Biol 2401 Test 2 chapter 5,6,7

BIOL 2401 – Chapter 5: Tissues – The Living Fabric

1. Four Basic Tissue Types

  • Nervous Tissue: Controls body functions, includes brain, spinal cord, nerves.

  • Muscle Tissue: Responsible for movement, includes skeletal, cardiac, and smooth muscle.

  • Epithelial Tissue: Covers and lines surfaces, forms glands.

  • Connective Tissue: Supports, binds, and protects; includes bone, blood, cartilage, fat.

2. Characteristics of Tissues

  • Similar Cells: Typically share an embryological origin and specialized function.

  • Cell Junctions:

    • Tight Junctions: Prevent leaks (e.g., in stomach lining).

    • Adherens Junctions: Provide structural support.

    • Desmosomes: Form strong connections (e.g., skin).

    • Hemidesmosomes: Anchor cells to the basement membrane.

    • Gap Junctions: Facilitate communication (e.g., in heart cells).

3. Epithelial Tissue

  • Characteristics:

    • Avascular: Lacks blood supply.

    • Innervated: Contains nerves.

    • Regenerative: Heals quickly.

  • Classification:

    • Layers: Simple (one layer), Stratified (multiple layers).

    • Shape: Squamous (flat), Cuboidal (cube-like), Columnar (tall).

4. Membranes (Coverings & Linings)

  • Cutaneous Membrane: Skin covering the body surface.

  • Mucous Membrane: Lines cavities open to the exterior (e.g., digestive and respiratory tracts).

  • Serous Membrane: Lines cavities closed to the exterior (e.g., pericardium, pleura).

5. Glandular Secretion (Types of Exocrine Glands)

  • Merocrine: Releases products by exocytosis (e.g., sweat glands).

  • Apocrine: Part of the cell pinches off (e.g., mammary glands).

  • Holocrine: Cell ruptures and is replaced (e.g., sebaceous glands).

6. Tissue Repair

  • Regeneration vs. Fibrosis:

    • Regeneration: Replaces damaged tissue with the same type.

    • Fibrosis: Replaces with scar tissue (collagen).

  • Tissue Healing Capacity:

    • Fast Healing: Epithelial tissue, bone, blood-forming tissue.

    • Moderate Healing: Smooth muscle.

    • Weak Healing: Skeletal muscle, cartilage.

    • No Healing: Cardiac muscle, nervous tissue.

7. Inflammation (First Step in Tissue Repair)

  • Vasodilation: Blood vessels widen.

  • Increased Permeability: Allows immune cells and nutrients to enter.

  • Inflammatory Response: Symptoms include redness, heat, swelling, pain, and loss of function.

Page 2 Summary

  • Tissue Healing Capacity: Emphasizes varied healing capabilities across tissue types, highlighting that skeletal muscle and cartilage exhibit weak healing, while cardiac muscle and nervous tissue show no healing capabilities.

Page 3: Epithelial Types

  • Simple Columnar Epithelium

  • Transitional Epithelium

  • Stratified Squamous Epithelium

  • Pseudostratified Columnar Epithelium

  • Stratified Cuboidal Epithelium

Connective Tissue Types

  • Loose Areolar Connective Tissue

  • Loose Adipose Connective Tissue

  • Stratified Columnar Epithelium

Page 4: Connective Tissue Types Continued

  • Loose Reticular Connective Tissue

  • Dense Regular Connective Tissue

  • Hyaline Cartilage

  • Elastic Cartilage

  • Dense Irregular Connective Tissue

  • Dense Elastic Connective Tissue

  • Fibrocartilage

  • Compact Bone

Page 5: Muscle and Tissue Types

  • Blood

  • Cardiac Muscle

  • Skeletal Muscle

  • Smooth Muscle

  • Nervous Tissue

BIOL 2401 – Chapter 6: The Integumentary System

1. Overview of the Skin

  • Largest Organ: Composed of all four tissue types: epithelial, connective, muscle, nervous.

Functions:

  • Protection: Acts as a chemical, physical, and mechanical barrier.

  • Temperature Regulation: Maintains body temperature.

  • Sensation: Includes detection of touch, pressure, and pain.

  • Vitamin D Synthesis

  • Blood Reservoir: Stores approximately 5% of blood volume.

  • Excretion: Sweat helps remove waste.

2. Skin Structure

  • Epidermis: Outer layer, stratified squamous epithelium, avascular, keratinized.

  • Dermis: Strong connective tissue with nerves, blood vessels, and lymphatics.

  • Hypodermis (Subcutaneous Layer): Adipose and areolar connective tissue, anchors skin.

3. Layers of the Epidermis (Deep to Superficial)

  1. Stratum Basale: Deepest, mitotic, contains melanocytes.

  2. Stratum Spinosum: Thick layer, has Langerhans cells.

  3. Stratum Granulosum: Keratinization begins here.

  4. Stratum Lucidum: Present only in thick skin (palms, soles).

  5. Stratum Corneum: Outermost layer, dead keratinized cells.

4. Skin Glands

  • Sudoriferous (Sweat) Glands:

    • Eccrine: Regulates body temperature.

    • Apocrine: Associated with hair follicles, odor-producing.

  • Sebaceous (Oil) Glands: Connected to hair follicles, secretes sebum for skin waterproofing.

    • Absent on palms and soles.

5. Hair & Nails

  • Hair Types:

    • Vellus Hair: Fine body hair.

    • Terminal Hair: Coarse hair (e.g., scalp, axillary).

  • Nails:

    • Nail bed: Supports nail.

    • Nail matrix: Area for nail growth.

Page 7: Skin Pigmentation and Healing

6. Skin Pigmentation

  • Melanin: Produced by melanocytes, responsible for skin color. More melanin = darker skin.

  • UV Exposure: Increases melanin production.

7. Wound Healing

  • Epidermal Healing: Regeneration of skin layers.

  • Dermal Healing: May result in scar tissue formation.

8. Skin Cancer Types

  1. Basal Cell Carcinoma: Most common, least dangerous. Slow growth. Treatment: Surgical removal.

  2. Squamous Cell Carcinoma: Fast-growing, may spread if untreated. Treatment includes surgical removal.

  3. Malignant Melanoma: Most dangerous; highly metastatic. Uses ABCDE Rule for detection. Treatment includes surgery and immunotherapy.

9. Burns

  • Causes: Heat, chemicals, radiation, electricity.

  • Classification:

    • 1st-degree: Affects the epidermis, presents with redness and swelling.

    • 2nd-degree: Involves epidermis & dermis, blisters form.

    • 3rd-degree: Full-thickness burn, destroys nerves.

10. Rule of Nines

  • Head & Neck: 9%

  • Upper Limbs: 18%

  • Trunk: 36%

  • Perineum: 1%

  • Lower Limbs: 36%

  • Total: 100%

BIOL 2401 – Chapter 7: Bone Tissue

1. Functions of Bone

  • Support: Provides structure to the body.

  • Protection: Shields soft organs (e.g., skull protects brain).

  • Movement: Serves as attachment sites for muscles.

  • Mineral Storage: Stores calcium and phosphate.

  • Blood Cell Production: In red bone marrow (hemopoiesis).

  • Energy Storage: Yellow marrow stores fat.

2. Skeletal System Overview

  • Axial Skeleton: Comprising the skull, spine, ribs, sternum.

  • Appendicular Skeleton: Comprising limbs, shoulders, pelvis.

  • Skeletal Cartilage Types:

    • Hyaline: Most common, found in joints and ribs.

    • Elastic: Flexible, found in ear.

    • Fibrocartilage: Tough, found in intervertebral discs.

3. Bone Classification

  • Long Bones: (e.g., femur, humerus).

  • Short Bones: Cube-shaped (e.g., wrist, ankle).

  • Flat Bones: Thin, curved (e.g., ribs).

  • Irregular Bones: Unique shapes (e.g., vertebrae).

  • Sesamoid Bones: Small, round bones (e.g., patella).

4. Structure of a Long Bone

  • Epiphysis: Ends containing spongy bone, articular cartilage.

  • Diaphysis: Shaft composed of compact bone, containing the medullary cavity (yellow marrow).

  • Periosteum: Outer covering with nerves and blood vessels.

  • Endosteum: Inner lining of the bone.

5. Bone Tissue Structure

  • Osteoblasts: Cells that build bone.

  • Osteocytes: Mature bone cells present in lacunae.

  • Osteoclasts: Cells that break down bone.

  • Lamellae: Layers of bone matrix.

  • Canaliculi: Tiny canals that connect osteocytes.

  • Central Canal: Contains blood vessels and nerves.

  • Perforating Canals: Connect central canals.

6. Bone Growth & Remodeling

  • Wolff’s Law: Bone adapts to stress; increased force leads to stronger bone development.

  • Trabeculae: Form along stress lines, creating large projections where muscles attach.

7. Bone Growth in Length

  • Cartilage grows at the epiphyseal plate.

  • Bone replaces cartilage until adulthood.

8. Bone Fracture & Repair

Steps of Bone Healing:

  1. Hematoma forms at the break.

  2. Fibrocartilaginous callus forms as a soft repair tissue.

  3. Bony callus forms, replacing cartilage with hard bone.

  4. Bone remodeling occurs progressively over time.

9. Osteoporosis

  • A condition leading to low bone density and increased fracture risk.

  • Common in: Elderly, especially postmenopausal women.

  • Prevention: Engage in weight-bearing exercises and ensure adequate calcium and vitamin D intake.