SU 2 - Cells, Tissues, and Integumentary System

Study Unit 2: Cells, Tissues, and Integumentary System

2.1: Definition of Anatomy

2.1.1: Study Outcomes

• Figures referenced:

  • Figure 3-1: Pg. 114 - 115

  • Figure 3-2: Pg. 116

  • Figure 3-10: Pg. 129

  • Figure 3-25: Pg. 154

2.1.2: Individual Activities

• 1) General functions of the plasma membrane:

  • Physical isolation

  • Regulation of exchange with the environment

  • Sensitivity to the environment

  • Structural support

• 2) Components of the plasma membrane:

  • Membrane Lipids: Form the structure of the bilayer, creating a barrier.

  • Membrane Proteins: Assist in transporting substances and signaling.

  • Membrane Carbohydrates: Involved in cell recognition and signaling.

• 3) Primary component responsible for the physical barrier:

  • Phospholipid bilayer creates the boundary between internal and external environments.

• 4) Cytoplasm vs. Cytosol:

  • Cytoplasm: Material between the plasma membrane and the nuclear membrane.

  • Cytosol: Fluid portion of the cytoplasm, a mixture of water and solutes.

• 5) Differences between Cytosol and Extracellular Fluid:

  • Higher potassium and protein concentration in cytosol.

  • Lower sodium ion concentration in cytosol.

  • Presence of amino acids and lipids in cytosol.

• 6) Non-Membranous Organelles and their Functions:

  • Cytoskeleton: Provides strength, support, and facilitates movement.

  • Centrioles: Organize microtubules and aid in cell division.

  • Ribosomes: Synthesizes proteins.

  • Proteasomes: Break down and recycle proteins.

  • Microvilli: Increase surface area for absorption.

  • Cilia: Move materials over cell surfaces; act as environmental sensors.

  • Flagella: Responsible for sperm mobility.

• 7) Membranous Organelles and their Functions:

  • Endoplasmic Reticulum (ER): Synthesis, transport, and storage of materials.

    • Smooth ER: Lipid and carbohydrate synthesis.

    • Rough ER: Protein modification and packaging.

  • Golgi Apparatus: Modifies, packages, and sorts secretions.

  • Lysosomes: Breakdown of waste and damaged structures.

  • Peroxisomes: Detoxification of harmful substances.

  • Mitochondria: ATP production (95% of cell's energy).

2.1.3: Cellular Level of Organization

• Cell: Smallest living unit.

• Cytology: Study of cell structures and functions.

• Plasma Membrane: Outer boundary of a cell.

• Nucleus: Contains genetic material (DNA, RNA, proteins).

• Nucleoplasm: Fluid within the nucleus.

• Chromatin: Uncoiled DNA visible during interphase.

• Organelles: Specialized structures within a cell.

• Extracellular Fluid (ECF): Body fluids outside cells.

• Cytoplasm: Contents between the cell membrane and nucleus.

• Interstitial Fluid: Fills spaces between tissue cells.

• Centrosome: Contains centrioles and is involved in cell division.

• Cytoskeleton: Provides structural support in the cytoplasm.

• Cytosol: Fluid portion of cytoplasm.

• Matrix: Ground substance and fibers in connective tissue.

2.1.4: Clinical Terms

• Anaplasia: Irreversible change in cell size/shape.

• Dysplasia: Reversible change in cell size/shape.

• Hyperplasia: Increase in normal cell numbers.

• Hypertrophy: Enlarging of cells or tissue.

• Necrosis: Death of cells due to inadequate blood supply.

2.2: Tissue Level of Organization

2.2.1: Study Outcomes

• Figures referenced:

  • Figure 4-1: Pg. 162

  • Subsequent figures and tables from Pg. 167 to Pg. 189

2.2.2: Individual Activities

• 1) Define Histology: Study of tissues.

• 2) Major Types of Tissues:

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

  • Connective Tissue: Supports organs, stores energy, transports materials.

  • Muscle Tissue: Specialized for contraction (Skeletal, Cardiac, Smooth).

  • Nervous Tissue: Transmits signals via electrical impulses.

• 3) Characteristics of Epithelial Tissue:

  • Polarity

  • Cellularity

  • Attachment

  • Avascularity

  • Regeneration

• 4) Essential Functions of Epithelial Tissue:

  • Protection

  • Control permeability

  • Sensation

  • Secretion

• 5) Epithelial Cell Shapes:

  • Squamous: Thin and flat.

  • Cuboidal: Spherical, equidistant nuclei.

  • Columnar: Taller and slender.

• 6) Simple vs. Stratified Epithelia:

  • Single layer = simple

  • Multiple layers = stratified

• 7) Classification of Tissue Sample:

  • Simple squamous epithelium cannot be skin surface due to lack of protection.

• 8) Epithelial Organization in Certain Organs:

  • Pharynx, esophagus, anus, vagina have similar structures due to abrasion.

• 9) Types of Glandular Epithelia:

  • Endocrine: Secrete hormones; no ducts.

  • Exocrine: Secrete substances via ducts.

• 10) Functions of Connective Tissue:

  • Structural framework

  • Transport fluids

  • Protect organs

  • Store energy

  • Immune defense

• 11) Categories of Connective Tissues:

  • Connective Proper

  • Fluid Connective Tissues

  • Supporting Connective Tissues

• 12) Cells in Connective Tissue Proper:

  • Fibroblasts: Most abundant, always present.

  • Fibrocytes: Maintain connective tissue fibers.

  • Adipocytes: Store fat.

  • Mesenchymal Cells: Stem cells in connective tissues.

  • Macrophages: Large phagocytic cells in matrix.

  • Mast Cells: Secrete substances during inflammation.

  • Lymphocytes: Immune response.

• 13) Supporting Connective Tissue Types:

  • Cartilage

  • Bone

• 14) Bone vs. Cartilage Healing:

  • Bone heals faster due to better blood supply.

2.2.3: Tissue Level of Organization

• Tissue: Collection of cells performing a specific function.

• Histology: Study of tissues.

• Major Tissue Types:

  • Epithelial

  • Connective

  • Muscle

  • Neural

2.3: The Integumentary System

2.3.1: Main Structural Features of the Epidermis

• Epidermis: Stratified squamous epithelium for protection, avascular, reliant on the dermis for nutrients.

• Keratinocytes: Dominant cells containing keratin, arranged in layers.

• Layers of the Epidermis:

  • Stratum Basale: Deepest layer; attachment to the basement membrane.

  • Stratum Spinosum: Contains keratinocytes and immune cells (dendritic).

2.3.2: Glands and Nails

• Sebaceous Glands: Holocrine glands releasing sebum for lubrication.

• Sweat Glands: Apocrine and eccrine; involved in temperature regulation and excretion.

• Hair Structure: Layers include root, shaft, and bulb.

• Nails: Protect tip of fingers and toes, made of keratin.

2.3.3: Aging Effects on the Skin

• Thinning epidermis, decreased vascularity, red-aging; slower regeneration and sensitivity to heat.

Clinical Terms Summary

• Understand terminology related to conditions, diseases, and healing processes related to the integumentary system, such as carcinoma, eczema, and necrosis.

Review Questions

• Includes multiple choice questions covering the content of the unit, testing knowledge on anatomy, tissue functions, and organ systems.