Question

1. Describe the path of urinary filtrate from where it leaves the glomerulus to the ureter. Specifically, what happens to water, sodium and urea during this trip? How is the reabsorption of water and sodium regulated by hormones?

2. Discuss the difference between the sympathetic and parasympathetic nervous systems. Be sure to include a discussion of the different ganglia found in each system and their roles.

Answer 1

1. When blood passes through glomerular capillaries,the plasma is filtered into the Bowman's capsule. This process is called glomerular filtration.

Filtrate from Bowman capsule passes through the tubular portion of nephron. While passing through the tubules, the filtrate undergoes varios changes in quality and quantity. Many unwanted substances like glucose, amino acids and electrolytes are reabsorbed by process of tubular reabsorption. And, some unwanted substances are secreted into the tubules from the peritubular blood vessels. This is called tubular secretions.

After this, urine formed enters the renal sinus which include renal pelvis. After this, urine enters minor calyces and then into major calyces. Finally after this, urine enters ureters.

2.

sympathetic nervous system

it is located in thoracolumbar segment of spinal cord.

The postganglionic neuron is away from the target organ.

Length of preganglionic fibres are shorter.

Length of postganglionic fibres are longer.

Preganglionic neurotransmitter in acetylcholine.

Postganglionic neurotransmitter is noradrenaline.

Parasympathetic division

preganglionic neuron are located in cranial nerves and sacral segment of spinal cord.

Postganglionic neuron is located near or in the target organ.

Length of preganglionic fibre is long .

Length of postganglionic fibre is short.

Preganglionic and postganglionic neurotransmitter is acetylcholine.