Human Arterial
system :
consists of
two main arteries :
1. pulmonary
artery and
2. Aorta
pulmonary
artery :
Arises from
top Left region of Rt. ventricle and
divides into two branches : Rt. pulmonary artery and Lt. pulmonany artery. Rt-
Pulmonary artery Carry deoxygenated blood to Rt lungs. Lt. pulmonary artery
Carry deoxygenated blood to Lt lungs.
Urine and micturition
urine is liquid and Consists of 96% - water, 2 % urea, 2%
other substances. Other substances includes organic and inorganic Substances
like Uric acid, creatinine, Hippuric acid, Na, K, Ca, Mg, Chloride etc.
About 1.5 to 2 ltrs
urine is formed each day. It is transparent light yellow coloured due to
pigment urochrome.
Counter Current Mechanism
The countercurrent mechanism is a process that occurs in the kidneys, enabling
them to concentrate urine and maintain water and electrolyte balance in the
body. It primarily takes place in the loop of Henle, and involves the
countercurrent multiplier system in the loop of Henle and the countercurrent
exchanger in the vasa recta (the
parallel network of capillaries around LOH).
Mechanism of urine formation or Process of urine
formation:
The process of formation of
Urine is called Uropoiesis. It takes place in nephron. Each
nephron is independent and Can Produce miniscule amount of urine. This process
gets completed in 3 steps; Ultrafiltration, selective reabsorption and tubular
secretion.
• Ultrafiltration: It is process in which blood is
filtered under pressure in malphigian body of nephron.
The main driving pressure for it is hydrostatic pressure
of blood in glomerulus (A) which is about (60-70) mmHg. However, this
pressure is opposed by osmotic pressure of plasma protein or Blood Colloidal
osmotic pressure (B) which is about 30mmHg and also opposed by capsular
hydrostatic pressure or hydrostatic pressure of nephric filtrate in
Cavity of Bowmans Capsule (C) which is about 20 mmHg.
The
process of formation of urine, its transformation, its temporary storage and
its elimination from body form a system Called urinary system which is commonly
Called excretory system. It Consists of kidneys, ureter, urinary bladder and
urethra.
Respiration is involuntary process and is regulated by Nervous system and Some Chemicals in blood.
The voluntary regulation is done by higher Centres in cerebrum while involuntary regulation is of two types: Nervous regulation and chemical regulation.