Provide definitions/explanations for the following terms:
$(1)$ Excretion
$(2)$ Renal pelvis

The part through which arteries and veins enter or leave the kidney is called:

Analogy type question:
$(1)$ Inner concave notch of kidney : Hilum :: Broad funnel-shaped part of renal pelvis : ............. .
$(2)$ Renal tubule begins with a double-walled cup-like structure called Bowman's capsule :: Bowman's capsule along with glomerulus : ............. .

The wide funnel-shaped space inside the hilum of the kidney is called the .....

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Nephrons are of two types: Cortical and Juxta-medullary,based on their relative position in the cortex and medulla.
Reason $R$: Juxta-medullary nephrons have a short loop of Henle,whereas cortical nephrons have a longer loop of Henle.
In the light of the above statements,choose the correct answer from the options given below:

Kidneys are reddish-brown,bean-shaped structures situated between the levels of . . . . . . thoracic and . . . . . . lumbar vertebrae.