Gas Exchange and Circulation

I recommend you use paper for the diagram questions and that you draw the diagrams before filling in. I took the diagramds from lecture BIO 201 Lecture 22 Gas Exchange and Circulation (Creighton University)

What does a true circulatory system consist of?

1. Blood vessels

2. One or more hearts to generate hydrostatic pressure

3. Blood (or hemolymph) that moves through vessels

What are the 5 important processes of circulating blood?

1. Move respiratory gases

2. Move nutrients and wastes

3. Distribute hormones and immune system-cells

4. Distribute heat

5. Provide hydrostatic pressure

What are the two circulatory systems?

Open or closed

Where do vessels empty into in an open circulatory system?

Sinus (open, fluid filled spaces)

After vessels empty into the sinus, what re-enters the vessel/heart system?

Hemolymph

What animals contain an open circulatory system?

most invertebrates

In a closed circulatory system, where does blood stay during transit?

in vessels

What is a benefit of the closed circulatory system?

more percise delivery to needy tissues

What animals contain a closed circulatory system?

all vertebrates

Draw the open vs closed circulatory systems

Label this spiders circulatory system

Open systems where metabolic rates are ____ (sessile, slower-moving animals)

lower

Closed sustem for metabolic rates that are ____ (mobile, active and/or predatory animals)

higher

Fill this in

Do arteries carry blood towards or away from the heart?

Away

Arteries are large in diameter and thick-walled. What are the flow rates and pressure?

Highest flow rates, highest pressure

What are arterioles compared to arteries?

smaller versions with variable diameters

Do veins carry blood away or towards the heart>

towards

What are the flow rates and pressure in veins?

high flow rates, lowest pressure

What are vennules compared to veins?

thinner walled

What are venules compared to arterioles?

slightly larger

How many cells thick are capillaries?

1 cell thick

What do capillaries allow?

gas exchange between vessels and tissues

Capillaries are the ____ with the ____ flow.

Narrowest, slowest

Fills this in

What does the heart do?

Pumps to generate pressure

Peristaltic pumps -

part of blood vessels and limited to lower pressures

Chambered pumps -

specialized structures with one-way valves and can generate higher pressures

Label these pumps

How many ventricles do all vertebrate hearts have?

one or two

What is the main purpose of the ventricles?

Generate main pressure for circulation

How many atria do ventricles have?

one or two

What does the atria do?

help fill ventricles

What kind of valves are in the heart? 

one-way

What do one-way valves help with?

keeping blood flowing in the correct direction

What differs between vertebrate groups? Hint: heart

number of chambers and number of circulatory circuits

How are gasses carried through blood vessels?

by blood

When blood exits the heart and travels to the lungs/gills, what does it pick up and what does it get rid of?

gains O2 and loses CO2

What is it called when blood exits the heart and travels to the lungs/gills to pick up O2 and drop off CO2?

pulmonary circuit

When oxygenated blood leaves the lungs and returns to the heart to pump to the tissues, what is it called?

systemic circuit

How many circuits and chambers do fishes have?

1 circuit, 2 chambers

how many circuits and chambers do amphibians, turtles, lizards, and snakes have?

2 circuits, 3 chambers

how many circuits and chambers do crocadilians, birds, and mammals have?

2 circuits, 4 chambers

Left atrium and the left ventricle move blood through which circuit?

systemic circuit

Right atrium and right ventricle move blood throguh which circuit?

pulmonary circuit

Atrioventricular (AV) valves allow blood from where to where?

atria to ventricles

Semilunar (SL) valves allow blood from where to where?

ventricles to arteries

Fills in the steps and diagram

Fill in the steps and diagram

With no help from a photo, draw the full blood flow through the circulatory system of a mammal. Word bank: Lungs, Body, Right Atrium, Left Atrium, Right Ventricle, Pulmonary Artery, Pulmonary Veins, Superior Vena Cava, Aorta, AV valves, SL valves

What is the contraction of the heart?

Systole

What is the relaxed stage of the heart?

diastole

How is contraction of the heart triggered?

electrical signals

What is the primary pacemaker of the heart?

sinoatrial node

What influences the frequency (heart rate) of the heart?

nervous and endocrine systems

Contraction of the two atria followed by contraction of the two ventricles =

cardiac cycle

Step 1. of the Cardiac cycle

Sinoatrial node generates an electrical signal

Step 2. of the Cardiac cycle

Signal spreads to the atrial muscle cell and the atria contract, blood is ejected to the ventricles

step 3. of the cardiac cycle

Signal spreads to the atrioventricular (AV) node and is delayed before passing to the ventricles

Step 4. of the cardiac cycle

Signal spreads to the ventricles and causes them to contract. The atria relaxes and the ventricle empties toward the arteriesS

Step 5 of the cardiac cycle

ventricles relax

What barriers must O2 and CO2 cross to pass between air and blood inside the lungs?

Capillary wall, Extracellular Fluid, and Epithelial cells

How is most carbon dioxide transported from tissues to the lungs?

As bicarbonate ions (HCO3-)

Constricted blood vessels keeps you ____.

warm

Dialated blood vessels keeps you ____.

cold

By picking up hydrogen ions, hemoglobin prevents the blood from becoming too ____.

acidic

What promotes oxygen release from hemoglobin? 

a decrease in pH

The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in ____.

pH

Key aspect of cooperative binding by hemoglobin

permits rapid uptake of oxygen in the lungs and greater delivery of oxygen once blood reaches capillaries in the body’s tissues

How many polypeptide chains does Hemoglobin have?

four

What does each heme group on Hemoglobin contain?

one iron ion

How many O2 molecules can bind to a hemoglobin molecule?

four

Blood returns to the heart via

pulmonary veins

from pulmonary veins, blood flows to the

left atrium

from the superior vena cava, blood flows to the

right atrium

from capillaries of the abdonimal organs and hind limbs, blood flows to the

inferior vena cava

What is the function of the left ventricle?

pumps oxygenated blood around the body via systemic circulation

What event of the cardiac cycle occurs when systolic blood pressure is measured?

ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria