Do Now

Grab a lab and read over the front page (especially the introduction).

Complete the 2 definitions on the front page• Plasma• Pathogen

Introduction also has answer to question #3 on back

Blood Cell Lab½ period

State lab – once finished with blood lab, complete the final copy of your Making Connections State Lab

What you should see

Platelets White Blood CellsRed Blood Cells

pt

Do Now #11. How do the circulatory system and the respiratory system

work together?

2. How do the circulatory system and the digestive system work together?

Excretory System

How does the Excretory System help maintain homeostasis?

Excretory SystemHelps the body maintain homeostasis by

excreting nonsolid metabolic wastes through sweat, urine, and exhalation.

Where does the waste come from?Cells carrying out their life functions Example of cellular waste = Carbon Dioxide

Organs of the Excretory System

• Liver• Lungs• Skin• Urinary System

1 - Liver Functions Include:1. Waste removal – removes and recycles worn out red

blood cells (120 days) **New blood cells made in bone marrow (center of bones)

2. Detoxification – converts harmful substances into inactive or less toxic substances Converts harmful ammonia into safer urea

Ammonia?How does ammonia act in the body?• When ammonia enters the body as a result of breathing, swallowing or

skin contact, it reacts with water to produce ammonium hydroxide. This chemical is very corrosive and damages cells in the body on contact.

What are the specific signs and symptoms of ammonia poisoning?• Ammonia is corrosive. The severity of health effects depends on the

route of exposure, the dose and the duration of exposure. Exposure to high concentrations of ammonia in air causes immediate burning of the eyes, nose, throat and respiratory tract and can result in blindness, lung damage or death. Inhalation of lower concentrations can cause coughing, and nose and throat irritation.

• Swallowing ammonia can cause burns to the mouth, throat and stomach. Skin or eye contact with concentrated ammonia can also cause irritation and burns.

2 - LungsFunctions Include:1. Waste removal – lungs remove CO2 and some H2O

vaporCarbon Dioxide & Water Vapor are waste products of:

Equation:Equation:

Do Now *write on back of do now sheet

Why are the lungs and the liver part of the excretory system (what do they do) ?

3 - SkinFunctions Include:1. Protection – keeps harmful pathogens from entering the body

2. Excretion – removes water, salts, and urea from the blood as sweat / perspiration

3. Regulation – helps control your body temperature

3 - SkinHow does the skin remove metabolic waste in sweat?

The circulatory system transports waste around the blood

Capillaries, containing blood, are next to sweat glands so waste (urea, salts and water) diffuse into sweat glands

Sweat glands then excrete waste as sweat

3 - SkinHow does the skin regulate or control body temperature?

Sweat glands excrete sweat (water, urea, salts) Sweat evaporates off skin taking heat away with it!

(evaporation is a cooling process) So, your body sweats to cool down!

Skin (back of Do Now Sheet)

1. What would happen if sweat glands become blocked?

2. Why do people pour water on themselves on a hot day after running?

3. Why do you urinate less when you run and sweat?

Do Now #21. Which human excretory structure aids in the maintenance of

normal body temperature? a) Sweat glandb) Nephronc) Liverd) Urinary bladder

2. An individual running a marathon may experience periods of oxygen deprivation that can lead to

a) Anaerobic respiration in muscle cells, forming lactic acidb) Aerobic respiration in muscle cells, generating glycogenc) Anaerobic respiration in liver cells, producing glucose d) Aerobic respiration in liver cells, synthesizing alcohol

3. What is the name of the process that breaks-down larger molecules such as starch?

4 – Urinary System

Urinary system includes 4 major parts:1. Kidney

2. Ureter

3. Bladder

4. Urethra

KidneyFunction: Kidneys filter metabolic wastes from

the blood to produce urine

Kidneys control the concentration of substances in the body fluids

Made up of millions of nephrons that are the actual filters of the kidney

Nephron SnapchatWhere are nephrons?

Nephrons: About 1.25 million nephrons

found in each kidney Filters and cleans blood

Formation of urine takes place at the nephron in 2 stages:

http://www.zo.utexas.edu/faculty/sjasper/images/nephron.mov

1. Filtration

2. Reabsorption

Structure and function of Nephrons:1. Arteries carry blood to

kidneys2. Artery branches off and forms

a cluster of capillaries called the glomerulus

1 – Filtration

3. Due to high pressure in artery, waste diffuses out of blood into a cup-shaped structure surrounding the glomerulus called the Bowman’s capsule.

4. The concentrated waste (salts, urea, amino acids, glucose, water) then travel through the renal tubes

2 – Reabsorption

5. As the waste mixture travels through the renal tubes, the surrounding capillaries reabsorb water, salts, glucose, amino acids and vitamins and minerals.

6. After the waste mixture undergoes reabsorption, it travels to a collecting tube that leads to the Ureter! The waste mixture is now called Urine

Blood leaving the kidneys in veins has what it needs and is waste free!

Where does the Urine go?After urine formation, it goes to:1. Ureter – two tubes from each kidney

that carry urine to the bladder

2. Bladder – temporary storage site of urine until it is time to be released

3. Urethra – one tube that carries the urine from the bladder to the outside of the body

Final Stop for Urine

Excretory Review