UF APK2100C Exam 4 Ch. 24, 25 Ahlgren

General Functions of the Kidney

- elimination of wastes: formation of urine and filtering blood

- Chemical consistency of blood

- regulation of blood volume and pressure

Kidney: location, mesentery, function, symmetry

- lumbar region of the posterior abdominal wall, deep to false ribs

- retroperitoneal

- produces urine

- right kidney is inferior to left because of liver

Root of the kidney

- cluster of vessels and nerves coming into and out of kidneys

Renal hilus/hilum

- where roots of kidneys are located

Adrenal gland

- not apart of the urinary system but sits directly on top of the kidneys

Ureter

- extends from kidney anterior to psoas muscle and connects to urinary bladder

What structures function to support and protect the kidneys?

- dense fibrous capsule

- perirenal fat capsule for cushioning around renal hilus to fill the renal fat

- bands of renal fascia anterior and posterior to kidney

Types of kidney trauma

- bruise

- laceration

- torn attachment: complete detachment of kidney root

Layers of the kidney

- renal cortex

- renal medulla

Renal cortex

- outer layer of the kidney

Renal medulla: def, composed of

- inner layer

- composed of pyramids and columns

Renal pyramids

- pyramidal striped structures in the renal medulla

- contains the renal papilla

Renal papilla

- tip of the renal pyramid that drains urine into a tubular structure

Renal columns

- part of the renal cortex that comes down between the renal pyramids

Minor calyx

- tube like structures where the renal papilla drains urine into

Major calyx

- group of minor calyces

Renal pelvis

- group of major calyces that catches all of the urine and narrows down to become the ureter

Renal sinus

- gaps in the renal medulla

What part of the blood is primarily filtered?

- blood plasma

- NOT cells or proteins

Nephron

- smallest functional unit of the kidneys composed of the renal corpuscle and the renal tubule

Renal corpuscle

- composed of the glomerulus and the glomerular capsule

Glomerulus

- specialized cell of fenestrated capillaries that enter from an afferent arteriole

Afferent arteriole

- brings arteriole blood toward the glomerulus to circulate through capillaries

Efferent arteriole

- where arteriole blood exits after being filtered in the glomerulus

Glomerular capsule

- contains the glomerulus and extends to form the renal tubule

Renal tubule

- proximal convoluted tubule

- loop of henle

- distal convoluted tubule

- collecting duct

Proximal convoluted tubule: def, tissue

- tube that arises from the bowman's capsule near the glomerulus

- simple cuboidal epithelial tissue

Loop of henle

- long tubular portion that dips into the renal medulla

- contains ascending and descending limb

Distal convoluted tubule: def, tissue

- tube formed from the ascending limb of the loop of Henle

- simple cuboidal epithelial tissue

Collecting duct: formed by, function, location

- formed from the distal convoluted tubule

- received fluids from multiple convoluted tubules and nephrons

- travels throughout the entire renal pyramid from cortex to medulla

Papillary duct

- end of the collecting duct near the opening

Where are you able to change the consistency of the urine? Where can the urine not be changed?

- collecting duct

- out of papillary duct, into minor calyx

What processes form urine

- glomerular filtration

- tubular secretion

What process filters urine

- tubular resorption

Types of nephrons

- cortical nephrons

- juxtamedullary

Cortical nephrons: location/characteristics, abundance

- sits higher in the renal cortex with a short loop of Henle

- common

Juxtamedullary nephrons

- placed lower in the renal cortex near the renal medulla with a long loop of Henle

- rare

The glomerulus is always within the _______

- renal cortex

How is blood filtered?

- like the hepatic portal system but with an arteriole in between the 2 capillary beds

Movement of blood through the nephrons

- blood travels through arteriole which turns into afferent arteriole

- blood enters glomerular capillaries and some fluid is filtered into the Bowman's capsule

- fluid travels in the tubular portion of the nephron while blood exits the efferent arteriole

How are the peritubular capillaries formed?

- efferent arteriole turns into peritubular capillaries

Differences of the peritubular capillaries in cortical and juxtamedullary capillaries

- in cortical: peritubular capillaries are convoluted with no order--> turns into post capillary venule--> vein

- in juxta: peritubular capillaries near the loop of Henle are extremely neat and organized

Vasa recta

- peritubular capillaries in juxtamedullary nephrons that are extremely straight near the loop of Henle

The Bowman's capsule is composed of what tissue?

- simple squamous epithelium

What are the cells attached to the glomerular capillaries called? Function

- Podocytes: specialized epithelial cells whose branches interdigitate

- site of filtration

Parietal Layer of the glomerular capsule

- outer wall of the Bowman's capsule

Visceral layer of glomerular capsule

- formed by podocytes

Glomerular capsular space

- space around the capillaries that funnels into the proximal convoluted tubule

Filtration Membrane

- all the structures that the blood must pass through in order to get to the glomerular capillary space

- capillary membrane: wall of glomerular capillaries, basement membrane, podocytes

Proximal convoluted tubule modifications that help with absorption

- microvilli on cell

- mitochondria present

Distal convoluted tubule modifications

- few microvilli and mitochondria

- lots of protein receptors to regulate movement of substances

Juxtamedullary Apparatus: def, function, cells

- area where the tubular portion of the nephron comes in contact with the arteriolar region

- regulates blood pressure and volume

- contains granular and macula densa cells

Granular cells: def, function

- specialized smooth muscle cells that make up the wall of the arteriole

- secretes renin in response to low blood pressure

Macula densa cells: def, function

- specialized epithelial cells that make up the wall of the distal convoluted tubule and come in contact with the granular cells

- regulate sodium concentration for blood volume

Urinary bladder

- collapsible muscular sac that stores and expels urine

Detrusor muscle

- smooth muscle wall of the bladder

- INVOLUNTARY

Contraction of the _____________ pushes on the bladder to cause urine to come out faster

- abdominal muscles (skeletal muscles)

Where do ureters come in contact with the bladder? Where do they enter the bladder?

- posteriorly and joins the wall of the bladder

- opens up into the inferior surface of bladder

Where is the urinary bladder placed in both males and females?

- Females: posterior to the pubic symphysis and anterior to the uterus

- Males: posterior to the pubic symphysis and superior to prostate

The bladder contains _________ like the stomach. These structures are present when bladder is collapsed and absent when bladder is distended

- rugae

Female urethra structures

- trigone

- internal urethral sphincter

- urogenital diaphragm

Trigone: location, components, characteristics

- located at the posterior floor of the bladder and contains 3 openings

- susceptible to infection

Openings of the trigone

- 2 openings (inverted triangle= openings for ureters

- 1 opening= opening from bladder into the internal urethral orifice

Internal urethral sphincter: location

- outside the bladder neck

- smooth muscle on internal urethral orifice that makes up sphincter

Urogenital diaphragm: tissue/location, contains

- layer of smooth muscle that passes that the urethra passes through

- external urethral sphincter

External urethral sphincter

- circularly arranged skeletal muscle around the urethra that we contract so we don't pee

Where does the sensation to pee come from?

- stretch on the urinal bladder

Why are women more prone to urinary infections than men?

- the female uretha is much shorter which allows pathogens to reach the bladder easier

Male urethra structures

- trigone

- internal urethral sphincter

- prostate

- external urethral sphincter

- urogenital diaphragm

- penis

Prostatic urethra

- part of the urethra that passes through the prostate- produces some of seminal fluid

Membranous urethra

- part of the urethra that passes through the urogenital diaphragm in males

Spongey urethra

- part of the urethra that passes through the spongey portion of the penis

External urethral orifice

- located at the tip of the penis

Process of micturition

- elimination of waste from the body

- bladder fills up with urine and stretches detrusor muscles

- stretch information comes through a visceral sensory neuron that travels up the spinal cord

- interneuron sends it up to the pons to be integrated at the pontine micturition center

3 things that must happen to get urine out of the body? Signal is from...

- signal is from pons

1. squeeze the bladder wall

2. open internal urethral sphincter

3. open external urethral sphincter

Squeezing bladder wall: tissues, activated neuron, inhibited neuron

- smooth muscle contraction activated by a parasympathetic autonomic neuron

- inhibit sympathetic neuron- keeps bladder wall relaxed

Open internal urethral sphincter

- parasympathetic neuron inhibits contraction of internal urethral sphincter

Open the external urethral sphincter

- inhibit somatic motor neuron to relax muscle and open sphincter

Primary sex organs: name, function, male and female

- gonads

- produce sex cells (gametes)

- male: testes produce sperm

- females: ovaries produce ova

Accessory Sex Organs: def, function

- all aspects of the reproductive anatomy including the external genitalia

- nourish and transports gametes

Accessory sex organs of the male genitalia

- penis, scrotum, glandular structures

Testis

- primary sex organs

- individual testes

Epididymis

- c shaped structure that sits along the superior and posterior aspect of the testis

The testes and epididymis are located where?

- in the scrotum: connective tissue pouch

Tunica albuginea

- connective tissue pouch that surrounds the testis

Tunica vaginalis

- sac like pouch of peritoneum that surrounds the entire scrotum

Dartos Muscle

- layer of smooth muscle that makes up the outer skin of scrotum that crinkles during contraction to increase thickness

Cremaster muscles

- skeletal muscle bands that elevate testes to keep sperm at optimal temperature

Pampiniform plexus

- network of veins that provides countercurrent heat exchange to cool arterial blood at it travels toward the testes

Spermaticord is made up of

- pampiniform plexus, arteries, nerves, and vas deferens

Seminiferous tubules: function, location

- where gametes(sperm) are produced and sperm is immature

- within testes

Lobule

- group of seminiferous tubules

Rete testes

- posterior in the testis

- channeling pool where immature sperm gets deposited

Efferent ductule: def/turns into

- tube that leads the sperm into the head of the epididymis

The tail of the epididymis turns into the _____________

- vas (ductus) deferens

Where is sperm fully matured and functional

- vas deferens

Vas ductus deferens travels anterior to the ________, superior to the _________ to turn into the __________

- pubis symphisis

- urinary bladder

- ampulla of the ductus deferens

Seminal vesicle

- produces most of seminal fluid

- located next to the ampulla of the ductus deferens

Ejaculatory duct is formed by

- ampulla of the ductus deferens and seminal vesicle

- produces semen

Semen is a combination of

- seminal fluid and sperm