Organs & Organ Systems

Organs:

Group of tissues that work together to perform a specific function

Organ system:

Group of organs that work together to perform a certain task

Different Types of Organ Systems in Us:

• Circulatory system (blood, heart, arteries)

• Respiratory System (lung, throat)

• Nervous system (brain, spine, nerves)

• Excretory System (kidneys, bladder, urethra)

• Digestive System (mouth, stomach, intestines)

• Skeletal System (bones, cartilage)

• Muscular System (all muscles in body, heart)

• Integumentary System (skin, hair, nails, sweat glands)

Digestive System

How you turn food you chew into a 'number 2'

1. Your digestive system is in charge of breaking down the food you eat into parts small enough to be used by your cells.

2. Each of the different energy sources (carbohydrates/lipids/proteins) must be broken down into small usable particles as they travel through your digestive system.

3. As food moves through your digestive system, nutrients and water are absorbed through various tissues

Food’s path through digestive system:

Digestion begins in the mouth

1. Digestion begins with the mouth and the mechanical breakdown of your food by your teeth grinding your food into smaller pieces.

2. Saliva (mouth) contains an enzyme known as salivary amylase that chemically digests large starch molecules into smaller sugar molecules.

Mechanical Digestion:

Involves the physical breakdown of food into very small pieces.

• Ex. Teeth break down food in the mouth.

Chemical Digestion : 

Involves the breakdown of large particles into smaller particles by substances called enzymes.

• Ex. Salivary amylase breaks down carbohydrates in the mouth.

Enzymes:

A substance created by the body to speed up chemical digestion. 

• Ex. Protease breaks down protein in the stomach

3.Food is funnelled to the esophagus, it by-passes the windpipe which is covered by a flap of skin called the epiglottis.

4.Food moves down toward your stomach by peristalsis.

Peristalsis :

Wave-like contractions of muscle tissue that pushes food through the organs of the digestive system.

ACID BATH TIME!

5. Chewed up food (aka bolus) enter the stomach. Gastric juice components, hydrochloric acid and enzymes, chemically digests proteins into smaller particles. A mucus in the stomach helps to prevent the gastric juice from digesting the stomach itself.

Gastric Juice :

Composed of mucus, hydrochloric acid, water, and enzymes.

A lot of action happens in the intestines!

6. Chemical digestion continues as the food moves into the small intestine.

7. The liver produces a substance called bile, which is stored in the gall bladder. The gall bladder shoots bile into your small intestine to chemically digests large globules of lipids into much smaller droplets.

8. The pancreas is like the master enzyme digester, it also shoots many different enzymes into intestines which further chemically breakdown carbohydrates, lipids, and protein.

9. As food (at this point it’s called chyme) travels through the small intestine it begins to be digested by millions of gut bacteria. ‘Digested wastes’ from the gut bacteria are absorbed along with nutrients, water, and minerals.

10. The large intestine (also known as colon) is home to even more bacteria that digest food. The large intestines absorb nutrients, water, along with some vitamins and minerals with its villi & microvilli.

Villi :

Small, finger-like projections. Each villus is covered with epithelial tissue.

Microvilli :

The cells of the epithelial tissue have modified cell membranes that form more finger-like projections called microvilli.

11. Undigested material forms feces and exits the rectum.

Digestive system diseases:

Ulcers - painful holes in the stomach cause by bacteria H. pylori which brake down mucus layer in stomach. Can also be cause by stress

Appendicitis - appendix becomes inflamed and filled with pus, must be removed before further infection spreads.

Acid reflux - stomach acid flows back up into the esophagus

CHECKPOINT 1

USING YOUR Respiratory System

Your respiratory system is responsible for supplying your blood with the oxygen and removing the carbon dioxide from your blood and returning it to the air outside your body.

Breathing is the process your respiratory system uses to move air in and out of your lungs.

Diaphragm:

Large muscle below the lungs that helps move air in and out of the lungs.

Bronchi:

Two main branches of the airway (trachea) that lead into the lungs. Lined with cartilage to keep airway from collapsing.

Alveoli:

Tiny air-filled sacs in the lungs; the site of gas exchange.

Respiratory System DISEASES

Bronchitis – occurs when mucus builds up in the bronchi and causes them to become narrower - think chest cold.

Asthma - occurs when bronchi become inflamed and bronchi muscles constrict more than usual. An inhaler/puffer is used to relax the muscles and open the airway.

Pneumonia - The infection causes the lungs' air sacs (alveoli) to become inflamed and fill up with fluid or pus.

Lung Cancer – 40 chemicals in a cigarette are known to cause cancer, a tumour or cancerous growth. Smoking = bad!

 Circulatory System

your heart is the pump station of the circulatory system.

• The job of the circulatory system is to deliver nutrients absorbed by your digestive system to each cell in your body, transport oxygen and remove waste products.

Your heart is separated into two sides:

• Right side of the heart receives deoxygenated blood from your body and pumps it to your lungs (Pulmonary system)

• Left side of the heart receives oxygenated blood from your lungs and pumps it to your body (Systemic system)

your heart has two different kinds of chambers:

Atria:

The upper chambers of the heart that receive blood from your lungs and body.

Ventricles:

Lower chambers of the heart that pump blood to the body.

Blood vessels

Arteries:

Vessels that carry blood away from your heart to all parts of your body.

Veins:

Vessels carry blood from all parts of your body towards the heart.

Capillaries :

Specialized blood vessels located between the arteries and veins that allow the diffusion of nutrients and gases.

• Made of specialized epithelial tissue, only one layer thick.

• They are very narrow so blood cells must go through in single file.

• Super thin walls allow for an increase in gas exchange.

Blood!

Your blood is the highway of the body, it carries nutrients, oxygen, carbon dioxide, water, and many more things.

Red blood cell: (the ‘cars’ of the highway) 

Function of red blood cells is to carry oxygen.

White blood cell: (The ‘police’ of the highway)

Blood cells that are specialized to fight infections.

Platelets : (the ‘repairmen’ of the highway)

Are cells in your blood that help to stop bleeding at cuts.

Plasma: (the ‘transportation semi truck’ of the highway)

The liquid portion of your blood, transports nutrients to your cells and carries wastes, such as carbon dioxide away.

cIRCULATORY sYSTEM dISEASES

Arteriosclerosis - Build up of plaque that can blocks arteries, can increase chance of strokes, heart attacks, & angina

Hemorrhage - The blocking or bursting of a blood vessel, can develop in the brain (stroke)

Anemia - An inherited red blood cell disorder in which there aren't enough healthy red blood cells to carry oxygen throughout your body.

Allergies - an over-response to a non-hazardous substance, the immune system perceives a threat, and reacts as if you have a cold/infection.

CHECKPOINT 2

Excretory System

All organisms create wastes! Those wastes need to leave the body and the excretory system does just that. Not poop! This is a different kind of waste!

Excretion : 

The removal of waste products formed by the body.

• Many organs are involved with excretion, the lungs remove carbon dioxide, the liver removes dead blood cells, kidneys remove wastes from blood, and skin can be excretory (mostly in amphibians).

The largest excretory system in mammals is the urinary system. The urinary system is comprised of:

• kidneys

• ureter

• bladder

• urethra

Kidney (think ORGAN MADE OF TINY FILTERS):

1. The main organs (yes there’s two) of excretion. Filters the blood, straining out the unwanted urea, water and other wastes. It takes these wastes and produces urine.

2. Regulates the amount of water and salt in our blood. Very important for blood pressure!

Nephrons (think tiny filter):

Small filtering units of the kidney (each kidney has one million nephrons) that remove wastes from the blood and produce urine.

What’s a waste?

When gut bacteria break down proteins in the intestines, they produce a very toxic compound called ammonia. The liver takes the highly toxic ammonia in your blood and converts it into less harmful substances called urea.

Urea:

A waste product found in urine. Created by a chemical conversion of ammonia in the liver.

Urine formation

1. Blood enters the kidney via the renal artery

2. The artery splits into many small capillary networks, blood in this network is filtered by the million nephron.

3. Nephrons filter the blood, collect the waste, and funnels these wastes into a large collection duct in the kidney.

4. Blood that has been filtered exits the kidney via the renal vein.

5. The wastes collected in the kidneys flows into the ureter, which eventually leads to the bladder and urethra.

excretory SYSTEM DISEASES

Kidney disease - caused by many factors, mostly caused by high blood pressure, can lead to kidney failure.

Dialysis machine :

A machine that removes all the wastes from the blood that a kidney normally would.

Kidney stones - salts that crystallize due to highly concentrated urine, causes by chronic dehydration. Can be broken up by shooting concentrated ultrasound waves. Yep, you pee it out, yikes!

CHECKPOINT 3

The Nervous System

The nervous system is like the computer CIRCUIT of the body!

An organism must interpret and respond to all the different stimuli (plural for stimulus btw) from its environment and surroundings to survive. Thus organisms developed the nervous system!

Nervous Tissue (Think hardware) :

Tissue of the brain, spinal chord, and nerves. Two main parts:

1. Central Nervous System (CNS)

2. Peripheral nervous system (PNS)

Central Nervous System (Think computer chip):

Nerve cells (aka neurons) that compose the brain and the nerves of the spinal cord. 86 billion neurons! 100 trillion connections!

• CNS is like a computer (it does all the math)

• Named the central nervous system because all information flowing through nerves flows to this ‘centre’

Peripheral Nervous System (Plugs into computer):

Sensory and motor neurons that carry messages from the cell to the central nervous system.

• PNS is like all the tools you connect to a computer to interact with it (ex. mouse, keyboard, screen, mic, camera)

• All of the sensory information from the body is sent to the brain via the PNS

• Called the peripheral nervous system because all of these nerves are located outside this CNS (periphery means outside or outer edge btw)

Software of the brain

Just like a computer your brain runs ‘softwares’, specifically two different softwares:

• Somatic nervous system

• Autonomic nervous system

Somatic Nervous System (THINK APPS):

Nerves that control voluntary responses.

• All of the ‘programs’ an organism can control (walking, moving muscles, urination, eye ball movement, etc.) Basically any kind of muscle movement of the body is somatic.

• Somatic refers to the word soma which is greek for ‘body’

Autonomic Nervous System (THINK BACKGROUND APPS):

Nerves which an organism can’t control the responses.

• All of the ‘background programs’ an organism can’t control (ex. sweating, heart rate, breathing, blinking, body temperature, pupil dilation)

• Why autonomic and not call it automatic? Because autonomic means it does it by itself, you have zero control!

Reflex arc:

A neural circuit that creates an automatic link between a sensory input and a specific motor output. It essentially by-passes your brain!

• Because of possible dangers a message will skip the brain to save time, and reduce the impact of the danger (ex. Have you touched a stove lately).

• Tickling and scratching an itch are technically reflexes as well

Wires of the brain

Neuron cell (THINK WIRES):

Specialized cells of the nervous system that receives and transmit information.

The cell is made up of the following substructures:

• Dendrites: receives stimulus (think microphone)

• Soma: main body of cell (nucleus, mitochondria, ribosomes, etc)

• Axon: relays stimulus to other neurons (think speaker)

There are three types of neurons!

Sensory Neurons:

Carry information from the body to the central nervous system.

Motor Neurons:

Carry information from the central nervous system to the muscles or organs.

Interneuron:

Connects one neuron to another.

Nervous system diseases

Alzheimer’s disease - progressive neurologic disorder that causes the brain to shrink and brain cells to die. Causes dementia.

Parkinson's disease - a progressive nervous system disorder that affects movement. Causes tremors (shaking), slowed speech, rigid muscles.

Multiple sclerosis - one’s own immune system attacks its own nerve cell degenerating the axon of nerves. Numbness and tingling in hands/feet, vision problems, fatigue.

Paraplegia and Quadriplegia - not a disease but a paralysis of the limbs is caused by an injury to the spinal chord.

Head ache - head pain caused by many factors (could be stress, injury, muscle tightness, dehydration, and teaching grade 8 science)

CHECKPOINT 4

Factors that affect the health function of body systems.

Many factors affect the health of your cells:

1. Diseases or conditions inherited from your family. (Keep an eye out for pre-existing conditions)

2. How you treat your body in general. (Eat well and exercise)

3. Environmental factors causing physical, psychological, and even emotional stress. (Reduce physical injuries and take care of mental health)

protecting the body from harm

Immunity:

Our immune system create a resistance to particular infections. (The word Immune means not affected by)

Pathogen:

A general term for a bacteria or virus that causes illness in an organism.

Smallpox is a disease which has been around since human civilization, it produces a rash and high fever and can cause blindness and death; estimated to have killed 300 million people world wide.

Along comes Edward Jenner, an English doctor who used observation and deduction to created the first small pox vaccine using cow pox (1796). The vaccine has been advanced and small pox was eradicated worldwide in 1979.

Vaccine :

Substance that is taken by or injected into an animal or person to produce an immunity to a disease; usually prepared from a mild form of the disease.

1. Our immune system does a wonderful job of destroying harmful bacteria and viruses. However it takes some time for the immune system to stage a defence against any intruders. We need to give the immune system a heads up!

2. Essentially vaccines contains an inactive virus much like a ‘fake boogey man’ which is harmless, but when set free in the body will create an immune response.

3. Now that your immune system has mounted a response on the ‘fake boogey man’ (the inactive virus), when the ‘real boogey man’ shows up the immune system is ready to respond and kill the virus before it does any harm.

Harmful bacteria

On occasion our food may contain harmful bacteria (micro-organisms) if digested:

• E. coli - (diarrhea, stomach pain, cramps)

• Listeria - (fever, muscles aches, vomiting)

• Salmonella - (diarrhea, fever, cramps)

How do we deal with bacteria in our foods?

Louis Pasteur was a chemist who also enjoyed in wine:

1. Louis Pasteur was the first person to identify living micro-organisms in wine and alcohol, this micro-organism was yeast!

2. During the ageing process, too much yeast makes wine (and beer) go sour !

3. Louis Pasteur heated the wine to 60°C which killed the yeast and the wine could be aged without souring.

Pasteurization:

Named after Louis Pasteur it is the process of heating food to kill pathogens. (keeps the shelf life of foods longer)

Why do we cook and heat food?

1. Kills off bacteria and viruses that may make us sick (ex. E. coli bacteria)

2. Helps to break down the food (eases digestion)

3. Certain food is more nutritious cooked (green veggies!)

4. It tastes amazing!

Public announcement: Don’t smoke or vape

There are over 4000 different chemicals in a cigarette. Here’s a few:

1. Tar – is a dark, sticky substance that forms as a cigarette burns, settles on the surface of the organs of the respiratory system

2. Carbon Monoxide – is a colourless, odourless gas that is released when a cigarette burns. During the gas exchange process this gas attaches to red blood cells quicker than oxygen, which can seriously reduce oxygen to the body.

3. Nicotine – is a drug that speeds up the heart, and raises the blood pressure. The addictive part of a cigarette.

If you smoke you can look forward to:

• Emphysema (alveoli damage)

• Lung cancer (tumors in your lung tissue)

• Chronic obstructive pulmonary disease (COPD) (mucus in bronchi, alveoli collapse)

CHECKPOINT 5

Section Review

Unit Project

Re-enactment of Body Systems

Re-enactment of Body Systems Rubric