BIOL Lab Exam After Lan 9

❖ What is the function of the cardiopulmonary system?

The cardiopulmonary system facilitates gas exchange and nutrient transport. It allows terrestrial vertebrates to collect atmospheric oxygen, distribute it to tissues via the bloodstream, and remove carbon dioxide and metabolic wastes.

❖ Why is the cardiopulmonary system an adaptive feature for vertebrates?

It supports a high metabolic rate, which is essential for activity and survival on land. It enables efficient delivery of oxygen and nutrients and removal of wastes, helping maintain homeostasis.

❖ Describe the evolution of the heart, lungs, and circulatory systems in vertebrates.

  • Fish: 2-chambered heart (atrium, ventricle); blood flows through gills before body – pressure drops after gills.

  • Lungfish: 3-chambered heart; mix of oxygenated and deoxygenated blood; uses both gills and lungs.

  • Amphibians: 3-chambered heart; pulmocutaneous circulation; blood mixes in the single ventricle.

  • Reptiles: Partial septum in ventricle; less mixing of blood.

  • Crocodilians/Birds/Mammals: Fully divided 4-chambered heart (dual-circuit circulation) for complete separation of oxygenated and deoxygenated blood, allowing for efficient oxygen delivery at high pressure.

❖ Be able to trace the flow of blood through the cardiopulmonary system in mammals.

  1. Body → Superior/Inferior Vena Cavae

  2. Right Atrium → Right Ventricle → Pulmonary Artery → Lungs

  3. Pulmonary Veins → Left Atrium → Left Ventricle → Aorta → Body

❖ Be able to trace the flow of air through the respiratory system of birds. Why/how is it so much more efficient than ours?

Air flows:

  1. Trachea → Posterior air sacs → Lungs → Anterior air sacs → Exhale

  • Air flows in one direction through the lungs, allowing continuous oxygen uptake even during exhalation.

  • Efficiency: avoids mixing fresh and used air.

❖ Be able to trace the flow of air through the respiratory system of mammals including humans.

  1. Nose/Mouth → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli (gas exchange).

❖ Know the names of the waves on an ECG and what they represent.

  • P wave: Atrial depolarization (atria contract)

  • QRS complex: Ventricular depolarization (ventricles contract), includes atrial repolarization

  • T wave: Ventricular repolarization

❖ Be able to identify these waves on a real ECG.

Practice using ECG printouts or software (SparkVue was used in lab) to recognize the waves.

❖ Be able to calculate Mean Arterial Pressure (MAP).

MAP=Diastolic BP+13(Systolic BP−Diastolic BP)\text{MAP} = \text{Diastolic BP} + \frac{1}{3}(\text{Systolic BP} - \text{Diastolic BP})

❖ Be able to identify major structures in the mammalian heart.

  • Right/Left Atrium

  • Right/Left Ventricle

  • Aorta, Pulmonary Arteries/Veins

  • Tricuspid, Pulmonary, Mitral, Aortic valves

  • Chordae Tendineae

  • Septum

❖ What reflexes make up the diving response?

  • Bradycardia – slows heart rate

  • Apnea – holding breath

  • Peripheral vasoconstriction – diverts blood to vital organs

❖ Which part of the brain processes the diving response?

The medulla oblongata, part of the brainstem.

❖ What stimuli trigger the diving response?

  • Facial immersion

  • Apnea

  • Facial cooling (e.g., cold gel packs)

❖ Define key terms:

  • Aerobic Dive Limit (ADL): Max time an animal can dive using only aerobic metabolism.

  • Bradycardia: Lower than normal heart rate.

  • Tachycardia: Higher than normal heart rate.

  • Thermoneutral zone: Temp range where the body doesn't need to expend energy to heat or cool.

  • Open Circulation: Blood not confined to vessels (arthropods).

  • Closed Circulation: Blood confined to vessels (vertebrates).

  • Dual-Circuit Circulation: Blood is pumped to lungs and back before being pumped to the body – maintains pressure and efficiency.

❖ Why do we not want a test subject who will panic underwater?

Panic can interfere with accurate data collection and pose a safety risk to the subject.

❖ What functions do the cold packs and snorkels perform in the experiments?

  • Cold packs simulate facial cooling and test if temperature alone triggers the dive response.

  • Snorkels isolate apnea from facial immersion, allowing control over different triggers of the response.