My Classroom Material 107 - BIOLOGY JUNCTION

Physiology of the Circulatory System

Physiology of the Circulatory System

Introduction:
The circulatory system functions to deliver oxygen an nutrients to tissues for growth and metabolism, and to remove metabolic wastes. The heart pumps blood through a circuit that includes arteries, arterioles, capillaries, venules, and veins. One important circuit is the pulmonary circuit, where there is an exchange of gases within the alveoli of the lung. The right side of the human heart receives deoxygenated blood from body tissues and pumps it to the lungs. The left side of the heart receives oxygenated blood from the lungs and pumps it to the tissues. With increased exercise, several changes occur within the circulatory system, thus increasing the delivery of oxygen to actively respiring muscles cells. These changes include increased heart rate, increased blood flow to muscular tissue, decreased blood flow to non muscular tissue, increased arterial pressure, increased body temperature and increased breathing rate.

Blood Pressure
An important measurable aspect of the circulatory system is blood pressure. When the ventricles of the heart contract, pressure is increased throughout all the arteries. Arterial blood pressure is directly dependent on the amount of blood pumped by the heart per minute and the resistance to blood flow through the arterioles. The arterial blood pressure is determined using a device known as a sphygmomanometer. This device consists of an inflatable cuff connected by rubber hoses to a hand pump and to a pressure gauge graduated in millimeters of mercury. The cuff is wrapped around the upper arm and inflated to a pressure that will shut off the brachial artery. The examiner listens for the sounds of blood flow in the brachial artery by placing the bell of a stethoscope in the inside of the elbow below the biceps.

Figure 10.1 The sphygmomanometer

At rest, the blood normally goes through the arteries so that the blood in the central part of the artery moves faster than the blood in the peripheral part. Under these conditions, the artery is silent when one listens. When the sphygmomanometer cuff is inflated to a pressure above the systolic pressure, the flow of blood is stopped and the artery is silent again. As the pressure in the cuff gradually drops to levels between the systolic and diastolic pressures of the artery, the blood is pushed through the compressed walls of the artery in a turbulent flow. Under these conditions, the blood is mixed, and the turbulence sets up vibrations in the artery that are heard as sounds in the stethoscope. These sounds are known as the heart sounds or sounds of Korotkoff. The sounds are divided into five phases based on the loudness and quality of the sounds.

Phase 1. A loud, clear tapping sound is evident that increases in intensity as the cuff is deflated.
Phase 2. A succession of murmurs can be heard. Sometimes the sounds seem to disappears during this time which may be a result of inflating or deflating the cuff too slowly.
Phase 3. A loud, thumping sound, similar to that in Phase 1 but less clear, replaces the murmurs.
Phase 4. A muffled sound abruptly replaces the thumping sounds of Phase 3.
Phase 5. All sounds disappear.

The cuff pressure at which the first sound is heard (that is, the beginning of Phase 1) is taken as the systolic pressure. The cuff pressure with the muffled sound(Phase 4) disappears (the beginning of Phase 5). is taken as the measurement of the diastolic pressure. A normal blood pressure measurement for a given individual depends on a person’s age, sex, heredity, and environment. When these factors are taken into account, blood pressure measurements that are chronically elevated may indicate a state deleterious to the health of the person. This condition is called hypertension and is a major contributing factor in heart disease and stroke.

Table 10.1: Normal Blood Pressure for Men and Women at Different Ages

	Systolic Pressure		Diastolic Pressure
Age in Years	Men	Women	Men	Women
10	103	103	69	70
11	104	104	70	71
12	106	106	71	72
13	108	108	72	73
14	110	110	73	74
15	112	112	75	76
16	118	116	73	72
17	121	116	74	72
18	120	116	74	72
19	122	115	75	71
20-24	123	116	76	72
25-29	125	117	78	74
30-34	126	120	79	75
35-39	127	124	80	78
40-44	129	127	81	80
45-49	130	131	82	82
50-54	135	137	83	84
55-59	138	139	84	84
60-64	142	144	85	85
65-69	143	154	83	85
70-74	145	159	82	85

Exercise 10A: Measuring Blood Pressure:
Note: These labs are ONLY for experimental, and not diagnostic, purposes.

A sphygmomanometer (blood pressure cuff) is used to measure blood pressure. The cuff, designed to fit around the upper arm, can be expanded by pumping a rubber bulb connected to the cuff. The pressure gauge, scaled in millimeters, indicates the pressure inside the cuff. A stethoscope is used to listen to the individual’s pulse. The ear pieces of the stethoscope should be cleaned with alcohol swabs before and after each use.

Procedure:
1. Work in pairs. Those who are to have their blood pressure measured should be seated with both shirt sleeves rolled up.

2. Attach the cuff of the sphygmomanometer snugly around the upper arm.

3. Place the stethoscope directly below the cuff in the bend of the elbow joint.

4. Close the valve of the bulb by turning it clockwise. Pump air into the cuff until the pressure gauge goes past 200 mm Hg.

5. Turn the valve of the bulb counterclockwise and slowly release the air from the cuff. Listen for pulse.

6. When you first hear the heart sounds, note the pressure on the gauge. This is the systolic pressure.

7. Continue to slowly release air and listen until the clear thumping sound of the pulse becomes strong and then fades. When you last hear the full heart beat, note the pressure. This is the diastolic pressure.

8. Repeat the measurement two more times and determine the average systolic and diastolic pressure, then record these values on the data sheet .

9. Trade places with your partner. When your average systolic and diastolic pressure have been determined, record these values on the blood pressure data sheet.

Exercise 10B: A Test of Fitness
The point scores on the following tests provide an evaluation of fitness based not only on cardiac muscular development but also on the ability of the cardiovascular system to respond to sudden changes in demand. Caution: Make sure that you do not attempt this exercise if strenuous activity will aggravate a health problem. work in pairs. Determine the fitness level for one member of the pair (Tests 1 to 5 below) and then repeat the process for the other member of the pair.

Procedure:
1. The subject should recline on a laboratory bench for at least 5 minutes. At the end of this time, measure the systolic and diastolic pressure and record these values below.

reclining systolic pressure ____________ mm Hg reclining diastolic pressure _______ mm Hg

2. Remain reclining for two minutes, then stand and IMMEDIATELY repeat measurements on the same subject (arms down). Record these values below.

standing systolic pressure ____________ mm Hg standing diastolic pressure _______ mm Hg

3. Determine the change in systolic pressure from reclining to standing by subtracting the standard measurement from the reclining measurement. Assign fitness points based on Table 10.2 and record the fitness data sheet.

Table 10.2: Changes in Systolic Pressure from Reclining to Standing

Change (mm Hg)	Fitness Points
rise of 8 or more	3
rise of 2-7	2
no rise	1
fall of 2-5	0
fall of 6 or more	-1

Cardiac Rate and Physical Fitness

During physical exertion, the cardiac rate (beats per minute) increases. This increase can be measured as an increase in pulse rate. Although the maximum cardiac rate is usually the same in people of the same age group, those who are physically fit have a higher stroke volume millimeters per beat) then more sedentary individuals. A person who is in poor physical condition, therefore, reaches their maximum cardiac rate at a lower work level than a person with of comparable age who is in better shape. Maximum cardiac rates are listed in Table 10.3. Individuals who are in good physical condition can deliver more oxygen to their muscles before reaching maximum cardiac rate than can those in poor condition.

Table 10.3: Maximum-Pulse Rate

Age (years)	Maximum Pulse Rate (beats/min)
20-29	190
30-39	160
40-49	150
50-59	140
60 and above	130

Test 2: Standing Pulse Rate
Procedure:
1. The subject should stand at ease for 2 minutes after Test 1.

2. After the two minutes, determine your partner’s pulse.

3. Count the number of beats for 30 seconds and multiply by 2. The pulse rate is the number of beats per minute. Record this on the fitness data sheet. Assign fitness points based on Table 10.4 and record them on the data sheet.

Pulse Rate (beats/min)	Fitness Points
60-70	3
71-80	3
81-90	2
91-100	1
101-110	1
111-120	0
121-130	0
131-140	-1

Test 3: Reclining Pulse Rate
Procedure:
1. The subject should recline for 5 minutes on the laboratory bench.

2. The other partner will determine the subject’s resting pulse.

3. Count the number of beats for 30 seconds and multiply by 2. ( Note: the subject should remain reclining for the next test!) Record it on the Data Sheet. Assign fitness points based on Table 10.5 and record them on the fitness data sheet.

Table 10.5: Reclining Pulse Rate

Pulse Rate (beats/min)	Fitness Points
50-60	3
61-70	3
71-80	2
81-90	1
91-100	0
101-110	-1

Test 4: Baroreceptor Reflex (Pulse Rate Increase from Reclining to Standing)
Procedure:
1. The reclining subject should now stand up.

2. Immediately take the subject’s pulse. Record this value below. The observed increase in pulse rate is initiated by baroreceptors (pressure receptors) in the carotid artery and in the aortic arch. When the baroreceptors detect a drop in blood pressure they signal the medulla of the brain to increase the heart beat, and consequently the pulse rate.

Pulse immediately upon standing = ___________________ beats per minute

3. Subtract the reclining pulse rate (recorded in Test 3) from the pulse rate immediately upon standing (recorded in Test 4) to determine the pulse rate increase upon standing. Assign fitness points based on Table 10.6 and record on the fitness data sheet.

Table 10.6: Pulse Increase from Reclining to Standing

Reclining Pulse (beats/min)	Pulse Rate Increase on Standing (# beats)
0-10	11-18	19-26	27-34	35-43
	Fitness Points
50-60	3	3	2	1	0
61-70	3	2	1	0	-1
71-80	3	2	0	-1	-2
81-90	2	1	-1	-2	-3
91-100	1	0	-2	-3	-3
101-110	0	-1	-3	-3	-3

Test 5: Step Test- Endurance
Procedure:
1. place your right foot on an 18-inch high stool. Raise your body so that your left foot comes to rest by your right foot. Return your left foot to the original position. Repeat these exercise five times, allowing three seconds for each step up.

2. Immediately after the completion of the exercise, measure the pulse for 15 seconds and record below; measure again for 15 seconds and record; continue taking the pulse and record at 60, 90, and 120 seconds.

Number of beats in the 0-to 15 second interval ____ X4= ____ beats per minute

Number of beats in the 16-to 30 second interval ____ X4= ____ beats per minute

Number of beats in the 31-to 60 second interval ____ X4= ____ beats per minute

Number of beats in the 61-to 90 second interval ____ X4= ____ beats per minute

Number of beats in the 91-to 120 second interval ____ X4= ____ beats per minute

3. Observe the time that it takes for the pulse rate to return to approximately the level as recorded in Test 2. Assign fitness pints based on Table 10.7 and record them on the fitness data sheet.

Table 10.7: Time Required for Return of Pulse Rate to Standing Level after Exercise

Time (seconds)	Fitness Points
0-30	4
31-60	3
61-90	2
91-120	1
121+	1
1-10 beats above standing pulse rate	0
11-30 beats above standing pulse rate	-1

4. Subtract your normal standing pulse rate (recorded in Test 2) from your pulse rate immediately after exercise (the 0-to 15-second interval) to obtain pulse rate increase. Record this on the data sheet. Assign fitness points based on Table 10.8 and record them on the fitness data sheet.

Standing Pulse (beats/min)	Pulse Rate Increase Immediately after Exercise (#beats)
0-10	11-20	21-30	31-40	41+
	Fitness Points
60-70	3	3	2	1	0
71-80	3	2	1	0	-1
81-90	3	2	1	-1	-2
91-100	2	1	0	-2	-3
101-110	1	0	-1	-3	-3
111-120	1	-1	-2	-3	-3
121-130	0	-2	-3	-3	-3
131-140	0	-3	-3	-3	-3

Data Sheet:

Blood Pressure Data

Measurement	1	2	3	Average
Systolic
Diastolic

Fitness Data

	Measurement	Points
Test 1. Change in systolic pressure from reclining to standing	mm Hg
Test 2. Standing Pulse Rate	beats/min
Test 3. Reclining Pulse Rate	beats/min
Test 4. Baroreceptor reflex Pulse Rate increase on standing	beats/min
Test 5. Return of Pulse Rate to Standing after Exercise	seconds
Pulse Rate increase immediately after exercise	beats/min
	Total Score

Total Score	Relative Cardiac Fitness
18-17	Excellent
16-14	Good
13-8	Fair
7 or less	Poor

Topics for Discussion:
1. Explain why blood pressure and heart rate differ when measured in a reclining position and in a standing position.

___________________________________________________________________

2. Explain why high blood pressure is a health concern.

___________________________________________________________________

3. Explain why an athlete must exercise harder or longer to achieve a maximum heart rate than a person who is not as physically fit.

___________________________________________________________________

4. Research and explain why smoking causes a rise in blood pressure.

___________________________________________________________________

Pedigree Lab

Constructing a Pedigree

Introduction

A pedigree is a special chart or family tree that uses a particular set of standardized symbols. Pedigrees are used to show the history of inherited traits through a family. In a pedigree, males are represented by squares and females by circles . An individual who exhibits the trait in question, for example, someone who suffers from hemophilia, is represented by a filled symbol or . A horizontal line between two symbols represents a mating . The offspring are connected to each other by a horizontal line above the symbols and to the parents by vertical lines. Roman numerals (I, II, III, etc.) symbolize generations. Arabic numerals (1,2,3, etc.) symbolize birth order within each generation. In this way, any individual within the pedigree can be identified by the combination of two numbers (i.e., individual II3).

Objective

Inherited traits can be traced through a family’s history by constructing a pedigree chart.

Materials

Large sheet of paper or poster board
Markers
Ruler
Protractor

Procedure
Part 1

1. Examine Figure 1 that traces the ability to roll your tongue through three generations in a family. Remember: Blackened circles show the trait and circles are females and squares are male.

2. Determine which parents and which offspring would be able to roll their tongue.

FIGURE 1

Part 2

3. Read the Passage 1 about the Smith family and their inherited trait of dimples.

4. After reading the passage, construct a pedigree showing all family members in each generation that does and does NOT have dimples.

5. Once the pedigree is constructed, write the correct genotype by each person in the family.

Passage 1

Grandfather and Grandmother Smith smiled a lot and showed off their dimples each time. They had a son named John, who had dimples, and daughter named Julie, who did not. Julie died at an early age, but her brother John Smith met and married Mary Jones because she had the most beautiful dimples when she smiled. They had 5 children, 2 boys and 3 girls. Only one of their sons, Tom, had dimples, but both girls, Judy and Kay, had dimpled smiles. Their sister June lacked dimples. After college, Tom met and married Jane Kennedy who also had dimples. They had 3 children, all girls, who shared their parent’s dimpled smile. Tom’s sister Kay married a lawyer named James who seldom smiled and didn’t have dimples. Their only son Matthew was like his mother when he smiled. Judy never married. Tom’s sister, June, married a doctor and had 5 children. Three of the children were boys, Jay, Fred, and Mike. Mike and Fred had dimples like dad, but Jay’s smile was like his mom’s lacking dimples. One sister, Susan, had dimples, but the other, Katherine, didn’t.

Questions

1. What type of information does a pedigree contain?

2. How do you show the presence of a trait in a pedigree?

3. How do you denote males & females in a pedigree?

4. From your pedigree, is the presence of dimples a dominant or recessive trait?

5. How could examining a family pedigree be helpful to a couple wanting to have children?

Percents, Fractions, Decimals

Decimals, Fractions and Percentages

Decimals, Fractions and Percentages are just different ways of showing the same value:

A Half can be written…
As a fraction:	1/2
As a decimal:	0.5
As a percentage:	50%

A Quarter can be written…
As a fraction:	1/4
As a decimal:	0.25
As a percentage:	25%

Example Values

Here is a table of commonly occurring values shown in Percent, Decimal and Fraction form:

PERCENT	DECIMAL	FRACTION
1%	0.01	1/100
5%	0.05	1/20
10%	0.1	1/10
12½%	0.125	1/8
20%	0.2	1/5
25%	0.25	1/4
331/3%	0.333…	1/3
50%	0.5	1/2
75%	0.75	3/4
80%	0.8	4/5
90%	0.9	9/10
99%	0.99	99/100
100%	1	100/100
125%	1.25	5/4
150%	1.5	3/2
200%	2	4/2

Conversions

From Percent to Decimal

To convert from percent to decimal: divide by 100, and remove the “%” sign.

The easiest way to divide by 100 is to move the decimal point 2 places to the left. So:

From Percent	To Decimal
		move the decimal point 2 places to the left, and remove the “%” sign.

From Decimal to Percent

To convert from decimal to percent: multiply by 100, and add a “%” sign.

The easiest way to multiply by 100 is to move the decimal point 2 places to the right. So:

From Decimal	To Percent
		move the decimal point 2 places to the right, and add the “%” sign.

From Fraction to Decimal

The easiest way to convert a fraction to a decimal is to divide the top number by the bottom number (divide the numerator by the denominator in mathematical language)

Example: Convert 2/5 to a decimal

Divide 2 by 5: 2 ÷ 5 = 0.4

Answer: 2/5 = 0.4

From Decimal to Fraction

To convert a decimal to a fraction needs a little more work.

Example: To convert 0.75 to a fraction

STEPS	EXAMPLE
First, write down the decimal “over” the number 1	0.75 / 1
Then multiply top and bottom by 10 for every number after the decimal point (10 for 1 number, 100 for 2 numbers, etc)	0.75 × 100 / 1 × 100
(This makes it a correctly formed fraction)	= 75 / 100
Then Simplify the fraction	3 / 4

From Fraction to Percentage

The easiest way to convert a fraction to a percentage is to divide the top number by the bottom number. then multiply the result by 100, and add the “%” sign.

Example: Convert 3/8 to a percentage

First divide 3 by 8: 3 ÷ 8 = 0.375,
Then multiply by 100: 0.375 x 100 = 37.5
Add the “%” sign: 37.5%

Answer: 3/8 = 37.5%

From Percentage to Fraction

To convert a percentage to a fraction, first convert to a decimal (divide by 100), then use the steps for converting decimal to fractions (like above).

Example: To convert 80% to a fraction

STEPS	EXAMPLE
Convert 80% to a decimal (=80/100):	0.8
Write down the decimal “over” the number 1	0.8 / 1
Then multiply top and bottom by 10 for every number after the decimal point (10 for 1 number, 100 for 2 numbers, etc)	0.8 × 10 / 1 × 10
(This makes it a correctly formed fraction)	= 8 / 10
Then Simplify the fraction	4 / 5

Adapted from MATH IS FUN!

Perch Dissection

Perch Dissection

Introduction:

Perch Dissection 2

Perch Dissection

Introduction:

The fish in the class Osteichthyes have bony skeletons. There are three groups of the bony fish — ray-finned fish, lobe-finned fish, and the lung fish. The perch is an example of a ray-finned fish. Its fins have spiny rays of cartilage &/or bone to support them. Fins help the perch to move quickly through the water and steer without rolling. The perch also has a streamline body shape that makes it well adapted for movement in the water. All ray-finned fish have a swim bladder that gives the fish buoyancy allowing them to sink or rise in the water. The swim bladder also regulates the concentration of gases in the blood of the fish. Perch have powerful jaws and strong teeth for catching and eating prey. Yellow perch are primarily bottom feeders with a slow deliberate bite. They eat almost anything, but prefer minnows, insect larvae, plankton, and worms. Perch move about in schools, often numbering in the hundreds.

The scientific name for the yellow perch, most often used in dissection, is Perca flavescens (Perca means “dusky”; flavescens means “becoming gold colored”). The sides of the yellow perch are golden yellow to brassy green with six to eight dark vertical saddles and a white to yellow belly. Yellow perch have many small teeth, but no large canines. Yellow perch spawn from mid-April to early May by depositing their eggs over vegetation or the water bottom, with no care given. The eggs are laid in large gelatinous adhesive masses.

Prelab Questions (Click Here)

Materials:

Preserved perch, dissecting pan, scalpel, scissors, forceps, magnifying glass, dissecting pins, apron, gloves, eye cover, tape measure

Procedure (External Anatomy):

Obtain a perch & rinse off the excess preservative. Place the perch in your dissecting pan.
Label the anterior, posterior, dorsal, and ventral sides of the perch on Figure 1.
Use your tape measure to determine the total length, fork length, and girth of your fish. Record this in Table 1.

Table 1 – Fish Measurements (inches)

Total Length
Fork Length
Girth

Locate the 3 body regions of the perch — head, trunk, and tail. Label these on Figure 1.
Open the perch’s mouth and observe its bony jaws. Locate and label the upper jaw or maxilla and the lower jaw or mandible.
Feel the inside of the mouth for the teeth. Locate & label the tongue & teeth on Figure 1.
Open the mouth wider and use a probe to reach back to the gill chamber.
Locate the nostrils and label on Figure 1.
Locate and note the location of the eyes. Label on Figure 1.
Find the bony covering on each side of the fish’s head called the operculum. The opercula cover & protect the gills. Label these on Figure 1.

Figure 1 – External Perch anatomy

Use a probe to lift the operculum and observe the gills. Note their color.
Use a scissors to cut away one operculum to view the gills. Find the gill slits or spaces between the gills.
Use your scalpel to carefully cut out one gill. Find the cartilage support called the gill arch and the soft gill filaments that make up each gill. Label the parts of the gill in Figure 2.

Figure 2 – Gill Structure

Observe the different fins on the perch. Locate the pectoral, dorsal, pelvic, anal, and caudal fins. Note whether the fin has spines. Label these on Figure 1 and complete Table 2 on fins.

Table 2 – Fins

Name of Fin	Spines (yes or no)	Number of Fins	Location	Function

Locate the anus on the perch anterior to the anal fin. In the female, the anus is in front of the genital pore, and the urinary pore is located behind the genital pore. The male has only one pore (urogenital pore) behind the anus. Determine the sex of your perch.
Find the lateral line on the side of your perch. Label this line on Figure 1.
Use forceps to remove a few scales from your fish. Observe the scales under the magnifying glass. Sketch a scale on Figure 3.

Figure 3 – Structure of a Scale

Count the growth rings on your scale to tell the age of your fish. (Hint: each ring represents one year’s growth.)

Procedure (Internal Anatomy):

Use dissecting pins to secure the fish to the dissecting pan. Use scissors to make the cuts through skin and muscle shown in Figure 4.

Figure 4 – Cut Lines for Internal dissection

After making the cuts, carefully lift off the flap of skin and muscle to expose the internal organs in the body cavity.
Locate the cream colored liver in the front of the body cavity. Also locate the gall bladder between the lobes of the liver. Label these on Figure 5.
Remove the gall bladder & liver to observe the short esophagus attached to the stomach. Label the stomach on Figure 5
At the posterior end of the stomach are the coiled intestines. Locate and then label these on Figure 5.
Find the small reddish brown spleen near the stomach and label this on Figure 5.
Below the operculum, are the bony gill rakers. Locate these & them label them on Figure 5.
In front of the liver & behind the gill rakers is the pericardial cavity containing the heart. The heart of a fish only has 2 chambers — an atrium & and a ventricle. Locate the heart & label it on Figure 5.
In the upper part of the body below the lateral line is the swim bladder. This sac has a thin wall and gives the fish buoyancy. Label the swim bladder on Figure 5.
Below the swim bladder are the gonads, testes or ovaries. In a female, these may be filled with eggs. Label the gonads on Figure 5.
Find the 2 long, dark kidneys in the posterior end of the perch. These filter wastes from the blood. Label the kidneys in Figure 5.
Wastes exit the body through the vent located on the ventral side of the perch. Label this structure on figure 5.

Figure 5 – Internal Perch Anatomy

Questions & Observations:

1. Are both jaws of the fish equally movable? Explain your answer.

2. Does the perch have eyelids?

3. How many gills are located on each side of the perch? What covering protects them?

4. What is the function of the gill rakers?

5. Explain how gas exchange occurs at the gills.

6. Which fin was the largest? What other difference do you notice in this fin when it was compared to the others?

7. What was the sex of your fish?

8. What is the function of the lateral line?

9. Describe how the scales are arranged on the trunk & tail of your fish.

10. Explain how the swim bladder controls buoyancy.