Exercise 11- Animal Physiology:

Respiration and Circulatory Systems

Exercise 11- Overview

• Generate a hypothesis about the relationship between

ambient temperature and metabolic rate in ectotherms

• Design and conduct an experiment with crickets to test

this hypothesis

• Measure the human heart rate under different conditions

(e.g., resting, holding breath, face in water, after exercising,

final resting)

• Measure human blood pressure under different conditions

(e.g., initial resting, after exercising, final resting)

Do all animals need to regulate their

body temperature?

Thermoregulation vs. Thermoconformers

Homeotherms: (thermoregulators):

stable body temperatures.

Poikilotherms: (thermoconformers):

their body temperature changes with the

environment.

Ectotherms vs. Endotherms

Endotherms: rely on internal heat

produced by metabolically active organs

(liver, kidney, heart, brain, muscle)

Ectotherms: rely on environmental heat

sources.

What is the independent variable?

What is the dependent variable?

What is the effect of increasing ambient

temperature on oxygen consumption?

Can you explain the difference between

endotherms and ectotherms?

Gas Exchange- Physiologic Respiration

How could you measure metabolic rate in a cricket?

Physiologic Respiration: Spiracles

Metabolic activity and Crickets

Draw a graph of the expected relationship between

ambient temperature, body temperature and metabolic

activity for a cricket.

Equipment: crickets, environmental chamber, CO2 probe,

temperature probe.

8

Crickets Belong to the Order Orthoptera

OvipositorRudimentary wings

Acheta domesticus, commonly called the house cricket

Equipment

Temperature and Respiration

What is your testable hypothesis?

What are your dependent and independent variables?

How will you manipulate your independent variable?

How will you measure your dependent variable?

What variables do you need to control?

What is your unit of replication? Do you think using one cricket work?

What is your sample size? In other words, how many replicates do you need?

Can you ‘reuse’ crickets to increase your sample size?

Exercise 11- Overview

• Generate a hypothesis about the relationship between

ambient temperature and metabolic rate in ectotherms

• Design and conduct an experiment with crickets to test

this hypothesis

• Measure the human heart rate under different conditions

(e.g., resting, holding breath, face in water, after exercising,

final resting)

• Measure human blood pressure under different conditions

(e.g., initial resting, after exercising, final resting)

Circulatory System: Movement of blood cells

In vertebrates: a closed

circulatory system

Blood flows in two connected,

continuous circuits through the

body

What kind of circulatory

system does a crayfish have?

LUNG =

PULMONARY

CIRCUIT

BODY =

SYSTEMIC

CIRCUITVideo: https://www.youtube.com/watch?v=5tUWOF6wEnk

Cardiac Cycle: Moving the blood

Diastole = whole heart is relaxed.

Systole = heart contraction.

With each contraction, a wave of blood is pushed from the heart.

Can be felt as pulsations in arteries close to the skin surface, such as those in the wrist and neck.

Pulse Points

The pulse may be palpated in any place that allows an artery to be compressed against a

bone:

The neck (carotid artery)

On the inside of the elbow (brachial artery)

At the wrist (radial artery),

At the groin (femoral artery)

Behind the knee (popliteal artery)

Near the ankle joint (posterior tibial artery)

On foot (dorsalis pedis artery).

Take your pulse using the pulse point in

your neck.

Heart Rate (beats per minute)

Average = 70 bpm

Trained athlete = 50 bpm

Anxious/excited = 125 bpm

Faster rate: Tachycardia

Slower rate: Bradycardia

Irregular Rate: Arrhythmia

What will be the effect of holding your breath on your heart rate? Exercise? Immersing your face in really cold water?

The Mammalian Diving Response/Reflex

http://www.youtube.com/watch?v=nhd8Yr_u_18

Bradycardia: slowing down of heart rate

Peripheral vasoconstriction: restriction of circulation to vital capillary beds (brain & heart) circulation to muscles.

Do you think my daughter (an 11 year-old competitive swimmer) or me is

more likely to have the mammalian diving response?

Blood pressure

Blood Pressure

Category

Systolic

mm Hg (upper #)

Diastolic

mm Hg (lower #)

Normal less than 120 and less than 80

Prehypertension 120 – 139 or 80 – 89

High Blood Pressure

(Hypertension) Stage 1140 – 159 or 90 – 99

High Blood Pressure

(Hypertension) Stage 2160 or higher or 100 or higher

Hypertensive Crisis

(Emergency care needed)Higher than 180 or Higher than 110

Blood pressure at rest

Sphygmomanometer & stethoscope(Sphyg-mo-ma-nom-e-ter)

https://www.youtube.com/watch?v=VJrLHePNDQ4 https://www.youtube.com/watch?v=-LqKmrmaHsk

What Determines Resting Blood Pressure?

The exact causes of high blood pressure are not known,

but several factors and conditions may play a role in its

development, including:

• Smoking

• Being overweight

• Lack of physical activity

• Alcohol consumption

• Older age

• Genetics

What happens to your systolic

and diastolic pressure when you

exercise?

Exercise 11- Overview

• Generate a hypothesis about the relationship between

ambient temperature and metabolic rate in ectotherms

• Design and conduct an experiment with crickets to test

this hypothesis

• Measure the human heart rate under different conditions

(e.g., resting, holding breath, face in water, after exercising,

final resting)

• Measure human blood pressure under different conditions

(e.g., initial resting, after exercising, final resting)