Students will be able to describe cell characteristics and cell physiology.
Students will be able to describe the anatomy and physiology of musculo-skeletal, circulatory, nervous, endocrine, reproductive, digestive, and excretory (urinary) systems.
Students will be able to explain the role of the endocrine system and central nervous system in maintaining homeostasis.
Students will be able to characterize pathological conditions of the musculo-skeletal, circulatory, nervous, endocrine, reproductive, digestive, and excretory (urinary) systems.
Students will be able to apply principles of genetics to solve simple patterns of inheritance.
Students will be able to list the properties of pathogens in relation to human health.
Evaluation Plan
Unit quizzes (10) - 15%
Assignments (10) - 15%
Discussions / wiki entries (10) - 10%
Tests (3) - 60% (1x 15%, 1x 20%, 1x 25%)
Unit Timeline
Assignments: 15%
Quizzes: 15%
Discussions / Wiki: 10%
Tests: 60%
Important Topics
Anatomy and physiology - understand the difference
Levels of organization: organism, systems, organs, tissues, cells
Signs of life
Cell as a basic unit of a living matter
Organelles (the most important ones)
Cellular transport
Positive and negative feedback
Anatomy and Physiology
Anatomy: study of the structure of an organism and relationships of its parts (means “cutting apart”).
Physiology: study of the functions of living organisms and their parts (requires active experimentation).
Pathology: scientific study of disease (comes from pathos, the Greek word for "disease.")
Levels of Organization
Organization is the most important characteristic of body structure.
The body as a whole is a unit constructed of the following smaller units:
Atoms and molecules—chemical level
Cells—the smallest structural units; organizations of various chemicals
Tissues—organizations of similar cells
Organs—organizations of different kinds of tissues
Systems—organizations of many different kinds of organs
Organism – the highest level of organization
Levels of Organization
Gross levels
Atom
Molecule
Chemical level (Chapter 2)
Microscopic levels
Vesicles
Organelle levels (Chapter 3)
Neuron
Cellular level (Chapter 3)
Group of neurons and support cells
Tissue level (Chapter 4)
Brain
Organ level (Chapter 5)
Organ system level(Chapters 5-23)
Integumentary
Skeletal
Muscular
Cardiovascular
Endocrine
Reproductive
Urinary
Homeostasis
Survival of the individual and of the genes that make up the body is of the utmost importance
Survival depends on the maintenance or restoration of homeostasis (relative constancy of the internal environment)
The body uses negative feedback loops and, less often, positive feedback loops to maintain or restore homeostasis
Feedback loops involve a sensor, a control center, and an effector
Homeostasis
All organs function to maintain homeostasis
Ability to maintain balance of body functions is related to age: peak efficiency occurs during young adulthood; diminishing efficiency occurs after young adulthood
Homeostatic Control Loops
Most homeostatic control loops in the body involve negative feedback.
Temperature Regulation – an Example of Negative Feedback
An engineer’s diagram showing how relatively constant room temperature (controlled condition) can be maintained.
A thermostat (control center) receives feedback information from a thermometer (sensor) and responds by counteracting change from normal by activating a furnace (effector).
A physiologist’s diagram showing how a relatively constant body temperature (controlled condition) can be maintained.
The brain (control center) receives feedback information from nerve endings called cold receptors (sensors) and responds by counteracting a change from normal by activating shivering by muscles (effectors).
Positive Feedback
An example of positive feedback occurs when a baby is born.
As the baby is pushed from the womb (uterus) into the birth canal (vagina), stretch receptors detect the movement of the baby.
Stretch information is fed back to the brain, triggering oxytocin (OT) release.
OT travels through the bloodstream to the uterus, where it stimulates stronger contractions.
Stronger contractions push the baby farther along the birth canal, increasing stretch and stimulating the release of more OT.
Uterine contractions get stronger and stronger until the baby is pushed out of the body and the positive feedback is stopped.
Uterine Contraction - an Example of Positive Feedback
Variable: Stretch increase
Detected by Stretch receptors
Fetus moves into birth canal
Hypothalamus feeds information via nerve fibers back to brain
Correction signals via oxytocin
Uterine muscle effector
Stronger, more frequent labor contractions
Positive Feedback Loop Amplifies Change
Instead of opposing a change in the internal environment, positive feedback loop temporarily amplifies the change that is occurring.
Uterine contractions are an example of positive feedback loop.
Temperature regulation in the body is an example of negative feedback loop.
The Cell
Size and Shape
Human cells vary considerably in
An ovum has a diameter of 150 micrometers.
A red blood cell has a diameter of 7.5 micrometers.
Size
All are microscopic
Cells differ notably in shape (flat, brick-shaped, threadlike, and irregular)
Cells perform all living functions: What are they? Example: eating, …..
Cell Composition
Cells contain cytoplasm—a substance found only in cells.
Organelles are specialized structures within the cytoplasm.
Cell interior is surrounded by a plasma membrane.
Encloses the cell and is a boundary
The Cell - Organelles
Nucleus
Nuclear envelope: membrane enclosing the nucleus. Protein-lined pores allow material to move in and out.
Chromatin: DNA plus associated proteins.
Nucleolus: condensed region where ribosomes are formed.
Peroxisome: metabolizes waste
Endoplasmic reticulum
Rough: associated with ribosomes; makes secretory and membrane proteins.
Cytoskeleton
Microtubules: form the mitotic spindle and maintain cell shape.
Centrosome: microtubule-organizing center.
Intermediate filaments: fibrous proteins that hold organelles in place.
Microfilaments: fibrous proteins; form the cellular cortex.
Vacuole
Plasma membrane
Lysosome: digests food and waste materials.
Golgi apparatus: modifies proteins.
Cytoplasm
Mitochondria: produce energy.
Organelles
Little organs within the cell
We will only talk about the most important ones
Plasma Membrane
Forms outer boundary of cell
Composed of a thin, two-layered membrane of phospholipids containing proteins
Is selectively permeable (does not allow everything to enter or leave the cell; it chooses what passes through)
It expands
It is not a uniform ‘fabric’
Cytoplasm and Ribosomes
Cytoplasm
Internal living material of cells
Fills space between plasma membrane and nucleus
Contains organelles—numerous small structures (little organs)
Ribosomes
May attach to rough endoplasmic reticulum (ER) or lie free in cytoplasm
Made of two tiny subunits of mostly ribosomal RNA
Manufacture enzymes and other protein compounds
Often called protein factories
Endoplasmic reticulum - ER
Network of connecting sacs and canals
Carry substances through fluid cytoplasm
Two types—rough and smooth
Rough ER collects, folds, and transports proteins made by ribosomes
Smooth ER synthesizes chemicals; makes new membrane
Golgi Apparatus and Mitochondria
Golgi Apparatus
Group of flattened sacs near the nucleus
Collect chemicals into vesicles that move from the smooth ER outward to plasma membrane
Called the chemical processing and packaging center
Mitochondria
Composed of inner and outer membranous sacks
Involved with energy-releasing chemical reactions
Contains one DNA molecule
Produce and store energy for the cell.
Nucleus
Surrounded by nuclear envelope
Made up of two separate membranes
Contains nuclear pores
Nucleolus
Dense region of nuclear material
Controls cell because it contains DNA, the genetic code—instructions for making proteins, which in turn determine cell structure and function
Component structures include nuclear envelope, nucleoplasm, nucleolus, and chromatin granules
DNA molecules become tightly coiled chromosomes during cell division
Each cell has 46 chromosomes in the nucleus
Flagella, Microvilli, and Cilia
Flagella
Single projections extending from cell surfaces
Much larger than cilia
“Tails” of sperm cells only example of flagella in humans
Microvilli
Small, fingerlike extensions of the plasma membrane
Increase absorptive surface area of the cell
Cilia
Fine, hairlike extensions found on free or exposed surfaces of some cells
Capable of moving in unison in a wavelike fashion
Centrosome
Region of cytoplasm near nucleus
Serves as microtubule-organizing center of cell
Centrioles found within centrosome
Paired organelles that lie at right angles to each other near the nucleus
Function in cell reproduction
Lysosomes
Membranous-walled organelles
Contain digestive enzymes
Have a protective function (eat microbes)
Formerly thought to be responsible for apoptosis (programmed cell death)
Cell Structure Matching
Group A
Cytoplasm: "Living matter"
Plasma membrane: Surrounds cells
Cholesterol: Component of plasma membrane
Nucleus: Controls reproduction of the cell
Centrioles: Paired organelles
Group B
Ribosomes: "Protein factories"
Endoplasmic reticulum: "Smooth and rough"
Mitochondria: "Power plants"
Lysosomes: "Digestive bags"
Golgi apparatus: "Chemical processing and packaging center"
Movements of Substances Through Cell Membranes
Passive transport processes
Do not require added energy
Result in movement “down a concentration gradient”
Diffusion
Substances scatter themselves evenly throughout an available space
It is unnecessary to add energy to the system
Movement is from high to low concentration
Osmosis and Dialysis
Osmosis and dialysis are specialized examples of diffusion across a selectively permeable membrane.
Osmosis is diffusion of water (when some solutes cannot cross the membrane).
Dialysis is diffusion of solutes.
Filtration
Movement of water and solutes caused by hydrostatic pressure on one side of membrane
Responsible for urine formation
Active Transport – Ion Pumps
Active transport processes occur only in living cells
Movement of substances is “up the concentration gradient”
Requires energy from adenosine triphosphate (ATP)
Ion pump: a protein complex in the cell membrane
Ion pumps use energy from ATP to move substances across cell membranes against their concentration gradients
Examples: sodium-potassium pump; calcium pump
Some work with other carriers
Phagocytosis and Pinocytosis
Both are active transport mechanisms because they require cell energy.
Phagocytosis is a protective mechanism often used to destroy bacteria.
Pinocytosis is used to incorporate fluids or dissolved substances into cells.
Cell Transport and Diseases
Cystic fibrosis, characterized by abnormally thick secretions in the airways and digestive ducts, results from failed Cl− transport.
Cholera is a bacterial infection that causes Cl− and water to leak from cells lining the intestines, resulting in severe diarrhea and water loss.
In cystic fibrosis, the absence of chloride ion pumps causes thickening of some glandular secretions. Because thickened secretions block airways and digestive ducts, children born with this disease become weakened, often dying before adulthood
Cell Division
Reproduction of cell involving division of the nucleus (mitosis) and the cytoplasm
Two daughter cells result from the division
Period when the cell is not actively dividing is called interphase
DNA replication—process by which each half of a DNA molecule becomes a whole molecule identical to the original DNA molecule; precedes mitosis Mitosis
Process in cell division that distributes identical chromosomes (DNA molecules) to each new cell formed when the original cell divides
Enables cells to reproduce their own kind
Makes heredity possible
Stages of Mitosis
Prophase
Chromatin granules become organized
Chromosomes (pairs of linked chromatids) appear
Centrioles move away from nucleus
Nuclear envelope disappears, freeing genetic material
Spindle fibers appear
Metaphase
Chromosomes align across center of cell
Spindle fibers attach themselves to each chromatid