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Flashcards in Excretion Deck (81)
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Metabolism

All chemical reactions taking place in a cell

1

Example waste products of metabolisms

  • CO2
  • Excess water
  • Salts
  • Nitrogenous wastes (e.g. Urea, uric acid, creatinine)
  • Bile pigments

2

Excretion definition

Removal of metabolic wastes from the body

3

Egestion definition

Removal of undigested substances from the alimentary system

4

Secretion

Release of useful substances produced by cells for important functions

5

Where do waste products first go when they leave cells?

  • Diffuse from cells into tissue fluid
  • From here they are moved to the blood stream

6

Excretory organs

  • Lungs
  • Kidneys and bladder
  • Liver and intestines
  • Skin

7

Origin of CO2 as a waste

  • Product of cellular respiration
  • All cells in the body

8

Origin of excess water as a waste

  • Product of cellular respiration
  • Also from intake of fluid and food

9

Origin of urea as a waste

  • Formed largely in the liver
  • from deanimation of excess amino acids

10

Origin of uric acid as a waste

  • End product of metabolism of nucleic acids
  • e.g. DNA and RNA

11

Origin of creatinine as a waste

Formed from creatinine phosphate in the cells

12

Origin of bile pigments as a waste

  • Formed in liver with haemoglobin breakdown.
  • Haemoglobin from red blood cells

13

Main parts of the urinary system

  • Two kidneys
  • Two ureters
  • The bladder
  • The urethra

14

Blood vessels associated with the kidneys

  • Renal artery carrying oxygenated blood and rich in wastes
  • Renal vein carrying deoxygenated blood and purified of wastes

15

What is the urinary bladder

  • Thin walled muscular sac
  • Urine is temporarily stored here
  • Urine enters trough the two ureters
  • Exits through the urethra

16

Function of the ureters

Transport urine from the kidneys to the bladder

17

Function of the urethra

Transport urine from the bladder to outside the body

18

Function of the sphincter muscle

  • Found at the base of the bladder
  • it controls the flow of urine to the urethra

19

External structure of kidney

  • Dark bean shaped organ
  • Kidneys enclosed in fat for insulation and protection
  • Hilum - renal artery, vein and ureter enter/leave
  • Renal capsule - membrane surrounding kidney

20

Internal (macro) structure of kidney - what you see when you dissect a kidney

  • Renal capsule (outer membrane)
  • Cortex (directly under capsule, dark red brown colour)
  • Medulla (inner region, lighter in colour)
  • Collecting tubes form pyramid (broad bases face cortex)
  • Renal papilla (inner tips of pyramids)
  • Renal calyx (renal papilla open into renal calyces)
  • Renal pelvis (calyces open into this widened region of ureter)

21

Nephron

Structural and functional unit of kidney

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Two main parts of a nephron

  • Malpighian body
  • Renal tubule

23

Two main parts of the Malpighian body

  • Bowmans capsule
  • Glomerulus

24

Parts of the renal tubule

  • Bowman's capsule
  • proximal convoluted tubule
  • loop of Henle 
  • distal convoluted tubule
  • collecting duct

25

Parts of the glomerulus

  • Wide afferent arteriole
  • Capillary network
  • Narrow efferent arteriole

26

Parts of the loop of Henle

  • Descending limb
  • Ascending limb

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Parts of the nephron in the cortex

  • Malpighian body
  • Proximal convoluted tubule
  • Distal convoluted tubule

28

Parts of the nephron in the medulla

  • Loop of Henle
  • Collecting duct

29

Structure of the Bowman's capsule

  • Inner lining of cells are specialised (called podocytes)
  • Tiny slit pores between podocytes
  • pores open into hollow capsular space