ANAT 7390 Lecture Notes - Lecture 2: Renal Papilla, Renal Fascia, Renal Pyramids
17 Jun 2018
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1
TOPIC XVI: URINARY SYSTEM
A) Urinary System: Overview
Structures:
- 2 kidneys
- 2 ureters
- 1 urinary bladder
- 1 urethra
Functions:
- Regulates:
- blood volume
- blood pressure
- pH
- ion concentrations
- Eliminates wastes
- e.g. urea, uric acid, hormones, drugs
B) Urinary System Structures
1) Kidneys:
- external anatomy:
- retroperitoneal
- right lower than left
- supported & protected by 3 layers of CT:
a) fibrous capsule
b) perirenal fat capsule
c) renal fascia
- renal hilus (hilum)
- medial indentation
- entry point of:
- renal artery (superior)
- renal vein (inferior)
- ureter
- nerves
- internal anatomy:
- renal cortex (superficial)
- renal medulla
- contains:
i) renal pyramids
- apex of pyramid = renal papilla
2
ii) renal columns
- separate pyramids
- contain blood vessels
2) Nephron:
- functional unit of kidney (microscopic)
- composed of:
a) renal corpuscle
- in cortex
- site of blood filtration (first step in urine formation)
- parts:
i) glomerulus
= capillary bed
ii) Bowman’s capsule
- surrounds glomerulus
- collects filtrate from glomerulus
-2 layers
1) outer = simple squamous epithelium
2) inner = podocytes ⇒ wrapped around
glomerular capillaries
iii) filtration Membrane
- consists of:
1. glomerular endothelium (capillaries)
- simple squamous with pores (=
fenestrations)
2. basement membranes
3. podocytes (of Bowman’s capsule)
- simple epithelium
- projections “cling” to glomerulus
b) renal tubules
- 4 parts:
i) proximal convoluted tubule (PCT)
- in cortex
ii) loop of Henle
- descending + ascending limbs
- in medulla
iii) distal convoluted tubule (DCT)
- in cortex
iv) collecting ducts
- in cortex & medulla
Document Summary
Topic xvi: urinary system: urinary system: overview, urinary system structures, kidneys: Supported & protected by 3 layers of ct: fibrous capsule, perirenal fat capsule, renal fascia. Site of blood filtration (first step in urine formation) 2 layers: outer = simple squamous epithelium, inner = podocytes wrapped around glomerular capillaries, filtration membrane. Simple squamous with pores (: glomerular endothelium (capillaries, basement membranes, podocytes (of bow(cid:373)a(cid:374)"s capsule) Projectio(cid:374)s (cid:862)cli(cid:374)g(cid:863) to glo(cid:373)erulus: renal tubules. 4 parts: proximal convoluted tubule (pct) In medulla: loop of henle, distal convoluted tubule (dct, collecting ducts. Connect nephron to ureter (via calyces/renal pelvis) Renal corpuscles near kidney surface in cortex. Short loop of henle in outer medulla. Long loops - penetrate deep into medulla. Allow concentration of urine, depending on need. 4: juxtaglomerular complex renal corpuscle of the same nephron. Point of contact between end of ascending limb, afferent and efferent arterioles at the. Modified smooth muscle cells contain renin (enzyme + hormone: tubular portion, arteriolar portion.
