Exam 3 Flashcards
4 structures of urinary system
Kidney x 2
Ureter x 2
Urinary bladder x 1
Urethra
kidney layers
Renal fascia – dense irregular connective tissue
Fat capsule/adipose capsule – helps ancho kidney in place and acts as a cushion
Renal capsule
Nephroptosis
inferior displacement of the kidney, drops down from where it should be sitting. Primary reason it occurs is due to a person having less fat in their body
regions of the kidney
Outer layer – renal cortex
Inner layer – renal medulla
structures of the kidney
Renal pyramids
Renal papilla
Renal columns
Minor calyx
Major calyx
Renal pelvis
nephrons
Renal corpuscle
Renal tubules
renal corpuscle
Glomerulus – cluster of capillaries
Bowman’s capsule – doubled wall membrane that surrounds glomerulus
renal tubules
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting duct
proximal convoluted tubule (PCT)
Arises from bowman’s capsule
Simple cuboidal epithelium
Microvilli facing lumen
Loop of Henle
Sits mostly in medulla
Descending = water permeable – simple epithelia
Ascending = water impermeable – lots of active transport
distal convoluted tubule
Begins as tubule enters cortex
Simple cuboidal epithelium
Principal and intercalated cells
collecting duct
Several nephrons empty into a single collecting duct
Extend from renal cortex to renal medulla
Principal and intercalated cells
2 different types of nephrons
Cortical nephron
Location: mainly in renal cortex
Capillaries: peritubular capillaries
Function: primarily involved in producing dilute urine
Juxtamedullary nephron
Location: loop of Henle dips a lot deeper in the renal medulla
Capillaries: peritubular capillaries, vasa recta capillaries
Function: primarily produce concentrated urine
Layers of glomerular filtration membrane
Fenestrated endothelium
Basement membrane
Podocyte
Filtration slits
pathway of blood through the kidney
Renal artery -> interlobar artery -> arcuate artery -> cortical radiate artery -> afferent arteriole -> glomerulus -> efferent arteriole -> vasa recta or peritubular capillaries -> cortical radiate vein -> arcuate vein -> interlobar vein -> renal vein
major functions of the urinary system
Routine – production and excretion of urine
Protective – eliminate toxins, alter blood pressure
Balancing – regulate pH and electrolytes
what do kidneys filter
The kidneys filter blood
The waste products filtered out of the blood are excreted as urine
If no blood is filtered, no urine is produced
urine formation
Glomerular filtration
Tubular reabsorption
Tubular secretion
tubular reabsorption
The process of reclaiming water and solutes from the filtrate and returning them to the blood
Filtrate -> blood
tubular secretion
The process of secreting excess or waste substances from the blood into filtrate in the tubules
Blood -> filtrate
GBHP
CHP
BCOP
Glomerular blood hydrostatic pressure (GBHP) = 55mHg – blood pressure in glomerular capillaries. Promotes filtration
Capsular hydrostatic pressure (CHP) = 15 mmHg – hydrostatic pressure against the filtration membrane from fluid in capsular space. Opposes filtration
Blood colloid osmotic pressure (BCOP) = 30 mmHg – induced by the presence of proteins (I.e., albumin) in blood plasma which draw water into capillaries. Opposes filtration
Net Filtration Pressure (NFP)
= GBHP – CHP – BCOP
= 55 mmHg – 15 mmHg – 30 mmHg
= 10 mmHg
if GFR is to high
if GFR is to low
If GFR is too high = decreased H20 and solute reabsorption
Increase urine output, dehydration, electrolyte depletion
If GFR is too low = increase H20 and solute reabsorption
Reabsorb wastes that should be eliminated in urine
myogenic mechanism
The mechanism by which arteries and arterioles react to an increase or decrease in blood pressure to keep the blood flow within the blood vessel constant
sympathetic stimulation
The kidneys are supplied by sympathetic fibers that release norepinephrine
Norepinephrine causes vasoconstriction of the afferent arteriole
With increase sympathetic stimulation the afferent arteriole constricts
Constriction of the afferent arteriole also acts to redirect blood to other tissue
hormones affecting kidney function
Angiotensin II
Aldosterone
Antidiuretic hormone (ADH)
Atrial natriuretic peptide (ANP)
Parathyroid hormone
angiotensin II
Active hormone in renin-angiotensin-aldosterone system, stimulated by low blood pressure
Angiotensin II acts in a variety of ways
Systemic vasoconstriction
Binds to hypothalamus to stimulate thirst
Acts on adrenal cortex to release aldosterone
aldosterone
Released from adrenal cortex in response to angiotensin II, ACTH and high blood potassium concentration
Stimulates principal cells in the collecting ducts to reabsorb more Na+ and Cl- and secrete more K+
The consequence of reabsorbing more Na+ and Cl- is that more water is reabsorbed
antidiuretic hormone
Vasopressin
Released from posterior pituitary gland in response to increased blood osmolarity
Increased permeability of principals cells in DCT and collecting duct to water
Stimulates insertion of aquaporins into membrane
atrial natriuretic peptide
Released in response to an increase in blood volume
Inhibits reabsorption of Na+ and water
Suppresses secretion of aldosterone and ADH
Increases Na+ secretion and urine output
parathyroid hormone
Released from the parathyroid gland in response to low blood Ca+ levels
Stimulates opening of calcium channels in membranes of cells in early DCT
Results in increased calcium reabsorption
aging and urinary system
Kidneys shrink in size, and there is a decrease in the number of functioning glomeruli
Muscles in bladder become weaker, stretch receptors become less sensitive
Sensation of thirst reduced
ureter
Mucosal layer
Smooth muscle
Fibrous connective tissue
bladder - hollow, extendable and muscular organ
Mucosal layer
Smooth muscle, longitudinal, circular and longitudinal. Internal sphincter and external sphincter
Fibrous connective tissue – peritoneum, holds bladder in place
urethra
Mucosal layer – protects tissue
Muscularis layer – propels urine
micturition reflex
Afferent impulses from stretch receptors to pons
Pontine micturition center activated
Parasympathetic efferents stimulate detrusor muscle, opening internal urethral sphincter
Sympathetic efferents inhibited
Somatic efferents inhibited; external; urethral sphincter relaxes
urine
1-2 liters produced per day
Affected by fluid intake, blood pressure, osmolarity, diet, body temperature, diuretics, mental state and general health
95% water, 5% solutes
Solutes include electrolytes, wastes derived from cellular metabolism, and exogenous substances such as drugs
Urine is typically protein free
urinalysis
An analysis of the volume and physical, chemical and microscopic properties of urine
If disease alters metabolism or kidney function, traces of substances not normally present may appear in urine
Protein
Glucose
Red blood cells
Microbes
scrotum
Loose bag of skin located outside the abdominal cavity
Divided into two sacs via scrotal septum
Each sac contains one teste
2 – 3 degrees Celsius lower than core body temperature
Temperature is regulated by
Dartos muscle – smooth muscle
Cremaster muscle - skeletal muscle
Pampiniform plexus – network of small veins
Sperm survival is 2-3 degrees Celsius lower than core body temperature
Scrotum (and testes) located outside of the pelvic cacity
Dartos and cremaster contract when its cold
Cremaster muscle moves testes closer to the body
Dartos muscle wrinkles scrotal skin
Exposure to warm these reverses these actions
Pampiniform plexus – heat exchange vessels
testes
Paired oval glands located in the scrotum
Location of spermatogenesis -> sperm production
Produce male sex hormones (e.g., testosterone)
Ducts of testis
Seminiferous tubules -> site of sperm production
Epididymis -> site of sperm maturation
Ductus deferens -> carry sperm from epididymis to the ejaculatory duct
spermatogenesis
Begins at puberty
50-200 million sperm produced per day
Occurs in the seminiferous tubules
Lined with sperm-forming cells called spermatogenic cells
Sertoli cells located between developing sperm -> nurture and control the developing sperm
Leydig cells located in the spaces between the tubules -> synthesis and secrete testosterone
sperm
Produced in seminiferous tubules and matures in the epididymis
Adaptations for fertilization
Elongated tail (flagellum) for movement
Body contains mitochondria for energy
The head is covered in an acrosomal cap that contains enzymes to assist with the penetration of the egg
Genetic material contained within the head
ductus of the male reproductive system
Epididymis -> site of sperm maturation
Ductus deferens -> carry sperm from epididymis to the ejaculatory duct
Ejaculatory ducts -> carry sperm from ductus deferens to into the urethra
Urethra (three parts) -> carry sperm from ejaculatory ducts to outside (terminal duct)
Sperm plus the secretions provided by the accessory sex glands
The volume of typical ejaculation is 2.5 - 5 mL
50-150 million sperm per milliliter
Accessory sex glands secrete the liquid portion
Seminal vesicles
Prostate
Bulbourethral glands
seminal vesicle (paired)
Alkaline -> combat acidic environment in vagina
Fructose -> energy source
Clotting protein -> coagulation after ejaculation
prostate
Citric acid -> energy source
Zinc -> sperm function and motility
Prostate-specific antigen (PSA) -> liquefy semen in the ejaculate
bulbourethral gland
Alkaline mucus (pre-ejaculate) -> neutralizes urethra, lubricates urethra and end of penis
passageway for the ejaculation of semen and excretion of urine
Root of the penis is the attached portion (proximal)
Body of the penis (erectile tissue) - corpus cavernosa -> dorsal, corpus spongiosum penis -> surrounds urethra
Glands penis – distal end of corpus spongiosum, opening of urethra (external urethral orifice)
ovaries
Produce oocytes that develop into a mature ova (egg)
4-5 million primordial oocytes in utero
0.5 million by puberty
500 used
Produce hormones
Oestrogen -> stimulate the growth of the egg follicle
Progestogen -> thickening the endometrial lining
Inhibin -> inhibit the secretion of FSH
Relaxin -> relaxes the ligaments in the pelvis, softens and widens the cervix
oogenesis
Formation of gametes (oocytes) in the ovaries
uterine tubes
Extend laterally from the uterus
Funnel-shaped at the ovarian end
Smooth muscle -> peristalsis
Ciliated simple columnar cells
Site of fertilization
fimbriae
Finger-link projections at the end of the uterine tubes
Movements produce local currents
Sweep ovulated oocyte into tubes
uterus
Site of implantation of fertilized ovum
Hollow, thic walled, muscular organ
Body -> major portion
Uterine cavity -> interior of the body
Fundus -> rounded superior portion
Cervix -> narrow neck; projects and opens into vagina
uterine wall
Perimetrium -> outer layer
Myometrium -> middle layer
Smooth muscle
Contracts during childbirth
Endometrium -> inner layer
Stratum functionalis (shed during menstruation)
Stratum basalis (permanent layer and gives rise to new stratum functionalis)
endometriosis
Growth of endometrial-like tissue outside the uterine cavity
Affects approximately 1 in 10 women of reproductive age
Symptoms – pain, heavy bleeding, bladder and bowel problems, bloating, infertility
Treatment – pain management, hormonal contraception, surgery
vagina
Thin-walled tube 8-10cm in length
Located between bladder and rectum
PH 3.8 - 4.2 (inhibits bacteria growth)
two cycles of the female reproductive cycle
Ovarian cycle -> events that occur in the ovaries (oogenesis)
The uterine cycle -> prepares the uterus to receive a fertilized ovum
hormones released in female reproductive cycle
Gonadotropin-releasing hormone (GnRH) release of FSH and LH
Follicle-stimulating hormone (FSH) -> follicular growth
Luteinizing hormone (LH) -> ovulation
Oestrogen -> growth of endometrium
Progestogen -> growth and maintenance of the endometrium
ovarian cycle phases
Days 1 – 14: follicular phase
FSH stimulates growth of follicles
Mature follicle releases oestrogen
Day 14: ovulation (LH)
Mature follicle ruptures
Oocytes released from the ovary
Day 14 – 28: luteal phase
Corpus luteum secreting progesterone
Maintains endometrium
uterine cycle
Days 1 – 5: menses
Decreased progesterone
Stratum functionalis shed (bleeding)
Days 5 – 14: proliferative
Increased oestrogen
Building of stratum functionalis
Day 14 – 28: secretory
Increased progesterone (corpus luteum)
Increased blood flow to the endometrium
Thickens and maintains endometrium
fertilisation and implantation
Involves the union of sperm and egg
Sperm swim through the female cervix and uterine cavity to the fallopian tubes
Most sperm die, never reaching the oocyte
Fertilization usually occurs in a uterine tube
Implantation occurs days later in the uterus
sperm entry (fertilisation)
Capacitation – biochemical changes which occur post ejaculation to improve sperm motility
Acrosome reaction – the release of hydrolytic enzymes which softens the zone pellucida (jelly coat)
Cortical reaction – hardening of the jelly coat post fertilization to prevent potential polyspermy
preventing menstruation
Human chorionic gonadotropin (hCG) secreted by the blastocyst and placenta
HCG stops the corpus luteum from degrading
Corpus luteum continues to produce oestrogen and progesterone
Oestrogen and progesterone maintain the endometrium
Placenta takes over the production ~8 weeks until birth
placenta
Temporary organ of pregnancy
Meeting point foetal circulation and maternal circulation
Facilitates the exchange of materials between the mother and the foetus
two parts of placenta
Foetal portion
Maternal portion
functions of placenta
Exchange of gases, nutrients and waste
Protective barrier from most microorganisms
Storage of nutrients
Produces hormones needed to sustain the pregnancy
Changes in cardiovascular system during pregancy
Increased cardiac output
Increased blood volume
Vasodilation
changes in urinary system during pregnancy
Increased GFR
Increased urine output
Increased risk of urinary tract infections
changes in GI system during pregnancy
Increased appetite
Pressure on stomach may cause heartburn
Decreased GI motility can cause constipation
Nausea
changes in respiratory system during pregnancy
Increased tidal volume
Increased O2 consumption
Diaphragm displaced upwards – decreased space for lung expansion
changes in skin during pregnancy
Increased pigmentation around eyes and cheeks
Stretchmarks on breasts and abdomen
changes in reproductive system during pregnancy
Increased blood flow to vagina and vulva
Changes to vaginal microbiota
stages of labour and delivery
Stage of dilation (6 – 12 hours) - onset of labor to the complete dilation of the cervix (10cm) the cervix relaxes, causing it to dilate and thin out
Stage of expulsion (10 min- several hours) - from complete cervical dilation to delivery of the baby. Uterine contractions increase in strength and the infant is delivered
Placental stage (5 – 3- min) - after delivery until the placenta or “afterbirth” is expelled by powerful uterine. The contractions also constrict blood vessels that were torn during delivery, thereby reducing the likelihood of hemorrhage. The placenta is expelled
