CH 42 Circulation and Gas Exchange BIO 2 exam 3

cellular resp formula

C6H12O6 + O2 → co2 + h20

what ate the different structures of ox and co2 exchange

specialized structures

pump

wide thick vessels

networks of highly branched thin walled vessels

diffusion

small molecules can move between cells and their surroundings by diffusion

should every cell in the organism exchange substances with its environment

true

what does it mean to have no circulatory system

In some animals, many or all cells are in direct contact with the environment

Gastrovascular cavity

Function in both digestion and distribution of substances (exchange)

• body wall of gastrovascular cavity is only two cells

  thick, so no need for circulation

ex of organisms with GVC

cnidarians and flatworms

multicellular organisms exchange with enviroenment how

not directly,

through specialized systems. cells exchange materials with the environment via a circulatory system

gills, how do they work

they are specialized structures that:

• O2 diffuses from the water into blood vessels

• CO2 diffuses from blood into the water

circulatory system functions

Circulate gases, nutrients, wastes, hormones, antibodies, heat to the areas of the body that need them

3 parts of the circulatory system

1) a muscular pump

2) Circulatory fluid

3) A set of interconnecting vessels

muscular pump characteristics

1 or many

muscular tube from simple to complex

pumps in 1 direction

• ex heart

ex of circulatory fliud

blood

vessel purpose

take pumped blood from heart to rest of tissues

valve purpose

keep blood flowing in a correct direction

open circulatory system examples

insects and molluscs

what is an ostia

dorsal tubular heart with pores

what is the fluid of closed circulatory system

hemolymph

• it is not completely contained within vessels. enters heart through ostia and pumped forward when heart contract

closed circulatory is found in

annelids, earthworms, and vertebrates

where is blood found

it is confined to vessels and is distinct from the interstitial fluid

cardiovascular system

in humans and other vertebraes, they have a closed circulatory system

3 main types of blood vessels

arteries, veins, and capillaires

arteries carry blood_______from the heart

veins carry blood________ to the heart

away

to

arteries branch into____ and carry blood away from heart into_____

arterioles, capillaries

capillary beds

networks of capillaries. sites of chemical exchange between the blood and interstitial fluid

venules converge into _____ and return blood from ________ to the heart

veins, capiilaries

the vertebrate heart caontains how many chamber

2 or more

blood enters through ____ and it pumps out through _____

atrium, ventricles

single circulation ex

fishes, bone fishes, rays, and sharks

single circulation is how many chambers in heart

2

how does single circulation work

blood leaving the heart passes through two capillary beds before returning

blood pressure in single circulation

Blood pressure is really low after passing through gills, so it’s hard to get blood to the rest of the body.

double circulation animals:

Amphibians, reptiles, and mammals

other name for double circulation

pulmonary/systemic

pulmonary circuit

Oxygen-poor blood gets pumped to

the lungs through this

systemic circuit

Oxygen-rich blood delivers oxygen

to the body through this

which one has higher blood pressure? double or single circulation

double circulation

what animals have four chambers in their heart

mammals, birds, and some reptiels(crocs)

how many heart chambers so that ox and deoxy blood doesnt interact

4

pulmocutaneous circuit

In amphibians, oxygen- poor blood flows through a _______________ to pick up oxygen through the lungs and skin

• some mixing of blood ox and deox

describe circulation, and heart chambers in FISH

single circulation, 2 chambered heart

describe circulation, and heart chambers in AMPHIBIANS

three-chambered heart: two atria and one ventricle.

• breathe with lungs AND skin: have a pulmocutaneous circuit and systemic circuit

describe circulation, and heart chambers in TURTLES, SNAKES, AND LIZARDS

three-chambered heart: two atria and one

ventricle, partially divided by an incomplete septum

describe circulation, and heart chambers in MAMMALS, BIRDS, CROCS

four-chambered heart with two atria and

two ventricles

The left side of the heart pumps and receives only ____________, while the right side receives and pumps only _______________

oxygen-rich blood

oxygen-poor blood

do endo or ecto therms require more O2

endotherms

purpose of pulmonary circuit

gain O2 in the blood and get rid of CO2 in the blood

describe pulmonary circuit

• Contraction of the right ventricle pumps deoxygenated blood to the lungs via the pulmonary arteries/arterioles

• The blood flows through capillary beds in the left and right lungs and loads O2 and unloads CO2

• Oxygen-rich blood returns from the lungs via the pulmonary venules/pulmonary veins to the left atrium of the heart

describe the systemic circuit

• Oxygen-rich blood flows into the left ventricle and is pumped out to body tissues via the systemic circuit

• Blood leaves the left ventricle via the aorta, which conveys blood to arteries/arterioles, leading throughout the body

• O2 diffuses from blood to tissues, and CO2 diffuses from tissues to blood in capillary beds all over the body (organs, etc)

• Capillaries rejoin, forming venules, conveying blood to veins

• Oxygen-poor blood from the head, neck, and forelimbs is channeled into the superior vena cava, from trunk and hindlimbs to inferior vena cava

• Venae cavae empty their oxygen-poor blood into the right atrium then to the right ventricle

heart chambers

2 atria, 2 ventricles

atria

2 in mammals, have thin walls and serve as a collection chambers for blood returning to the heart

ventricles

2 in mammals, have thicker walls and contract much more forcefully

aorta

pumps oxygenated blood from teh left ventricle to the systematic circuit

what type of blood is in the vana cavae

Deoxygenated blood

returns to the right atrium of

the heart via the vena cavae

what starts the pulm circuit

when the ventricle pumps deoxy blood to teh lungs via pulmonary artery

how many valves are in the heart

4

Atrioventricular Valve

AV valve, seperate each atrium and ventricle

Semilunar valves

control blood flow to the aorta and hte pulmonary artery

heart murmur

is sometimes

caused by blood flowing back

through a defective valve

• *innocent murmur is harmless

cardiac cycle

The heart contracts and relaxes in

a rhythmic cycle called this

systole

contraction or pumping phase

diastole

relaxation or filling phase

cardiac output

depends on heart rate and strooke volume

• is the volume

  of blood pumped into the systemic

  circulation per minute

heart rate

number of beats per minute

stroke volume

is the amount of blood pumped in a single contraction

where is bp highest

close to heart and lessens as you move further away, vena cava has lowest pressure

why do arteries withstand more pressure

Arteries and veins are

structurally different, which

allows for higher blood

pressure in arteries, and

accommodates low blood

pressure in veins.

artery structure

Arteries have thick, strong smooth muscle layer to handle high blood pressure from pumping heart

capillary structure

Capillary walls are one-layer thick, to allow exchange with nearby cells

veins structure

Veins do not have thick smooth muscle layer because they don’t need to accommodate high blood pressure. But they have VALVES

how does blood go to the heart in veins

through muscle contractions

varicose veins

Lack of muscle contraction or

damaged valves can cause

swelling, varicose veins

avg volume of blood in a human

4-6 liters

structure of blood

• 45% of blood is cellular (red and white blood cells and platelets)

• 55% of blood is plasma (90% water and 10% dissolved molecules)

red blood cells are formed where

bone marrow, circulate about 3-4 months before removed by liver

structure of erythrocytes

biconcave disk, maximizes ratio of surface areas to volume, allowing for max gas excahnge

most numerous blood cell type

red blood cells

hemoglobin is in

RBC, they transport oxygen, oxygen bind to heme on the hemoglobin molecule

sickle cell disease is caused by

is caused by abnormal hemoglobin proteins that form aggregates. aggregates can deform an RBC into a sickle shape

effect of sickle cells

can rupture and block blood vessels

capillary function

• Site of all exchange between blood and body cells

• No cell is far away from at least one capillary

• Low blood pressure, lowest velocity in entire system (allows exchange)

3 ways that material is exchanged between blood and tissues

diffusion, secretion, filtration

diffusion in capillaries

across endothelial cell (blood to cells or cells to blood)

- O2, CO2, lipid soluble hormones

secretion in capillaries

Vesicles in endothelial cells can pick up materials by endocytosis on one side of the cell, move it across the cell, and expel the materials by exocytosis on the other side

filteration in capillaries

clefts between adjacent endothelial cells will allow water and small particles through but not proteins

Which of the following is likely to push the

most fluid out of the lumen of a capillary near

the heart?

filtration

endothelial cells in brain vs liver/kidney

• In the brain, gaps are small (blood-brain barrier), little filtration

• In the liver and kidney, endothelial cells have large spaces between and everything but cells and large proteins can pass between

filtration depends on what

depends on balance of blood pressure

(BP) and osmotic pressure (solute differences

between blood and interstitial fluid)

lymphatic system is an ________ circulatory system

open

function of lymphatic system

When interstitial fluid pressure

is high due to fluid lost from

capillaries, it flows into

lymphatic system

what is lymphatic system similar to

like veins but no pressure flow

use one way valves and muscle action to move lymph back to duct aht ends venous system near heart

how does lymph travel

• Lymph travels in ducts to nodes where macrophages engulf dead cells and

bacteria

• Lymph reenters the circulatory system

through the thoracic duct and the right lymphatic duct (fuse with veins in the shoulder)

The material entering the lymphatic system

comes from where?

Fluid that was lost from the capillaries during filtration.

gas exchange is what

is the uptake of

O2 from the environment and the

discharge of CO2 to the

environment

• occurs in specialzed resp surfaces

respiratory medias and describe them

 Air: Breathing air is relatively

easy (20x more O2 than water)

 Water: less oxygen in water;

getting O2 from water requires

greater efficiency

gas exchange organ requirements

1) high surface area/volume ratio

2) in contact with internal transport(circulatory) ssytem

3) must lack scales, exoskeleton, fur, etc

4) must be moist

5) must be kept ventilated

what are gills used for

are outfoldings of the body with large surface

area for gas exchange

describe ventilation

moves the respiratory medium (water) over the

respiratory surface (gills)

how do aquatic animals ventilate

Aquatic animals move through water or move water over their gills for ventilation

concurrent exchange system

where blood flows in

the opposite direction

to water passing over

the gills