Anatomy 2 Unit 3 Test

kidneys

filter blood and maintain homeostasis

ureters

urine exits the kidneys; located along the posterior body wall

urinary bladder

stores urine

urethra

allows urine to exit the body

erythopoietin

involved in RBC count

adrenal gland

endocrine organ; located directly on top of the kidney

layers of connective tissue (on kidney)

renal capsule, adipose tissue, renal fascia

renal capsule

thin layer of dense irregular CT; physically touches the kidneys

adipose tissue

cushions kidney and protects from trauma

renal fascia

anchors each kidney to posterior wall

hilum

opening where renal artery, vein, nerves and ureter enter and exit

renal cortex

90-95% of all kidneys blood vessels are located here (filtration)

renal columns

extensions of cortex

nephrons

functional unit of cortex; each one does a bit of filtration and then the urine produced by all of them come together

collection system

minor calyx → major calyx → renal pelvis → ureter

renal corpuscle

filters blood; glomerulus, glomerular capsule, capsular space

glomerulus

group of fenestrated capillaries

glomerular capsule

outer parietal and inner visceral layer; all the capillary beds put together

capsular space

hollow region between parietal and visceral layers

renal tubule

filtrate from the glomerular capsule enters here; proximal tubule, nephron loop, distal tubule and collecting duct

proximal tubule

reabsorption of glucose; bendy and twisty for SA

nephron loop

reabsorption; easier to move molecules through due to the simple squamous epithelium

distal tubule

reabsorption and secretion; bendy and twisty for SA; most of the work is done by this point

collecting duct

located in the renal medulla; at this point the filtrate is now urine

cortical nephrons

short nephron loops that barely enter the renal medulla (80% of nephrons)

juxtamedullary nephrons

long nephron loops that travel deep within the renal medulla; more important in systems that need to conserve water (much less common)

nephrolithiasis

formation of renal calculi (kidney stones); form when concentrations of irons are present in filtrate in higher amounts

glomerular filtration

filtration is dependent on size; smaller substances exit the blood (occurs in the glomerulus and glomerular capsule)

tubular reabsorption

reclaiming substances such as water, amino acids, and electrolytes (occurs in the tubules and blood)

tubular secretion

substances added into filtrate; help maintain homeostasis; remove toxins from the blood that do not leave through filtration

an active process

fenestrated glomerular capillary

large pores, water and solutes pass easily

nitrogenous wastes

easily filtered small substanes

urea and ammonium

waste from protein metabolism

creatinine

waste from muscle metabolism

uric acid

waste from nucleic acid metabolism

glomerular filtration rate (GFR)

180 liters day; has 3 driving forces

glomerular hydrostatic pressure (GHP)

blood pressure; higher than average capillary bed pressure

glomerular colloid osmotic pressure (GCOP)

created by albumin; pulls water back in

capsular hydrostatic pressure (CHP)

opposes filtration; generated as capsular space rapidly fills with new filtrate

net filtration pressure (NFP)

NFP=GHP-(GCOP+CHP)

10=50-(30+10)

the pressure going out is stronger than the pressure going in

glomerulonephritis

inflammation of glomerular capillaries; leads to loss of blood cells and protein to urine

myogenic mechanism

constriction of smooth muscle in response to an increase in BP

tubuloglomerular feedback

uses macula densa to control pressure

renin-angiotensin-aldosterone system (RAAS)

complex system that maintains systemic BP

atrial natriuretic peptide (ANP)

released by atria in response to increasing fluid volume; lowers blood volume and BP to reduce workload of the heart

renal failure

if GFR decreases, kidneys may not be able to perform their vital functions; can be acute or become chronic

uremia

develops when GFR is less than 50% of normal; leads to coma, seizures and death is left untreated

ACE inhibtors

inhibit conversion of angiotensin I to II

angiotensin-receptor blockers

prevents vasoconstriction and reabsorption of water and sodium

aldosterone antagonists

decrease reabsorption of sodium and water; diuretic effect

glycosuria

if too much glucose is present in filtrate, excess will appear in urine; common in diabetes

secretion in proximal tubule

ammonium ions, creatine and urea; penicillin and morphine have significant renal secretion

facultative reabsorption

water is reabsorbed based on body’s needs

aldosterone

increases reabsorption of sodium ions from filtrate and secretion of potassium ions into filtrate

antidiuretic hormone

water reabsorption; reduces urine output

medullary collecting system

last chance for regulation before filtrate becomes urine

dilute urine

more water and less solutes in blood

countercurrent mechanism

creates and maintains osmotic gradient by exchanging materials in opposite directions between filtrate and interstitial fluids

countercurrent multiplier

NaCl actively transported

urochrome

breakdown of hemoglobin

darker urine

more concentrated (less water)

lighter urine

less concentrated (more water)

renal clearance

measurement of rate at which kidneys remove a substance from blood

asparagus urine

due to mercaptan; determined by genetics

trigone

triangular region on bladder floor; openings for 2 ureters

detrusor muscle

middle layer of urinary bladder; squeezes bladder (contains internal urethral sphincter)

female urethra

about 4 cm long; opens at external urethral orifice between the vagina and clitoris

male urethra

about 20cm long; has 3 sections; contains both urine and semen

mictrution

urination

micturition reflex

when urine fills bladder and stretches the walls

electrolytes

substances that dissociate into ions or charged particles; controlled by hormonal mechanisms

intracellular fluid

60% of body fluids

extracellular fluid

blood plasma and interstitial fluid

obligatory water loss

urine produced daily (500mL); required to prevent toxic buildup

sensible water loss

about 100mL in feces

insensible water loss

about 600mL from skin; sweat and evaporation

dehydration

decreased volume and increased concentration of ECF; increases osmotic pressure

overhydration

decreases osmotic pressure

sodium

most abundant in ECF; ANP decreases sodium and water reabsorption

hypernatremia

elevated concentration of sodium; commonly caused by dehydration

hyponatremia

decreased concentration of sodium; commonly cause by overhydration

potassium

most abundant in ICF; excess is secreted into urine

hyperkalemia

high potassium concentration in plasma; potentially fatal

hypokalemia

low potassium concentration; commonly caused by diuretics

acid base homeostasis

normal pH of 7.35-7.45

acidosis

ph less than 7.35; neurons are less excitable

alkalosis

ph greater than 7.45; causes neurons to fire innapropriately

gonads

secrete sex hormones and produce gametes

mitosis

identical daughter cells

meiosis

produces sex cells

fertilization

sperm and egg cell fuse and form a zygote

diploid

full paired set of chromosomes (2n)

testes

located in scrotum

seminiferous tubules

where sperm is produced

spermatogenic cells

form sperm

sustentacular cells

support production of sperm

interstitial cells

between seminiferous tubules; produce testosterone

myoid cells

contract to push sperm and fluid through tubules

epididymis

site of sperm maturation and storage

ductus deferens

travels with the arteries, veins, and nerves within a spermatic cord; can store sperm for months

site of vasectomy