Post on 25-Mar-2020
Chapter 3
Organization of the
Body
Human Physiology
Introduction
Molecules are placed into levels of organization, or
hierarchies
Series of ordered groupings within a system
• Each level relies on properties of the lower level
Hierarchy of Human Structure
Cell – basic structural unit and functional unit of the
human body
Simplest characteristic of all organisms
• Unicellular – body comprised of one cell
• One cell must carry out all life functions (constant communication with
environment)
• Multicellular – consisting of many cells
• Cells cooperate with each other to carry out jobs
• DIFFERENTIATION
• Process by which cells mature in order to carry out the cells needs
Levels of Organization
Cell – from previous
Tissue – organized group of cells
Organ – organized group of tissues
Organ system – organized group of organs
Organism – individual biological unit capable of reproduction Any living thing
Levels of Organization, cont.
The organism is NOT the highest level of
organization
Society – groups of organisms interacting
• Outcomes of human interactions affect homeostasis
Envirome – highest level of organization
• All environmental factors that affect the survival of organisms
• Enviromics
• Study of the envirome
• Investigates the balance of the environmental conditions and processes
that affect an organisms adaptations for survival
The Human Physiological
Environment
Physiological environment – internal conditions
that optimize individual cell function and body
organization
Cells would not survive without a suitable environment
• Internal environment – condition inside the cell
• External environment – conditions outside the cell
Water
No life possible without water
Most abundant molecule in the body 55-60%
When water level falls below a certain level, the body is dehydrated State in which tissues are deprived of water
• Occurs from inadequate water in take or excessive water loss
• Diarrhea, sweating, vomiting
• Indicators are – extreme thirst, nausea and exhaustion
Overhydration – body contains too much water Termed water excess or water intoxication
• Harmful because it disrupts the physiological environment
Water, cont.
Human environment is aqueous Pertaining to water
Water is a polar molecule Polarity permits water to dissolve most of the biochemicals
needed for human survival.
Water is universal solvent Solvent – substance that dissolves other chemicals
Solute – substances that dissolves in a solvent • When a solute dissolves in a solvent, it forms a solution
• Uniform mixture of two or more substances
Water has high specific heat Energy required to raise the temperature of a substance
• Prevents the body from heating or cooling too quickly
Ions
play roles to help maintain the physiological
environment
Electrically charged particles
Classification of ions
Minerals – nutrients needed for the body
Metals – several elements that conduct heat and electricity
Cations – positively charged ions
Anions – negatively charged ions
All ions are water soluble
Most are lost by kidneys are they produce urine
2nd is sweating, then feces, and vomiting
Major Ions Related to Human
Health
Bicarbonate – fluid buffer that makes acidic conditions neutral to slightly basic Regulated by kidneys and lungs
Calcium – two forms: Diffusable – found in salts in bone
Nondiffusable – bound to blood and cell proteins
Chloride – in association with potassium and sodium Potassium chlorine (KCl) and sodium chloride (NaCl)
Copper, Iodine, and Iron help carry out chemical reactions in the cell
Major Ions Related to Human
Health, cont.
Magnesium – carries out many jobs done by calcium Critical for energy production and proper nerve function
Phosphate – body fluid buffer regulated by kidney 80% is used in the body bonds with calcium for bone
hardening
Potassium – most abundant element inside of cells Controls muscle and heart contractions
Sodium – most common mineral found outside of the cell Controls water retention
Sulfate – found as an anion attached to other moelcules Acidic, lower the pH of body fluids
STOP!!!!!
What’s the difference between
minerals and vitamins?
Difference Between Vitamins and Minerals by Laura Niedziocha, Demand Media
Everyone knows that vitamins and minerals are an essential part of a healthy diet. When part of a well-balanced diet, they provide the structure for a healthy, functioning body. You may be unaware that taking extra vitamins and minerals is unnecessary if you maintain a nutritious diet -- it may even be unsafe. You also may not know what differentiates vitamins from minerals.
Composition: Vitamins and minerals vary mostly in their composition. Vitamins are naturally occurring organic nutrients. Minerals are inorganic compounds and are smaller particles that come mostly from natural geological processes. This makes them much simpler than vitamins. Another difference in their composition lies with their solubility. Vitamins are either fat or water soluble, minerals are not.
Working Together: Any healthy and well-balanced diet assures that you are getting adequate vitamins and minerals. Although they are two different substances, many vitamins and minerals work together to maintain bodily processes. For instance, without vitamin D, calcium would not be able to promote proper bone growth.
3.2 Enzymatic Reactions and
Energy
Enzymes facilitate most of the chemical reactions
that occur in the body
Catalysts – enzymes that start reactions
Hydrolysis – chemical process of breaking down water
• Water is needed
Synthesized – process of building molecules
Reduced – process of molecule gaining or losing an
electron
Chemicals Reactions in the cell
Most reactions involve some sort of energy
transfer
Some require energy, some provide energy
Endergonic – require energy to set off and carry out
reaction
Exergonic – release cell energy
• Energy is used to build cell structures or carry out physiological
functions
Energy
Energy is the capacity for doing work
Potential energy – ability to do work food
Kinetic energy – associated with motion or action Muscle action
Body uses 4 types of energy Chemical
Electrical
Mechanical
Thermal • Calorie – used to measure body energy
• Amount of heat required to raise the temp one of gram of water 1 degree Celsius.
• Kilocalorie – food calories
• 1,000 times larger than the standard calorie.
Enzymes
Promote exergonic reactions
needed to obtain cell energy
Carry out endergonic
reactions that build body
structures or are used in cell
work
Active site
Provides attachment area
• Enzymes lock on to a substrate
molecule converting it into a molecule
called the product
Enzymes, cont.
Lock and key idea
Active site fits a particular molecule
Substrate – chemical that an enzyme modifies in
the active site
Product – result of an enzymatic reaction
Allostery – modification to allow an enzyme to work
slower or faster
Allosteric site – region of enzyme where a chemical binds
Enzymes, cont.
Other factors Competitive inhibition – chemical resembling substrate
(fake)
Feedback inhibition – enzyme’s product is not removed
Non-competitive inhibition – alter the enzymes structure or charges
pH, Electrolytes,Temperature – can alter shape of enzyme
Coenzyme – organic molecules that activate certain enzymes
Cofactor – elements or ions that facilitate enzyme activity
Molecular Transport
Membrane – separates internal from external
conditions
Sheet-like structure that surrounds and keeps the internal
environment contained
Selectively permeable membrane
• Allows certain molecules to pass, but not all
• 5 methods (each one will be discussed in detail)
• Diffusion
• Passive transport
• Active transport
• Osmosis
• Bulk mechanical transport
Diffusion
Mixing of molecules in gases and liquids as a result of thermal stirring All molecules are vibrating due to
heat • Amount of heat determines speed and
intensity
**Odors – diffusion is obvious when you open a can of something with a nasty smell
Cells depend on diffusion for essential molecules Also transports wastes from cells
Passive Transport
Diffusion that requires no cell energy
Relies on diffusion gradient as driving force
• Cell’s internal and external environments have unequal quantities
• Higher to lower = wants to even out
3 types (discussed individually)
Membrane diffusion
Facilitated diffusion
Filtration
Membrane Diffusion
Certain particles can pass through a membrane Membranes covering cell are typically lipids
• Molecules that dissolve in lipids usually have no trouble passing
• Polar molecules cannot dissolve through lipids
Hypertonic Greater quantity of a particular molecule that exists in the cell
Oxygen – moves into the cell
Hypotonic Less quantity of a particular molecule than exists in the cell
Carbon dioxide – moves out of the cell
Isotonic Equal quantity of a particular molecule in the solution in the cell
• Molecules move back and forth across the membrane in equal numbers
Nitrogen
Facilitated Diffusion
Uses a carrier protein, or channel, to move ions
and molecules through a membrane
Reserved for molecules that normally do not pass on their
own
• Slight amount of energy is used (not from the cell)
• Energy comes from carrier protein changing shape as it bonds to
transport
Only so many carrier channels available
• If all are full, the molecules pass out of the body
Osmosis
Diffusion of water across selectively permeable membrane Move from low solute to high solute(less water)
Water always moves towards the more concentrated solution
Counteracts diffusion of particles into and out of the cell Osmolarity – water’s potential to move across a membrane
Hyperosmotic – solution contains higher concentration of solute
Hypoosmotic – solution contains lower concentration than exists in the cell
Isoosmotic – equal in solute concentrations
Hypertonic vs. hypotonic
Active Transport
Requires cell energy
Useful for moving materials from an area of lower
concentration to an area of higher concentration
Works against the diffusion gradient (hence needs
energy)
2 types (will discuss in detail)
Active transport pumping
Bulk active transport
Active transport pumping
Uses proteins called pumps to move several ions
or molecules at a time across the membrane
Require energy
Consumes roughly 70% of the body’s energy
strengths
Bulk Active Transport
Moves large amounts of particles into and out of
the cells
Relies on membrane movement and modification
Endocytosis – moves particles into the cell
• Receptor-mediated endocystosis – uses a special protein on the
cell membrane (receptor) to bind specific types of molecules
Exocytosis – process of moving particles out of a cell
• Excretion – removal of waste via exocytosis
• Removal of worn out cell components
• Secretion – transport of molecules using exocytosis
• Digestive juices and mucus, nerve cell communication
STOP!
Bell Ringer
Answer the following questions on a separate
piece of paper.
What is osmolarity?
What do the terms hypertonic and hypotonic
mean?
What would happen to an individual’s red blood
cells if the osmolarity of the plasma (liquid potion of
the blood) was altered by continuous intravenous
administration of pure water (containing no
electrolytes)?
3.3 Cell Structure
Leeuwenhoek and Hooke were first to recognize
microscopic attributes of the body
Cell theory, or cell doctrine – all organisms are
made of cells
Proposed by Schleiden and Schwann in 1839
Remains foundation of modern medicine
Louis Pasteur
Showed that all essential functions of an organism occur
within cells
Cell Structure, cont.
3 structural components
Cell membrane
• Covering around the outside of cell – involved in transport
Cytoplasm
• Contents inside of cell
Genome
• Genetic material passed down from one generation to the next
Acellular Pathogens
All disease causing agents that do not use cells as
their basic unit of structure
Viruses
• Infectious agents composed of a genome (either DNA or RNA) and
a protein coat
• No ribosomes or means of protein synthesis
• Not Alive, but has living properties
Viriods
• Simply short pieces of RNA
Prions
• Puzzling – no more than a piece of protein resembling abnormal
proteins found in other organisms
Cells of Microbes
Microbes (microorganism) – must be viewed with a
microscope
Bacteria
• Most common microorganism in the human body
• Most help, do not cause disease
• Circular DNA – single-celled
• Prokaryotes – genome located in nucleoid (no nucleus), no
membrane bound organelles
• Flagella – swimming appendages
• Cell wall – made of peptidoglycan
More ex - Fungi, Protista, viruses
• Protista – malaria and sleeping sickness
Fungus
Diverse group – range from single cell to a body
mass of branched elongated/stringy cells
Single celled – yeast
Filamentous fungi – mass of stringy cells
Similar to human cells – eukaryotes
Have DNA inside the cell – specialized organelles
Most produce specialized structures
mushrooms;
Can be harmless – some fatal
Human Cells
Eukaryotic – very diverse
Fluid mosaic model – “ocean” of proteins and lipids Fluid – describes motion of proteins in the membrane
Mosaic – membrane is composed of variety of molecules
Cytoplasm – cell carries out chemical reactions for homeostasis Cytosol
• gel-like fluid composing 54% of cell volume
• Thousands of enzymes – obtain cell energy
Organelles • Perform specialized functions
Human cells, cont.
Membrane-bounded structures – manufacture and move molecules and cell parts Nuclear envelope
• Transmits genetic information
Endoplasmic reticulum (ER) • Production of protein and lipid components of cells
Golgi bodies • Modifying, storing, and shipping cell products from the ER
• Produces vesicles
Vesicles • Move products
Cell membrane
Use transport vesicles to transfer back and forth to each other
Human cells, cont.
Lysosome – recycle cell components with digesting enzymes Cause activate cell death, if needed
Programmed death cell, apoptosis Can program their own death
Vacuoles – storing materials
Mitochondria – originates from eggs cytoplasm Comes from your mother
Produce energy for the cell
Can take on different jobs depending on where they are located
Human cells, cont.
Cytoskeleton – meshwork of protein filaments and tubules in the cytoplasm that gives the cell shape and capacity for movement Coordinates the function of:
• Centrioles – assist the cell with reproduction
• Cilia - Hairlike processes on cell membrane capable of motion
• Flagella – found only on sperm, gives ability to move in body fluids
Nucleus – more like instruction manual, than brain With few exceptions, nucleus carries the genetic material of
the entire genome
Main role – genetic expression • Genetic material’s coded information is used to produce cells
structures and carry out cell physiology
STOP
Bell Ringer
Place this answer in your notes.
In terms of energy conversion (going from one type
of energy to another) how is the energy needed by
a weight lifter created, and what type of energy
does his/her activity create?
Use chemical energy, electrical energy, mechanical
energy and thermal energy in your answer.
Tissues (3.4)
As the fetus develops, groups of cells are
organized into functional units called tissues
First three to form – embryological germ layers
Ectoderm – outer layer, forms the skin and brain
Mesoderm - middle layer, builds bone and muscle
Endoderm – innermost, produces the digestive organs
Stem cells – retain their ability to undergo cell
division
Assist further development and healing later in life
Tissues, cont.
Each germ layer responsible for each of the four
human tissue types
Epithelial
• Forms layers of cells that line body cavities creating coverings over
external and internal body structures
Connective
• Supports the framework of the organs and the body
Muscle
• Contractile tissue that provides the body with movement
Nervous
• Highly specialized – capable of conducting and coordinating body
information
Epithelial Tissue
Come in a variety of shapes and arrangements Determined by function
Simple – single layer Squamous – thin coverings – flat
Cuboidal – cube-shaped associated with structures that produce secretions
Columnar – tall – involved in secretion and uptake of materials
Stratified – multi-layered arrangments – subject to wear and tear (skin)
Pseudostratified – only has single layer – gives impression that it is stratisfied
Transitional – occurs in places of stretch and expansion Cells change from columnar to squamos
Some are ciliated – have cilia
Simple Columnar
Simple Cuboidal
Simple Squamos
Ciliated Pseudostratified Epithethial
Stratified Squamos Transitional
Connective Tissue
Composed of cells throughout a matrix of gel, liquid, protein fibers, or salts Common proteins found in connective tissue
• Collagen – strength
• Elastin – flexibility
• Reticulum – support
Classified as loose or dense Loose – most abundant type found in the body
• Provides attachment, stabilization, structure, and support
• Ex – blood
Dense • Strength – bone and cartilage
• Storage – adipose(fat)
• Flexibility – ligaments and tendons
LOOSE DENSE ADIPOSE
Muscle Tissue
Consists of cells with cytoskeleton fibers organized into bands or bundles that contract to cause body movement
Three types: Smooth – made of spindle or tear-drop shaped cells where
fibers are not visible • Provide weak contractions, found in the linings of blood vessels and
tubular organs
Cardiac – striated – fibers lined up as visible bands • Connected by intercalated disks
• heart
Skeleton • Large cells with distinct striations with provide strong directional
movement
• Attach to bones and joints – produces body movement
Muscle Tissue, cont.
Voluntary Under conscious control – skeletal muscles
You choose movements
Involuntary Work without conscious effort
• Heart
Striated Skeletal & cardiac
Non-striated Smooth muscle
Skeletal Muscle
Ways to identify:
Striated – no
intercalated discs
Each cell, many
nuclei
SmoothMuscle
Ways to identify:
No Striations
Each cell, single
nucleus
Cardiac
Ways to identify:
Straitions
Intercalated Discs
Nervous Tissue
Composed of two highly specialized cells Neurons
• Nerve cells – made up of a nerve cell body and various extensions from cell body that produce electrical impulses
• Motor neuron
• Sensory neuron
• interneuron
Neuroglia • Not involved in conduction of impulses
• Types
• Astrocytes – provide organization and support for nervous system
• Oligodendrites – from sheaths called myelin around neuron fibers
• Myelin speeds up transmission of nerve impulses
• Ependymal cells – secrete fluids that protect the brain
• Microglia – believed to maintain ion balance needed for nerve cell function
STOP!
3.5 Organs & Organ Systems
(pgs 112-121)
Organs are groups of tissues that work together to perform a function Organs working together = organ system
Cardiovascular – regulates blood flood
Digestive – regulates nutrition
Endocrine – regulates body function and development
Integumentary – provides protection
Lymphatic – regulates body fluids, helps fight disease
Muscular – provides structure and movement
Nervous – regulates flow of information
Reproductive – regulates sexual function
Respiratory – regulates atmospheric gases and certain bodily wastes
Skeletal system – provides support and movement
Urinary – regulates production, storage, and removal of urine
Organ Systems
Be sure to check out the images on page 113-
118….
Those images match up some body parts to which
system they belong to.
Use this as a reference for test
Wellness and Illness over the
Life Span
Cell pathology is basis of dysfunction
Abnormal, impaired, or incomplete functioning of a part of
the body’s hierarchy.
• Almost all gross diseases are due to dysfunction
Biopsy – surgical removal of diseased cells for
study
Cell Pathology conditions
Amyloid deposition (amyloidosis) – accumulation of amyloids in a cell Amyloid – protein-like material
• Indicators of cell damage • Intended to help, but cause harm when they build up
• Can cause cell death • EX – Alzheimer’s
Atrophy – wasting or decrease in size of cell, tissue, or organ Causes undernutrition and blood flow problems
Dysplasia – disorderly growth pattern in a tissue or organ
Dystrophy – “ill growth” Caused by malnutrition, undernutrition, or decreased blood
flow
Cell Pathology conditions, cont.
Fatty change – accumulation of lipids in the cell in response to cellular injury Excessive alcohol intake – leads to build up in liver cells
Hyperplasia – abnormal multiplication on the number of normal cells in a tissue Increases risk of cancer
Hypertrophy – enlargement of a tissue or organ
Metaplasia – abnormal change in cell and tissue function
Metastasis – cancerous or highly abnormal cells Cells break away from where there are supposed to be and move to
other locations in the body
Necrosis – localized tissue death From decreased blood flow, infections, injury, etc.
Cellular Aging
Fat cells, skeletal muscle and nervous tissue do
not undergo mitosis
Mitosis not only replicates cells, but also repairs cells
Cells accumulate damage over the years
Accumulated cell damage
• Eventually, the cells will fail at their task
Stress even causes cell aging
Releases certain hormones
Cellular Aging
Even cells that regularly replicate undergo damage
DNA can become damaged in the S(synthesis) phase of
mitosis
Every round of mitosis shortens the ends of the
chromosomes – called telomeres
They do not carry genes, but too much shortening can
make the structure abnormal
• Malfunction or cell death
Cancer cells do not go through telomere
shortening, they are immortal.