Kidney and Skin Flashcards
Describe the excretory pathway
Bowman’s space –> proximal convoluted tubule –> descending limb of the loop of henle –> ascending limb of the loop of henle –> distal convoluted tubule –> collecting duct –> renal pelvis –> ureter –> bladder –> urethra
Kidney:
Contains a cortex and medulla. Produces urine which
dumps into the ureter at the renal pelvis. Urine is then
collected in the bladder until it is excreted through the
urethra.
Nephron
: Functioning unit of the kidney.
what are the two capillary beds that make up the renal portal system?
Two capillary beds in series (glomeruli & nephron).
How does blood flow in the renal portal system?
renal artery –> afferent arterioles –> glomeruli –> efferent arteriole –> vasa recta –> renal vein
Filtration:
Bowman’s capsule moves solutes from blood –> filtrate.
Direction and rate determined by hydrostatic and oncotic
pressure differentials between the glomerulus and
Bowman’s space
Secretion:
The movement of solutes from blood –> filtrate anywhere
other than Bowman’s capsule.
Reabsorption
: The mvmt of solutes from filtrate –> blood
How does the kidney regulate pH?
with bicarbonate and H+
What type of hormone is aldosterone
Steroid
Where is aldosterone synthesized?
adrenal cortex in response to angiotensin 2 or high potassium concentration
What is aldosterone derived from?
Cholesterol
What effect does aldosterone have on sodium reabsorption in the distal convoluted tubule and collecting duct?
Increases sodium reabsorption in both the dct and collecting duct thereby also increasing water reabsorption
What effect does aldosterone have on blood pressure?
Increase BP but no change in blood osmolarity
Where is ADH synthesized from?
Hypothalamus and released by posterior pituitary
What effect does ADH have on the permeability of the collecting duct to h2o
Increases the permeability of the collecting duct to water which increase water reabsorption and as a result the BP increases and blood osmolarity decrease. concentrated urine is produced
Proximal Convoluted
Tubule (PCT
Site of bulk reabsorption of glucose, amino acids,
soluble vitamins, salt, and H2O. Site of secretion
for H+, K+, NH3, and urea
Descending Limb of the
Loop of Henle
Permeable to H2O but NOT salt; therefore, as the
filtrate moves into the more osmotically
concentrated renal medulla, water is reabsorbed
from the filtrate.
Countercurrent
Multiplier System:
The vasa recta and nephron flow in opposite
directions, creating a countercurrent multiplier
system that allows maximal reabsorption of water
Ascending Limb of the
Loop of Henle
Permeable to salt but NOT to H2O; therefore, salt
is reabsorbed both passively and actively. The
diluting segment is in the outer medulla; because
salt is actively reabsorbed in this site, the filtrate
becomes hypotonic compared to the blood
Distal Convoluted
Tubule (DCT):
Responsive to aldosterone and is a site of salt
reabsorption and waste product excretion, like
the PCT
Collecting Duct
Responsive to both aldosterone and ADH. Has
variable permeability, which allows reabsorption
of the right amount of H2O depending on the
body’s needs
Detrusor Muscle:
Muscular lining of bladder. Parasympathetic control
Internal Urethral Sphincter:
: Smooth muscle. Parasympathetic control
External Urethral Sphincter:
Skeletal muscle. Voluntary control
List the layers of the epidermis from bottom to top
Stratum Corneum Stratum Lucidum Stratum granulosum Stratum spinosum Stratum basale
Come lets get sun burnt
Stratum Basale:
Stem cells –> keratinocytes
Stratum spinosum
Lagerhan cells
Stratum granulosum
Keratinocytes die
Stratum luciderm
only thick and hairless skin
Stratum corneum
Multiple thin layers, flat keratinocytes
Langerhan cells
: Macrophages that are antigen-presenting cells in skin
Melanin:
: Produced by Melanocytes. Protects skin from DNA damage
caused by ultraviolet radiation
Sensory layers of the dermis
papillary layer and reticular layer
Merkel cells of dermis
deep pressure and texture
Free nerve endings of dermis
Pain
Meissner’s corpuscles of the dermis
Light touch
Ruffini endings of dermis
Stretch
Pacinian corpuscles of the dermis
Deep pressure and vibration
Hypodermis
Fat and connective tissue. connects skin to the body
Thermo- regulation
Sweating
Evaporation and cooling
Thermo-regulation
Piloerection
Warming
Thermo-regulation
Shivering
Warming
