Functions of the Urinary System
1. Maintains normal bloood fluid volume and therefore blood pressure
2. Helps regulate normal blood hydrogen and bicarbonate ion levels and therefore blood pH
3. Regulates blood calcium, sodium and potassium levels
4. Removes urea and ammonia
Major Excretory Organs - two structures located on each side of the lumbar region that filter blood and secrete impurities, forming urine
Adheres directly to the kidney's surface
-dense irregular connective tissue
-helps prevent infection
On the medial, concave surface of the kidney
-leads into the renal sinus
-the ureters, blood vessels, lymphatics, and nerves enter or exit here
Renal Cortex (outer region)
contains the nephron (glomerular corpuscle, proximal convoluted tubule, loop, distal convoluted ducts, collecting duct) which are the functional untis of a kidney
Renal Medulla (inner region)
Pyramids - cone -shaped tissue mases of the medulla containing ducts
-renal pelvis - open area
Blood Flow through the Kidneys
Blood orginates at renal artery, distributed throught the kidney via a variety of arteries into the cortex where blood flows into the "afferent:" arterioles that regulate flow into the glomerular capillaries (where water and smaller substances are filtered into the glomerular capsule). Non-filtered blood exits glomerular capillaries into "efferent" arteriole which regulates flow into the "Vasa Recta" capillaries. Frome there blood is drained via a variety of veins into the renal vein.
Bowman's capsule - receives filtered blood from the very leaky glomerular capillaries (allowing filtration of blood components into nephron)
(includes proximal convoluted tubule, loop of nephron, distal convoluted tubule, collecting duct) filtrate meanders through the tubules allowing tubular reabsorption (movement of substance back into blood supply) and tubular secreation (movement of substance from blood supply into urine)
The functional units of kidneys - functions blood by filtration red and white blood cells, platelets and large proteins are prevented from being filtered into urine so are conserved by the body. Some filtered substances are then secreted (removing materials from blood into urine) or reabsorbed (reclaiming materials from the urine into blood)., filtering units of the kidney that remove wastes from the blood and produce urine
Vasa Recta Capillaries
Allow Reabsorption and Secretion
Filtrate/Urine Flow in Kidney
(Microscopic) glomerular capsule to PCT to Loop to DCT to collecting ducts to papillary ducts to (gross) calyces to renal pelvis
Convey urine from the renal pelvis in kidneys to the urinary bladder
Enter the posterior wall of the urinary bladder
3 layers of the Ureters
1. Mucosa : Transitional epithelium
2. Muscularis : Smooth Muscle
3. Adventitia: Outer layer, fibrous connective tissue.
Holds urine and ejects urine (micturition)
Filled by the paired ureters and ejects urine through opening of the urethra
3 layers of the Urinary Bladder
1. Mucosa; Transitional epithelium allows stretch to store urine. Folded into rugae for even more stretch.
2. Muscularis; smooth muscle to eject urine
3. Adventitia; outer layer, fibrous connective tissue or serosa (visceral peritoneum)
Drains urine from the urinary bladder and carries it outside of the body
Sphincters of the Urethra
1. Internal - involuntary
2. external urethral sphincter - voluntary
-surrounds the urethra as it passes through the pelvic floor
- skeletal muscle
Entire system of Urine Flow
Blood > Filtrate in glomerular capsule of nephron> Nephron Tubules > Pyramidal ducts > Calces> renal pelvis > ureter> urinary bladder > urethra
Produced and released by Hypothalamus and Posterior Pituitary
-known as the neurohypophysis
-sits in the sella turcica or sphenoid bone
Causes the collecting ducts of the kidneys to reabsorb water more, thereby increasing blood volume and blood pressure. it decreases urine output.
Produced in the Adrenal Cortex
Promotes Na reabsorption and K secreation at the collecting ducts. So Na is reclaimed and K is lost into the urine.
Functions of Reproductive System
1. Production of gametes sperm (spermatogenesis) and ova (oogenesis)
2.Regulation of reproductive structure functions via hormone production
4. Development and nourishment of embryo and fetus
-Male Gonads descended from the pelvic cavity in the scrotum
-composed of seminiferous tubules which are the sites of spermatogenesis
-also contain interstitial cells which produce testosterone.
-a sac of skin and underlying fascia suspending and supporting the testes and epididymis
Allows teperature regulation to promote sperm development
In the scrotum wraps around the posterior side of each testis, receives sperm from seminiferous tubules, The site of sperm maturation, become motile
able to move independently
Two tubes transporiting sperm from each epididymis to the ejaculatory duct (in prostate)
- Peristaltic waves of smooth muscle move the sperm along
-Form as the vas deferens and seminal vesicles meet, within the prostate
Semen enters the prostatic urethra just prior to ejaculation
Tube carrying ejaculated semen (sperm and fluids from glands) out of body, through penis.
Male copulatory Organ
lie along the posterior aspect of the urinary bladder between the urinary bladder and the rectum superior to the prostate, emptying into the ends of the vas deferens.
-produce 60% of semen components, including fructose to provide nutrition to sperm cells.
Immediately inferior to the urinary bladder, surrounds the proximal portion of the urethra.
-produces weakly acidic semen, and contains a chemical to activate sperm.
Specific division process to produce male gamete (sperm)
-male variety of meiosis-body cell chromosome count (46) is halved to 23
Testosterone, produced by interstitial cells, promotes spermatogenesis; and maintains male secondary sexual structures
Near the lateral walls of the pelvic cavity
-site of oogenesis, production of ova
-gametes develop in follicles, progesterone and estrogen are produced by cells of these follicles
Uterine tube or Oviduct (fallopian tubes)
tube not physically connecting to ovaries
collects ova, after ovulation , and transfers it towards uterus
site of fertilization
broad ligaments, double folds of the peritoneum, attache it to either side of the pelvic cavity.
Layers in the uterine body
1. Endometrium - inner layer supplies nutrients to embryo/fetus stimulated by estrogen and progesterone.
2. Myometrium - smooth muscle ejects fetus during birth, stimulated by Oxytocin
3. Perimetrium - visceral peritoneum
-the site of most embryonic and all fetal development.
necklike opening to the uterus -dilation and effacement during birth
Anterior to the urethral orifice, cylindrical mass of erectile tissue promoting sexual stimulation
A muscular tube extending from the cervix of the uterus to its opening.
-passageway for semen and menstrual flow
-female copulatory organ
Mammary Glands / Breasts
lie over the pectoralis major and serratus anterior muscles.
1. Alveoli (mammary, lactiferous) glands
-milk secreting glands, stimulated by prolactin
2. Lactiferous ducts and sinuses
-carries milk from glands to the exterior, movement stimulated by oxytocin.
the production, growth, and maturation of an egg, or ovum
- division process that is interrupted so ova does not have half normal body cell chromosome count.
division proceeds after fertilization by sperm. Result is fertilized ovum (46 chromosomes, half from dad, half from dad.
Ovarian cycle results from cyclical changes of estrogen and progesterone. These hormones promote proliferation and maintenance (repectively) of endometrium, both maintain female secondary sexual characteristics
Results in endometrium proliferates in preperation for implantation of ferilized ovum, but is sloughed off if ovum does not implant.
-also involves ovarian cycle where levels of estrogen and progesterone ready endometrium or cause sloughing.