Principles of General Physiology Flashcards
Study of biological function of organs and their inter-relationships
Physiology
Brings together everything known about an animal’s function to crate and integral picture of how it operates in its environment
integrative science
study the structure and function of the various parts of animals and plants
physiologist
learn about the control and regulation of processes within groups of cells and how these groups affect the function of animal
design experiments
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 chemical laws
- regulate to maintain internal conditions and trigger appropriate response
- physiological state of an animal and its interaction with the environment
Subdisciplines of Physiology
- Comparative Physiology
- Environmental Physiology
- Evolutionary Physiology
- Developmental Physiology
- Cell Physiology
Species are compared to discern physiological and environmental patterns
comparative physiology
Examines organisms in the environments they inhabit (evolutionary adaptations)
environmental physiology
Used to understand the evolution of organism from physiological viewpoint
evolutionary physiology
how physiological processes unfold during the organism development from embryo through larva or fetus to adulthood
developmental physiology
information on the physiology of cells can be used to understand the physiological responses of tissues, organs, and organ systems
cell physiology
Central themes in physiology
- Structure/ Function relationships
- Adaptation, Acclimatization, and Acclimation
- Homeostasis
- Feedback
- Conformity and Regulation
Form fits function at all the levels of life, from molecules to organisms
structure/ function relationships
knowledge of structure provide insights into ___ ___ and ___ ___
what it does and how it works
Example of form fits function
aerodynamic efficiency in the shape of bird wing
Biological level of organization
molecular > macromolecular > cellular > tissue > organ > organ system > organism
Physiology of an organism is well matched to the environment it occupies, ensuring its survival
adaptation, acclimatization, and acclimation
evolution through natural selection leading to an organism whose physiology, anatomy, and behavior are matched to the demand of its environment
adaptation
a physiological, biochemical, or anatomic change that results from chronic exposure in its native habitat to a new
acclimatization
refers to the same process as acclimatization when the changes are induced experimentally in the laboratory or in the wild
acclimation
tendency of organisms to regulate or maintain relative internal stability
homeostasis
French pioneer of modern physiology
Claude Bernard (1872)
the ability of animals to survive in often stressful and varying environments directly reflect their ____
ability to maintain a stable internal environment
Coined the terms homeostasis
Walter B. Cannon (1871-1945)
The evolution of homeostasis and physiological systems allow animals to venture from relatively “___ ___” environments and invade habitats more ___ to life processes
physiologically friendly; hostile
Definition of homeostasis
- Dynamic equilibrium
- In spite of multiple stimuli
- Maintained by negative feedback
Homeostatic Control Mechanism
- Stimulus
- Change detected by receptor
- Information sent along afferent pathway to control center
- Information sent along efferent pathway to effector
- Response
Antagonistic hormones that help maintain glucose homeostasis
Insulin and glucagon
Pancreas has cluster of endocrine cells called ___
islets of Langerhans
Alpha cells produce
glucagon
Beta cells produce
insulin
Type 1 diabetes mellitus (insulin dependent)
- autoimmune disorder
- appears in childhood
- treatment: insulin injections
Type 2 diabetes mellitus (non-insulin dependent)
- decrease responsiveness of target cells to insulin
- occurs after age of 40
- accounts for 90% of diabetes cases
Animals can survive large fluctuations in external osmolarity
Euryhaline
Lose of body water to survive in a dormant state
anhydrobiosis of tardigrades
Basic components of a homeostatic control systems
receptor, control center, 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 cell and multicellular organisms
Feedback
occurs when sensory information about a particular variable is used to control processes that influence the internal level of that variable
feedback
Regulatory mechanism which a change in a controlled variable triggers a response that opposes a change
negative feedback
In negative feedback systems, the output ___ or ___
shuts off or somehow alleviates the original stimulus
A mechanism that enhances or exaggerates the original stimulus so that activity is accelerated
positive feedback
In positive feedback systems, the output ___ or ___
enhances or exaggerates the original stimulus
Positive feedback does not maintain homeostasis. It is characterized by being ___ and ____
short in duration and infrequent
Feedback mechanisms may be overwhelmed or may be not functioning correctly
Homeostatic imbalances
it occurs if a disturbance in homeostasis or the body’s normal equilibrium is not corrected
illness
When an organism is confronted with changes in its environment
conformity and regulation
Environmental challenges induce internal body changes parallel to external conditions
conformers
Biochemical, physiological, and other mechanisms to regulate internal environment over a broad range of external changes
regulators
Maintain ion concentrations of body fluids above environmental levels when placed in dilute water or vice versa
osmoregulators
based largely on controlled movements of solutes between internal fluids and the external environment
osmoregulation
