urinary bladder Flashcards
where is the bladder situated? which system does it belong to?
The bladder is an organ of the urinary system, situated anteriorly in the pelvic cavity
how is the urinary bladder like?
It is hollow, highly distensible, and rounded in shape
what is the main function of the bladder?
the collection, temporary storage, and expulsion of urine
how does the structure of the bladder help its function
It has a unique muscular structure, and a complex neurological control
Embryologically, where is the bladder is derived from?
the hindgut
what are the 2 main functions of the bladder?
Temporary store of urine
Assists in the expulsion of urine
how does the bladder temporarily store urine?
The bladder is a hollow organ. The walls are very distensible, with a folded internal lining (known as rugae), this allows it to hold up to 600ml
how does the bladder assist in the expulsion of urine?
During voiding, the musculature of the bladder contracts, and the sphincters relax
how does the morphological appearance of the bladder vary?
varies with filling. When full, it exhibits an oval shape, and when empty it is flattened by the overlying intestines.
what are the important external features of the bladder?
apex, body, fundus and neck
describe the location of the apex of the bladder
This is located superiorly, pointing towards the pubic symphysis.
what is the apex of the bladder connected to and via what?
It is connected to the umbilicus by the median umbilical ligament
what is the umbilical ligament?
a remnant of the urachus
what is the body of the bladder? where is it located?
The main part of the bladder, located between the apex and the fundus
what is the fundus (base) of the bladder? where is it located?
Located posteriorly. It is triangular-shaped, with the tip of the triangle pointing backwards
how is the neck of the bladder formed?
Formed by the convergence of the fundus and the two inferolateral surfaces
what does the neck of the bladder join?
joins the bladder to the urethra
how does urine enter the bladder?
by the left and right ureters
how does urine exit the bladder?
via the urethra
internally, what are the orifices of the bladder marked by?
the trigone – a triangular area located within the fundus
what is the trigone?
a triangular area located within the fundus
how is the trigone like in contrast to the rest of the internal bladder?
the trigone has smooth walls
what are the 2 sphincters controlling the outflow of urine?
the internal and external urethral sphincters
which gender is the urethral sphincter present in?
male
which structures play a key role in the function of the bladder?
The musculature of the bladder, and coordination of its action
In order to contract during micturition, what does the bladder have to carry out this function?
the bladder wall contains specialised smooth muscle
what are the specialised smooth muscles called which contract during micturition?
detrusor muscle
how are the fibres of the detrusor muscle orientated? what does this ensure?
Its fibres are orientated in three directions, thus retaining structural integrity when stretched
what does the detrusor muscle receives its innervation from?
from both the sympathetic and parasympathetic nervous systems
what happens to the detrusor muscle during micturition?
it contracts
what are the two other muscular sphincters located in the urethral orifices?
internal and external urethral sphincter
which gender is the internal urethral sphincter located in?
The internal urethral sphincter is located in males only
what does the internal urethral sphincter consist of?
circular smooth fibres
which control is the circular smooth fibres of internal urethral sphincter located under?
autonomic control
what is the function of the internal urethral sphincter?
prevent seminal regurgitation during ejaculation
which gender is the external urethral sphincter present in?
The external urethral sphincter is present in both sexes
which control is the external urethral sphincter under?
voluntary
what is the function of the external urethral sphincter?
During micturition, it relaxes to allow urine flow
what type of muscle is the external urethral sphincter?
skeletal
