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

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

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 CO 2 = 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: NH 3 (ammonia), salts H 2 O CO 2  Structures: Cell membrane – wastes are excreted by the process of ________________ Contractile vacuole – collects and pumps ____________ out of organism

Representative Organisms Hydra  Waste products: NH 3, salts, H 2 O CO 2  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 – H 2 O, salt, urea, NH 3 CO 2  Structures: Nephridia-pair of excretory organs that lead outside the body  Nephridia absorb wastes from the blood and release them out of pores CO 2 diffuse through moist skin

Representative Organisms Grasshopper  Waste Products: Uric Acid (instead of urine) CO 2  Structures: Malpighian Tubules- filter uric acid from the blood Uric Acid gets deposited into digestive tract so a grasshopper “poops” uric acid CO 2 is excreted through special air sacs called spiracles