excretory system Flashcards Preview

β–Ί Med Misc 05 > excretory system > Flashcards

Flashcards in excretory system Deck (53):
1

– medial side
-where renal artery and nerve enter kidney
-where renal vein, ureter, lymphatic vessels exit kidney
-opens into the renal sinus

hilum

2

contains blood vessels
-part of the system for collecting urine and adipose tissue

renal sinus

3

– cone-shaped
-tip project toward the center

Renal Pyramids

4

surrounds tip of renal pyramid
-calyces join to form renal pelvis

Calyx –

5

functional unit of each kidney
-approx. 1.3 M for each kidney

nephron

6

enlarged end of nephron, double-walled chamber

bowman's capsul

7

tuft of capillaries (ball of yarn)

glomerulus

8

carry fluid from cortex through medulla

Collecting ducts –

9

– (15%) have loops of Henle that extend deep into the medulla

Juxtamedullary nephrons

10

(85%) loops of Henle do not extend deep into the medulla

Cortical nephrons –

11

parts of filtration membrane


 Endothelium of glomerular capillaries
 Podocytes
 Basement membrane

12

Structures consisting of Simple cuboidal epithelium

 Proximal convoluted tubules
 Thick segments of Loop of Henle
 Collecting ducts

13

consists of microvilli and mitochondria that actively transport ion & molecules across the wall of nephron

Simple Cuboidal epithelium –

14

Structures consisting of Simple Squamous

 Thin segments of the descending and ascending loop of henle

15

– formed when the distal convoluted tubule come in contact with afferent arteriole
-certain cells secrete renin

Juxtaglomerular apparatus

16

movement of water, ions and small molecules through filtration membrane into Bowman’s capsule

A.FILTRATION –

17

portion of plasma entering the nephron
-formation depends on filtration pressure (pressure gradient)

Filtrate -

18

– blood pressure in the glomerular capillary

Glomerular capillary pressure

19

– pressure of the filtrate already inside Bowman


Capsular Pressure

20

– pressure within glomerular capillary
-Because most plasma proteins do not pass the filtration membrane, they produce an osmotic pressure that favors fluid movement into the glomerular capillary from Bowman’s capsule


Colloid Osmotic Pressure

21

– allows small solutes and water to readily pass but not blood cells and most proteins except for albumin
-thus filtrate contains no cells and little protein (albumin)

Filtration membrane

22

– movement of substances from filtrate across nephron wall back into the blood of peritubular capillaries

TUBULAR REABSORPTION

23

active transport of solutes across nephron walls into the filtrate
-can either be active or passive


C. TUBULAR SECRETION –

24

– secreted by cells of juxtaglomerular apparatuses in kidneys
-acts on angiotensinogen to convert it into angiotensin I
-angiotensin-converting enzyme converts angiotensin I into angiotensin II

renin

25

– acts on the adrenal cortex, causing it to secrete aldosterone

angiotensin II

26

– increases rate of active transport of Na in distal convoluted tubules and collecting ducts

Aldosterone

27

– secreted by posterior pituitary gland
-passes through circulatory system to the kidneys
-regulates amount of water reabsorbed by the distal convoluted tubules and collecting ducts
-release is regulated by hypothalamus
-also influenced by baroreceptors (monitor BP) ↓BP, ↑ADH secretion

ADH

28

– secreted from cardiac muscle cells in the right atrium of the heart

C. ATRIAL NATRIURETIC HORMONE

29

– small tubes that carry urine from renal pelvis of kidney to posterior inferior portion of urinary bladder
-transitional epithelium

Ureters

30

hollow, muscular container in the pelvic cavity posterior to pubic symphysis
-stores urine, thus its size depends on the quantity of urine present

ub

31

– tube that carries urine from urinary bladder to the outside of the body
-extends to the end of penis in males
-female urethra: shorter and opens into the vestibule

Urethra

32

– triangle-shaped portion of the urinarybladder located between the opening of the ureters and opening of urethra

Trigone

33

contracts to keep semen from entering the UB during sexual intercourse

Internal urinary sphincter –

34

– made of skeletal muscle that surrounds urethra as the urethra extends through the pelvic floor
-under voluntary control
-normally contracted as a result of stimulation somatic nervous system

External urinary sphincter

35

activated by stretch of the urinary bladder wall
-↑urine volume in UB, ↑pressure, baroreceptors stimulated, AP conducted along parasympathetic nerves, UB contracts
-an automatic reflex, but could be inhibited or stimulated by higher brain centers

MICTURITION REFLEX-

36

– includes fluid inside all cells of the body
-enclosed by cell membranes of individual cells
-composition of fluid in all compartment and regulation of fluid movement are similar
-hold 2/3 of all the water in the body

INTRACELLULAR FLUID COMPARTMENT

37


– all the fluid outside the cells
β€’ Interstitial fluid
β€’ Plasma within BV
β€’ Fluid in lymphatic vessels
-has 1/3 of the total body water

EXTRACELLULAR FLUID COMPARTMENT

38

– contain fluid with composition different from other extracellular fluid

Subcompartments

39

fluid in subcompartments

β€’ Aqueous humor
β€’ Vitreous humor
β€’ CSF
β€’ Synovial fluid
β€’ Serous fluid
β€’ Fluid secreted by glands
β€’ Renal filtrate
β€’ Bladder urine
β€’ Interstitial fluid
β€’ Plasma within BV
β€’ Fluid in lymphatic vessels

40

compartment with ↑conc of ions such as K, Mg, PO4, SO4
-lower conc of Na, Ca, Cl, HCO3
-more protein than ECF

intracellular

41

– major influence controlling the movement of water between intra and extracellular space

Osmosis

42

*Total amount of water and ions in the body long termdoes not change unless individual is

growing, gaining or losing weight

43

– the thirst center, controls water intake

hypothalamus

44

Body fluid ph:

7.35 – 7.45

45

chemicals that resist change in the ph of a solution when either acids or bases are added to the solution

buffer

46


β€’ Proteins
β€’ PO43- buffer system
β€’ HCO3- buffer system

3 Major Buffers in Body Fluids:

47

powerful regulator of ph, but it responds more slowly than does the respiratory system
-cells in the walls of DCT are primarily responsible for H+ secretion

KIDNEYS-

48

occurs when blood ph falls below 7.35

ACIDOSIS –

49

– when respiratory system is unable to eliminate adequate amounts of carbon dioxide

Respiratory acidosis

50

excess production of acidic substances such as lactic acid and ketone bodies
-caused by increased metabolism or decreased ability or urine to eliminate H in the urine

β€’ Metabolic acidosis –

51

– occurs when blood ph increases above 7.45
-major effect: hyperexcitability of nervous system
-spasms and tetanic contractions, extreme nervousness, convulsions

ALKALOSIS

52

alkalosis resulting from hyperventilation

respiratory alkalosis

53

alkalosis caused by rapid elimination of H from body (during severe vomiting or excess aldosterone secretion)

β€’ Metabolic alkalosis –

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