Dive Reponse (Lab 9)

How do jellfish and other small organism particpate in gas exhchange?

Rely on SIMPLE DIFFUSION for their oxygen needs

How do salamanders partcipate in gas exchange?

Use their skin as a respiratory organ

Simple diffusion for gas exchange in small organism cause them to be…

SLUGGISH

Open Circulatory System

• Few to no blood vessels outside the heart itself
• Blood flows freely around the organs
• Arthropods and most Molluscs

Closed Circulatory System

• Blood vessels run throughout the body
• More efficient
• Found in Vertebrates

Which organisms have we looked at with an open circulatory system?

Arthropods, 3 classes of Molluscs, plus (partially)the Branchiopods

Which organisms have we looked at with a closed circulatory system?

Vertebrates, Cephalopod Molluscs, and Phylum Annelida

What advantages does dual-circuit circulation have over more primitive types of circulation?

1. Keeps the blood pressure high through the capillaries

2. Keeps the blood from mixing

What stimulus or stimuli trigger the dive response?

Cold and pressure on the face, plus lower O2 lvls in arteries

What part of the brain processes the dive response stimuli?

Medulla Oblongata

What are the 3 responses of the dive response reflex?

Apnea, Bradycardia, and Peripheral Vasoconstriction

ECG

Electrocardiogram - represents the electrical conduction across the heart

What are the major events on an ECG?

• P - Wave

• QRS Complex

• T- Wave

What major heart activity is happening during a P-Wave?

Atria Contraction

What major heart activity is happening during a QRS Complex?

Ventricles Contract & Atria Relax

What major heart activity is happening during a T-Wave?

Ventricles Relax

Mean Arterial Blood Pressure (MAP)

MAP = Diastolic + ((Systolic-Diastolic)/3)

Aerobic Dive Limit (ADL)

the amount of time a diving animal can remain submerged while utilizing aerobic respiration

Bradycardia

lower than normal heart rate

Tachycardia

higher than normal heart rate

Thermoneutral zone

a range of ambient temperatures at which the surrounding medium (either water or air) will feel neither warm nor cold (NO heat gained or loss