Lecture Notes on Transport in Animals and Plants

Introduction

• Focus on transport systems within animals and plants.
• Two main sections: transport within animals and transport in plants.

Transport in Animals

Cardiovascular System

• Definition: System responsible for moving substances throughout the body.
• Components:
  • Heart (cardio) and vessels (vascular).
  • Blood contains red blood cells, white blood cells, nutrients, oxygen, carbon dioxide.
• Function: Distributes nutrients and oxygen to cells, removes waste.
• Relationship with Other Systems: Works with respiratory system to transport oxygen from lungs to bloodstream and distribute it.

Circulatory System Overview

• Heart: Central pump in circulatory system.
• Arteries and Veins:
  • Arteries: Carry oxygen-rich blood away from the heart.
  • Veins: Carry waste blood back to the heart.
• Capillaries: Smallest vessels where exchange of oxygen, nutrients, and waste occurs.

Blood Flow Process

• From Heart to Body: Oxygen-rich blood pumped through arteries to arterioles to capillaries.
• Capillary Exchange: Nutrients and oxygen leave blood to enter cells; waste enters blood.
• Return to Heart: Waste blood travels back through venules to larger veins to heart.
• Pulmonary Circulation: Heart pumps waste blood to lungs for oxygenation.

Vessel Structure & Function

• Arteries:
  • Thick muscular walls to handle high pressure.
  • Elastic fibers for stretch and recoil, ensuring continuous blood flow.
  • Narrow Lumen maintains high-pressure flow.
• Capillaries:
  • Thin walls for efficient exchange of materials.
  • Very small Lumen slows blood flow for nutrient exchange.
• Veins:
  • Thinner walls than arteries, larger Lumen for blood return.
  • Valves to prevent backflow.
  • Aided by skeletal muscle contractions to move blood.

Pulse Rate and Coronary Arteries

• Pulse Rate Measurement: Carotid and radial arteries are common sites.
• Coronary Arteries: Supply the heart itself with oxygen and nutrients.
• Coronary Heart Disease: Caused by blocked coronary arteries, can lead to heart attacks.

Transport in Plants

Plant Transport Systems

• Overview: Transport of water, minerals, and nutrients using xylem and phloem.
• Xylem: Transports water and minerals from roots to leaves.
• Phloem: Transports sugars and nutrients throughout the plant.

Structure of Plant Transport

• Roots:
  • Absorb water and minerals from the soil.
  • Structures: Epidermis, cortex, endodermis, xylem, phloem.
• Stem:
  • Vascular bundles dispersed, containing xylem and phloem.
• Leaves:
  • Site of transpiration (water loss through stomata).

Xylem and Phloem Structure

• Xylem:
  • Dead cells creating a hollow tube, strengthened by lignin.
  • Transports water via capillary action.
• Phloem:
  • Living cells that transport sugars from leaves to other parts of the plant.

Capillary Action in Plants

• Process: Cohesion and adhesion properties of water enable upward transport.

Summary and Key Concepts

• Animal Transport: Involves cardiovascular and circulatory systems for efficient nutrient and waste transport.
• Plant Transport: Xylem and phloem essential for water and nutrient distribution.
• Comparison: Differences in mechanisms and structures between animal and plant transport systems.