Anatomy 2nd Year

Anatomy

• Anatomy is the science of structure and design of the organs and systems of the human body.
• There are two main ways to study anatomy: regional anatomy and systemic anatomy.
• Regional anatomy divides the body into parts, including:
  • Head
  • Neck
  • Trunk
  • Upper and lower limbs
• Systemic anatomy studies the body systems, including:
  • Skin
  • Skeleton system
  • Muscular system
  • Respiratory system
  • Cardiovascular system
  • Digestive system
  • Urinary system
  • Nervous system
  • Male and female reproductive system

The Cell and Tissues

• The cell is the basic structural, functional, and biological unit of all known organisms.
• Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids.
• There are 300 different types of cells in the human body, differing in shape and size.
• The human egg (ovum) is the largest cell in the body, visible to the naked eye.
• There are two main types of cells:
  • Eukaryotic cells (have a nucleus) - human cells
  • Prokaryotic cells (no nucleus) - primitive cells

Cell Theory

• All living things are composed of one or more cells.
• Cells are the base unit of structure and function in an organism.
• Cells come from the replication of existing cells.

Cell Organelles

• Cell membrane: controls the passage of materials in and out of the cell, maintains cell shape and structure.
• Nucleus: controls all cell activities, contains genetic materials (DNA and RNA).
• Mitochondria: produces energy for cell functions.
• Nucleolus: keeps chromosomes and cell identity.
• Golgi body: manufactures and stores materials.
• Ribosomes: produces proteins.

The Cell Membrane

• The cell membrane is a semi-permeable membrane that surrounds the cytoplasm, controlling the passage of materials in and out of the cell.
• The cell membrane is composed of proteins, phospholipids, and cholesterol.
• The cell membrane has several functions, including:
  • Diffusion
  • Osmosis
  • Facilitated diffusion
  • Active transport
  • Endocytosis and exocytosis

Cell Shape and Function

• Cell shape differs according to tissue function.
• Examples of cell shape and function:
  • Neurons: long to transmit signals
  • Blood cells: small to pass through capillaries
  • Fibrous tissue cells: elongated and elastic to withstand deforming forces
  • Mucous membrane cells: have cilia to sweep out foreign particles
  • Muscle cells: have contractile elements to function in flexion and extension of joints
  • Bone and cartilage cells: produce hard matrix to give rigidity to tissue

Tissues

• Tissues are groups of cells that have a similar structure and act together to perform a specific function.
• There are four main types of tissues in the human body:
  • Epithelial tissue
  • Connective tissue
  • Muscular tissue
  • Nervous tissue

Epithelial Tissue

• Epithelial tissue is formed by cells that cover organ surfaces, such as the skin, airways, and soft organs.
• Epithelial tissue provides a barrier between the external environment and the organ it covers.
• Epithelial tissue also functions in secretion, excretion, and absorption.

Connective Tissue

• Connective tissue is a type of fibrous tissue made up of cells separated by non-living material (extracellular matrix).
• The extracellular matrix can be liquid or rigid.
• Examples of connective tissue include:
  • Blood
  • Bone
  • Tendon
  • Ligament
  • Adipose tissue
  • Areolar tissue

Muscular Tissue

• Muscular tissue is composed of cells that have the ability to shorten or contract to produce movement.
• Muscular tissue is highly cellular and well-supplied with blood vessels.
• Muscle cells are long and slender, and are arranged in bundles or layers surrounded by connective tissue.
• There are three main types of muscle tissue:
  • Skeletal muscle tissue
  • Smooth muscle tissue
  • Cardiac muscle tissue

Nervous Tissue

• Nervous tissue is composed of cells that make up the central nervous system and peripheral nervous system.
• Nervous tissue forms the brain and spinal cord in the central nervous system.
• Nervous tissue forms the cranial nerves and spinal nerves, including motor neurons, in the peripheral nervous system.