Organ Systems
Organ Systems
Chapter Overview
Copyright Information: © 2024, Elsevier Inc. All Rights Reserved.
Learning Objectives: Lesson 5.1
Define and contrast the terms organ and organ system.
Identify and locate the major organs of the integumentary, skeletal, and muscular systems, and briefly describe their major functions.
Identify and locate the major organs of the nervous, endocrine, and cardiovascular systems, and briefly describe their major functions.
Definitions and Concepts
Organ: A structure made up of two or more kinds of tissues that can together perform a more complex function than a single tissue.
Organ System: A group of organs that perform a more complex function than can any organ alone.
Integumentary System
Structure
Consists of one organ: the skin.
Contains many appendages (attached structures):
Hair
Nails
Microscopic sense receptors
Sweat glands
Oil glands
Functions
Protection: The primary function of the integumentary system.
Regulation of body temperature: Helps maintain stable internal conditions.
Synthesis of chemicals: Involved in producing important substances.
Sense organ: The skin provides sensory input from the environment.
Skeletal System
Structure
Bones: The primary organs of the skeletal system, with 206 named bones typically present in the human skeletal system.
Variable Bones: Additional bones may occur in individual variability.
Cartilage: Connects and cushions joined bones.
Ligaments: Bands of fibrous tissue that hold bones together.
Joints: Connections allowing for movement between bones.
Functions
Supporting Framework: Provides structure and support for the entire body.
Protection: Safeguards the brain and internal organs.
Movement: Facilitates movement in conjunction with joints and muscles.
Storage of Minerals: Acts as a reservoir for minerals such as calcium and phosphorus.
Formation of Blood Cells: Hematopoiesis occurs within certain bones.
Major Bones in the Skeletal System
Cranium: (includes parietal bone, frontal bone, occipital bone)
Vertebrae: Include cervical, thoracic, and lumbar regions.
Facial Bones: Maxilla, mandible.
Shoulder Girdle: Clavicle, scapula.
Chest: Sternum, ribs.
Upper Limb: Humerus, radius, ulna, carpal bones, metacarpal bones, phalanges.
Pelvis: Hip (coxal) bones.
Lower Limb: Femur, patella, tibia, fibula, tarsal bones, metatarsal bones.
Muscular System
Structure
Muscles: The primary organs of this system.
Voluntary (Striated) Muscles: Skeletal muscle under conscious control.
Involuntary (Smooth) Muscles: Found in walls of some organs, functioning autonomously.
Cardiac Muscle: Specialized muscle found in the wall of the heart.
Functions
Movement: Facilitates all bodily movements.
Skeletomuscular System: A combination of the skeletal and muscular systems, working interdependently.
Nervous System
Structure
Central Nervous System (CNS):
Brain
Spinal Cord
Peripheral Nervous System (PNS):
Cranial Nerves and their branches
Spinal Nerves and their branches
Sense Organs
Functions
Communication Between Body Organs: Ensures coordination throughout the body.
Integration of Body Functions: Synthesizes sensory input and response mechanisms.
Control of Body Functions: Governs voluntary and involuntary activities.
Recognition of Sensory Stimuli: Processes information from the environment.
Endocrine System
Structure
Major glands include:
Pituitary Gland
Pineal Gland
Hypothalamus
Thyroid Gland
Parathyroid Glands
Thymus Gland
Adrenal Glands
Pancreas
Gonads: Ovaries (female) and testes (male)
Functions
Functions similarly to the nervous system:
Communication: Coordinates different body functions.
Integration: Ensures that various systems work cohesively.
Control: Hormonal control is generally slow and of long duration.
Neuroendocrine System: The interaction between the nervous and endocrine systems to maintain homeostasis.
Cardiovascular System
Structure
Also referred to as the Circulatory System.
Primary components include:
Heart
Blood Vessels
Functions
Transportation: Moves substances such as oxygen, nutrients, and hormones throughout the body.
Regulation of Body Temperature: Helps maintain thermal balance.
Immunity: Participates in the body's defense mechanisms against pathogens.
Lymphatic/Immune System
Learning Objectives: Lesson 5.2
Identify and locate the major organs of the lymphatic and immune, respiratory, digestive, and urinary systems, and briefly describe their major functions.
Identify and locate the major organs and subdivisions of the male and female reproductive systems, and briefly describe their major functions.
Describe the body as a whole, including listing the major organ systems of the body, discussing homeostasis, and applying organ system concepts.
Describe current approaches to organ replacement.
Lymphatic System: Structure
Lymphatic Vessels
Lymph Nodes and Tonsils
Thymus
Spleen
Lymphatic System: Functions
Transportation of Lymph: Moves lymph fluid throughout the body.
Immunity: Key role in the body's immune response.
Immune System: Structure
Phagocytes: Protective cells that engulf pathogens.
Secretory Cells: Produce defensive protein compounds, including:
Antibodies
Complements
Immune System: Functions
Phagocytosis: Engulfs and destroys bacteria.
Chemical Reactions: Provides protection from harmful agents.
Respiratory System: Structure
Nose
Pharynx
Larynx
Trachea
Bronchi
Lungs
Respiratory System: Functions
Gas Exchange: Exchanges waste gas (carbon dioxide) for oxygen in the alveoli of the lungs.
Filtration: Filters irritants from inspired air.
Regulation of Acid-base Balance: Maintains pH in the body.
Digestive System: Structure
Primary Organs (forming the alimentary canal, gastrointestinal (GI) tract):
Mouth
Pharynx
Esophagus
Stomach
Small Intestine
Large Intestine
Rectum
Anal Canal
Accessory Organs: Assist in digestion:
Teeth
Salivary Glands
Tongue
Liver
Gallbladder
Pancreas
Appendix
Digestive System: Functions
Mechanical and Chemical Breakdown: Involves digestion of food substances.
Absorption of Nutrients: Uptake of vital nutrients into the bloodstream.
Elimination of Undigested Waste: Waste product referred to as feces.
Appendix: Holds bacteria that assist in digestion.
Urinary System: Structure
Kidneys
Ureters
Urinary Bladder
Urethra: Part of both urinary and reproductive systems in males.
Urinary System: Functions
Blood Cleansing: Removes waste products excreted as urine.
Electrolyte Balance: Maintains proper ion concentrations.
Water Balance: Regulates hydration status.
Acid-base Balance: Maintains pH level in the body.
Male Reproductive System: Structure
Gonads:
Testes
Other Structures:
Vas Deferens
Urethra
Prostate
External Genitalia: Penis and scrotum.
Female Reproductive System: Structure
Gonads:
Ovaries
Other Structures:
Uterus
Uterine (Fallopian) Tubes
Vagina
External Genitalia: Vulva
Mammary Glands: Breasts
Functions of the Reproductive Systems
Survival of Genes: Ensures genetic diversity.
Production of Sex Cells:
Male: Sperm
Female: Ova
Transfer and Fertilization of Sex Cells: Critical for reproduction.
Development and Birth of Offspring: Supports fetal growth and delivery.
Nourishment of Offspring: Through lactation.
Production of Sex Hormones: Essential for reproductive functions.
Body as a Whole
Overview of Body Systems
There are 11 body systems:
Integumentary
Skeletal
Muscular
Nervous
Endocrine
Cardiovascular
Lymphatic/Immune
Respiratory
Digestive
Urinary
Reproductive
Interconnectedness of Body Systems
No single body system functions entirely independently of others.
All systems are structurally and functionally interrelated and interdependent.
Homeostasis can only be maintained through coordinated and carefully regulated functioning of all body systems.
Organ Replacement
Considerations
Loss of function in nonvital organs is not immediately life-threatening, but vital organs’ loss can be critical.
Loss of function in organs may be treated through organ replacement strategies:
Nonvital Organ Replacement: Use of prostheses.
Vital Organ Transplantation: Surgical methods to replace crucial organs.
Surgical Transplants: Operative procedures to restore organ function.
Free-flap Surgeries: Techniques to replace skin and soft tissue.
Stem Cell Treatment: Innovative methods for regenerating tissues.
Examples of Prostheses
Artificial Arm and Hand
Dialysis Machine (artificial kidney)
Cochlear Implant (artificial ear)
Artificial Joint (hip)
Contact Lens
Insulin Infusion Device (artificial pancreas)
Pacemaker
Artificial Heart Pumps
Questions?
For any inquiries or clarifications, please advise for further assistance.
Copyright Information: © 2024, Elsevier Inc. All Rights Reserved.