Flashcards for:
Nutrient and Gas Exchange Systems Overview

Gills have a high surface area that allows water to flow over surfaces within the pharynx. Oxygen is absorbed into the secondary lamellae of the gills and into the blood, while carbon dioxide is released from the blood back into the water.

Large insects may use active ventilation in addition to passive diffusion, actively moving air in and out of the tracheal system to ensure proper gas exchange for their increased metabolic demands.

Spiracles are openings on the body surface of insects that allow air to enter the trachea. This structure branches into smaller tubes reaching every cell, facilitating oxygen diffusion into cells and carbon dioxide out.

Xylem vessels consist of long, water-filled tubes strengthened by lignin, which are hollow after cell death. Pits and perforations allow for sideways water movement between adjacent vessels, aiding effective water transport.

Insects have an open circulatory system where nutrients and gases dissolve in hemolymph and travel directly to tissues, while fish have a single circuit closed system with blood flowing through vessels.

The stomach mechanically churns food while gastric juices chemically break down food particles, proteins are denatured, and enzymes like pepsin further digest proteins.

In a single circulatory system, like in fish, blood flows from the gills through the body without returning to the heart. In a double circulatory system, like in mammals, blood passes through the heart twice during circulation, providing more efficient oxygenation.

A high surface area increases the rate of gas exchange by providing more space for oxygen to be absorbed and carbon dioxide to be expelled, making the process more efficient.

Phloem consists of sieve tubes (transport sugars), companion cells (support sugar transport), parenchyma cells (provide structure), and sclerenchyma cells (offer structural support).

Parenchyma cells provide structural support and storage within the vascular tissue, while sclerenchyma cells provide additional rigidity and mechanical support.

In plants, water is involved in maintaining cell turgidity and transport of nutrients, while carbon dioxide is used in photosynthesis to produce glucose and oxygen, which is then released.

The small intestine has a highly folded surface with villi and microvilli, increasing the surface area for nutrient absorption. It also receives digestive enzymes and bile, enhancing chemical digestion.

Water moves up xylem vessels through transpirational pull and capillary action. Tracheids transport water horizontally through pits that connect adjacent tracheids, facilitating water movement across the plant.

Companion cells support sieve tubes by carrying out metabolic processes necessary for the maintenance and functionality of the sieve tubes, enabling efficient sugar transportation.

Sieve tubes have thin cell walls and are perforated by sieve plates, allowing the flow of nutrients. Their living cells facilitate rapid transportation of sugars and other nutrients throughout the plant.