Human Body Systems. 1. The Circulatory System Purpose of the system: transport food, oxygen, waste...
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Transcript of Human Body Systems. 1. The Circulatory System Purpose of the system: transport food, oxygen, waste...
Human Body Systems
1. The Circulatory SystemPurpose of the system: transport food,
oxygen, waste and hormones. We have a closed system (all blood is in vessels)
Heart-about the size of your fist, it is a 4 chambered pump, upper chambers are called atria and bottom chambers are called ventricles.
VesselsVein-a vessel going to the heart, has thin walls
Artery-vessel going away from the heart, has thicker walls
Capillary-smallest vessel, has walls one cell layer thick, where the exchange of oxygen and CO2 takes place.
Blood is mostly water (plasma) it carries cells and dissolved materials
RBC- cells that carry oxygen
WBC-cells that fight infection
Platelet-cell fragments that clot blood
Blood pressure-push of blood against artery walls. Recorded when heart is pumping and when it is relaxed.Normal is 120/80
Interesting facts about the circulatory system:
1. Our bodies contain 60,000 miles of blood vessels
2. Adults have 10 pints of blood
2. The Respiratory System
Purpose of the system: to exchange carbon dioxide and oxygen
Nose-warms, filters, moistens airPharynx-throat (where nose and mouth
combine)
Larynx-contains vocal cords, as air goes past they vibrate and we can form sounds
Trachea-windpipe, carries air to lungs
Bronchi-branches of the trachea
Lungs- spongy tissue made up of millions of air sacs
Alveoli- air sacs
Normal lung Smoker’s lung
Diaphragm-breathing muscle, located under lungs, it changes the size of the chest cavity pulling in or pushing out air
Interesting facts about the respiratory system:
1. A sneeze has a speed of 102 mph
2. You have 300 million alveoli, flattened out that is the size of a tennis court
3. The Muscular SystemPurpose of the system: movement (of the body, blood,
and food)
40% of the body is muscle.There are approximately 600 muscles in the body
There are 3 types of muscle tissue:1. Smooth
-not under voluntary control-has one nucleus-not striped -found in walls of hollow structures (like the stomach)
2. Cardiac-found only in the heart-striated (striped)-not under voluntary control
3. Skeletal-attached to bone-under voluntary control-striated-large cells with many nuclei
Antagonistic musclesmuscles that cause the opposite action of another muscle
example: bend arm up (biceps) bend arm down (triceps)
Interesting facts about the muscular system:
1. Eye muscles are the busiest in the body. It is estimated that they may move 100,000 times a day.
2. Muscles can’t push, they can only pull
4. The Digestive SystemPurpose of the system-to turn food into a
usable form for cells to get energy from
Structures:Mouth-teeth make food smaller, saliva moistens food, starches get broken down here
Esophagus-a muscular tube that pushes food to the stomach
Stomach-a muscular sac that mixes digestive juices with food.
Proteins are digested here, food averages 3 hours in the stomach.
Liver-large structure that makes bile which breaks down fats
Gall bladder-small sac under liver that stores bile until needed
Pancreas-located under stomach, it adds digestive enzymes to the small intestine
Small intestine-long tube (25 ft. in an adult) where fats get broken down and food is absorbed into the blood.
Large intestine-(colon) shorter tube (5 ft.) that removes water from waste and gets it ready to eliminate.
Interesting facts about the digestive system:
1. In your lifetime your digestive system will break down as much as 35 tons of food (that is 10 elephants)
2. A horse’s digestive tract is 89 ft. long3. Americans eat 2 billion pounds of
chocolate a year
5. The Skeletal SystemPurpose of the system: bones protect
organs, give us shape, store minerals, make blood cells
Bones-the organs of the skeletal system, there are 206 in the body
Marrow-the soft tissue inside of bonesred marrow makes blood cellsyellow marrow is fat cells
Joints-where two bones come together
Tendons-connect muscle to bone
Ligaments-connect bones to other bones
Cartilage-material that is lighter and more flexible than bone, it makes a cushion between bones
Interesting facts about bones:
1. The smallest bones are in the ear, the largest bone is in your thigh (femur)
2. Cartilage decays faster than bone which is why skeletons have no ears or noses
3. The most frequently broken bone is the clavicle (collar bone)
6. The Nervous SystemPurpose of the nervous system is to control
and coordinate body functions, respond to external and internal stimuli
Brain-divided into areas that control different body functions
Spinal cord-dorsal, links the brain to the rest of the body
Motor nerves-carry message from brain to muscle
Sensory nerves-carry message from organ to brain
Nerve cell:
Dendrite-receives information
Cell body-contains nucleus and other cell organelles
Axon-tail that carries message to next cell
Neurotransmitters-chemicals that carry the message across the space between nerve cells
Interesting facts about the nervous system:1. Humans have 100 billion nerve cells in the
brain2. Nerve cells cannot be replaced if damaged
7. The Endocrine SystemPurpose of the endocrine system-deliver
chemical messages throughout the body
Gland-group of cells that makes and secretes a hormone
Hormone-chemical that gives instructions to cells
Hypothalamus-in the brain, it controls the pituitary
Pituitary-size of a pea, located below brain, called the master gland as it controls many other glands. It makes growth hormone and endorphins
Thyroid-in the neck, makes two hormones that control metabolism (turning food into energy)
Adrenal-on top of kidneys, control water/salt balance, releases adrenaline for stress
Ovaries-estrogen for female characteristics
Testes-testosterone for male characteristics
Interesting facts about the endocrine system:
1. A girl is born with over 60,000 eggs in her ovaries
2. It takes 72 days to make a sperm cell
8. The Lymphatic/Immune System
Purpose of the lymphatic system-filter blood of disease causing organisms and make antibodies
Lymph-milky fluid that contains WBC, proteins, fat
Nodes-over 100 small oval structures that filter out germs and toxins
Spleen-large structure that produces WBC, filters out worn out RBC, recycles iron for new cells
Thymus-located under sternum, helps the defense cells mature
Interesting facts about the lymphatic system:
1. Tonsils are lymph nodes in the back of the mouth. If they are chronically infected they are often removed
2. There is a parasitic worm that can live in lymph vessels. It causes the fluid to back up resulting in elephantiasis
9. The Excretory System
Purpose of the excretory system: filter blood and remove toxic waste, maintain salt and water balance
Kidneys-blood enters, waste is removed, water is recycled
Ureters-tubes that carry urine from kidney to bladder
Bladder-elastic sac that stores urine until it can be eliminated
Urethra-tube that carries urine from the body
Interesting facts about the excretory system:
1. Each kidney has 1 million filtering units
2. The ancient Romans used urine as bleach when they did their laundry