Marine Vert.-- ppt 4 (Cardiovascular and Thermoregulation)

What is the purpose of the cardiovascular system?

-oxygenate blood at gills

-distribute oxygen, nutrients, metabolites to tissues

-collect wastes (CO2 and metabolites) from tissues

transport waste for removal

Where does waste removal occur?

-gills

-kidneys

What kind of waste is expelled from the gills?

-salts

-CO2

What kind of waste is expelled through the kidneys?

-water

-salts

-metabolites

Where do the arteries run?

-heart to tissue capillaries via gills

-O2 diffusion happens in gills

Where do veins run?

-tissues to heart

What do capillaries do?

-O2 + nutrient diffuse into tissue

-CO2 + wastes diffuse into capillaries

How many chambers does that heart have in fish?

2

T/F The heart is a muscular organ.

True

What are the different components of the heart?

-bulbus arteriosus

-ventricle

-atrium

-sinus venosus

How does blood flow through the heart and the different chambers?

sinus venosus→atrium→Ventricle→bulbus arteriosus

The final chamber of the heart is more muscular conus arteriosus in…

Chondrichthyes and lungfish

What type of gill ventilation do most fish use?

buccal pump

What type of gill ventilation is used by tunas and some sharks?

Ram ventilation

How does gill ventilation work?

water goes in through the mouth and exits the body out of the gills

T/F Ram ventilation only works in the organism does not move.

False — organism must be in constant motion

Why are most fish that breath air located in the tropics?

warm water has less dissolved oxygen

Are most fish ectotherms?

yes

What does ectothermic mean?

rely on external heat for body regulation

Where does the blood temperature equilibrate with the water temperature?

at the gills

What are two ways that fish del with changes in the environmental temperture?

-avoidance

-temp. flexibile/multiple enzymes

How do tuna, lamnid sharks, billfish, and opah keep warm?

by retaining heat from a core muscle using a countercurrent heat exchange system

What is the countercurrent heat exchange system called that is used in tuna?

rete mirable (miraculous net)

How opah more close to an endotherm than exotherm?

-blood warmed by pectoral fin muscle

-rete mirable at gills to prevent heat loss

-warmed blood is circulated throughout the body