Cummings, 2004. Print.