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Sperm Formation

By: HWC, Views: 5743

Spermatogenesis takes place inside the seminiferous tubules. Diploid spermatogonia located near the outer edge of the tubule divide mitotically to form primary spermatocytes. The first meiotic division produces secondary spermatocytes with a haploid number of duplicated chromosomes. T...

Chemical Synapse Animation

By: HWC, Views: 5119

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...

Osmosis - water transport

By: HWC, Views: 7863

Osmosis is the flow of water down its concentration gradient, across a semi-permeable membrane. Osmosis is an example of diffusion, which is when molecules tend to distribute themselves evenly in a space. what is a semi-permeable membrane? It is a membrane or barrier that allows some molec...

Factors that increase metabolic rate and heat production

By: HWC, Views: 7786

• All vital biochemical reactions are temperature dependent. • The overall rate at which metabolic reactions use energy is known as the metabolic rate. • Metabolic rate greatly determines body temperatures. • Temperature is maintained by balancing the loss of heat to the environment...

Steps of glucose catabolism

By: HWC, Views: 7929

• During digestion, complex carbohydrates are hydrolyzed into monosaccharides, primarily glucose. • The catabolism of glucose is the primary source of energy for cellular production of ATP. • The anabolism of glucose is important in regulating blood glucose levels. • Glucose cat...

Structures that affect circulation - heart and systolic/diastolic BP

By: HWC, Views: 7664

• Heart generates blood pressure. • Arterioles produce resistance thereby regulating blood flow to tissues. • Veins store blood; kidneys regulate blood volume; both affect venous return and cardiac output. ■ Contractions of the ventricles determine blood pressure, which drives th...

Definitions of stroke volume, preload definition & Factors influencing stroke volume

By: HWC, Views: 7534

• Stroke volume is directly correlated with cardiac output-the greater the stroke volume the greater the cardiac output. • Stroke volume represents the difference in the amount of blood between: • the volume in the ventricles at the end of diastole (end-diastolic volume EDV); • the ...

Exercise and cardiac output & Definition of stroke volume

By: HWC, Views: 7690

▪ Cardiac output: • Maintains blood flow throughout the body. • Measure of blood volume ejected from the heart over a given time. • Determined by multiplying heart rate by stroke volume (CO = SV x HR). • Heart rate: Number of beats/min. • Stroke volume: Amount of blood eject...

Role of the urinary system - acidosis and alkalosis

By: HWC, Views: 7966

• Tubular cells of the proximal convoluted tubule and collecting tubules can alter filtrate pH and therefore blood pH. • These cells can affect blood pH with two coupled mechanisms: • Reabsorption of bicarbonate ions. • Secretion of hydrogen ions. • The reabsorption of bicarbonate...