Chapter 29: Physiology, Homeostasis, and Temperature Regulation Flashcards
physiology
the study of how organisms function
involves analysinc exchanges of energy and materials
intracellular fluid
the fluid inside of the cells
most of the water in a multicellular organism is intracellular fluid
extracellular fluid
fluid outside of the cell
not as much as intracellular
ex. plasma and interstitial
plasma
the liquid portion of blood
extracellular fluid
interstitial fluid
fluid between the cells of the body
extracellular fluid
Is it important to maintain constant internal conditions? If so, why? If not, why not?
Protects the cells from external and harsh conditions
Lets animals occupy habitats that would kill the cells with direct exposure
Cell health depends on internal environment
They are teeny tiny baby birds that must be protected from the world
homeostasis
the process of maintaining stable conditions in the internal environment
organ
a part of an organism that has a specific function and is made of tissues
tissue
an assemblage of cells (using that fancy art terminology)
ONLY 4 KINDS (which seems kind of super weird because there are like a bazillion cell types and lots of different organs, but I mean we only have 4 different base pairs to make tons of proteins)
The 4 types are:
epithelial
connective
nervous
muscle
Epithelial tissue
sheets of densely packed, interconnected epithelial cells that cover inner and outer body surfaces
think lining/liners
Can secrete stuff/sense stuff/transport stuff/be a border/etc…. (many different ways it can show up/exist)
Connective tissue
Dispersed populations of cells embedded in an extracellular matrix that the selves themselves secrete
The properties and composition differentiate different types
Protein fibers may make cartilage, while a liquid one may allow blood to flow
Adipose tissue
connective tissue of energy storing fat-cells with little extracellular matrix
Nervous tissues
neurons + glial cells
(peripheral and central nervous system)
communicate with neurotransmitters
glial cells don’t communicate. They are glue!
Muscle tissues
they are like intense
bodyy masss
elongated cells contract to generate movement
Skeletal Muscle
(usually attached to bones)
responsible for locomotions and body movements
Cardiac Muscle
generates heartbeat and pumps blood
Smooth Muscle
generates forces in hollow internal organs
organ systems
organs that work together to carry out certain functions
what controls an animals physiological systems?
the nervous and endocrine systems
What is necessary to regulate physiological systems?
Information
control
kind of like how you make stuff happen
ex. control car with brake and accelerator
controlling car if you are going 394239048923049320849 mph or 0
regulate
Use current state to get tot he desired one
ex. have to know how fast you are going and how fast you want to go
(Where are you going, where have you been?)
set point
the desired state(not really a state but I couldn’t think of a better word)
ex. desired speed in a car
feedback information
the reported info on current state
ex. speedometer reading
error signal
the difference between the set point and feedback information
they suggest corrective actions
Regulatory systems
obtain, process, and integrate feedback information and then issue commands
like the government
sensor
part of regulatory system
provides the feedback info that is compared with the set point
effectors
effect changes in the internal (or external environment)
negative feedback
most common use of sensory information
counteracts or negates whatever is pushing the system away from its set point
stabilizing
Brings it back to the set point
positive feedback
Amplifies a response Increases deviation from set point ex. emptying body cavities sexy times labor basically lots of stuff that you really want to think about at the same time
feedforward information
Changes the set point
predictive of a change before it occurs (like changing seasons)
ex. deer more important than speed limit
Ambient environment
External environment
Cell survival range
0 to 40 degrees Celsius, but varies based on species
Q10
Factor of temperature sensitivity
=Rt/(Rt-10)
Q10=1
Reaction is not temp sensitive
Ectotherm
An organism where body temp depends on outside environment
Endotherms
High and constant body temperatures are maintained over wide range of ambient ones
Thermoneutral Zone (TNZ)
Like TMZ but not at all
Temperature range where Mr is low and constant
Basal metabolic rate (BMR)
MR at minimal level compatible with all of physiological functions to maintain homeostasis of the internal environment in the resting animal
In biological systems, Q10 is usually between
2 and 3
Ambient environment
External environment
Cell survival range
0 to 40 degrees Celsius, but varies based on species
Q10
Factor of temperature sensitivity
=Rt/(Rt-10)
Q10=1
Reaction is not temp sensitive
Ectotherm
An organism where body temp depends on outside environment
Endotherms
High and constant body temperatures are maintained over wide range of ambient ones
Thermoneutral Zone (TNZ)
Like TMZ but not at all
Temperature range where Mr is low and constant
Basal metabolic rate (BMR)
MR at minimal level compatible with all of physiological functions to maintain homeostasis of the internal environment in the resting animal
In biological systems, Q10 is usually between
2 and 3
Heat budget question
The combination of heatin and heatout
Metabolism
All energy conversions produce heat as a by-product, including the all powerful metabolism
Produces heat in animal
Radiation
Heat transfers from warmer to cooler objects via exchange of infrared radiation
Ex standing in front of a fire
Rabs
Incoming radiation that is absorbed
Rout
Outgoing radiation which is emitted
Convection
Heat transfers to a surrounding medium such as air or water as that medium flows over a surface
Ex. Wind chill
Conduction
Heat transfers directly when objects of two different temperatures come into contact
Ex ice pack on an ankle
Evaporation
Heat transfers away from a surface when water evaporates on that surface
Ex sweating
What processes contribute to heatin (generally)?
Metabolism and Rabs
What processes generally contribute to Heatout?
Rout + convection + conduction + evaporation
Brown fat
Adipose tissue that has a high density of mitochondria and blood vessels
Found in newborns
Shivering thermogenesis
Shivering to increase MR
Lower critical temperature
The lower end of a thermoneutral zone
An animal with a smaller body size has a _____________ BMR per gram compared to a larger animal
higher
Smaller surface area to volume
more support tissue (skin and bone)
What is the major adaptation of endotherms to cold climates?
insulation
How to measure thermal insulation?
MR= K(Tb-Ta) K= slope of curve or thermal conductance
Thermal conductance
A measure of how readily the animal loses heat
K
insulation
how effectively an animal conserves heat
Can MR be 0?
Nope
How can the MR value be at BMR level for a wide range of temperatures?
Above the lower critical temperature, the animal can change the value of K by ruffling fur/feathers or blood vessel movement
countercurrent heat exchange
Heat is exchanged between blood vessels carrying blood in opposite directions
run parallel
daily torpor
lowering of the body temp during a portion of the day to save energy
Hibernation
An extreme form of torpor
bouts of torpor last multiple days
can be regulated slightly above freezing
