1. Homeostasis Flashcards
What is physiology? (1)
THE STUDY OF THE BIOLOGICAL FUNCTIONS OF ORGANS AND THEIR INTERRELATIONSHIPS
What is physiology? (2)
STUDIES INTERPLAY OF FACTORS THAT AFFECT GROWTH (connectedness of each aspect of the body)
Physiological difference in plants
- unlimited scheme of growth
- non-motile and must rely on immediate nutrient sources
- use large amounts of oxygen
- conserve nitrogen
- transports fluids/food through vascular tissues
- Grow throughout their entire lifetime
Physiological difference in animals
- limited
- can move around
- give off CO2
- Gives off nitrogen as waste
- Bloodstream
- Reaches a certain stage and growth more or less stops
What are physiologists studying?
how these parts work together to allow organisms to perform their normal behaviors and respond to their environment
Physiologists (1)____, learn about the (2)_____, and (3)_____ the function of the animal.
- design experiments
- control and regulation of processes within groups of cells
- how the combined activities of these cell groups affect
He is a French physiologist and the father of modern physiology
CLAUDE BERNARD (1813-1878)
What did Claude Bernard discover?
The “milieu interieur” or the “bodily fluids”
What did Claude Bernard observe?
observed that the internal environment remains remarkably constant despite changing conditions in the external environment.
Claude described homeostasis as ?
“Constancy of the internal environment is the condition of free life”
Claude Bernard observed the ability of animals to?
survive in often stressful and varying environments directly reflects their ability to maintain a stable internal environment.
Walter Cannon (1871-1945)
an American physiologist coined the term homeostasis to describe this stable internal environment in 1932
How did Walter Cannon described homeostasis?
stable internal environment
Walter Cannon described the … ?
extended notion of internal consistency to the organization and function of cells, tissues and organs
TWO THEMES OF PHYSIOLOGY
- Integration
- Homeostasis
What is homeostasis according to Walter Cannon?
tendency towards internal stability (1929 – Nobel Prize)
The evolution of homeostasis and the physiological systems that maintain it were?
essential factors in allowing animals to venture from relatively “physiologically friendly” environments and invade habitats more hostile to life processes.
TWO THEMES OF PHYSIOLOGY
Integration
Homeostasis
Research levels from whole body, to organs, tissues, cells, organelles, and genes
integrative physiology
Examples that systems don’t work alone
The respiratory system takes in oxygen and removes waste gases.
The cardiovascular system is responsible for delivering the oxygen to all parts of our bodies.
examples of organ interrelationships
Nutrients and oxygen are distributed by the blood
Metabolic wastes are eliminated by the urinary and respiratory systems
Hierarchy of biological systems
- molecule
- organelle
- cell and tissue
d. organ
4 types of tissues
- connective tissue
- muscle tissue
- nerve tissue
- epithelial tissue
Binds together or supports cells, other tissues/organs
connective tissue
Contracts on stimulation
Movement, posture and heat production
muscle tissue
Conducts nerve impulses throughout the body
nerve tissue
Covers all body surfaces; lines all cavities; forms glands
Protective barrier against the environment
epithelial tissue
Enumerate the 11 major organ systems
Digestive
Urinary
Reproductive
Nervous
Endocrine
Integumentary
Skeletal
Muscular
Circulatory
Lymphatic
Respiratory
Unifying themes of physiological processes are 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.
5 Subdisciplines of Physiology
- comparative physiology
- environmental physiology
- evolutionary physiology
- developmental physiology
- cell physiology
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 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 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
What is comparative physiology?
species are compared in order to discern physiological and environmental patterns
What is environmental physiology?
examines organisms in the context of the environments they inhabit (evolutionary adaptations)
What is evolutionary physiology?
techniques are used to understand the evolution of organisms from physiological viewpoint, focusing on physiological markers rather than anatomic markers
Physiology of an organism is very well matched to the environment it occupies, thereby ensuring its survival
Adaptation, Acclimatization, and Acclimation
What is developmental physiology?
how physiological processes unfold during the organism development from embryo through larva or fetus to adulthood
What is cell 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
evolution through natural selection leading to an organism whose physiology, anatomy, and behavior are matched to the demands of its environment
adaptation
5 Central themes in physiology
- structure/function relationship
- adaptation, acclimatization. and acclimation
- homeostasis
- control systems
- conformity and regulations
What does function/structure relationship mean?
- 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 it works
- Conversely, knowing the function of a structure provides insight about its construction
5 Examples of structure-function relationship
in the aerodynamic efficiency in the shape of bird wing.
A honeycombed internal structure produces light but strong bones.
The flight muscles are controlled by neurons that transmit signals between the wings and brain.
Ample mitochondria provide the energy to power flight.
Phenotypic plasticity
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.
genetically based, passed on from generation to generation (DNA) and constantly shaped and maintained by natural selection.
physiological and anatomic adaptations
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
Acclimatization
refers to the same process as acclimatization when the changes are induced experimentally in the laboratory or in the wild by an investigator
acclimation
example of acclimatization
animal in migrate to high altitude
example of acclimation
animal placed in hypobaric chamber
The tendency of organisms to regulate and maintain relative internal stability
homeostasis
3 definitions of Homeostasis
- DYNAMIC EQUILIBRIUM
- IN SPITE OF MULTIPLE STIMULI
- MAINTAINED BY NEGATIVE FEEDBACK
ability to maintain a relatively stable internal environment in an ever-changing outside world
homeostasis
Variables in Homeostasis
- stimulus
- reception
- input
- output
- response
What systems regulate homeostasis?
Endocrine and nervous
antagonistic hormones that help maintain glucose homeostasis
insulin and glucagon
the pancreas has clusters of endocrine cells called
islets of Langerhans
blood glucose level increase
beta cells release insulin
blood glucose level decrease
glucagon
diabetes mellitus: high blood sugar levels – sugar excreted in the urine
hyperinsulinism
autoimmune disorder
usually appears in childhood
treatment: insulin injections
Type 1 diabetes mellitus (insulin dependent)
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 (non-insulin-dependent diabetes)
animals can survive large fluctuations in external osmolarity
euryhaline
opposite of euryhaline, survive shortly
stenohaline
Some aquatic invertebrates in temporary ponds lose almost all their body water and survive in a dormant state
anhydrobiosis
BASIC COMPONENTS OF A HOMEOSTATIC CONTROL SYSTEM (3)
Receptor
Control Center
effector
detects changes (stimuli) in the body.
receptor
A __ __ 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
control systems
return of information to a controller that regulates a controlled variable
feedback
A regulatory mechanism in which a change in a controlled variable triggers a response that opposes the change.
negative feedback
enhances or exaggerates the original stimulus so that activity is accelerated
positive feedback
example of positive feedback
Break or tear in blood vessel wall
Clotting occurs as platelets adhere to site and release chemicals
Released chemical attract more platelets
examples of conformers
osmoconformers and oxyconformers
environmental challenges induce internal body changes that simply parallel the external conditions (unable to maintain homeostasis)
conformers
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: __ or ____
conformity and regulation
biochemical, physiological, behavioral, and other mechanisms to regulate their internal environment over a broad range of external environmental changes (maintain homeostasis)
regulators
is based largely on the controlled movement of solutes between internal fluids and the external environment
osmoregulation
maintain ion concentrations of body fluids above environmental levels when placed in dilute water vice versa
osmoregulators
