[BIO 11.1] E13 - Animal Cells and Tissues

• Epithelial Tissues

  • Membranous
  • Stratified
  • Glandular
• Simple Squamous


  Single layer flat cells that allow passive diffusion of gasses and tissue fluids. Example: Liver, Lungs
• Simple Cuboidal


  Single layer cube-shaped cells that line small ducts and tubules for absorption and secretion. Example: Kidney
• Simple Columnar


  Single layer elongated cells that line the villi for active absorption and secretion. Example: Small Intestine
• Simple Stratified


  Multiple layers of cells (can be classified into different shapes). Example: Skin, Cheek

  
• Goblet Cells


  Unicellular exocrine glands interspersed among columnar epithelia that secrete mucus. Example: Small Intestine
• Cutaneous Glands


  Multicellular exocrine glands found beneath epithelial layers that secrete poison
• Connective Tissues


  • Composed of abundant extracellular matrix (ECM) where specific cell types are dispersed
• Loose Connective Tissue


  Anchors various blood vessels, nerves, muscles, etc. with messily-arranged collagen and amorphous ground substance. Located outer to epithelial layer
• Dense Connective Tissue


  Densely packed fibers found in the skin, tendons, and ligaments with a neater arrangement and greater number of fibrocytes. Located beneath epithelial layer
• Cartilage


  Flexible supportive tissue with chondrocytes embedded in an extracellular matrix of chondroitin sulfate and collagen/elastic fibers
• Chondrocytes


  • Pink-stained nuclei
  • Lodged singly or in pairs in lacunae

  
• Bone


  Provides internal support and protection, anchors muscles, and facilitates movement. Composed of compact and spongy bone tissue
• Compact Bone


  External hard layer of all bones, composed of osteons
• Erythrocytes (Red Blood Cells)


  Contain hemoglobin that binds oxygen, giving them their red color. Frog RBCs are larger, oval, and have a central nucleus, while human RBCs are smaller, disc-shaped, and lack a nucleus
• Leukocytes (White Blood Cells)


  • Agranulocytes (Lymphocytes, Monocytes)
  • Granulocytes (Neutrophils, Basophils, Eosinophils)

  
• Skeletal Muscle


  Striated, with light I-bands and dark A-bands, has more than one nucleus per cell (syncytium), allows for voluntary contraction, and is attached to bones via tendons

  
• Smooth Muscle


  No striations, one nucleus per cell, allows for involuntary contraction, may occur singly or in small groups, often arranged in sheets in the walls of organs like the stomach, uterus, and intestines
• Cardiac Muscle


  Striated, one nucleus per cell, allows for involuntary contraction, found only in vertebrate hearts, cells connected by intercalated discs to synchronize contraction, regulated by hormones and the autonomic nervous system
• Nerve


  Small string-like structure that carries impulses across the body, composed of epineurium, fascicles/nerve bundles, perineurium, endoneurium, myelin sheath, and axons
• Neuron


  Functional unit of the nervous system, with dendrites, soma, nucleus, protoplasmic extensions, and axons
• • Haversian Canal
  • Central
  • Runs longitudinally, parallel to the bone
  • Contain the blood vessels that supply nutrients
  • Volkmann’s Canal
  • Transverse channels that connect adjacent Haversian Canals
  • Lamellae
  • Concentric rings that surround the Haversian Canal
  • Lacunae
  • Interspersed along concentric rings
  • House osteocytes
  • Canaliculi
  • Thin, small canals projecting from lacunae

  
• Blood is composed of thrombocytes (platelets), erythrocytes (RBC), leukocytes (WBC), and its ECM is plasma.