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Stroke volume - preload, sarcomere length and Frank -Starling law

By: HWC, Views: 7352

• Sarcomere length affects muscle tension and the force of contraction. • Increased muscle stretch (increased sarcomere length) at the beginning of contraction increases tension produced during the contraction. • A more forceful contraction ejects more blood, thus increasing stroke volu...

Antidiuretic hormone (vasoconstriction, water reabsorption & sweat inhibition)

By: HWC, Views: 7601

• Dehydration, blood loss, and low amounts of water in the blood can cause blood volume and pressure to decrease. • Neurosecretoxy cells in the posterior pituitary release antidiuretic hormone(ADH). • ADH binds to smooth muscle cells in blood vessel walls, stimulating them to vasoconstr...

Chemical Synapse Animation

By: HWC, Views: 5095

A neuromuscular junction is a chemical synapse between the axon endings of a motor neuron and a muscle cell. A narrow synaptic cleft separates the presynaptic cell (the motor neuron) from the postsynaptic cell (the muscle cell). The presynaptic cell contains vesicles filled with neurotransmitt...

Neural regulation of mechanical digestion- CNS voluntary, ANS & ENS controlled involuntary movements

By: HWC, Views: 7682

• The gastrointestinal [GI] tract is basically a muscular tube that contains and processes food as it moves from the mouth to the anus. • Mechanical digestive functions consist of both voluntary and involuntary muscle contractions and relaxation including: • Chewing and swallowing food....

ACTH/Cortisol (glycogenolysis, protein catabolism, lipolysis and gluconeogenesis)

By: HWC, Views: 7576

• A decline in blood glucose concentration stimulates corticotropic cells in the anterior pituitary to produce adrenocorticotropic hormone (ACTH). • ACTH binds with cells in the zona fasciculata of the adrenal cortex. • Increased ACTH promotes the production of cortisol, the major gluco...

Regulation of GFR: autoregulation via myogenic mechanism Myogenic mechanism

By: HWC, Views: 9198

• GFR can be regulated by adjusting: • Blood flow in and out of the glomerular capillaries. • Surface area of glomerular capillaries. • There are three main ways to make these adjustments: • Renal autoregulation. • Nervous regulation. • Renal autoregulation occurs when...

Labor and Childbirth - The Three Stages of Labor: Dilation, Expulsion & Placental مراحل الولادة

By: HWC, Views: 8166

Regulation of labor and birth - effects of estrogen and oxytocin on onset of labor • Just prior to birth, high placental corticotropin-releasing hormone levels stimulate the production of more estrogen. • High estrogen levels overcome the inhibitory effects of progesterone on uterine sm...

Gastrin (gastric emptying) & Secretin (buffering gastric acid)

By: HWC, Views: 7242

• Gastrin also binds to the smooth muscle cells in the stomach causing: • Increased gastric motility. • Opening of pyloric sphincter. • Increased gastric emptying. • The intestinal phase of digestion begins as chyme enters the duodenum. • The chyme's acidity can damage int...

ATPase function - membrane transport, contractile proteins and synthesis

By: HWC, Views: 8090

• Energy from ATP is used to move ions across the cell membrane during active transport. • This membrane protein transports sodium out of the cell and potassium into the cell. As such, it is called a sodium-potassium pump. • Because this pump also acts as an enzyme to hydrolyze ATP it i...