Body organization and feedback. Ch 40.BIO150.km(1)

Key Concepts of Animal Form and Function

Anatomy and Physiology

• Anatomy: Biological structure that varies widely among animals.

• Physiology: Biological function closely related to structure; examining anatomy provides insight into physiology.

Hierarchical Organization of Body Plans

• Multicellular animals consist of:

  • Cells: Basic units of life.

  • Tissues: Groups of similar cells performing a common function.

  • Organs: Structures composed of two or more tissue types.

  • Organ Systems: Groups of organs that work together in coordination.

Specific Structures and Functions

• Cells: Fundamental units of life.

• Tissues: Types include epithelial, muscle, connective, and nerve (nervous).

• Organs: Can be a bladder, which is part of the urinary system, showing complex functions.

Organ Systems in Mammals

Major Organ Systems and Functions

• Digestive System: Components include mouth, esophagus, stomach, intestines. Function: food processing (ingestion, digestion, absorption, elimination).

• Circulatory System: Components include heart and blood vessels. Function: distributes materials internally.

• Respiratory System: Includes lungs and trachea. Function: gas exchange (oxygen uptake and carbon dioxide disposal).

• Immune and Lymphatic Systems: Main components include bone marrow and lymph nodes. Function: body defense against infections.

• Excretory System: Comprises kidneys and ureters. Function: disposes metabolic waste and regulates osmotic balance.

• Endocrine System: Includes glands such as the pituitary; coordinates body activities like digestion.

• Reproductive System: Involves ovaries or testes. Functions include gamete production and embryonic support.

• Nervous System: Contains the brain and spinal cord; coordinates body functions and responses to stimuli.

• Integumentary System: Encompasses skin and derivatives; provides protection and thermoregulation.

• Skeletal System: Comprises bones and ligaments; supports and protects internal organs.

• Muscular System: Consists of skeletal muscles; facilitates locomotion and movement.

Tissues Overview

Types of Tissues

• Epithelial Tissue: Covers outside of the body and lines internal organs, tightly packed.

• Muscle Tissue: Responsible for movement:

  • Skeletal Muscle: Voluntary movement.

  • Smooth Muscle: Involuntary activity.

  • Cardiac Muscle: Specialized for heart contraction.

• Connective Tissue: Holds many tissues and organs together; includes blood, cartilage, and adipose tissue.

• Nerve Tissue: Involved in information processing and transmission.

Coordination and Control

• Two Major Systems:

  • Nervous System: Directs immediate responses to stimuli.

  • Endocrine System: Coordinates gradual body changes.

Homeostasis

• Definition: Maintaining a steady internal state despite external changes.

• Regulators vs. Conformers:

  • Regulators use internal controls; Conformers adjust to external changes.

• Set Points: Organisms maintain variables like temperature and pH around a set point, using sensors and responses.

• Feedback Mechanisms:

  • Negative Feedback: Reduces stimulus (e.g., regulating glucose via insulin).

  • Positive Feedback: Amplifies stimulus to drive processes to completion (e.g., childbirth).

Alterations in Homeostasis

• Set points may vary with age or environmental conditions.

• Acclimatization: Physiological adjustments in response to environmental changes.