ch 26: urinary Flashcards
describe the flow of urine
urine flows from the kidneys, through the ureters, to the bladder, out through the urethra
describe the ureters
25-30 cm in length. transport urine from the kidney to the urinary bladder, primarily by peristalsis
describe the innermost layer of the ureter
- The mucosa layer: innermost layer; formed of a transitional epithelium (can stretch) and lamina propria (has elsatic fibers, and lymphatic tissue)
mucus is secreted to prevent the cells from coming in contact w/ acidic urine
3 layers of wall of the ureters
- the mucosa layer
- the muscularis layer
- the adventitia layer
describe the muscularis layer of the ureter
contains a longitudinal layer and circular layer of smooth muscle cells; peristalsis contributes to urine flow
describe the adventitia layer of the ureters
it’s the outermost layer
consists of connective tissue that anchors the ureters in place.
Contains blood vessels and nerves to supply the ureters
what is the trigone
the area is bordered by 2 ureteral openings and one urethral opening
what are the 3 layers of the wall of the bladder
- the mucosa layer
- the muscularis layer
- the adventitia
describe the mucosa layer of the bladder
inner most layer
formed of a transitional epithelium and lamina propria (has elastic fibers and lymphatic tissue). Mucus is secreted to prevent the cells from coming in contact with the acidic urine
describe the muscularis layer of the bladder
(detrusor muscle)
composed of 3 layers of smooth muscle; outer longitudinal, middle circular and longitudinal inner
function of rugae in bladder
permits expansion of the bladder
circular smooth muscle vs circular skeletal muscle in the bladder
circular smooth muscle forms te internal urethral sphincter; under involuntary control
circular skeletal muscle forms the external urethral sphincter; under voluntary
describe the adventitia
the outermost layer of the bladder. It consists of loose connective tissue that anchors the bladder in place.
Which of the following is a funnel-shaped area
where the openings for the ureters and the
urethra are found in the urinary bladder?
a) Detrusor
b) Rugae
c) Trigone
d) Lamina
c) Trigone
how does urination occur (receptors and pathways)
- stretch receptors detect stretching when the volume exceeds 200-400 mL
- sensory neuron carries information to the spinal cord (S2-S4)
- pre-ganglionic neuron carries motor impulses to the bladder
- post-gangionic neuron stimulates the detrusor muscle to contract
- sensory impulses are relayed to the cerebral cortex (via the thalamus) for awareness of fullness
- cerebral cortex can initiate voiding or delay it occurrence by controlling the external urethral sphincter (skeletal muscle)
Which part of the urine elimination pathway is
under voluntary control?
a) Internal urethral sphincter
b) External urethral sphincter
c) Detrusor muscle
d) a and b
b) external urethral sphincter
Which region of the spinal cord contains the
center of the micturition reflex?
a) Pelvic
b) Sacral
c) Thoracic
d) Lumbar
b) sacral
Which branch of the nervous system carries
motor impulses of the micturition reflex?
a) Parasympathetic
b) Sympathetic
c) Somatic
d) Spinal
a) parasympathetic
in females the urethra length
4 cm in length.
what are the 2 layers the wall of the female urethra
- The mucosa layer is the innermost layer. It goes from transitional epithelium to nonkeratinized stratified squamous epithelium.
The lamina propria has elastic fibres and blood vessels
- the muscular consists of circular smooth muscle
describe the male urethra
The male’s urethra is much longer
than the female’s urethra (~20 cm).
It goes through the prostate
(prostatic urethra), then through the deep muscles of the perineum
(intermediate urethra), and through
the penis (spongy urethra)
what are the 2 layers in the wall of the male urethra
- The mucosa layer is the inner most layer. It goes from transitional epithelium to pseudostratified columnar epithelium to nonkeratinized stratified squamous epithelium. The lamina propria has
elastic fibers, and blood vessels. - The muscularis consists of smooth muscle fibers in the prostatic urethra (internal
sphincter), and skeletal muscle in the intermediate urethra (external sphincter)
describe the kidneys
The kidneys are found just above
the waist between the
peritoneum and the wall of the
abdomen; they are
retroperitoneal organs (along with
the adrenal glands & the ureters).
The kidneys are protected by
the 11th & 12th ribs.
what are the renal functions?
Filtration, reabsorption, secretion = Excretion of waste products
1.1 Regulation of water and electrolyte balance
blood ionic composition Na+, K+, Ca+2, Cl- and phosphate ions
1.2 Regulation of acid-base balance (blood pH)
1.3 Regulation of blood volume and pressure conserving or eliminating water
2. Endocrine functions
2.1 Secrete erythropoietin (stimulate RBC production)
2.2 Renin (enzyme) → regulates aldosterone levels
2.3 Calcitriol (activated form of vit D) → promotes intestinal calcium absorption
3. Gluconeogenesis
how are lobes, pyramids and papilla related
A kidney contains 8-18 lobes. A
lobe is formed of a pyramid
(medulla), the overlying area of
renal cortex, and one half of each
adjacent renal column.
Papilla = apex of pyramid
what is a nephron and where are they found
a nephron is the functional unit of the kidney
nephrons are found in the renal cortex and the renal medulla
a kidney has over 1 million nephrons each composed of a corpuscle and tubule
describe the path of urine drainage
Many nephrons drain into
a collecting duct, which
drain into papillary ducts,
which further converge
into minor calyces (one per
lobe) and major calyces (2
3 per kidney). Urine drains
into a single, large renal
pelvis, then into the ureter
to the bladder
what are nephrons made of and what happens there
a kidney has over 1 million nephrons each composed of a corpuscle and a tubule
the renal corpuscle is where blood plasma is filtered
what happens in the renal tubule
substances get reabsorbed into the blood
cortical nephrons vs juxtamedullary nephrons
80-85% of nephrons are cortical
nephrons; the tubule doesn’t
go deep into the medulla
15-20% of nephrons are juxtamedullary
nephrons. The tubule goes deep into the medulla. They allow for excretion of very
dilute or very concentrated urine (see later)
Juxtamedullary nephrons:
a) Make up about 80-85% of the nephrons within the kidney.
b) Allow regulation of blood volume and pressure.
c) Have renal corpuscles located in the outer portion of the renal
cortex.
d) Have very short nephron loops.
e) Have very thick descending nephron loops.
b - more space for osmosis
what are nephrons composed of?
Vascular component –
connects to circulatory system and is made
of 2 arterioles
◦ Afferent arteriole (carries unfiltered blood) enters the high pressure (glomerular capillaries)
◦ Efferent arteriole (carries filtered blood) branches to form low-pressure peritubular
capillary bed
Tubular component –
connects to circulatory system and
elimination functions of kidney
what are peritubular capillaries
As solutes flow through the
renal tubules, they get
reabsorbed from the tubules
into peritubular capillaries
what are the 3 basic processes that the nephron and collecting ducts perform
- In the renal corpuscle, blood plasma flowing through the glomerulus gets filtered into
the glomerular capsule. - All along the renal tubule and collecting duct, water, ions, and other substances get
reabsorbed from the renal tubule lumen into the blood - substances such as wastes, drugs, and excess ions get secreted from the blood into the
renal tubule. These substances ultimately make their way into the urine.
where does filtration of blood start
Filtration of blood
starts at renal
corpuscle made of:
Glomerulus
Glomerular (aka
Bowman’s) capsule
blood flows from the afferent arteriole into the ______
glomerular capillaries