Animal Lesson 6

Question 1

Animals either what?

Answer 1

regulate their physiological parameters OR allow their
bodies to conform to external conditions

Question 2

River otter example

Answer 2

A temperature regulatory. It’s able main body temp no matter the outside temp.

Question 3

Largemouth bass

Answer 3

A temperature conformer. Change and mimics with outside temp. Low outside temp = low body temp.

Question 4

Regulators use what?

Answer 4

homeostatic mechanisms to control internal changes. Have large external fluctuations but have small internal fluctuations because if homeostatic mechanism.

Question 5

Conformers allow what?

Answer 5

their internal condition to change in response to external changes. May be able to tolerate greater ranges for physiological parameters (capable of being alive with large fluctuations). Internal stability is possible in stable environments (live in environments that don’t change much. why they don’t live in Canada).

Question 6

Physiological parameters being regulated?

Answer 6

• Thermoregulation
  – Temperature
• Osmoregulation
  – Body water, and solute concentration (salt conc).

Question 7

Thermoregulation

Answer 7

the maintenance of an internal temperature within a
tolerable range.

Question 8

Why does body temperature matter?

Answer 8

Biochemical and physiological processes are sensitive to changes in temperature. ie. Enzyme reaction rates decrease when temp decreases. Proteins (include. enzymes) can denature when temp increases. Membrane fluidity (how much flow through membrane) can vary with temp.

Each animal species has an optimal internal temp range. Can be narrow or wide. Temps outside range impairs functioning, lead to death, so maintaining thesis internal body temp is really important for the survival of the bodies we have.

Question 9

Body temperature can be what?

Answer 9

variable or relatively stable

Question 10

Poikilotherm

Answer 10

Body temperature of varies with environment

Question 11

Homeotherm

Answer 11

have a relatively constant body temperature (mammals and birds)

Question 12

Thermal strategies can be defined
based on what?

Answer 12

Source of heat. Where does the heat come from.

Question 13

Endotherms

Answer 13

Endotherms rely on (internal) metabolism as their major heat source. From inside our bodies. We do this.

Question 14

Ectotherms

Answer 14

rely primarily on external environment as their
major heat source (i.e., don’t produce enough body heat to raise above external temperature; rely mostly on behaviour (like sunbathing))

Question 15

Homeotherm and Endotherm example?

Answer 15

Mostly mammals and birds

Question 16

Homeotherm and ectotherm example?

Answer 16

Some tropical reptiles; Antarctic and deep-sea fish. Only can survive in specific areas that don’t change in temp.

Question 17

Poikilotherm and endotherm example?

Answer 17

Birds/mammals that undergo hibernation/torpor; some insects.

Question 18

Poikilotherm and ectotherm example?

Answer 18

Most invertebrates, amphibians, reptiles, and fish.

Question 19

Thermoregulation requires maintaining what?

Answer 19

equal rates of heat gain and heat loss

Question 20

The two ways of maintaining equal rates of heat gain and heat loss?

Answer 20

Anatomical/physiological processes and behaviour responses.

Question 21

Anatomical/physiological processes

Answer 21

1. Evaporative heat loss
2. Circulatory adaptations
3. Metabolic heat production
4. Insulation

Question 22

Evaporative heat loss

Answer 22

o Water lost from moist surfaces cools/carries away heat. To cool down body, bring water to the surface.
o Adaptations that augment this cooling effect include
panting (encourages more water loss) and sweating.

Question 23

Circulatory adaptations

Answer 23

Vasoregulation and Countercurrent heat exchangers.

Question 24

Vasoregulation

Answer 24

common to endotherms and ectotherms. Capillary control blood flow. Vasoregulation is achieved via nerve impulses and hormones. Hypothalmulus starts it and controls how much of blood flow is spread out or narrowed down. Has Vasodilation and Vasoconstriction.

Question 25

Vasodilation

Answer 25

relaxes smooth muscle walls of surface blood vessels. –Allows more blood to flow from core to surface for cooling. Blood is warm, causes us to get cool because blood is getting close to surface and that's cool.

Question 26

Vasoconstriction

Answer 26

tenses smooth muscle walls of surface blood vessels. Reduces blood flow from core to surface to prevent heat loss. It goes to brain, organs, and important parts that need to stay warm.

Question 27

Countercurrent Heat Exchangers

Answer 27

found in birds and mammals. One vessel; with fluid going in one direction and another vessel really close to the first but fluid going in opposite direction. The close proximity allows for heat to be transferred back and forth. Heat is transferred between fluids flowing in opposite directions. Heat from warm arterial blood is transferred to cooler venous blood as it returns to the body core. The foot is cold cause water is cold.

Question 28

Metabolic heat production

Answer 28

All metabolic activity produces heat. Endotherms have much higher metabolic rates than similarly sized ectotherms. Muscle contraction: Activity and Shivering. To produce heat. Brown adipose tissue (some mammals). Fat with high concentration of mitochondria (why it's brown). Cellular respiration produces heat instead of ATP (it doesn't need the chemical energy). Organisms that live un arctic

Question 29

Hypothalamus thermostatic function in human thermoregulation

Answer 29

Homeostasis: Internal body temp about 36 to 38. Stimulus: Increased body temp. Sensor/control centre: thermostat in hypothalamus. Response: sweat and blood vessels in skin dilate. Body temp decreases. Back to Homeostasis. Homeostasis: Internal body temp about 36 to 38. Stimulus: decreased body temp. Sensor/control: thermostat in hypothalamus. Response: shivering and blood vessels in skin constricted. Body temp increases and back to homeostasis.

Question 30

Insulation

Answer 30

Fur, feathers, fat. Major adaptation to prevent heat loss in mammals and birds (especially those that live in cold areas).

Question 31

Insulation for fur and feathers

Answer 31

Extra layer that traps a layer of air that doesn't move around, so it can get warmed up by your internal body and that heat remains close to your skin.

Question 32

Insulation for fat

Answer 32

Just an extra layer from the external temp.

Question 33

Behaviour responses

Answer 33

Do things to ensure they can regulate their temp. ie. Shade seeking, sun basking, migration (moves to areas that are warm or cooler).

Question 34

Blubber is a thick layer of vascularized adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians. Would you expect blubber to contain more or fewer blood vessels than human skin?

Answer 34

Fewer

Question 35

Water crosses cell membranes via what?

Answer 35

Simple diffusion (through membrane on their own) and facilitated diffusion (through membrane with help of protein). Don't require energy.

Question 36

Osmoregulation

Answer 36

the control of solute concentrations and the balance of water gain and loss from the body.

Question 37

Physiological parameters for Osmoregulation

Answer 37

– Body water (volume) * E.g., in blood, in interstitial fluid, within cells – Total solute concentration * E.g., calcium + potassium + sodium + urea + certain amino acids + water soluble hormones – Individual solute concentrations. Certain organs will function better with certain types of solutes in a right kind of balance versus other parts. * E.g., calcium vs potassium vs sodium vs urea vs certain amino acids vs water soluble hormones.

Question 38

Osmosis

Answer 38

the movement of water across a selectively permeable membrane (with the membrane it's just diffusion). Only water can go through the membrane so we end up will different conc. of solutes on both sides. Salts can only move with the help of something else. There is a natural tendency to try and equal out both sides of membrane.

Question 39

Hyperosmotic solution

Answer 39

Lower free H2O concentration (not attached to a molecule). Higher solute concentration. Water will naturally flow to this side to balance out conc.

Question 40

Hypoosmotic solution

Answer 40

Higher free H2O concentration. Lower solute concentration.

Question 41

Animal cells are affected by what?

Answer 41

the relative osmolarity of their surrounding fluid.

Question 42

Red blood cell example of hyper osmotic fluid

Answer 42

– Higher [solutes] outside cell – Water leaves cells through osmosis – Cells that lose too much water shrivel and (may) die

Question 43

Red blood cell example of hypo osmotic fluid

Answer 43

– Lower [solutes] outside cell; (higher [S] inside) – Water enters cells through osmosis – Cells that gain too much water burst and die

Question 44

Red blood cell example of isoosmotic fluid

Answer 44

– Same [solutes] inside and outside cell; (i.e., balanced). – No net movement of water into or out of cells but still moves in and out.

Question 45

What's the fluid around the red blood cells

Answer 45

Plasma but can also be interstitial and lymph fluid.

Question 46

Two ways animals maintain water balance

Answer 46

Osmoconformers are isoosmotic with their environment and Osmoregulators maintain a stable internal osmolarity.

Question 47

Osmoconformers are isoosmotic with their environment

Answer 47

– No tendency to gain or lose water. – All are marine. – Some have stable osmolarities while others tolerate variable osmolarities. – ATP Actively transport specific solutes to maintain homeostasis and have it be equal. They live in environments that the same as there body. ie. sharks.

Question 48

Osmoregulators maintain a stable internal osmolarity

Answer 48

– Found in marine, freshwater, and terrestrial environments. – A particular internal osmolarity is achieved by ATP actively transporting solutes into or out of cells in hopes that the water will follow. Have help of enzymes. * Water then flows in response to osmotic gradients Live in environment different than their body.

Question 49

Osmoregulation requires

Answer 49

Energy. Energy costs are reduced by minimizing osmotic differences between body fluids and the surrounding environment. Different animals adapt differently. – E.g., freshwater molluscs have adapted to have lower internal osmolarities than do marine molluscs to start at a level not as extreme to not spend to much energy.

Question 50

If osmoregulation is energetically costly, why aren’t all animals osmoconformers?

Answer 50

Access to more niches and more resources. Cost-benefit analysis.

Question 51

The osmotic challenge faced by osmoregulators depends on what?

Answer 51

their environment. Body fluids of most vertebrates ~ 300 mOsm/L Freshwater lake/pond 20 – 40 mOsm/L Seawater 1000+ mOsm/L

Question 52

Freshwater osmoregulators

Answer 52

Gain water (through surface of gils).

Question 53

Marine osmoregulators

Answer 53

Lose water

Question 54

Terrestrial animals

Answer 54

Lose water because of evaporative tendencies of water.

Question 55

Osmoregulation in a marine fish

Answer 55

Marine fish are hypoosmostic relative to the seawater (hyperosmotic env.). Osmotic water lost through gills and other parts of body surface. Loss of water increases internal osmolarity (so how can the fish recoup water?). Marine fish drinks seawater to replace water lost across the body surfaces. Get water from food, but also salt ions. Get water from drinking seawater, but also salt ions. Excretion of salt ions from gills (Cl- cells (lots)). Osmotic water lost through gills and other parts of body surface (lots). Excretion of salt ions and small amounts of water in scanty urine from kidneys (low)

Question 56

Osmoregulation in a freshwater fish

Answer 56

Freshwater fish are hyperosmostic relative to the lake/river (hypoosmotic env.). Gain of water decreases internal osmolarity (so how can the fish get rid of excess water?). Freshwater fish excretes water but must also take up salt ions to bring internal osmolarity back up. Freshwater fish drinks almost no water. Osmotic water gained through gills and other parts of body surface. Gain some ions in food, but also some water. Lots of excretion of large amounts of water in dilute urine from kidneys, but also salt ions lost. Uptake of salt ions by gills (Cl- cells they reverse depending in what they need).

Question 57

Dehydration is a challenge for what?

Answer 57

terrestrial animals

Question 58

Adaptations to reduce water loss (evaporation)

Answer 58

– Body coverings: cuticle, shells, keratinized skin – Nocturnal: comes out at night when it's not hot out.

Question 59

terrestrial animals maintain water balance by what?

Answer 59

drinking and eating moist food and producing metabolic water through cellular respiration.

Question 60

Animals control the solute concentration of an internal body fluid Via what?

Answer 60

Transport epithelia (layer of tissue) ie. skin (it protects lining of surfaces). – One or more layers of epithelial cells specialized for moving particular solutes in controlled amounts and in specific directions. Ie. simple and factilicted diffusion, and active transport (the active transport proteins with the help of ATP).

Question 61

Which structural characteristic is most important for transport epithelia involved in osmoregulation?

Answer 61

A large surface area

Question 62

Transport epithelia have large surface areas

Answer 62

Some face the external environment directly (e.g., gills) that have lots of branching. But many line tubular networks that connect to the outside by an opening on the body surface (e.g., those in salt glands or kidneys). Transport epithelia are closely connected to circulatory fluid to remove some of extra solutes.

Question 63

salt-excreting glands

Answer 63

How Seabirds, sea turtles, and marine iguanas remove excess salt, taken in when drinking sea water.

Question 64

Salt glands have transport epithelia that rely on what?

Answer 64

countercurrent exchange. The animals look like they are crying but it's just the extra salty fluid. They have secretory tubule and central duct that leads to outside. Salt concentration is always higher in the blood vessel than the secretory tubule. The blood flow and secretion flow in opposite directions. Salt ions flow from blood vessel to secretory cell of transport epithelium to lumen of secretory tubule. Blood becomes less and less salty as it moves up. It naturally moves across.

Question 65

Countercurrent exchange is a what?

Answer 65

homeostatic mechanism seen in multiple contexts.