Transcript 02. Organizing principles of human body

Organizing
principles of
human body
Hierarchy of Structural
Organization
Each of these build upon one another
to make up the next level:
Chemical level
Cellular
Tissue
Organ
Organ system
Organism
Hierarchy of Structural
Organization
Chemical level
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Atoms combine to make molecules
4 macromolecules in the body
 Carbohydrates
 Lipids
 Proteins
 Nucleic acids
Hierarchy of Structural
Organization
Cellular
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Made up of cells and cellular organelles
(molecules)
 Cells can be eukaryotic or prokaryotic
 Organelles are structures within cells that
perform dedicated functions (“small organs”)
http://cmweb.pvschools.net/~bbecke/newell/Cells.html
Hierarchy of Structural
Organization
Tissue
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Collection of cells that work together to
perform a specialized function
4 basic types of tissue in the human body:
 Epithelium
 Connective tissue
 Muscle tissue
 Nervous tissue
www.emc.maricopa.edu
Hierarchy of Structural
Organization
Organ
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Made up of tissue
 Heart
 Brain
 Liver
 Pancreas, etc……
Pg 181
Hierarchy of Structural
Organization
Organ system (11)
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Made up of a group of related organs that
work together
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Integumentary
Skeletal
Muscular
Nervous
Endocrine
Cardiovascular
Lymphatic
Respiratory
Digestive
Urinary
Reproductive
Circulatory
Pg 341
Urinary System
Levels of Organization:
COHN – 99.5%
99.9% =
See figs. 1.3 & 1.4
Hierarchy of Structural
Organization
Organism
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An individual human, animal, plant, etc……
Made up all of the organ systems
Work together to sustain life
The Cell
Cells:
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structural and functional units of all living
organisms.
building blocks of the human body.
adult human body contains ~ 75 trillion cells.
Each cell type performs specific functions.
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~200 cell types in humans
 subcategories of most
Common Characteristics of
Cells
Perform the general functions necessary to
sustain life:
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Obtain nutrients and other materials from its
surrounding fluids.
 Fuel molecules, O2, building blocks, minerals,etc
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Dispose of wastes products
 Urea (from nitrogen), CO2, metabolic waste
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Maintain shape and integrity
 Size and shape are related to function
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Cell division:
 Mitosis: growth and repair
 Meiosis: gamete formation
Study of Cells
Cytology: study of cells
Microscopic anatomy
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Individual cells observable by light microscopy
Subcellular structures observable by electron
microscopy.
 TEM
 SEM
Unit of measure: micrometer (um)
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RBC: 7-8um
2. Bilateral Symmetry
- left half of the body is a mirror image
of the right half.
- structures in the median plane are
unpaired, but have identical left and
right sides.
Cells
Parts of a cell
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Cell Membrane (or plasma membrane)
Cytoplasm
 Cytosol
 Organelles
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Membranous Organelles
Non-membranous Organelles
 Inclusions
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Nucleus
Plasma (Cell)
Membrane
the outer,
limiting barrier
separates the
internal
contents of the
cell from
external
materials.
Cytoplasm
general term for all cellular contents
located between the plasma membrane
and the nucleus.
Nucleus
“control center” of the cell
controls protein synthesis
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directs the functional and structural
characteristics of the cell.
Plasma membrane: composition
Lipids
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Phospholipids
 Head: hydrophilic
 Tail: hydrophobic
 Form lipid bilayer
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Cholesterol
Glycolipids
 Carbohydrate component
 Part of glycocalyx
Plasma membrane: composition
Protein
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Integral membrane proteins
Peripheral membrane proteins
Some serve as enzymes, ion channels or
receptors
Glycoproteins
Fertilization: Four Major Steps
1. Sperm contacts the egg
2. Sperm or its nucleus enters the egg
3. Egg becomes activated and
developmental
changes begin
4. Sperm and egg nuclei fuse
Words to know…
Fuse- to physically join together
Ovum – egg cell (female gamete)
Cleavage – process of cell division
during development
Differentiation – the process of
forming different kinds of cells from
similar cells of the early embryo
Embryo – an organism in an early
stage of development
Morula – solid ball of cells formed from
cleavage
Fertilization
The Nuclei Fuse Together
Development of the zygote, the
study of which is known as
embryology or
developmental biology.
The zygote undergoes a series of mitotic cell
divisions called cleavage.
The stages of development are: Fertilized
ovum (zygote)  2-cell stage  4-cell
stage  8-cell stage  Morula 
Blastula  Early Gastrula  Late
Gastrula
Cleavage (divide via mitosis)
forms the 2 cell stage
And eventually form a Morula
And next, a gastrula
The Regents Diagram…
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Sperm and ovum
Zygote (fertilized ovum)
2-cell stage
4-cell stage
Morula
Blastula
Gastrula
Differentiation (Organogenesis)
Organogenesis is the formation of the organs
(Organo = organs, genesis = creation)
Arises from the layering of cells that occurs during
gastrula stage
The layers are germ layers; they have specific fates
in the developing embryo:
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Endoderm
 The innermost layer
 Goes on to form the gut
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Mesoderm
 In the middle
 Goes on to form the muscles, circulatory system, blood
and many different organs
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Ectoderm
 The outermost
 Goes on to form the skin and nervous system
Late Gastrula
Endoderm
Ectoderm
Mesoderm
Differentiation of Primary Germ Layers
Ectoderm Mesoder
m
Nervous
Skeleton
system
Epidermis Muscles
of skin
Circulatory
system
Gonads
(from the gastrula)
Endoderm
Digestive
tract
Respiratory
system
Liver, pancreas
Bladder
Early Human Development
Summary
Meiosis makes sperm in males
and ovum in females
Sperm and ovum unite nuclei to
form a zygote
Zygote undergoes cleavage and
becomes gastrula with 3 germ
layers
11 Organ systems
different organs work together to provide specialized functions
 Body Coverings
 Support & Movement
 Integration &
coordination
 Transport
 Absorption / Excretion