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303 Cards in this Set

  • Front
  • Back
Definition of Anatomy
from the Greek “anatome” = to cut up, dissect
What do you mean when you speak of the anatomy of the body?
You are referring to the study of structures and the relationships between structures.
Definition of Physiology
from the Greek “physis” = nature
What do you mean when you speak of the physiology of the body?
You are referring to the functions of the body parts.
Why can't physiology and anatomy be wholly separated?
Structure usually determines function and, in turn, the function of a body part usually influences its size, shape, and overall health.
What are the six levels of structural organization of the human body?
1. chemical level
2. cellular level
3. tissue level
4. organ level
5. system level
6. organismic level
chemical level
1st level of structural organization of human body

– lowest level; includes all atoms and molecules essential for maintaining life
cellular level
2nd level of structural organization of human body

– cells are the basic structural and functional units of life; formed from molecules and atoms
tissue level
3rd level of structural organization of human body

– tissues are groups of similar cell types and the extracellular matrix around them; cells work for a common function
organ level
4th level of structural organization of human body

– organs are comprised of two or more different tissues; each organ has a specific function and shape
system level
5th level of structural organization of human body

– consists of an association of related organs that have a common function
organismic level
6th level of structural organization of human body

– highest level; all body parts are functioning together to comprise the individual
Life Processes
All living forms carry on certain processes that distinguish them from nonliving things.
What is growth and in what two ways can it occur?
Growth refers to an increase in size and complexity of an individual. It can occur as:

(1) an increase in the number and size of cells and as

(2) an increase in the amount of extracellular matrix between
cells, pushing the cells farther apart.
What is differentiation?
Differentiation is the process a cell undergoes as it moves developmentally from an unspecialized stage to a more specialized one.
What is reproduction?
Reproduction refers either to the formation of new cells for growth, repair, or replacement (mitosis), or to the production of a new individual (sexual).
What is the anatomical position?
The subject stands upright facing the observer, with feet flat on the floor, arms at the sides, palms and eyes facing forward.
What are the five most commonly used directional term pairs?
superior vs. inferior
anterior (ventral) vs. posterior (dorsal)
medial vs. lateral
proximal vs. distal
superficial vs. deep
What is a plane and how does it compare to a section?
A plane is an imaginary flat surface that passes through the body. A section is a two-dimensional surface resulting from a cut made through the three-dimensional structure along one of planes described below.
maintaining physiological limits
(Greek “homoi-“ = same, “stasis” = standing still)

A condition in which the body’s internal environment remains within certain physiological limits
What three conditions must be maintained at all times to ensure that a cell remains in homeostasis?
1. optimum levels of gases, ions, nutrients, water
2. optimum temperature
3. optimum pressure
Why must the fluid bathing body cells by precisely maintained?
For the cells of the body to live, the composition of their surrounding fluids must be precisely maintained at all times, since this is the fluid with which they exchange materials.
Define extracellular fluid and its two major components?
Extracellular fluid (ECF) is that fluid outside of cells:

1. Interstitial fluid (intercellular or tissue fluid) is that fluid filling the
narrow spaces between the cells.
2. Plasma is the fluid components of the blood
What is intracellular fluid?
Intracellular fluid is the fluid within cells.
why is interstitial fluid considered to be the internal environment.
There is constant movement of water and solutes between these three compartments. Because the interstitial fluid services the intracellular fluid, the interstitial fluid is said to be the internal environment.
Regulation by Nervous and Endocrine Mechanisms
The combined effects of the nervous system and the endocrine system regulate the homeostatic responses of the body.
positive feedback
the response of the body enhances the original stimulus.
Can you list the six important life processes of humans?
1. Metabolism
2. Responsiveness
3. Movement
4. Growth
5. Differentiation
6. Reproduction
1st Important Life Process in Humans

-catabolism + anabolism
2nd Important Life Process in Humans

-excitability, irritability of neurons (messengers) to recipients
4th Important Life Process in Humans

-cell division, and size
5th Important Life Process in Humans

the specification of cells
6th Important Life Process

-mitosis & meiosis
What is metabolism?
Metabolism is the sum of all chemical processes in the body.
Metabolism can be broken down into two processes that contribute to the whole. Name them.
Catabolism – breaking-down processes that provide energy by breaking large molecules into their components parts

Anabolism – building up processes that use energy and raw materials to build and maintain the body’s structural and functional components
breaking-down processes that provide energy by breaking large molecules into their components parts
building up processes that use energy and raw materials to build and maintain the body’s structural and functional components
What is responsiveness (excitability, irritability)
Responsiveness is the ability to detect and respond to changes in the external and internal environments.
What roles do the nervous and endocrine systems have in this process?
The nervous and endocrine systems detect changes in the environment, then integrate and interpret those changes.
What roles do the muscles and glands have in this process?
Muscular and glandular tissues respond to input from the nervous and endocrine systems to elicit changes in the body to counteract changes in the environment.
What is movement and what does it include?
Movement includes motion of the whole body, individual organs, tissues, cells, or even organelles within cells.
Can you list the four major planes of the body?
sagittal plane
One of 4 major planes that is a:

vertical plane that divides a structure into right and left sides.
frontal (coronal) plane
One of the 4 Major Planes that:

divides the body or part into anterior (front) and posterior (back).
transverse (horizontal or cross) plane
One of 4 major planes that:

divides the body or part into superior (top) and inferior (bottom) parts.
oblique plane
One of 4 major planes that:

passes through the body or part at an angle between the transverse plane and the others.
What are the five sections you can make through the body or a body part?
midsagittal, parasagittal, transverse, frontal, oblique
What is a body cavity?
Body cavities are confined spaces within the body that separate internal organs and serve to protect, separate, and support the organs. There are two, dorsal and ventral.
Name the subdivisions of the dorsal cavity?
cranial cavity- contains the brain
vertebral (spinal) cavity- contains the spinal cord
vertebral (spinal) cavity
contains the spinal cord
cranial cavity
contains the brain
Name the subdivisions of the ventral body cavity?
thoracic cavity contains: pleural cavities (lungs)
middle (pericardial cavity)
How is the ventral body cavity divided?
The abdominopelvic cavity is separated from the thoracic cavity by the muscular diaphragm.
How does the nervous system operate to return the body to within normal limits?
The nervous system is the body’s rapid-response system, using electrical messages to counteract stress and return the body to within normal ranges.
How does the endocrine system operate to return the body to within normal limits?
The endocrine system is the body’s long-term regulator, using chemical messengers called hormones to maintain the body within normal ranges.
Define the concept of a feedback system.
a cycle of events in which status of a condition is continuously monitored and information regarding the condition is fed back (reported) to a central control region.
Name the three components necessary for successful operation of a feedback system.
1. Control Center
2. Receptor
3. Effector
Describe the three components necessary for successful operation of a feedback system.
control center- center determines the point at which some aspect of the body, called the controlled condition, should be maintained

receptor-monitors changes in the controlled condition and then sends information, called the input, to the control center. Any stress that changes the controlled condition is called the stimulus.

effector- receives information, called the output, from the control center and produces a response. The response is continually monitored by the receptor and information is fed back to the control center.
Control Center
1st Component of Operation of a Feedback System

-center determines the point at which some aspect of the body, called the controlled condition, should be maintained
2nd Component of Operation of a Feedback System

- monitors changes in the controlled condition and then sends information, called the input, to the control center. Any stress that changes the controlled condition is called the stimulus.
3rd Component of Operation of a Feedback System

-receives information, called the output, from the control center and produces a response. The response is continually monitored by the receptor and information is fed back to the control center.
Distinguish between negative and positive feedback
In negative feedback, the response of the body reverses the original stimulus. These systems maintain conditions that require frequent monitoring and fine adjustment.
All animal cells have four anatomical features in common. Name them.
1. Plasma (cell) membrane
2. Cytosol
3. Organelles
4. Inclusions
The plasmalemma (cell or plasma membrane) is the
outer limiting membrane that separates the cell’s internal components from the extracellular material and external environment.
Cytoplasm is the term used for all cellular material between
the plasma membrane and the nucleus of the cell.
Cytosol is the thick, semi-fluid portion of the cytoplasm called
the intracellular fluid. It contains soluble proteins, enzymes, ions, and nutrients, and suspends the organelles.
Organelles are highly organized structures with characteristic shapes that are highly specialized for specific activities.
Inclusions are temporary structures suspended or stored
within the cytoplasm that contain secretions and storage products of the cell.
What is the function of the cell membrane?
It is the thin barrier that separates the cell’s internal fluid from the external fluid. It serves as the gatekeeper that regulates passage of substances into and out of the cell.
Describe the fluid mosaic model of the membrane structure.
The fluid mosaic model of membrane structure describes the molecular arrangement of the cell membrane. The membrane is a mosaic of protein molecules “floating” like icebergs in a “sea” of lipid molecules.
Describe the three types of membrane lipids.
1. Phospholipids (75%) -- hydrophilic “head” and hydrophobic
2. Glycolipids (5%) -- role obscure (cell adhesion, recognition)
3. Cholesterol (20%) -- membrane strength and steroid
hormone precursor
Type of membrane lipid (75%)
hydrophilic “head” and hydrophobic
Type of membrane lipid (5%)
role obscure (cell adhesion, recognition)
Type of membrane lipid (20%)

membrane strength and steroid
hormone precursor
Compare integral membrane proteins with peripheral membrane proteins.
Integral proteins extend across the lipid bilayer into the extracellular fluid on one side and into the intracellular fluid on the other. They have a number of functions

Peripheral proteins do not extend across the lipid bilayer but rather are loosely attached to either the inner or outer surfaces of it. Their roles in cell function remain obscure.
Channels (pores)
Membrane Protein:

allows a specific substance to
move through water-filled passageways. Most cell membranes include specific channels for several ions. Most common are for Na+ and K+
Transporter (carrier)
Membrane Protein:

transports specific substances
across membrane by changing shape. For example, amino acids, needed to synthesize new proteins, enter body cells via transporter.
Membrane Protein:

-- recognizes a specific ligand and alters the cell’s
functions in some way. For example, this is a classic mechanism by which protein-based hormones affect cells.
Membrane Protein:

catalyzes reactions inside or outside (depending
upon which direction the active site faces) the mem-brane. *ex. small intestinal enzymes for digestion of food)
Cytoskeleton anchor
Membrane Protein:

anchors filaments and tubules of the cytoskeleton inside cell membrane to provide struc-tural stability and shape for the cell. May also partici-pate in movement of the cell.
Cell identity markers
Membrane Protein:

-- distinguish your cells from anyone else’s (unless you are an identical twin) and from microbial cells. An important class of such markers is the histocompatibility (MHC) proteins.
List the three major functions of the cell membrane.
1. Communication
2. Electrochemical gradient
3. Selective permeability
With what must cells of the body be able to communicate?
The cell, via the plasma membrane, communicates with other body cells, foreign cells, and ligands (neurotrans-mitters, enzymes, hormones, nutrients, and antibodies) in the extracellular fluid.
Describe the chemical components of the electrochemical gradient formed by the cell membrane.
The chemical portion of the gradient is formed because the membrane maintains very different chemical compositions in the cytosol and the extracellular fluid.
*The major extracellular cation is Na+ and the major
anion is Cl-
*The major intracellular cation is K+ and the major
anions are organic phosphates and amino acids.
Describe the electrical components of the electrochemical gradient formed by the cell membrane.
The electrical gradient arises because the inside of the membrane is more negatively charged than the outside. As a result, there is a voltage (voltage is electrical potential or potential difference as expressed in volts.) called the membrane potential across the membrane.
The third major function of the cell membrane is to provide selective permeability. What is this?
The plasma membrane regulates the entry and exit of materials by permitting certain substances to pass freely while restricting the passage of others. This property is called selective permeability.
A membrane is said to be permeable to a substance if...
It allows that substance free passage into and out of the cell.
Permeability of a membrane is dependent upon four factors that relate to membrane structure. List these factors.
1. Solubility in Lipids
2. Size
3. Charge
4. Presence of specific channels or transporters
Solubility in lipids
Permeability Factor

-Substances that dissolve in lipid pass
easily across the membrane while water-soluble substances do not. For example: oxygen is fat-soluble and crosses the membrane easily; glucose is water -soluble and does not cross the membrane.
Permeability Factor

-Ions and molecules less than 8 Angstroms in
diameter can cross the cell membrane freely. Substances larger than 8 Angstroms are restricted from crossing the membrane because they are too large to pass between the molecules that form the membrane itself.
Permeability Factor

- The membrane is impermeable to all charged ions
and molecules. However, the overall negative membrane potential of most cells aids the influx of cations and hinders the influx of anions.
Presence of specific channels or transporters
Permeability Factor

- Channels increase membrane permeability for some substances by providing specific routes of entry or exit. This is done by either attaching to and shuttling the substances through the channel or by simply letting it pass through the channel’s water-filled space.
Why are the mechanisms that enable substances to move across cell membranes essential to life?
Without these mechanisms the cell would be unable to procure oxygen, nutrients, etc., or rid itself of carbon dioxide and other waste products of metabolism.
Compare passive processes with active processes.
Mechanisms that move materials across the cell membrane without the
use of cellular energy are called passive processes.

Mechanisms that move material across the plasma membrane with the
use of cellular energy are called active processes.
List the four passive processes
1. Simple diffusion
2. Osmosis
3. Filtration
4. Facilitated diffusion
List the four active processes
1. Primary active transport
2. Secondary active transport
3. Endocytosis
4. Exocytosis
osmotic pressure.
pressure generated by movement of water through the selectively permeable membrane, which is impermeable to the solute, thus not allowing to satisfy the diffusion gradient.
Simple diffusion
Since all substances have kinetic energy,

they are constantly moving about, colliding into one another and then moving off into various directions.
concentration gradient
the difference in concentration between the two areas when the substance is present in high concentration in one area over another
Describe the process of osmosis.
water moves across the membrane from an area of higher water concentration to an area of lower water concentration until a uniform water concentration is reached.
isotonic solution
total concentrations of water molecules and impermeable solutes are the same on both sides of the membrane.
hypotonic solution
has fewer solutes than cells have. A cell placed in such a solution will have a net osmosis into the cell, causing it to swell and burst.
hypertonic solution
greater concentration of solutes that do cells. A cell placed in such a solution will have a net osmosis out of the cell, causing the cell to shrink (crenate).
Describe the process of filtration.
In this passive process, water and solutes move across a cell membrane due to gravity or hydrostatic (water) pressure.

Such movement is always from an area of high filtration pressure to an area of low filtration pressure.
What is facilitated diffusion?
Some substances are too large to pass through membrane channels and too lipid-insoluble to diffuse through the lipid bilayer.

Such substances may move through the membrane with the aid of transporter proteins, moving down their concentration gradient to a region of lower concentration.
3 factors of facilitated diffusion
(1) concentration gradient
(2) number of transporters available
(3) rate at which transporter and substrate combine
What are active processes?
When cells actively participate in moving substances across membranes, they must expend energy by splitting the ATP molecule.

Using the released energy from ATP, the cell then moves substances against their concentration gradients, from an area of low concentration to and area of higher concentration.
Describe a primary active transport process by discussing the Na-K ATPase membrane pump.
Energy from ATP is used to directly move substances across the membrane by changing the shape of transport (pump) proteins in the membrane.

Na+ in the cytosol binds to the pump protein. Remember that Na+ is the major extracellular cation whereas K+ is the major intracellu-lar anion

Na+ binding triggers the breakdown of ATP and the attachment of the released high-energy phosphate group to the pump protein. This changes the shape of the protein so that the Na+ ions are pushed through the membrane and expelled from the cell.

K+ binding to the transport protein triggers release of the phosphate molecule. This again causes the shape of the transport protein to change. As the pump returns to its original shape the K+ is pushed through the membrane and into the cytosol. At this point the pump is ready to bind Na+ again and renew the process.
Primary active transport
Energy from ATP is used to directly move substances across the membrane by changing the shape of transport (pump) proteins in the membrane.
What is exocytosis?
an active transport process whereby the cell expends energy to actively discharge large substances from the cell. Example: secretion from glands.
What is endocytosis?
Endocytosis is the process by which large substances are actively taken into the cell.
Name and define the three types of endocytosis
1. Phagocytosis -- “cell eating”
2. Pinocytosis -- “cell drinking”
3. Receptor-mediated endocytosis -- specific ligands are taken
into the cell by attaching to membrane receptors and being carried into the cell.
The nucleus is a spherical or oval membrane-bound organelle
that contains the heredity material (DNA) of the cell and is there-fore considered to be its control center.
The nucleolus is a nonmembrane-bound spherical body
within the nucleus composed of DNA, RNA, and proteins. It functions in the synthesis and storage of ribosomal RNA and is therefore necessary for protein synthesis within the cell.
Ribosomes are organelles in the cell cytoplasm, composed
of ribosomal RNA and ribosomal proteins. They function in the synthesis of proteins.
Smooth Endoplasmic Reticulum
network of
membrane-bound channels running through the cytoplasm. It serves in intracellular transport, support, storage, synthesis, and packaging of molecules.
Rough Endoplasmic Reticulum
Rough ER bears ribosomes and is
specifically involved in the synthesis of proteins destined for secretion.
Golgi complex
a cytoplasmic organelle consisting
of 4-6 flattened membranous sacs stacked upon one another. It functions in processing and packaging materials destined for secretion from the cell, for use by the cell membrane, or for use by the lysosomes.
Lysosomes are membrane-bound organelles that contain
very strong digestive enzymes. They function in destruction of intracellular debris and are used extensively for destruction of foreign matter ingested by phagocytes.
membrane-bound organelles that
produce hydrogen peroxide, which is then used to oxidize a number of toxic substances. This function is particularly important n the liver and kidneys.
Microfilaments are rodlike, protein structures (about 6nm
in diameter). They provide the contractile apparatus in muscle cells and are used by other cells for support, shape, and movement.
Microtubules are cylindrical protein filaments (18-30 nm
diameter) that provide support, structure, and transportation routes within the cell.

Microtubules are cylindrical protein filaments (18-30 nm
diameter) that provide support, structure, and transportation routes within the cell.
long hairlike, motile process that extends
from the cell and is used for locomotion. Only the mature sperm cell of humans bears a flagellum.
short, hairlike processes that extend from some cells.
They are used primarily to sweep materials across the cell surface.
paired cylindrical structures associated with
ciliary function and cell division.
Briefly describe the process of transcription and its processes
Transcription, occurring in the nucleus, is the process by which the genetic information found within DNA is encoded and is copied onto a strand of RNA.
Three forms of RNA are created:
1. Messenger RNA (mRNA) directs synthesis of proteins
2. Ribosomal RNA (rRNA) joins with ribosomal proteins to form
the ribosomes where proteins are made
3. Transfer RNA (tRNA) binds to amino acids
Messenger RNA (mRNA)
directs synthesis of proteins
Ribosomal RNA (rRNA)
joins with ribosomal proteins to form
the ribosomes where proteins are made
Transfer RNA (tRNA)
binds to amino acids
Briefly describe the process of translation and its product.
Translation, occurring at ribosomes in the cytoplasm, is the process by which the nucleotide sequence of mRNA specifies the amino acid sequence of a particular protein.
Cell division
process by which cells reproduce themselves.
Each cell must divide in two ways in order to accomplish a normal cell division. Name them.
Nuclear division and cytoplasmic division
There are two types of nuclear division, so there are two types of normal cell division. Name them.
1. Somatic cell division (mitosis)
2. Reproductive cell division (meiosis)
Somatic cell division (mitosis)
a single starting cell called the parent cell divides to produce two identical daughter cells.

consists of a single nuclear division called mitosis and a single cytoplasmic division called cytokinesis.
Importance of Mitosis
This mechanism ensures that each daughter cell has the same number and kind of chromosomes as the original parent cell.

We use mitosis to replace dead or injured cells with like cells and to add new cells for body growth.
Reproductive cell division (meiosis)
the mechanism by which gametes (sperm and ova) are formed. In this type of cell division, there are two nuclear divisions and two cytoplasmic divisions.

Instead of two identical daughter cells, meiosis produces…

four daughter cells, each with half the number of chromosomes of the original parent cell.

Important because It ensures that with union of sperm and ovum at fertilization, the normal chromosome number is reestablished.
All human cells, except for sperm and ova contain how many chromosomes?
23 pairs
What are homologous chromosomes?
Two chromosomes of a pair, one contributed by the mother and one contributed by the father.
Homologous chromosomes are identical. What does this mean?
They have similar gene order; in other words, the two chromo-somes code for the same proteins (carry the same type of genetic information).
Define replication? Why is it important?
Prior to dividing by mitosis, a cell must replicate (form duplicates of) all its chromosomes so that its hereditary traits are passed to the succeeding daughter cells.
What is the cell cycle?
The cell cycle is a series of activities through which a cell passes form the time it is formed until it reproduces.
What are its two major divisions?
It is divided into interphase and mitosis.
What occurs during these divisions?
In interphase, the cell is doing the work for which it was intended in the body. Just prior to entering the mitotic phase, the cell ceases its work, and begins to replicate its DNA in preparation for division.
What is the result of replication?
Replication of a chromosome yields two DNA molecules held together by a special structure called the centromere. The two molecules are now called sister chromatids. This means that just before mitosis, the cell contains 4 copies of each gene.
What other things must the cell do to prepare for mitosis?
In addition, the cell creates duplicate centrioles and the appropriate enzymes to accomplish mitosis.
In one sentence, describe the net result of mitosis.
During mitosis, the two sets of chromosomes are distributed into separate and equal nuclei, resulting in the exact duplication of genetic information within the daughter cells.
For convenience, mitosis is divided into four continuous phases. Name them.
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
In prophase, the DNA coils and condenses into visible
chromosomes, nucleoli and nuclear envelope disappear, centrioles move to opposite poles of cell, and the mitotic spindle forms.
In metaphase, the centromeres of the chromosomes
of the chromatid pairs line up along the equatorial plane (metaphase plate) of the cell.
In anaphase, the centromeres divide and individual
sets of chromosomes move towards the opposite poles of the cell.
In telophase, the nuclear envelope reappears and
encloses the chromosomes, chromosomes, uncoil to regain interphase form, and mitotic spindles disappear.
In cytokinesis, a cleavage furrow forms around the
cell, progresses inward, and separates the cytoplasm into separate and usually equal portions.
How are gametes different from somatic cells?
Gametes are different from all of the other cells of the body (somatic cells) in that they contain only one of each of the 23 different types of chromosomes. As a result, they are said to be haploid or 1n. Somatic cells are diploid or 2n.
Compare the autosomes and sex chromosomes of somatic cells and gametes.
In any given body cell, there are 22 pairs of autosomes and one pair of sex chromosomes (XX or XY).

Since gametes are haploid cells, they have 22 autosomes + either an X or a Y chromosome.
Genetically, what occurs at fertilization?
At fertilization a new organism is produced by the union and fusion of the two different gametes, one from each parent. The single cell thus produced is the zygote. The zygote contains one set of chromosomes from each parent for a total of 23 pairs.
Why is a zygote not 4n (tetraploid)?
If gametes had the same number of chromosomes as somatic cells, then the zygote would have double (4n) the number of chromo-somes. But, because of meiosis (reduction division), chromosome number is halved, resulting in gametes with 1 chromosome of each pair.
Meiosis occurs in two successive nuclear divisions called reduction division (meiosis 1) and equatorial division (meiosis 2). During the interphase that precedes meiosis one the chromosomes replicate just as they do in mitosis.
prophase I
, all the events of mitotic prophase occur, with one difference. All homologous pairs come together in a process called synapsis and the four chromatids are known as a tetrad.

During this time, portions of one chromatid may be exchanged with portions of another, a process called crossing-over. This process allows an exchange of genes between homologous chromosomes so that the resulting daughter cells are genetically unalike.
metaphase I
homologous pairs of chromosomes line up along the metaphase plate, with the homologs side-by-side.
anaphase I
the homologs separate and begin to move to opposite poles of the parent cell. Notice that the centromeres did not break as in mitosis and that the sister chromatids stay together
telophase I
the events of mitotic telophase occur and cytokinesis results in two daughter cells, each with only a single set of chromosomes (haploid) but with 2 copies of each (sister chromatids) (diad).
metaphase II
the chromosomes line up along the equatorial plane, just as in mitosis.
anaphase II
the centromeres break and the sister chromatids begin to separate, moving towards opposite poles of the cell.
telophase II and Cytokinesis
the DNA of each chromatid reverts to chromatin and the nuclear envelope and nucleolus reappear.
Result of Meiosis
the formation of 4 cells each of which is now 1n and monad, bearing a single copy of each gene. Because of crossing-over, each cell is genetically similar but different.
passage of heredity traits from one generation to the next. It is the process by which you acquire your characteristics from your parents and will transmit some of your traits to your children.
What are homologs?
Homologs are the two chromosomes of a pair.
What is a gene?
The functional unit of heredity. It occupies a specific site on a chromo-some (locus), reproduces itself exactly at each cell division, and is capable of directing the formation of an enzyme or other protein.
What is an allele?
Genes that control the same inherited trait and are at the same location on homologous chromosomes are called alleles.
What is the difference between a dominant trait and a recessive trait?
An allele that dominates or masks the presence of the other allele and is fully expressed is said to be dominant and the trait it controls is the dominant trait. The allele that is masked codes for the recessive trait.
What is a person’s genotype?
The genotype is the total hereditary information, including all dominant and recessive traits, carried by an individual.
How are dominant and recessive genes designated?
By tradition, the dominant gene is designated with a capital letter and the recessive gene by the same letter in lower case.
Distinguish between homozygous and heterozygous genotypes.
Having two dominant genes (TT) or two recessive genes (tt) for a given trait would be homozygous for that trait. On the other hand, a person could have one of each gene (Tt) and be therefore heterozygous.
What is a person’s phenotype?
The phenotype is how the genotype is expressed in the body; it is the physical expression of the two genes in question.

A person who is TT and another who is Tt have different geno-types, but their phenotypic expression will be the same since each has the same dominant gene for the trait. A person who is tt, on the other hand, has no dominant gene for the trait so therefore expresses the recessive trait.
What is a Punnett square?
A Punnet square is a special chart used to determine the possible ways gametes can unite to form a fertilized egg.
Consider the simple inheritance of the condition phenylketonuria. Both parents are heterozygotes for the trait, so what types of gametes can they make?
If both the father and mother are heterozygous for PKU (Pp), then they will make gametes that carry either the P gene or the p gene.
What is the likelihood for the condition in each offspring?
In this example, there is a 25% chance with each pregnancy that the child will be pp, homozygous recessive, and have PKU.
What is incomplete dominance?
In incomplete dominance neither member of an allelic pair is dominant over the other. The heterozygote has a phenotype that is intermediate between homozygous dominant and homozygous recessive.
Sickle cell anemia is a disease of incomplete dominance. What does this mean?
The homozygous dominant individual is normal, the homozygous recessive individual has the disease, and the heterozygote is a carrier.
Describe the offspring if both parents are heterozygotes.
There is a 25% chance that each offspring will have sickle cell anemia, and 50% chance that each will be a carrier
Multiple Allele Inheritance
Seen in blood genes

leads to codominance
polygenic inheritance
When many traits are not controlled by one gene, but rather by the combined effect of many genes. It is greatly influenced by the environment.
From the genetic stand point, what is the difference between males and females?
In females the sex chromosome complement is XX, so each ovum can carry only a X chromosome. In males, the complement is XY, so that each sperm carries either the X or the Y.
What is sex-linked inheritance?
The Y chromosome is believed to carry genes used for male development in the embryo only. Therefore, there are genes on the X chromosome that are not present on the Y. This is the basis for sex-linked inheritance.
Describe the inheritance of red-green color blindness?
The gene for normal color is dominant and is located on the X chromosome. Since the Y has no corresponding gene, this feature of the eye is controlled by a single maternal gene in males.
What are other examples of sex-linked inheritance?
Other example include night blindness, some types of diabetes, juvenile muscular dystrophy, hemophilia, some cataracts, juvenile glaucoma, some types of deafness.
List three characteristics of a tissue?
1. Group of similar cells AND their extracellular matrices
2. Share a common embryological origin
3. Function together as a group to carry out particular functions
What determines the functions and properties of a tissue?
The functions and properties of a tissue are determined by the nature of the cells and the extracellular matrix, if present, created by and surrounding the cells.
List the four basic tissue types of tissue:
1. epithelium
2. connective
3. muscular
4. nervous
Epithelial tissues
cover the body surfaces; line hollow organs, body cavities, and ducts; form glands
Connective tissues
protect and support the body and its organs; binds organs together; store energy reserves as fat; provide resistance to disease in association with the immune system
Muscular tissues
responsible for movement and generation of force
Nervous tissue
initiate and transmit action potentials (nerve impulses) that help coordinate body activities
Describe the general features of epithelial tissues.
1. Closely packed cells with little or no extracellular material between them
2. Cells arranged into continuous sheets, in either single or multiple layers
3. Epithelial cells have an apical surface that is exposed to a body cavity, lining of an internal organ, or the exterior of the body.
4. Epithelial cells have a basal surface that is attached to a basement membrane
5. The basement membrane (basal lamina) is a connective tissue matrix that attaches the overlying epithelium to the underlying connective tissue
6. Epithelia are avascular, meaning that they have no blood supply. They receive their nutrition by diffusion from the underlying connective tissues.
7. Epithelial have a nerve supply.
8. Since epithelia are subject to a certain amount of wear, tear, and injury, they have a high capacity for mitosis.
simple epithelium
If the function is absorption or filtration, or the tissue is in an area of minimal wear and tear, the cells form a single layer, and is thus called a simple epithelium.
stratified epithelium
If the tissue is in an area with a high degree of wear and tear, then the cells are stacked into layers, and is thus called a stratified epithelium
pseudostratified epithelium
A third less common arrange-ment is the pseudostratified epithelium that has a single layer of cells, so it is simple, but some cells do not reach the apical surface, giving it a multilayered appearance.
squamous cells
squamous cells are flattened and scale-like
cuboidal cells
cuboidal cells are usually cube-shaped in cross-section, being roughly as tall as they are wide
columnar cells
columnar cells are tall and cylindrical or somewhat rectangular, and generally taller than they are wide
Exocrine glands
exocrine glands secrete their product(s) either onto the apical surfaces of the cells or into ducts for transport to the free surface.
List the two major structural classifications of exocrine glands
Unicellular glands
Multicellular glands
Unicellular glands
The best example of a unicellular gland is the goblet cell. This single cell secretes its product directly onto the free surface of many epithelia.
Multicellular glands.
A multicellular gland consists of a secreting organ found deep to the free surface and attached to it via a duct.
What is the basis for the functional classification of glands?
Functional classification is based on whether a secretion is a product of a cell or consists of entire or partial glandular cells themselves.
holocrine secretion
In holocrine secretion the cells accumulate secretory product in their cytosol, die, and are discharged with their contents as the secretion.
merocrine secretion
In merocrine (eccrine) secretion the cells form a secretory product, store it in the cytoplasm in secretory vesicles, and release it by exocytosis.
apocrine secretion
In apocrine secretion vesicles with product accumulate in the apical portion of the cells. That portion pinches off from the rest of the cell to form the secretion.
Name the three basic elements of all connective tissues.
1. cells
2. ground substance (ground substance is a more or less
homogeneous, amorphous, water-based background substance in which the specific differentiated elements of a connective tissue are suspended)
3. fibers
Name the three basic fiber types of the connective tissues.
1. collagen
2. elastin
3. reticular fibers
What is matrix?
Matrix is ground substance embedded with fibers that separate the cells.
Mature (adult) connective tissues are classified into five categories. List each of them, give their subdivisions, and the primary cell type of each.
1. loose connective tissues
areolar tissue (fibroblast)
adipose tissue (adipocyte)
reticular tissue (fibroblast)

2. dense connective tissues
dense regular connective tissues (fibroblast)
dense irregular connective tissues (fibroblast)
elastic connective tissues (fibroblast)

3. specialized connective tissues
hyaline cartilage (chondrocyte)
elastic cartilage (chondrocyte)
fibrocartilage (chondrocyte and fibroblast)
bone (to be discussed later)
blood (to be discussed later)
areolar (loose) tissue
papillary dermis of skin, hypodermis, mucous membranes, blood vessels, nerves, and around body organs (i.e. everywhere)

loosely woven fibers embedded in ground substance; many different cell types wander through; fibroblasts form basic tissue

strength, elasticity, and support
adipose tissue
hypodermis; around heart, kidneys, and eyes; yellow bone marrow; around joints

adipocytes that store fats, forming a characteristic “signet ring” appearance

provide insulation, energy storage, protection from mechanical injury
reticular tissue
stroma of liver, spleen, lymph nodes; red bone marrow; basement membranes

net work of very short interlacing collagen fibers and fibroblasts

form framework of organs, binds together smooth muscle cells
dense regular connective tissue
tendons, aponeuroses, and most ligaments

collagen fibers arranged in parallel bundles, with fibroblasts scattered between

provides strong attachments between parts
dense irregular connective tissue
dense fascia, reticular dermis, perichondrium, periosteum, joint capsules, dura mater, membrane capsules, heart valves

collagen fibers randomly arranged and fibroblasts, forming a sheet

strength, support, and protection
elastic connective tissue
lung, elastic arteries, trachea and bronchial tree, true vocal cords, vertebral ligaments, suspensory ligament of penis

elastic fibers that branch freely, forming sheets or ligaments

provides extensibility and elasticity to various organs that must be stretched
hyaline cartilage
articular surfaces of bones; anterior ribs; nose, parts or larynx, trachea, and bronchial tree; embryonic skeleton

Chondrocytes embedded in cartilage matrix rich in collagen fibers

resists compressive forces, provides smooth surfaces for articulation at synovial joints
pubic symphysis, intervertebral discs, menisci of shoulders and knees

consists of scattered Chondrocytes with hyaline cartilage matrix among bundles of collagen fibers

support, fusion (between pubic bones and between vertebrae), deepening of shoulder and knee joints
elastic cartilage
epiglottis, external ear, auditory tubes

Chondrocytes embedded in cartilage matrix rich in network of elastic fibers

allows structure to be semi-rigid and extensible; structure can return to resting shape
comprises the bones of the skeleton

osteocytes embedded in a mineralized matrix of collagen fibers and ground substance

support, protection, storage, provides levers for movement; provides for blood cell formation
within blood vessels and heart

formed cellular elements suspended ina liquid matrix (plasma)

transport of gases, immune function, blood clotting
What is a membrane?
An epithelial membrane is formed by a the combination of an epithelium and an underlying connective tissue layer.
Name the three true membranes and the one false membrane of the body.
mucous membrane (mucosa)
serous membrane (serosa)
cutaneous membrane (skin or integument)
False Membrane
synovial membrane, no epithelium
In general, where are mucous membranes found?
Mucous membranes line body cavities that open directly to the external environment.
What is the function of the epithelial layer?
The epithelial layer secretes mucous to protect the epithelium by lubricating it and trapping harmful agents.
Specifically, what body parts are lined by a mucosa?
Mucosae are found lining the respiratory tract, the digestive tract, and the genitourinary tract.
In general, where are serous membranes found?
Serous membranes line body cavities that do not open to the exterior of the body and cover the external surfaces of the viscera.
What are the parietal and visceral layers of a serosa?
The portion of the serosa attached to the body wall is called the parietal layer and the portion attached to an organ is called the visceral layer.
What is serous fluid, where is it found, and what does it do?
Between the layers of the serosa is a small amount of serous fluid that lubricates the two layers and allows the organs to move freely within the cavity
Where are synovial membranes located?
They line the joint cavity of synovial (freely movable) joints.
Why are they not considered to be true membranes?
Synovial membranes are not true membranes because they do not contain an epithelial layer.
What is the structure of a synovial membrane?
Synovial membranes are composed of areolar connective tissue with elastic fibers and varying amounts of adipose tissue. The cells are synoviocytes that secrete synovial fluid.
What is an organ?
A group of two or more tissues that performs a specific function is called an organ.
What is a system?
A group of two or more organs that work together towards a common goal is a system.
What are the components of the integumentary system?
The skin and organs that are embryonic epidermal derivatives comprise the integumentary system. These include hair, nails, glands, and enamel of teeth.
The epidermis is the outer, thinner, waterproof portion
of the skin. It is composed of keratinized stratified epithe-lium divided into four (thin skin) or five (thick) distinct layers or strata.
The epidermis is attached to the dermis, the inner,
thicker portion of skin. It is composed of elastic and collagenous connective tissues and bears a vascular supply. The dermis is very thick on the palms and soles, and tends to be thicker on the dorsal body surfaces than on the ventral surfaces.
Deep to the dermis is the hypodermis
(subcutaneous layer or superficial fascia). The hypodermis is not a true part of the skin. It is formed from areolar and adipose tissues and serves to attach the dermis to under-lying tissues, give protection from mechanical blows, and store energy.
List the seven functions of the skin.
-Regulation of body temperature
-Blood reservoir
-Synthesis of vitamin D
Regulation of body temperature
Function of the skin

In response to strenuous
exercise or high environmental temperature, evaporation of sweat from the skin surface lowers body temperature to normal. Sweating ceases when temperatures are low. Increased blood flow to the skin also participates in regulation of temperature.
Function of the skin

Skin covers the body and provides a physical barrier
that protects underlying tissues from physical abrasion, microbial invasion, dehydration, and ultraviolet (UV) irradiation.
Function of the skin

Skin contains abundant nerve endings and receptors
that detect stimuli related to temperature, touch, pressure, and pain.
Function of the skin

In addition to thermoregulation, sweat also is the vehi-
cle for excretion of a small amount of salts and several organic compounds.
Function of Skin

Certain cells of the epidermis are important compon-
ents of the immune system, working to fend off foreign invaders.
Blood reservoir
Function of Skin

Blood vessels in the dermis carry 8-10% of total
blood volume in a resting adult. This blood can be moved quickly to skeletal muscles to facilitate exercise.
Synthesis of vitamin D
Function of Skin

One step in the activation of vitamin D
requires UV light. This occurs as blood passes through the skin.
List the four cell types of the epidermis, give the percent of the total population of epidermal cells
-Keratinocytes -- (90%)
-Melanocytes -- (8%)
-Langerhans cells -- (1%)
-Merkel cells -- (1%)
produce the keratin that waterproofs and
protects the skin and underlying tissues. Anchoring junctions between cells called desmosomes “weld” cells together to form a formidable membrane.
produce the brown-black pigment melanin that
absorbs ultraviolet light. The cells produce melanin then transfer it to the keratinocytes in the stratum spinosum for distribution throughout the layers of the epidermis. Once inside a keratinocyte, melanin clusters over the apical side of the nucleus, giving it protection from the UV irradiation that penetrates it.
Langerhans cells
involved in immune function, working with
lymphocytes called helper T cells.
Merkel cells
make contact with the flattened portion of a
sensory nerve ending called a tactile (Merkel) disc and are thought to function in the sense of touch.
Stratum basale
single layer of cells, mostly mitotic keratinocytes,
resting on basement membrane; gives rise to new cells of the epidermis; also contains the melanocytes and Merkel cells.
Stratum spinosum
8-10 rows (sheets) of spiny-shaped cells
derived from the keratinocytes below; receive melanin from melanocytes; no longer mitotic.
Stratum granulosum
3-5 rows of cells that begin producing and
accumulating the molecule keratohyalin, a precursor of keratin.
Stratum lucidum
3-5 rows of clear, flattened, dead cells packed
with eleidin, the intermediate molecule in the formation of keratin; only present in thick skin.
Stratum corneum
25-30 rows of flattened dead cells, completely
filled with keratin; gives the skin a water-proof, anti-microbial, and abrasion-resistant barrier.
Describe the papillary dermis
The outermost portion (top one-fifth) of the dermis is the papillary
dermis. It consists of areolar connective tissue rich in fine elastin fibers. Its surface area is greatly increased by small, hill-like projections called dermal papillae. Each papilla contains loops of blood capillaries.
Describe the reticular dermis.
The deeper layer is the reticular dermis. It consists of dense irregular connective tissue rich in interlacing bundles of collagen and coarse elastin fibers.
What is the function of the dermis?
The combination of elastin and collagen, particularly in the reticular dermis, gives the skin strength, elasticity (the ability to return to shape after stretching), and extensibility (the ability to stretch). The dermis has a large blood supply, especially in areas of skin used for temperature regulation. This is the blood supply for the epidermis as well.
Sebaceous glands
secrete sebum, a mixture of lipids, proteins, and
salts onto the surface of the epidermis. It forms a protective film, in combination with sweat, called the acid mantle, that lubricates the skin and hair, prevents evaporation of water through the epidermis, and is anti-microbial.
Eccrine sweat glands
are most common, being found over most of the
skin. Secretion is copious and about 90% water. It is used as the body’s principal means of losing body heat via evaporation. The glands are poorly functional prior to the age of two; therefore, young children are poor thermoregulators in the heat.
Apocrine sweat glands
found mainly in the skin of the axillary region,
pubic region, areolar regions of the breasts, and the beard area of men. Beginning at about puberty, they produce only a very small amount of a viscous milky fluid. The role of this secretion is unknown, but it is released in response to emotional stress and sexual excitement. The glands apparently correspond to the scent glands of other mammals. The secretion does not have a disagreeable odor.
(warm-blooded animal) maintain a constant body temperature regardless of the environment.
List the six basic functions of bone tissue and the skeletal system
-Blood cell production
-Storage of energy
Function of Bone Tissue and Skeletal System

Bone provides a framework for the body by supporting soft
tissues and providing points of attachment or most of the skeletal muscles.
Function of Bone Tissue and Skeletal System

Bones protect many internal organs from injury very well,
such as the brain and spinal cord. In addition, the heart, lungs, and reproductive organs are given some degree of protection.
Function of Bone Tissue and Skeletal System

Most skeletal muscles attach to bones. When the muscles
contract, they pull on bones to activate lever systems, and move-ment is produced.
Mineral homeostasis
Function of Bone Tissue and Skeletal System

Bone tissue stores a number of minerals, particularly calcium and phosphorus. Under control of the endocrine system, bone releases the minerals into the blood or stores the minerals in bone matrix to maintain critical mineral balances.
Blood cell production
Function of Bone Tissue and Skeletal System

In all bones of the infant and certain bones of the
adult, a connective tissue known as red marrow produces blood cells by the process of hematopoiesis.
Storage of energy
Function of Bone Tissue and Skeletal System

In some bones, yellow bone marrow stores lipids,
creating an important energy reserve for the body.
Identify the following part of a long bone:
The diaphysis of a long bone is its shaft or long main portion.
Identify the following part of a long bone:
The epiphysis of a long bone is its end. The two ends
together are called the epiphyses. Each epiphysis is covered with articular cartilage.
Identify the following part of a long bone:
The metaphysis of a long bone is the region of mature
bones where the diaphysis meets the epiphysis
Identify the following parts of long bone:
Epiphyseal plate
In a growing bone, the epiphyseal plate is formed of
hyaline cartilage divided into four zones of cells. Under the influence of growth hormone, the plate continues to grow, giving length to the bone. When bone growth exceeds cartilage growth, beginning at puberty, the epiphyseal plate is slowly lost. Growth of long bones stops when the cartilage is completely gone.
Identify the following cell:
Osteoprogenitor cells
Osteoprogenitor cells are immature quiescent
cells lining the bone surfaces. When stimulated, they enter mitosis, giving rise to a new cell type called the osteoblast.
Identify the following cell:
Osteoblasts, once differentiated, lose their mitotic ability, and
begin producing new bone matrix in a process known as osteogenesis.
Identify the following cell:
Osteocytes are mature bone cells completely embedded in
bone matrix, are incapable of mitosis, and probably do not secrete new matrix. Their role in bone homeostasis is poorly understood.
Identify the following cell:
Osteoclasts reside scattered along the endosteal surfaces.
They function in a process known as bone resorption, the destruction of bone matrix. This process is required for normal bone function.
Identify the three main components of bone matrix
1. Tricalcium phosphate (hydroxyapatite--50% of total matrix)
2. Ground substance (25% of total matrix is water)
3. Collagen fibers (25% of total matrix)
Briefly describe the process of ossification (mineralization or calcification)
The predominant mineral salt is tricalcium phosphate (hydroxyapatite) (50% of total mineral) (there is also calcium carbonate, magnesium hydroxide, fluoride, and sulfate). As these salts are deposited into the framework of ground substance and collagen fibers, they crystallize and the tissue hardens or ossifies.
What is the process of bone remodeling?
Remodeling is the ongoing replacement of old bone tissue by new bone tissue. It occurs as a delicate balance between bone resorption by osteoclasts and bone formation by osteoblasts
What does bone remodeling accomplish?
1. Changes the way bone matrix resists stress
2. Removes worn or injured bone
3. Provides a reservoir for body calcium
PTH has three targets (effectors)- What are they?
1. increase bone resorption
2. increase calcium reabsorption by the kidneys
3. increased absorption of calcium by the gut (in
conjunction with vitamin D)
Identify the following part of long bone:
Articular cartilage is a thin layer of hyaline cartilage
covering the articular surfaces of the epiphysis at a joint.
Identify the following part of long bone:
The medullary (marrow) cavity is the space within the
bone containing either red or yellow bone marrow. Red bone marrow consists of blood precursors while yellow marrow consists of adipose tissue.
Identify the following part of long bone:
The periosteum is the double-layered connective tissue
surrounding the bone except where the articular cartilage is present. It is divided into an outer fibrous layer and an inner osteogenic layer.
Identify the following part of long bone:
The outer fibrous layer of the periosteum is
composed of dense irregular connective tissue containing blood vessels, lymphatics, and nerves that pass into the bone.
Identify the following part of long bone:
The inner osteogenic layer of the
periosteum contains elastic fibers and various bone cell types, particularly osteoprogenitor cells, that give rise to new osteoblasts when stimulated
Identify the following part of long bone:
The periosteum functions in bone growth,
repair, and nutrition. In addition, it provides attachment points for skeletal muscles.
Identify the following part of long bone:
The endosteum is a single layer of osteoprogenitor
cells lining the medullary cavity.
Compare spongy bone with compact bone
Spongy bone consists of lamellae (layers) of bone matrix arranged in an
irregular latticework of thin plates of bone called trabeculae. The spaces between the trabeculae are a part of the medullary cavity of the bone.
Compare spongy bone with compact bone
Compact bone contains very few spaces. The layers of bone matrix are
packed together tightly, forming osteons (Haversian systems). It forms the external layer of all bones, providing protection and support and helps the long bone resist the stress of weight applied to them.
Define: Volkmann's Canal
A Volkmann’s canal is a minute passageway by
means of which blood vessels and nerves from the periosteum of a bone penetrate into compact bone.
An Haversian (central) canal is a circular channel
running longitudinally in the center of an osteon of mature compact bone. It contains blood and lymphatic vessels and nerves.
Concentric lamellae are rings of calcified bone
matrix surrounding the Haversian canals of compact bone.
A lacunae (“little lake”) is a small hollow space within bone
matrix wherein resides an osteocyte. They are located between concentric lamellae.
A canaliculus is a small channel or canal connecting two
lacunae in compact bone. Each canaliculus contains a cellular process of an osteocyte.
An osteon (Haversian system) is the basic unit of structure in
adult compact bone. Each consists of a central canal with its concentrically-arranged lamellae of matrix, lacunae, osteocytes, and canaliculi.
Interstitial lamellae are fragments of older compact
bone found between newer osteons. They have been partially destroyed during bone replacement.