Lecture Exam 3 Study Guide

These flashcards are designed to help students review key concepts discussed in the lecture related to the respiratory, circulatory, and digestive systems.

What body part do insects breathe out of that covers their entire body?

Insects breathe out of a structure called tracheae.

What is the difference between external and internal respiration?

External respiration refers to gas exchange between the atmosphere and lungs, while internal respiration is the exchange of gases between the blood and body cells.

What makes amphibian lungs different from reptiles and mammals lungs?

Amphibian lungs are less efficient and often combined with cutaneous respiration through the skin.

What are the Alveoli and what is their function?

Alveoli are tiny air sacs in the lungs that enable gas exchange, allowing oxygen to enter the blood and carbon dioxide to be expelled.

What muscle is responsible for inhalation in mammals?

The diaphragm is the muscle responsible for inhalation in mammals.

What advantage does countercurrent flow provide in fish gills during gas exchange?

Countercurrent flow enhances gas exchange efficiency by maintaining a concentration gradient for oxygen and carbon dioxide across the gill membranes.

What is the main difference between single circulation and double circulation?

Single circulation has blood passing through the heart once for each circuit, while double circulation has blood passing through the heart twice: once for oxygenation and once for distribution.

What is responsible for delivering air throughout the entire human body besides the heart?

The respiratory system is responsible for delivering air throughout the entire human body.

Explain the roles of the Atrium and Ventricle?

The atrium receives blood entering the heart, while the ventricle pumps blood out of the heart.

What is the function of the crop? Does every animal have it?

The crop is a storage organ for food before digestion, and not every animal has a crop.

What does Polyphyodont mean? Name some examples of animals with this characteristic.

Polyphyodont means having multiple sets of teeth throughout life; examples include sharks and crocodiles.

How do villi and microvilli in the small intestine improve nutrient absorption?

Villi and microvilli increase the surface area of the small intestine, facilitating greater nutrient absorption.

What is the difference between mechanical and chemical digestion?

Mechanical digestion involves physical breakdown of food, while chemical digestion involves enzymatic breakdown of food into its molecular components.

Why do birds and some invertebrates require a gizzard?

Birds and some invertebrates require a gizzard for grinding and digesting food mechanically.