Transcript Why are we here? • • • Obviously, to learn about human anatomy and physiology. But, what does that mean? Before we begin, we’ve got to figure.

Why are we here?
•
•
•
Obviously, to learn about human anatomy
and physiology.
But, what does that mean?
Before we begin, we’ve got to figure a few
things out:
1.
2.
3.
What’s a human?
What’s anatomy?
What’s physiology?
What are humans?
• Organisms are classified as
human because they are:
– Animals
– Vertebrates
• Possess backbones
– Mammals
• Possess:
–
–
–
–
Mammary glands
Hair
Endothermy (i.e., we generate heat internally)
Heterodonty (i.e., we have teeth w/ different shapes
and functions)
– 3 middle ear bones.
What are humans?
– Primates
• Possess:
– Opposable thumbs (can you touch your pinky
with your thumb?). What advantage does this
confer?
– 2 clavicles (collarbones)
– Only 2 mammary glands. Why only 2? (Think
about how many kids a woman normally gives
birth to.)
– Forward facing eyes with stereoscopic vision (for
depth perception)
– Hominids
• Bipedal (walk on 2 legs)
• Possess a large brain size/body size ratio
• What is anatomy?
– Anatomy is defined as the study of…
• Structure refers to the shapes, sizes, and
characteristics of the components of the
human body.
• The word anatomy comes from 2 words:
– Ana which means “up or apart”
– Tomos which means “to cut”
Why these two words????
Types of Anatomy
•
We can divide our study of structure into 2 parts:
•
Study of stuff seen by the naked eye (Gross Anatomy).
•
Study of stuff seen ONLY with the microscope (Microanatomy).
–
We can divide microanatomy into:
» Histology – study of tissues
» Cytology – study of individual cells.
Physiology
• Physiology is defined as
the study of function – so
human physiology
attempts to explain how
and why humans function.
• Physiology is where we
figure out how stuff
works.
• How do muscles contract?
• How do we run?
• How does our heart beat?
Some Important Themes
1. Biology is hierarchical with each level building
on the level below it.
2. Each level of biological structure has emergent
properties.
3. Cells are an organism’s basic unit of structure
and function.
4. Structure and function are correlated at all levels
of biological organization!!!!!!!!
5. Regulatory mechanisms ensure a dynamic
balance in living systems.
Levels of Structure
• In order to understand how
something is built and how
something works, you must
look at all of its components
and analyze them both
individually and together.
• In doing these collective and
separate analyses, you must
examine things at multiple
structural levels, i.e., one must
break them down from large to
small – this is called
reductionism
• An organism (such as a human
being) may be broken down as
illustrated on the left.
Organelle
Cell
Tissue
Organ
Organ System
Organism
Levels of Structure
• The basic unit of life is the cell.
• All living organisms are composed of one or more
cells.
• The human body contains about 100 trillion cells.
• There are about 200 different types of cells in the
human body.
• The different types of cells have different features but
for the most part, all cells are made up of organelles
and various macromolecules (e.g., proteins, lipids,
carbohydrates and nucleic acids).
• Organelles themselves are made of these
macromolecules and macromolecules are polymers of
smaller molecules which consist of atoms of various
chemical elements.
A Prototypical Cell
Important Organelles
• Plasma Membrane → Separates the cell exterior from the
cell interior (cytoplasm).
• Nucleus → Membrane bound structure that contains
deoxyribonucleic acid (DNA) which is the set of
instructions for the synthesis of all the body’s proteins.
– CAN YOU SEE THE NUCLEUS AND THE
PLASMA MEMBRANE IN THE CELL TO THE
RIGHT?
• Mitochondria → Structure bound by a double membrane
and the site at which the energy stored in sugars and other
organic molecules is transferred to ATP, the chemical
which acts as the “currency” for energy in the cell.
• Ribosomes → Not bound by a membrane. Sites of protein
synthesis. May be free – floating in the cytoplasm – or
bound to the endoplasmic reticulum.
Are the 2 pictures on this page to the same
scale? How do you know?
Important Organelles
• Rough Endoplasmic Reticulum →
Membranous set of tubes with
ribosomes studded along its surface.
Site of the synthesis of proteins that
are destined to be exported from the
cell.
• Smooth Endoplasmic Reticulum →
ER w/o the attached ribosomes. Site
of cellular lipid synthesis, among
other things.
• Golgi Apparatus → Membrane
bound organelle responsible for
determining the direction of proteins
synthesized in the rough ER.
• Lysosomes → Membrane bound
organelle that houses digestive
enzymes that can be used to break
down ingested toxins or worn out
cell parts.
More Levels of Structure
• Similar cells and cell
products come together to
form tissues.
• A structure made of 2 or
more tissue types that
perform a particular
function is an organ.
• A group of organs with a
unique collective function
is an organ system. There
are 11 of these in the
human body.
Integumentary System
•
Structures:
-
•
Skin, hair, sweat and oil glands
Functions:
-
-
Forms the external body covering
Protects deeper tissues from injury
Involved in vitamin D synthesis
Prevents desiccation, heat loss, and
pathogen entry
Site of pain and pressure receptors
Skeletal System
• Structures:
– The 206 bones of the human body
• Functions:
– Protects and supports body organs
• What characteristics might bone have that
allows it to support and protect?
– Provides a framework that muscles can use to
create movement
– Hemopoiesis (synthesis of blood cells)
– Mineral storage
• Bone contains 99% of the body’s store of what
mineral? (Hint  you can get this mineral from
drinking milk)
Muscular System
• Structures:
– The 600+ muscles of
the body
• Functions:
– Locomotion
– Manipulation of the
environment
– Maintaining posture
– Thermogenesis
(generation of heat)
Nervous System
• Structures:
– Brain, spinal cord, and
peripheral nerves
• Functions:
– Fast-acting control
system of the body
– Monitoring of the
internal and external
environment and
responding (when
necessary) by initiating
muscular or glandular
activity
Endocrine System
• Structures:
– Hormone-secreting glands
• Pituitary, Thyroid, Thymus,
Pineal, Parathyroid, Adrenal,
Pancreas, Small Intestine,
Stomach, Testes, Ovaries,
Kidneys, Heart
• Functions:
– Long-term control system of
the body
– Regulates growth,
reproduction, and nutrient use
among other things.
Cardiovascular System
• Structures:
– Heart, Blood vessels (arteries,
veins, and capillaries)
• Functions:
– The heart pumps blood thru the
blood vessels.
– Blood provides the transport
medium for nutrients (glucose,
amino acids, lipids), gases (O2,
CO2), wastes (urea, creatinine),
signaling molecules (hormones),
and heat.
Lymphatic/Immune
System
• Structures:
– Lymphatic vessels, Lymph nodes,
Spleen, Thymus, Red bone
marrow
• Functions:
– Returning “leaked” fluid back to
the bloodstream,
– Disposal of debris
– Attacking and resisting foreign
invaders (pathogens i.e., diseasecausing organisms)
Respiratory System
• Structures:
– Nasal cavity, pharynx,
trachea, bronchi, lungs
• Functions:
– Constantly supply the
blood with O2, and
remove CO2
– Regulate blood pH
Digestive System
• Structures:
– Oral cavity, esophagus, stomach, small
intestine, large intestine, rectum, salivary
glands, pancreas, liver, gallbladder
• Functions:
– Ingestion and subsequent breakdown of food
into absorbable units that will enter the blood
for distribution to the body’s cells
Urinary System
• Structures:
– Kidneys, ureters,
urinary bladder,
urethra
• Functions:
– Removal of
nitrogenous wastes
– Regulation of body’s
levels of water,
electrolytes, and
acidity
Reproductive System
• Structures:
– Male:
• Testes, scrotum, epididymis,
vas deferens, urethra, prostate
gland, seminal vesicles, penis
– Female:
• Ovary, uterine tube, uterus,
cervix, vagina, mammary
glands
• Functions:
– Production of offspring
Why Are Levels of Structure Important?
• In this class, we’ll study all levels and see how they work
together to create structures and allow them to function.
• In essence, the combination of these different yet
connected levels allows life to proceed.
• But we must also be aware of emergent properties.
– Things are often much more than simply a sum of their parts.
– Consider a hammer which is made of a head and a handle. Either
piece by itself is of little use to drive a nail – but put together, they
perform the task quite easily.
– Or consider table salt – sodium chloride (NaCl). By themselves,
chlorine is a poisonous gas and sodium an explosive metal. But
when bound together, they create something much, much different.
We must be aware of emergent properties as well as
reducing structures to their component parts.
Stayin’ Alive
• Your body has about 100 trillion cells in it.
• For your life to NOT end abruptly, these cells
need to have the correct amount of:
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Oxygen
Nutrients
Waste removal
Heat
Ions (sodium, calcium, etc.)
Lots of other stuff
Homeostasis
• Defined as the body’s ability to maintain stable
internal conditions in spite of the changing
external conditions.
• We just said that our body needs to have the right
amount of stuff (i.e., temperature, blood [glucose],
pH etc.) at all times in order to function properly.
• First, let’s refer to all this stuff as “different
variables”
Note: the brackets surrounding the word glucose in the above paragraph mean “concentration
of glucose,” i.e., how much glucose is dissolved in a particular fluid (blood in this case)