Biology Unit: Tissues and Organs

Animal Tissues and Organ Systems

• Learning Targets: Differentiate animal tissues, identify organ systems, and distinguish between negative and positive feedback.

• Tissues: Specialized cells of the same type performing a common function.

• Major Types of Animal Tissue: Epithelial, nervous, muscle, and connective tissue.

• Epithelial Tissue:

  • Protection: Forms a barrier and protects underlying tissues from damage and infection.
  • Secretion: Glands release hormones and enzymes.
  • Absorption: Absorbs nutrients in the intestines.
  • Excretion: Filters waste products in the kidneys.

• Types of Epithelium: Simple squamous, simple cuboidal, simple columnar, stratified squamous, stratified cuboidal, and pseudostratified columnar, transitional.

• Simple Squamous Epithelium:

  • Structure: Single layer of thin, flat cells; tightly packed.
  • Location: Lining of blood vessels, alveoli of lungs, and serous membranes.

• Simple Cuboidal Epithelium:

  • Structure: Single layer of cube-shaped cells.
  • Location: Kidney tubules, ducts of glands, and the ovary.
  • Function: Secretion and absorption.

• Simple Columnar Epithelium:

  • Structure: Single layer of tall, column-shaped cells.
  • Location: Lining of the stomach, intestines, and gallbladder.
  • Function: Secretion, absorption, and protection.

• Stratified Squamous Epithelium:

  • Structure: Multiple layers of cells, outer layer is flat and squamous.
  • Location: Lining of the mouth, esophagus, vagina, and skin.
  • Functions: Protective barrier against abrasion and infection.

• Stratified Cuboidal Epithelium:

  • Structure: Multiple layers of cube-shaped cells.
  • Location: Ducts of sweat glands, salivary glands, and mammary glands.
  • Function: Secretion and Absorption

• Pseudostratified Columnar Epithelium:

  • Structure: Single layer of cells that appear layered due to varying heights and nuclei locations.
  • Location: Lining of the trachea and parts of the upper respiratory system.

• Transitional Epithelium:

  • Structure: Specialized epithelium that can stretch and change shape.
  • Location: Lining of the urinary bladder and ureters.

• Connective Tissue:

  • Functions: Fills spaces, attaches epithelium to other tissues, cushions and protects organs; has diverse flexibility and firm support.
  • Types: Loose connective tissue, dense connective tissue, adipose tissue, blood, cartilage, and bone.

• Loose Connective Tissue:

  • Structure: Flexible, web-like structure of cells embedded in a matrix of proteins.
  • Function: Supports and binds other tissues, provides cushioning and flexibility.

• Dense Connective Tissue:

  • Structure: Densely packed collagen fibers, forming a strong and resilient network.
  • Function: Structural support for tendons, ligaments, and fascia; provides strength and resistance to stress.

• Adipose Tissue:

  • Structure: Composed of specialized cells (adipocytes) that store fat in the form of triglycerides.
  • Function: Serves as an energy reserve, insulates the body, and cushions vital organs.

• Blood:

  • Components: Red blood cells, white blood cells, and platelets.
  • Functions: Transports oxygen, and aids in waste removal, fighting infections, and blood clotting.

• Cartilage:

  • Structure: Firm, flexible connective tissue composed of chondrocytes embedded in a matrix of collagen fibers.
  • Function: Provides support, cushions joints, facilitating smooth movement, and reduces friction.

• Bone:

  • Structure: Rigid connective tissue composed of osteocytes embedded in a matrix of collagen fibers and calcium phosphate.
  • Function: Provides structural support, protects vital organs, and serves as a reservoir for calcium.

• Muscle Tissue:

  • Types: Skeletal, smooth, and cardiac.
  • Skeletal Muscle: Attached to bones, responsible for voluntary movement; cylindrical fibers with striations.
  • Smooth Muscle: Found in organs (stomach, intestines, blood vessels), controls involuntary movements; spindle-shaped fibers lacking striations.
  • Cardiac Muscle: Found only in the heart to control involuntary rhythmic contractions, maintaining blood circulation through branched fibers with intercalated discs.

• Nervous Tissue:

  • Neurons: Specialized cells that transmit nerve impulses.
  • Neuroglia: Supporting cells that provide nutrients and protection to neurons.
  • Nervous System: Controls and coordinates all bodily functions (e.g., movement, thought, and sensation).
  • Components: Brain, spinal cord, and nerves.

• Functions of Animal Tissues: Protection, support and structure, movement, and communication and control.

• Regeneration and Repair: Injury, inflammation, regeneration, and scar formation.

• Disorders and Diseases: Cancer, inflammation, degenerative diseases, and infections.

• The Nervous System: Uses electrical impulses to send messages, controls activity, learning, and memory.

  • Central Nervous System (CNS): Brain and spinal cord.
  • Peripheral Nervous System (PNS): Nerves.

• Skeletal System:

  • Functions: Provides support (framework), protection (vital organs), blood cell production, and mineral storage.
  • Components: Bones, ligaments, and cartilage.

• Circulatory System:

  • Functions: Transportation (oxygen, nutrients, and waste), waste removal, temperature regulation, and immune response.
  • Components: Heart, blood vessels, and blood.

• Muscular System:

  • Functions: Movement, stability, and heat production.
  • Components: Muscles and tendons.

• Urinary System:

  • Functions: Filtration of blood (forming urine), urine storage, and elimination of urine.
  • Components: Kidneys, urinary bladder, and urethra.

• Respiratory System:

  • Functions: Gas exchange (oxygen and carbon dioxide), air filtration, warming, humidification, and voice production.

• Digestive System:

  • Functions: Break down food for absorption and energy.
  • Components: Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus; accessory organs.

• Endocrine System:

  • Functions: Hormone production and regulation (growth, metabolism, reproduction).
  • Components: Hormones and glands (pineal, hypothalamus, pituitary, thyroid, thymus, adrenal, pancreas, ovaries, testes).

• Reproductive System:

  • Functions: Reproduction of organisms and species continuation.

• Integumentary System:

  • Functions: Protection (skin), insulation (hair), and grasping/scratching (nails).
  • Components: Skin, hair, and nails.

Test your knowledge on human tissues and organs with this quiz covering muscle types, epithelial functions, and the roles of different bodily systems. Dive into questions about the heart, kidneys, and digestive system to assess your understanding of biology fundamentals.