Bio I Ch 38: Physiology, Homeostasis, and Temperature Regulation

to survive, animals must (6)

• extract energy and nutrients from the enviornment

• build all internal structures

• eliminate toxins and metabolic waste

• sense and respond to stimuli

• maintain internal conditions

• reproduce

advantage of multicellularity includes

large size and specialization of cells

advantage of bigger size includes

The ability to prey on an organism

how are size of single celled organisms constrained

by the cell membrane that limits exchange of materials with the environment

what are the four types of tissue

• epithelial

• connective

• muscle

• nervous

explain epithelial tissues function, cell relationship, and shape

• covers outside of body and lines organs

• cells closely packed

• shape is squamos, cuboidal, columnar

Describe connective tissue, its relationship with cells, and ECM

• hold tissues and organs together

• sparsely packed cells in ECM

• matrix includes fibers and ground substance

what are the 6 types of CT and their functions

loose CT: binds epithelia to underlying tissue

Fibrous CT: in tendons and ligmanets

Bone: mineralized

Addipose: stores fat

Blood: blood cells and fragments

Cartilage: strong and flexible support

Ligament vs Tendon

• bone to joint

• bone to muscle

Nervous tissue descriton, what two things make it up, and define them

• proceses and transmits info

• neuron: transmits nerve impulse

• glial cells: support cells

organizational hierarchy of organism

atom, molrecule, cell, tissue, organ, organ system, multicellular organism

what helped multicellular animals grow, beocme more complex, and evolve

evolution of physiologial systems and manintaing internal enviornment

what is ECF made of

blood plasma and interstitial fluid

what happens if homeostasis is compromised

cell is damaged and ides

mtaintence of homeostasis is a_____________.

cental theme of physiology

how are physiological systems controlled

nervous and endocrine system

What are the parts of the homeostatic control mechanism

• receptor

• control center

• effector

define

set point

comparator

feedback

error signal

• reference point

• compares new info to set point

• informaiton that is compared to the setpoint

• any difference in set point and feedback info

regulatory system

obtains, integrreates and proccesses icommans to effectors

effectors are ______ systems

control systems

define negative feedback

information that counteracts the simtulus. decreases it or gets rid of it

define positive feebback

amplifies stimulus

postitive feedback does or does not help maintain homeostaiss

does not

what does the response of the effector do in a positive feedback

reinforces or exaggerates stimulus

define feetfoward informaiton

ancticipates changes before it happens and changes the set point

example of feetfoward information

timer on a thermostate may lower set point at night

feedback control commands a ___________ and feetfoward control commands a _______________

• desired state

• specific response

heat shock protein

protein that stbailizes other proteins and prevents denaturatoin

to stay within normal temp organisms use ______

thermoregulation

what does Q10 describe

temperature sensitivity

change in body temp can disrupt ______ because_____

• physiology

• not all reactions have the same Q10

how do fish regulate in water and how does it effect their metabolic rate

acclimatize to colder water and their metabolic rate will be higher 

what are the two mechanisms of acclimatize

• express isozynes that have different temp optima

• change composition of cell membrane to maintain fluidity

Define these

homeotherm

poikilotherm

ectotherm

endother

heterotherm

• maintain constant temp

• fluctuating body temp

• body temp depends on external heat source

• vary metabolic heat production

• can be both endotherm or ectotherm

compared to ectotherms, endotherms produce more heat but their cells ______

are less efficient at using energy 

endotherm cells are ______ so ions must constantly be pumped

leaky

what does the pumping do

maintain ion concentration graduate

two major differences between ectotherm and endotherm

• resting metabolic rate

• response to changes in environmental temperatures 

In an endotherms body what happens when external temperature decreases

its body temp remains constant

what happens to ectotherms temperature when enviornemnt temp changes

it equilibirates

what happens with the metabolic rates

they react in opposite ways

define conformer

allow internal enviornment to conform to external

define regulators

use control mechanim to maintain constant internal enviornement despite external

ectoderms and endoderms use _______ to regulate body temp

behavior mechanism

define these

radiation

convection

conduction

evaporation

• heat transfer through infared radiation from warmer to colder

• heat exchange with surrounding medium like air or water

• heat transfer between objects in direct contact

• heat transfer as water evaporates from a surface

for body temp to be constant what must be equal

all heat gained and all heat lost

define energy budget

the balance of heat production and heat exchange

if environmental temperature is higher than skin temperature, what _______ and _______ are avenues of heat gain rather than loss

convection and conduction

surface temp can be contolled by ___________

altering the flow of blood to the skin

increases and decreasing blood flow and its impact on heat loss

increase blood flow increases the heat loss

constiction of blood vessels to the skin results in less heat lost

fish produce heat ______________

metabolically

countercurrent heat exchange and who uses it

keeps heat within the muscles by moving in opposite directions and arteries move close to veins

how does higher tempersture imact the fishes power output and what does it do to its swimming

increases the output and allows faster swimming

Poikilotherms 3 major time frames of physiological response

• acute response

• chronic responses

• evolutionary changes

what are the chronic responses and define them

• acclimation: short-term, reversible, for a specific envionrmental stressor

• acclimatization: long term, for multile stressors

Metabolic rate is measured by consumption of _____ and production of ____

O2

CO2

metabolic rate in thermoneutral zone

metabolic rate is independent of tmeperature

BMR

metabolic rate of resting animal at a temp in the theroneutral zone

How do size of animal impact BMR

larger animals have higher BMR

When BMR per gram of tissue increases animals are bigger or smaller

get smaller

bigger animals have ________ surface area to volume ratio

smaller

an endotherm’s thermoneutral zone is bounded by __________

upper and lower critical temperatures

thermoregulatory response use of energy in versus out of thermoneutral zone

dont use alot in thermoneutral

outside the zone, more energy needed

how do endotherms metabbolic heat production respond to cold

it increases it to reduce heat loss

mammals produce heat in _______, which has abundant mitochondria and blood supply

brown fat

endotherm adaptations to reduce heat loss (4)

• smaller surface area to volume ratios

• thermal insulation

• ability to decrease blood flow to the skin by consticting blood vessels

• countercurrent heat exchange in blood flow to appendages

adaptations to hot climates

• increase blood flow to the skin, decreasing activity levels

• increase surface area for heat dissipations

• largw mammals seek water

• evapuration by sweating

in mammals what is the main thermoregulatory center

hypothalamus