Biology Functioning Systems

Introduction

• Overview: This chapter focuses on how specialized cells in multicellular organisms are organized into systems. It emphasizes the interrelated functions of various systems, such as the digestive, endocrine, and excretory systems, and how they work together to ensure the survival of the organism.

• Key Systems Studied:

  • Digestive System: Obtains nutrients and energy.

  • Endocrine System: Regulates internal stability (homeostasis).

  • Excretory System: Removes waste products.

Functioning Systems

• Learning Intentions:

  • Understand specialized organization of animal cells into tissues, organs, and systems.

  • Describe functioning systems in mammals related to digestion, endocrine regulation, and waste removal.

  • Explore plant systems, especially vascular plants, and their cell organization.

Specialized Cells in Mammals

• 4A.1: Understand structure-function relationship in specialized cells (e.g., red blood cells for oxygen transport).

• 4A.2: Describe relationships among cells, tissues, organs, organ systems, and organisms in mammals.

• 4A.3: Explain the necessity of transport systems in multicellular organisms in context of size, activity levels, and surface area to volume ratios.

The Digestive System: Obtaining Nutrients

• 4B Learning Intentions:

  • Role of the Digestive System: Breaks down food into nutrient components.

  • Structures of the Digestive System: Identify key organs (mouth, esophagus, stomach, intestines).

  • Functions of Each Structure: Describe the specific roles of organs (chewing, enzymatic breakdown, nutrient absorption).

  • Malfunctions: Explore consequences of digestive malfunctions and diseases (e.g., coeliac disease).

The Endocrine System: Regulation of Body Functions

• 4C.

  • Role of the Endocrine System: Hormonal regulation of metabolic processes, homeostasis, growth, and development through glands.

  • Components of the Endocrine System: Hypothalamus, pituitary gland, thyroid, adrenal glands, pancreas, and their respective hormones (e.g., insulin, glucagon, thyroxine).

  • Regulatory Mechanisms: Feedback loops that maintain stable internal conditions.

  • Malfunctions: Discuss diseases like diabetes and Graves' disease, their impact, and treatment approaches.

The Excretory System: Elimination of Waste

• 4D

  • Overall Role of the Excretory System: Maintain water balance and eliminate metabolic wastes.

  • Components: Kidneys, ureters, bladder, and urethra, and their specific roles in urine formation.

  • Filtration and Reabsorption: Nephrons as functional units, understanding processes of filtration, reabsorption, and secretion during urine formation.

  • Malfunctions: Discuss conditions like urinary tract infections and kidney diseases.

Plant Systems: Structure and Function

• 4E

  • Plant Classification: Differentiate between vascular (with transport systems) and non-vascular plants.

  • Vascular Systems: Understand role of xylem (water transport) and phloem (nutrient transport) in vascular plants.

  • Xylem Structure and Function: Importance of specialised cells (tracheids and vessel elements) for water transport and structural support.

  • Transpiration: Mechanism of water movement through plants and its significance for nutrient transport and temperature regulation.

Structure of Tissues and Their Relationship to Function

• Levels of Organization in Animals: Cells → Tissues → Organs → Systems → Organisms

• Relationship: Each cell type is specialized to perform a specific function that contributes to overall organism survival.

Summary

• The chapter articulates the complexity of biological systems in both animals and plants, focusing on the intricate relationships between cellular structures and their functions within various systems. It underlines that organism health depends on seamless functioning of these systems.