Topic 4 1 - Barriers + Compartments 3a4b30f05c12494b8cfa67ab79517b91.pdf

🚧 Topic 4.1 - Barriers + Compartments Lecture 1 - Connective Tissue What are the main components/properties of Connective Tissues Cells (Fibroblasts) Extracellular Matrix...

🚧 Topic 4.1 - Barriers + Compartments Lecture 1 - Connective Tissue What are the main components/properties of Connective Tissues Cells (Fibroblasts) Extracellular Matrix Collagen - Tensile Strength Elastin - elasticity Ground Substance - transparent + surrounds and fills in spaces for volume Explain the general structure of loose/areolar connective tissue collagen + elastin embedded in an amorphous hydrated ground substance amorphous - no clear defined shape, amorphous ground substance fills the space between cells + fibres fibroblasts are also present for inflammatory, allergic + immune response It is located under the epidermis and dermis layers of the skin. Topic 4.1 - Barriers + Compartments 1  Explain the general structure of Dense Connective Tissue composed largely of collagen fibre along with sparse ground substance (hydrated) and fibroblasts Dense C.T can be…. “dense regular C.T. (e.g. Tendon)”, where fibres are organised “dense irregular C.T. (e.g. Dermis) where fibres aren’t organised Explain the general structure of Cartilage Chondrocytes embedded in an amphorous hydrated ground substance Chondrocytes - cells that secrete cartillage matrix and embed with the matrix structural support, resistance to compression - poorly vascularised Topic 4.1 - Barriers + Compartments 2  Explain the basic structure of Bone Osteocytes - bone cells formed from an osteoblast Osteocytes embedded in a mineralised matrix - not hydrated What is the interstitial compartment (Interstitum) a type of loose connective tissue that supports the bronchial tree, arterio-venous tree & continuous tubes in the digestive system Branching Structure of Tubes in the airways Topic 4.1 - Barriers + Compartments 3  A schematic diagram of the human digestive system Exocrine glands are linked to the Gut lumen by ducts (red arrow) Major glands → Liver, Pancreas, Salivary Glands What are the 5 airway layers 1. Respiratory Epithelium ciliated cells Includes a basement membrane. Topic 4.1 - Barriers + Compartments 4  2. Lamina Propria contains connective tissue, blood + lymph contains fibroelastic tissue → more prominent and muscular as tubes get smaller 3. Smooth Muscle Layer Controls airway diameter and resistance to airflow. Found beneath the mucosa. Becomes more prominent in smaller airways. 4. Submucosa Located under the smooth muscle layer. Contains seromucus glands. 5. Cartilage prevents collapsing becomes less prominent as tubes get smaller. What are the variations in airway structure for the Trachea Topic 4.1 - Barriers + Compartments 5  Trachea - C shaped cartillage, mucous glands What are the variations in airway structure for the Bronchi Bronchi has discontinuous cartilage, more smooth muscle, mucous glands What are the variations in airway structure for the bronchioles Bronchioles - no cartilage + no submucosal glands, no goblet cells What are the variations in airway structure for the Alveolar Duct no cilia, no glands What are the variations in airway structure for the Alveoli Alveoli have Type 1 & 2 Pneumocytes Structure of Veins (innermost to outermost) (veins are multilaminar) 1. Tunica Intima Thin layer with an endothelial lining. 2. Tunica Media smooth muscle + elastic fibers. 3. Tunica Adventitia/Externa Thickest layer with longitudinally arranged thick collagen fibers that merge with surrounding connective tissue. Topic 4.1 - Barriers + Compartments 6  Structure of Elastic Arteries (innermost to outermost) 1. Tunica Intima Thin layer with an endothelial lining. Contains little collagenous connective tissue. Includes a thin internal elastic lamina (exclusive to arterties) 2. Tunica Media smooth muscle + elastic fibres 3. Tunica Adventitia/Externa Almost as thick as the media. Merges with surrounding tissue. Composed of collagen. Describe the Structure of capillaries Topic 4.1 - Barriers + Compartments 7  Capillaries (Single Layer): Composed of a single layer of endothelium/endothelial cells Very small diameter, forcing red blood cells to fold to pass through. Clefts or slits between endothelial cells allow for effective material exchange. what are the 4 layers of the Gut tubes + Glands 1. Mucosa Divided into three layers: epithelial lining, supporting connective tissue (lamina propria), and a thin layer of smooth muscle (muscularis mucosae). 2. Submucosa A layer of connective tissue that supports the mucosa. Contains larger blood vessels, lymphatics, and nerves. 3. Muscularis Externa/Propria Topic 4.1 - Barriers + Compartments 8  Consists of smooth muscle 4. Adventitia/Serosa Conducts major blood vessels and nerves. When GI Tube is Below the diaphragm, it is called serosa, which is part of the visceral peritoneum Oesophagus Conducts swallowed substances from pharynx to stomach (about 25 cm). Normally collapsed with highly folded mucosa, which stretches when swallowing food. Mucosa/submucosa contain mucous glands. Lined by stratified squamous epithelium to resist abrasion from swallowed substances. What are the 4 layers of the stomach Gastro-oesophageal junction joins oesophogaus to stomach Topic 4.1 - Barriers + Compartments 9  Mucous Cells: Located at the surface. Produce mucus and bicarbonate to protect the surface from acid and digestion. Parietal (Oxyntic) Cells: Produce HCl (hydrochloric acid) and intrinsic factor. Chief (Peptic or Zymogenic) Cells: Produce enzymes Enteroendocrine Cells: Produce hormones Small Intestine primarily designed for absorption, and it accomplishes this by incorporating structural features that maximize its surface area for efficient nutrient uptake. Moreover, the mucosa forms finger-like projections called villi. Topic 4.1 - Barriers + Compartments 10  Structure of the Villus in the small intestine Villus Structure: Covered by simple columnar epithelium. Continuous with crypts (moat-like invaginations of the epithelium around the villi) Large Intestine Function: Large Intestine Absorb water and salt to produce a more solid waste product. Large Intestine Composition: Abundant goblet cells for lubrication. Enterocytes for absorption (active membrane transport but no digestion). Appendix: outgrowth of the cecum Topic 4.1 - Barriers + Compartments 11  During excretion of undigested material, what are the 2 sphincters which control muscular canal Internal Anal Sphincter: Smooth muscle thickening at the end of the rectum. Involuntary control. External Anal Sphincter: Skeletal muscle. Under voluntary control. Topic 4.1 - Barriers + Compartments 12 Topic 4.1 - Barriers + Compartments 13