Anatomy and Physiology of the Human Cell

Understanding Anatomy and Physiology

• Anatomy: Study of the form and structure of organisms.
• Physiology: Study of the processes and functioning of living organisms.
• Pathophysiology: Study of how diseases affect normal functioning (covered elsewhere).

Basic Cell Structures

• Cell Membrane:

  • Semi-permeable structure.
  • Allows nutrients in and waste out.
  • Maintains shape and keeps organelles inside.

• Cytoplasm:

  • Semi-fluid inside the cell.
  • Site of all chemical reactions.

• Organelles:

  • Structures within cytoplasm responsible for cell functions.

Organelles and Their Functions

• Nucleus:

  • "Brain" of the cell, controls functions and division.

• Nucleolus:

  • Located within nucleus, important for cell reproduction.
  • Manufactures ribosomes (composed of RNA and protein).

• Ribosomes:

  • Move from nucleus to cytoplasm, site for protein synthesis.

• Chromatin:

  • Loose thread-like DNA and protein within the nucleus.
  • Forms chromosomes (46 total in each cell) during cell division.

• Mitochondria:

  • "Powerhouse" of the cell.
  • Breaks down carbs, fats, proteins to form ATP (energy of the cell).

• Golgi Apparatus:

  • Stack of membrane layers.
  • Produces, stores, and packages secretions for discharge.

• Endoplasmic Reticulum (ER):

  • Transports materials to/from nucleus.
  • Aids in protein synthesis and storage.
  • Smooth ER: Involved in fat metabolism, cholesterol synthesis, and drug detoxification.
  • Rough ER: Regions with ribosomes for protein production.

• Lysosomes:

  • Digest proteins, fats, old cells, bacteria, and foreign materials.
  • Vital for the immune system.

• Pinocytic Vesicles:

  • Pocket-like folds in cell membrane.
  • Allow proteins and fat molecules to enter, forming vacuoles.

Quick Review

• Cell Membrane acts as the cell's skin.
• Cytoplasm contains all organelles.
• Organelles are responsible for cell functions.
• Nucleus is the cell's control center.
• Nucleolus creates ribosomes.
• Ribosomes synthesize proteins in the cytoplasm.
• Chromatin forms chromosomes with 46 in each human cell.
• Mitochondria generates cell energy.
• Golgi Apparatus manages secretions.
• Endoplasmic Reticulum handles transport and synthesis.
• Lysosomes handle digestion.
• Pinocytic Vesicles enable molecule entry.

With this foundational understanding, you're prepared for the following topic on cell reproduction.