Tissue Types and Metabolism Overview

Primary Tissue Types

• Four primary tissue types exist: Epithelial, Connective, Muscle, and Nervous.
• Epithelial tissue lines organs and the skin's surface.
• Connective tissue includes fat, bone, and tendons.
• Muscle tissue includes cardiac, smooth, and skeletal muscles.
• Nervous tissue forms the brain, spinal cord, and nerves.

Tissue Metabolism

• This section covers the metabolism of tissues.
• Chapters 47, 41, 42, 43, 44, 45, and 46 are referenced in this section.
• These chapters discuss extracellular matrix, hormone actions, erythrocyte biochemistry, blood plasma proteins, liver metabolism, muscle metabolism, and nervous system metabolism.

Blood Tissue System

• Proteins and cells in the bloodstream form a unique tissue system.
• Parts of this system include stem cells, kidneys, erythropoietin, red blood cells, and anemia.
• Red blood cell metabolism is key for oxygen transport and hemoglobin regulation.
• Hematology and the hematologic system are referenced in relation to blood vessels and blood.
• A tear in a vessel wall is a referenced injury.
• Cholesterol is referenced as a component of concern in blood vessels.

Platelets and Clots

• Platelets help form clots, sealing injuries.
• Platelet plugs are temporary, while blood clots are permanent.
• Deep vein thrombosis (DVT) is mentioned as a blood clot concern.
• Blood clots and thrombosis are referenced.

Blood Plasma Components

• The blood's plasma consists of:
  • Water
  • Glucose
  • Lipids and steroid hormones
  • Osmotic pressure
  • Plasma proteins

Endothelium-Lined Blood Vessels

• Endothelium-lined blood vessels play a role in hemostasis.
• Hemostasis and blood clots are referenced as key elements to this process.

Hemostasis and Thrombosis

• Hemostasis and thrombosis are related biological processes.
• A primary hemostatic plug forms at injury sites, consisting of aggregated platelets and a fibrin clot.
• Platelets are attached to vessel walls, activated, and use fibrinogen to aggregate.
• Damage to endothelium and exposure to tissue factor activates the blood clotting cascade.
• Regulation and impairments reference thrombosis, blood clots, and feedback mechanisms.

Plasma Proteins

• Plasma proteins maintain water distribution between blood and tissues.
• They aid in immune defense and circulatory system integrity.
• The Gibbs-Donnan effect is involved in this relationship between fluid and blood plasma.
• These proteins transport nutrients and hormones and are discussed in the context of maintaining a proper distribution of water between blood and tissues. A main component is albumin.
• A key role of plasma proteins is maintaining the proper distribution of water, nutrients, and hormones in the body.

Blood Fluid Maintenance

• Starling forces (hydrostatic and oncotic pressure) govern the movement of fluid between blood and tissues within capillaries.
• Hydrostatic pressure pushes fluid out, while oncotic pressure pulls fluid in.
• This movement, between extravascular and intravascular spaces, is crucial for proper tissue function and blood flow.

Major Serum Protein, Albumin

• Albumin is a significant serum protein.
• It transports free fatty acids, calcium, zinc, hormones (steroids), copper, and bilirubin.
• It's involved in maintaining fluid balance and drug transport.
• Osmotic pressure is influenced by albumin.

Complement System

• The complement system can be activated by antibodies or antigens.
• Activation results in a cascade of protein activation and releases various peptides mediating inflammatory responses and promoting antigen-antibody complex clearance.

Blood Coagulation

• Blood coagulation involves a cascade of reactions to form a clot after injury.
• Platelets form a plug at the site of injury to stop bleeding.
• The coagulation cascade involves interactions between the intrinsic and extrinsic pathways leading to thrombin formation.
• Fibrinogen is cleaved to fibrin, which polymerizes and forms the clot.
• Thrombin activation of XIIIa is crucial.

Blood Coagulation Cascade

• The blood coagulation cascade is a multi-step process resulting in thrombus formation.
• Proteins serve as enzymes and cofactors that accelerate thrombin formation at an injury site.
• These enzymes and cofactors are present in proenzyme forms.
• Protease regulation is critical for proper blood clotting, also referenced in the context of thrombus formation.

Regulation of Fibrinolysis

• Fibrinolysis involves the breakdown of fibrin to restore normal blood flow.
• Plasminogen activators activate plasmin, which digests fibrin.
• Tissue plasminogen activator and single-chain urokinase promote fibrin breakdown.
• This process is important for removing blood clots and preserving blood vessel patency.

Other notes

• Many diseases alter levels and types of plasma proteins, causing changes in their concentration in the blood. These changes can be diagnosed by electrophoresis.
• Protein C and S regulate thrombin.
• Heparin enhances ATIII-thrombin interaction.
• Endothelial cells regulate blood clotting.
• The processes of platelet activation, clot formation, and fibrinolysis are interdependent.