RESPIRATION AND EXCRETION

EXCRETION

Definition:

Why do we excrete?

What do we excrete?

From where do we excrete?

RESPIRATORY SYSTEM

The respiratory system excretes waste. The respiratory system brings oxygen into the

circulatory system and carbon dioxide out. Respiration means the transfer of oxygen and

carbon dioxide between external and internal environment. (the lungs)

PARTS OF THE RESPIRATORY SYSTEM The Nasal Cavity

Air enters nose Air is warmed Nose is lined with cilia

Cilia filters our particles

PARTS OF THE RESPIRATORY SYSTEM Pharynx (a.k.a. throat)

Passageway for air and food Mouth and Nose meet

PARTS OF THE RESPIRATORY SYSTEM Larynx

Voice box and vocal cords

PARTS OF THE RESPIRATORY SYSTEM Trachea

Wind pipe Surrounded by cartilage rings to prevent collapse Lined with cilia

Cilia “beat” upwards to remove foreign particles (makes you cough)

PARTS OF THE RESPIRATORY SYSTEM Bronchi

Trachea divides into 2 tubes Bronchi extend into lungs and then divide into

even smaller tubules called bronchioles

PARTS OF THE RESPIRATORY SYSTEM Bronchioles

No cartilage Lined with mucus Connects bronchi with air sacs, called alveoli

PARTS OF THE RESPIRATORY SYSTEM Alveoli

Functional unit of gas exchange One cell thick, allows for easy diffusion Moist, thin walls Surrounded by capillaries

DIFFUSION

PARTS OF THE RESPIRATORY SYSTEM Lungs

Surrounded and protected by 12 pairs of ribs Consist of bronchus, bronchioles and alveoli Separated from abdomen by diaphragm

PARTS OF THE RESPIRATORY SYSTEM Diaphragm

Muscular tissue that separates lungs from abdomen

Muscle contracts and relaxes when you breathe Hiccups are a spasm of the diaphragm

Gas Exchange

Breathing is the movement of air into and out of the lungs.

Breathing is controlled by the medulla in the brain. 2 Parts-

Inhalation Exhalation

Gas Exchange

Gas Exchange

Inhalation Ribs pull up and out Diaphragm pulls down Chest cavity enlarges Pressure around lungs decreases Outside pressure is greater than inside Air rushes into lungs, inflating them

Gas Exchange

Exhalation Ribs relax down Diaphragm becomes flat Chest cavity is reduced Pressure around lungs increases as ribs go down

Gas Exchange

Gas Exchange

Breathing is controlled by the medulla Breathing rate is controlled by the amount of

carbon dioxide in the blood In increase in CO

2 = increased breathing rate

Decrease in CO2 = decrease in breathing rate

External vs. Internal

External Respiration Gas exchange between alveoli and blood

Internal Respiration Gas exchange between blood and body cells

Disorders of the Respiratory System Asthma

Constriction of bronchi Makes breathing difficult

Disorders of the Respiratory System Bronchitis

Inflammation of bronchi and bronchioles Swollen, mucus clogged bronchioles

Produces a cough

Disorders of the Respiratory System Emphysema

Degeneration of the walls of the alveoli Results in lack of elasticity Causes shortness of breath

Disorders of the Respiratory System Pneumonia

Alveoli fill with fluid Makes gas exchange in lungs, difficult

Disorders of the Respiratory System Lung Cancer

Tumors within the lung More frequent in smokers

Excretion

The removal of metabolic (toxic) wastes from the cells.

Why do we excrete?

What do we excrete?

Kidney

The kidneys are part of the urinary system/excretory system.

Kidney

The kidneys filter the blood, removing the toxic urea and salts from the bloodstream.

The kidneys make urine. Urine is urea, salts and water

Kidney

Parts of the urinary system Kidney Ureter Urinary Bladder Urethra

Kidney Blood Flow

The renal artery brings blood, rich in urea, to the kidney for filtering.

The renal vein brings filtered blood out of the kidney.

Kidney

Structures of the kidney

Nephron

The functional unit of the kidney is the nephron.

The kidney contains millions of nephrons. The nephrons are the filtering unit of the

kidney.

Nephron structures

Drawing of nephron

From the Bodies exhibit

Liver

The liver gets rid of RBC’s. The liver removes toxic substances from the

blood and converts them to less toxic forms. Urea is made in the liver.

Skin

Sweat is a form of excretion. Why do humans sweat?

Sweat is made up of water, salts and a little bit of urea.

Disorders of the Excretory System Gout

Inflammation in joints due to deposit of uric acid Can be due to too much protein in diet

Disorders of the Excretory System Kidney Stones

Calcium deposits in the kidney. An ultrasound machine may be used to try and

break up the stones into smaller pieces

Disorders of the Excretory System Kidney Disease

Can be caused by heavy metals (mercury, lead) May be treated with dialysis

Disorders of the Excretory System Cirrhosis of the liver

Caused by too much alcohol Liver is enlarged

Representative Organisms

Protist (amoeba or paramecium) Waste products:

NH3 (ammonia), salts H

2O

CO2

Structures: Cell membrane – wastes are excreted by the process of

________________ Contractile vacuole – collects and pumps ____________

out of organism

Representative Organisms

Hydra Waste products:

NH3, salts, H

2O

CO2

Structures: Cell membrane – wastes are excreted by the process of

________________ Excess water is pumped out by _____________

transport (requires energy)

Representative Organisms

Earthworm Waste Products:

Urine – H2O, salt, urea, NH

3

CO2

Structures: Nephridia-pair of excretory organs that lead outside the

body Nephridia absorb wastes from the blood and release them

out of pores

CO2 diffuse through moist skin

Representative Organisms

Grasshopper Waste Products:

Uric Acid (instead of urine)

CO2

Structures: Malpighian Tubules- filter uric acid from the blood Uric Acid gets deposited into digestive tract so a

grasshopper “poops” uric acid

CO2 is excreted through special air sacs called spiracles