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The primary factors that affect circulation - MABP, CO and SVR

By: HWC, Views: 6931

Introduction Blood flow is determined by the relative intensities of factors that drive and resist moving blood. • Cardiac output (CO) equals the mean arterial blood pressure (MABP, a driving force) divided by systemic vascular resistance (SVR, a resisting force). • Hormones and the cen...

Depolarization of the SA node, Action potentials of the myocardium & ANS effects

By: HWC, Views: 6500

• A typical contractile cell in the myocardium has a resting membrane potential. • The resting membrane potential of cells in the SA node is not fixed, and is known as the pacemaker potential. • The action potential of a healthy SA nodal cell has three parts: • Pacemaker potential: ...

Carbohydrate digestion (brush border enzymes, end products) & Carb absorption (fructose, galactose)

By: HWC, Views: 6676

• Carbohydrate digestion concludes in microvilli of the small intestine, in brush border epithelial cells. Carbohydrate digestion -brush border enzymes • Four brush-border enzymes are involved: • Alpha-dextrinase breaks down alpha-dextrin chains by removing glucose units. • Sucras...

Hydrogen bonds - role in the body

By: HWC, Views: 7003

A hydrogen bond is the electromagnetic attraction between polar molecules in which hydrogen is bound to a larger atom, such as oxygen or nitrogen. This is not a sharing of electrons, as in a covalent bond. Instead, this is an attraction between the positive and negative poles of charged atoms. ...

Helper T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 6747

• Most cells which have CD4 on their surface become Helper T cells (TN cells). • The CD4 1 cells only recognize a foreign antigen when it is presented with an antigen presenting immune cell (APC) that includes MHC-II protein. • The Helper T cell antigen receptor must match the presented...

Hemoglobin's affinity with oxygen - carbon dioxide, temperature and bisphosphoglycerate (BPG)

By: HWC, Views: 6774

• The carbon dioxide gas is temporarily converted to carbonic acid in red blood cells by the enzyme carbonic anhydrase, and then further converted to hydrogen and bicarbonate ions. • The result of increased carbon dioxide is decreased pH causing the Bohr effect. • Elevated carbon dioxid...

Cellular Defects - Osteoblasts, Osteoclasts and Osteocytes

By: HWC, Views: 6302

■ Metabolically active bone-building cells that secrete astroid. ■ Cover surfaces of newly formed bone and respond to growth stimuli ■ Less responsive to growth factors as the body ages. ■ Contribute to hone loss once their reproductive and biosynthetic potential lessens....

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 6661

• The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone aft...

Parathyroid hormone (bone resorption) & Calcitonin (bone deposition)

By: HWC, Views: 6657

• Cellular needs for calcium may cause blood calcium concentrations to decline below the normal range. • This decrease stimulates cells in the parathyroid gland to secrete parathyroid hormone. • Binding of parathyroid hormone to osteoclasts in bone tissue promotes bone resorption and th...