LECTURE 1: PRINCIPLES OF PHYSIOLOGY Flashcards
-the study of the biological functions of organs
and their inter-relationships
-studies interplay of factors that affect growth
(connectedness of each aspect of the body)
Physiology
Physiology is an____________
Integrating Science
brings together everything
known about an animal’s function to create an
integral picture of how an animal operates in its environment
integrative science
Mostly producers
Plants
consumers
Animals
Unlimited scheme of
growth
Plants
Limited Scheme of Growth
Animals
Non-motile and must rely
on immediate nutrient
sources
Plants
Can move around
Animals
Use large amounts of O2
Plants
Give off CO2
Animals
Conserve nitrogen
Plants
Gives off nitrogen as waste
Animals
Transports fluids/food
through vascular tissues
Plants
Transports fluids/food
through bloodstream
Animals
Grow throughout their
entire lifetime
Plants
Reaches a certain stage and
growth more or less stops
Animals
- study the structure and function of the
various parts of animals and plants; how these
parts work together to allow organisms to
perform their normal behaviours and respond
to their environment. - design experiments - learn about the control
and regulation of processes within groups of
cells and how the combined activities of these
cell groups affect the function of the animal.
Physiologist
- hallmark of physiology
Diversity
meeting the demands of survival has resulted
in numerous ________ _________ on the
basic theme of life
evolutionary variations
Unifying themes of physiological processes
- obey physical and chemicals laws
- regulated to maintain internal conditions and
trigger an appropriate response - physiological state of an animal is part of its
phenotype, which arises as the product of
the genetic make-up, or genotype, and its
interaction with the environment
species are compared in order to
discern physiological and
environmental patterns
Comparative Physiology
examines organisms in the
context of the environments they
inhabit (evolutionary adaptations)
- Environmental Physiology
techniques of evolutionary biology and
systematics are used to understand the
evolution of organisms from physiological
viewpoint, focusing on physiological markers
rather than anatomic markers
Evolutionary Physiology
how physiological processes unfold
during the course of organism development
from embryo through larva or fetus to
adulthood
*Developmental Physiology
vital information on the
physiology of the cells
themselves, which can be used to
understand the physiological
responses of tissues, organs, and
organ systems
Cell Physiology
Central Theme of Physiology
- Structure/Function Relationships
- Adaptation, Acclimatization, and
Acclimation - Homeostasis
- Feedback – Control Systems
- Conformity and Regulation
- Function is based on ________
structure
– Form fits function at all the levels of life, from
molecules to organisms
- Knowledge of a structure provides insight into
what it does and how its works
– Conversely, knowing the function of a structure
provides insight about its construction
Structure/Function Relationships
This structure-function relationship is clear in the ___________ ___________ in the shape of bird wing
aerodynamic efficiency
A honeycombed internal structure produces _____ _____ _____bones
light but strong
The flight muscles
are controlled by
________ that
transmit signals
between the
wings and brain.
neurons
_______ ______
provide the energy
to power flight.
Ample mitochondria
Biological function at each level of organization (Simple to Complex)
- Atoms
- Molecules
- Organelles
- Cells
- Organ and Tissue
- Organ System
- Organism
Physiology of an organism is very well
matched to the environment it occupies,
thereby ensuring its survival
Adaptation, Acclimatization, and
Acclimation
o evolution through natural selection
leading to an organism whose
physiology, anatomy, and behavior are
matched to the demands of its
environment
o generally irreversible;
Adaptation
*a physiological process is adaptive - present at
high frequency in the population because it
results in a higher probability of survival and
reproduction than alternative processes.
*physiological and anatomic adaptations -
genetically based, passed on from generation to
generation (DNA) and constantly shaped and
maintained by natural selection
Adaptation
- a physiological, biochemical, or anatomic
change within an individual animal during its
life that results from an animal’s chronic
exposure in its native habitat to new,
naturally occurring environmental condition
*animal in migrate to high altitude
o reversible
Acclimatization
- refers to the same process as
acclimatization when the changes are
induced experimentally in the laboratory or
in the wild by an investigator
*animal placed in hypobaric chamber
o reversible
Acclimation
The tendency of organisms to regulate and maintain relative internal stability
Homeostasis
- French pioneer of modern
physiology
◦ The milieu interieur
◦ “Constancy of the internal
environment is the condition of
free life”
◦ the ability of animals to survive in
often stressful and varying
environments directly reflects their
ability to maintain a stable internal
environment.
Claude Bernard (1872)
o extended notion of internal
consistency to the organization and
function of cells, tissues and organs
o “Homeostasis” – tendency towards
internal stability (1929 – Nobel
Price)
Walter B. Cannon (1871-1945)
The evolution of _______________________that maintain it were essential factors in allowing animals to venture from relatively “physiologically friendly” environments and invade habitats more hostile to life processes
homeostasis and the physiological systems
o Dynamic equilibrium
o In spite of multiple stimuli
o Maintained by negative
feedback
Homeostasis
o Homeostasis is the ability to ________________ in an ever-changing outside world
maintain arelatively stable internal environment
The internal environment of the body is in a
_______________________
dynamic state of equilibrium
________, _______ and _____ factors interact
to maintain homeostasis
Chemical, thermal, and neural factors
o Regulation of
homeostasis is
accomplished
through the
nervous and
endocrine
systems
Control Mechanism
_______ and _______are antagonistic
hormones that help maintain glucose
homeostasis
Insulin and glucagon
pancreas has clusters of endocrine cells called
___________ with alpha cells that
produce glucagon and beta cells that produce
insulin
islets of Langerhans
hereditary factors and obesity play a role in its
development
high blood sugar levels – sugar excreted in the
urine
symptoms: excessive urination and excessive
thirst
if severe: fat substitutes for glucose as major
fuel source → production of acidic metabolites
→ life threatening lowering of blood pH
Hypoinsulinism: diabetes mellitus
-insulin-dependent
diabetes
autoimmune disorder
usually appears in childhood
treatment: insulin injections
Type I diabetes mellitus
-non-insulin-dependent
diabetes
usually due to target cells having a decreased
responsiveness to insulin
usually occurs after age 40 – risk increases
with age
accounts for over 90% of diabetes cases
Type II diabetes mellitus
Basic Component of a Homeostatic Control System
- A receptor
- A Control Center
- A n Effector
detects changes (stimuli) in the
body.
receptor
determines a set point for a
normal range.
control center
causes the response determined by
the control center.
effector
regulatory processes that maintain
homeostasis in the cells and multicellular
organisms depend on feedback
Feedback – Control Systems
– return of information to a
controller that regulates a controlled variable
– occurs when sensory information
about a particular variable (e.g. temperature,
pH, salinity) is used to control processes in
the cells, tissues, and organs that influence
the internal level of that variable
feedback
A regulatory mechanism in which a
change in a controlled variable
triggers a response that opposes the
change.
Negative Feedback
A ______ __________ mechanism
decreases the intensity of the
stimulus or eliminates it
negative feedback
The negative feedback mechanism
causes the system to change in the
______________from the stimulus
opposite direction
Most homeostatic control mechanisms
are ___________________
negative feedback mechanisms
In negative feedback systems, the
output shuts off or somehow alleviates
the _____________
original stimulus
a loop in which
the response
reduces the
initial stimulus
negative
feedback
-enhances or exaggerates the original stimulus so that activity is accelerated
- mechanisms usually
control infrequent events such as blood
clotting or childbirth
Positive Feedback Mechanism
Positive Feedback Mechanism is considered positive because it results in change occurring in the ________________________
same direction as the original stimulus
Positive feedback usually does not
maintain __________. It is
characterized by being short in
________ and ____________
-homeostasis
-duration, and infrequent.
- Break or tear in blood
vessel wall - Clotting occurs as
platelets adhere to site
and release chemicals - Released chemical
attract more platelets - Clotting proceeds until
break is sealed by
newly formed clot
Positive Feedback Mechanism
In positive
feedback systems,
the output
___________ or
_____________ the
original stimulus
enhances or exaggerates
- Most diseases cause homeostatic imbalances
(chills, fevers, elevated white blood counts etc) - Aging reduces our ability to maintain
homeostasis – heat stress - If a disturbance of homeostasis or the body’s
normal equilibrium is not corrected, illness
occurs. - Feedback mechanisms may be overwhelmed
or may be not functioning correctly (diabetes
mellitus, clotting disorders)
Homeostatic Imbalances
*when an organism is confronted with changes
in its environment (e.g. changes in oxygen
availability or salinity), it can respond in one or
two ways: conformity or regulation
Conformity and Regulation
environmental challenges induce
internal body changes that simply parallel the
external conditions (unable to maintain
homeostasis)
conformers
biochemical, physiological, behavioral,
and other mechanisms to regulate their internal environment over a broad range of external environmental changes (maintain homeostasis)
regulators
maintain ion
concentrations of
body fluids above
environmental
levels when placed
in dilute water vice
versa
Osmoregulators
based largely on controlled
movement of solutes between internal fluids and the external environment
Osmoregulation
Some aquatic
invertebrates in
temporary ponds
lose almost all their
body water and
survive in a dormant
state. This adaptation is
called _________
anhydrobiosis
a biological process that occurs when two or more species affect each other’s evolution through natural selection.
Coevolution
organisms that maintain an internal environment that is isotonic to their external environment
Osmoconformers
organisms that are unable to maintain their respiration independently of environmental oxygen concentration, and instead decrease their energy expenditure when oxygen levels are low
Oxyconformers
