Excretory system - Practice 2 worksheet - Free Printable

Here is the complete solution to your “Excretory System - Practice 2” worksheet, with clear explanations for each section.

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## ✔ SECTION 1: MATCHING TERMS TO DEFINITIONS

Word Bank:
bladder, urethra, kidneys, urea, ureters, liver, urine

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1. ureters – two ducts where urine travels to the bladder

> *Explanation:* The ureters are muscular tubes that carry urine from each kidney down to the urinary bladder.

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2. liver – where blood is filtered and waste is converted into urea

> *Explanation:* The liver detoxifies blood and converts toxic ammonia (from protein breakdown) into less harmful urea, which is then sent to the kidneys for excretion.

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3. bladder – a muscular bag that holds urine

> *Explanation:* The urinary bladder is a hollow, muscular organ that stores urine until it’s ready to be expelled from the body.

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4. kidneys – a pair of bean-shaped organs that filter urea from the blood

> *Explanation:* The kidneys are the main filtering organs of the excretory system. They remove waste (like urea), excess water, and salts from the blood to form urine.

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5. urea – the substance that the liver creates from nitrogen waste

> *Explanation:* Urea is the primary nitrogenous waste product formed in the liver during protein metabolism. It’s carried in the blood to the kidneys for removal.

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6. urethra – how urine leaves the body

> *Explanation:* The urethra is the tube that carries urine from the bladder out of the body during urination.

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7. urine – a mixture of urea and water

> *Explanation:* Urine is primarily composed of water, urea, creatinine, and other dissolved ions and wastes filtered by the kidneys.

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✔ Answers for Section 1:
1. ureters
2. liver
3. bladder
4. kidneys
5. urea
6. urethra
7. urine

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## ✔ SECTION 2: FILL-IN-THE-BLANK SENTENCE

> Blood is filtered by the kidneys which turns waste into a chemical called urea. Then the kidneys filter the urea out the blood and mix it with water. The urine then travels through the ureters to the muscular bag called the bladder. The urine leaves the body through the urethra.

> *Note:* Although the liver produces urea, the kidneys are responsible for filtering it from the blood and forming urine. So “kidneys” appears twice — once for filtering blood and again for producing urine.

✔ Answers for Section 2:
- kidneys
- urea
- kidneys
- urine
- ureters
- bladder
- urethra

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## ✔ SECTION 3: URINARY SYSTEM DIAGRAM LABELING

*(Based on standard anatomy)*

From top to bottom, left to right:

Top row (left kidney):
- Left Renal Artery → brings oxygenated blood to kidney
- Left Renal Vein → carries filtered blood away from kidney
- Left Ureter → carries urine from kidney to bladder

Top row (right kidney):
- Right Renal Artery
- Right Renal Vein
- Right Ureter

Bottom row:
- Bladder → stores urine
- Urethra → expels urine from body

> *Note:* In many diagrams, arrows point to:
> - Renal artery (red, carrying blood IN)
> - Renal vein (blue, carrying blood OUT)
> - Ureter (carrying urine DOWN to bladder)

✔ Labeling Suggestion (if boxes are numbered left-to-right, top-to-bottom):

Assuming 8 boxes total:

1. Left Renal Artery
2. Left Renal Vein
3. Left Ureter
4. Right Renal Artery
5. Right Renal Vein
6. Right Ureter
7. Bladder
8. Urethra

*(Adjust based on arrow direction if needed — but this is the standard layout.)*

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## ✔ SECTION 4: INTEGUMENTARY SYSTEM DIAGRAM (Sweat Gland)

This diagram shows a sweat gland in the skin.

Labels:

(1) Sweat Gland (Coiled portion) – deep in dermis, produces sweat
(2) Duct – carries sweat up to surface
(3) Pore – opening on skin surface where sweat exits
(4) Sweat – fluid secreted to cool body

> *Function:* Sweat glands help regulate body temperature and excrete small amounts of urea, salts, and water — making them part of the excretory system too!

✔ Answers for Integumentary Diagram:
(1) Sweat Gland (or Coiled Secretory Portion)
(2) Duct
(3) Pore
(4) Sweat

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## 📊 TOTAL SCORE: /36

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✔ Final Answer Summary:

Section 1:
1. ureters
2. liver
3. bladder
4. kidneys
5. urea
6. urethra
7. urine

Section 2:
kidneys, urea, kidneys, urine, ureters, bladder, urethra

Section 3 (Urinary Diagram):
Left side: Renal Artery, Renal Vein, Ureter
Right side: Renal Artery, Renal Vein, Ureter
Bottom: Bladder, Urethra

Section 4 (Integumentary):
(1) Sweat Gland
(2) Duct
(3) Pore
(4) Sweat

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