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Cardiovascular, Respiratory, Reproductive, and Digestive Systems
Cardiovascular System
The system that circulates blood throughout the body
Your heart is about the size of your fist, it is made of muscle, located on the left side of the chest and is protected by the ribs and sternum
The Fab Four
The four chambers of the heart that beat in rhythm, separated by valves
The Two Sides of the Heart
The left and right, separated by the sternum, they are both separated into two chambers
Left and right, the two upper chambers of the heart
Left and right, the two lower chambers of the heart
How the Heart Works
Low-oxygenated blood goes from the body and enters the right side of the heart, where it is pumped to the lungs, then the left side pumps oxygen-rich blood from the lungs to the rest of the body
SA Node (Sinoatrial Node)
A pacemaker which is a group of cells in the heart that create electronic impulses that makes your heart beat
Heart Murmur
Different from a heart beat, the sound occurs because the valves of the heart do not open/close properly
The heart beats from top to bottom, the atrium beats and then the ventricle beats, the heartbeat is due to the closing of the valves
Keep blood flowing in one direction, which prevents back flow of the blood
The Three Types of Blood Vessels
Arteries, Veins, and Capillaries
Carry blood AWAY from the heart, have a thick muscle around them that squeezes the blood, they are responsible for the pulse
Carry blood TOWARD the heart, do not have thick muscle around them, they do have valves, which keeps blood flow moving and not backed up, "sandwiched" between skeletal muscles,
Link the arteries to the veins and are the smallest of the blood vessels, deliver oxygen and other nutrients to the cells, they have very thin walls, about one cell thick, this allows materials to be transferred easily, but also allows them to be broken easily
The Four Components of Blood
Plasma, Red Blood Cells, White Blood Cells, and Platelets
The liquid part of the blood, it makes up 55% of blood volume, and carries proteins that regulate bleeding and clotting
Red Blood Cells (RBC)
Disc-shaped, they do not have a nuclei, they have a life span of about 120 days, they are made in bone narrows of long bones, they contain hemoglobin
White Blood Cells (WBC)
Fight viruses, bacteria, etc., their numbers increase when infection is present, bigger than RBC's but fewer in number and have a much shorter life span
Irregularly shaped fragments that help to clot blood, they live for four to nine days
Carries oxygen and carbon dioxide, this is what makes blood blue or red
First in clotting, platelets produce a chemical called fibrin, then the fibrin helps to make sticky "spider webs" to help blood clot, then they slowly tighten until the wound heals and the scab falls off
Respiratory System
The system by which humans breathe in order to get oxygen into their body and dispel of the waste
The movement of air into and out of the lungs, allows your respiratory system to take in oxygen and eliminate carbon dioxide
The human body needs oxygen in order to survive to use during cellular respiration
Carbon Dioxide Removal
The respiratory system removes carbon dioxide waste gasses from the body by exhaling
A tube-like passageway at the top of the throat that receives air, food, and liquids from the mouth and nose
A flap of tissue at the lower end of the pharynx, stops food and liquids from entering the lungs
A triangle-shaped structure, where air passes over, also called the voice box or Adam's apple,
Where the air enters after passing over the larynx
The two branches of the trachea, narrow tubes that lead into the lungs, they then branch into narrower tubes called bronchioles
Major organs of the respiratory system,
One cell thick, the microscopic sacs at the end of bronchioles, outside is covered in blood vessels, this is where gas exchange occurs
Gas Exchange
Oxygen from the air you breathe moves into the blood and carbon dioxide from the blood goes into the alveoli
How You Breathe
When high levels of carbon dioxide build up in your blood it signals your nervous system to exhale, then you inhale, your diaphragm is a large muscle below your lungs that contracts and relaxes, that's how the air moves in and out of your lungs, its simply a change in air pressure
Reproductive System
A system that allows a species to reproduce
A requirement for procreation: the act of producing offspring and the furthering of generations
The Two Types of Reproduction
Sexual and Asexual
Asexual Reproduction
Produces genetically identical offspring
Sexual Reproduction
The creation of a new organism by combining the genetic material of two organisms, produces genetically similar offspring,
The mixture of the egg and sperm that later develops into a baby
Vas Deferens
The tube connecting the testes and the urethra, semen: fluid mixed with sperm, is made here
Contains the opening to the urethra, urine and semen exit here
Urine and semen leave via this tube
Sperm and testosterone are produced here, they are outside of the body, sperm need cool temperatures for proper development
There are two, eggs and estrogen are produced here
Fallopian Tubes
Fertilization occurs here, egg passes through it to get to the uterus
Muscular organ where zygote implants, if no implantation, lining sheds cause menstruation, this is where the baby grows
Passageway that leads to the uterus, it is the "birth canal", very muscular to push the baby out
The uterus contains a lining where the zygote would implant and develop, each cycle if fertilization does not occur, the lining sheds and is released via the vagina, lining will be replaced in the next cycle, this shedding is also called a period, and can last 4-6 days, occurs from puberty until menopause (45-50) every 28 days or so, except during pregnancy
The maturation of reproductive organs leading to sperm production and ovulation, results in the ability to produce offspring
The Menstrual Cycle
A 28 day cycle in which an egg is released from the ovary into the fallopian tube, the egg then has 28-36 hours to be fertilized by the sperm, if it is fertilized then the zygote has 14 days to implant into the uterus, if not fertilized, the egg will be released via menstruation
Occurs if the fertilized zygote implants into the uterus, the zygote then develops into an embryo and then into a fetus, lasts 40 weeks
Babies are born either vaginally (naturally through the vagina) or by Cesarean Section
Cesarean Section
Cutting through the stomach muscles and the abdomen and surgically removing the baby
Oral Contraceptives
Hormones which prevent ovulation, keeping the egg from being released, when used properly, once a day, they are 99% effective in preventing pregnancy
Prevent sperm from entering the uterus, with proper use they are 96-98% effective in preventing pregnancy
What Happens to Consumed Food
The steps that food goes through are ingestion, digestion, absorption, elimination
Act of eating or putting food into your mouth
Mechanical and chemical breakdown of food into small particles and molecules that your body can absorb and use
Cells take in small molecules of digested food
Undigested food and wastes are eliminated
The Two Types of Digestion
Mechanical and Chemical
Mechanical Digestion
Food is physically broken down through chewing, grinding, mashing, etc.
Chemical Digestion
Chemicals break down food into small molecules with enzymes (proteins)
What Happens When You Chew
You cover your food with saliva, which contains chemicals that help to start breaking down the food
The Food Journey
Mouth -> Esophagus -> Stomach -> Small Intestine -> Large Intestine
Mechanical digestion begins in the mouth with chewing, salivary glands produce saliva which contains enzymes that help breakdown food
Saliva Released Each Day
Each day, a human's salivary glands release about one liter of saliva
Muscular tube that connects the mouth to the stomach
Muscle contractions that allow food to move through the esophagus (like squeezing a tube of toothpaste)
Large hollow organ that stores food, it is expandable, aids in chemical digestion
Gastric Juice
An acidic fluid found in the stomach that helps breakdown food further
An enzyme in the stomach that breaks down proteins into amino acids
Small Intestine
Long tube connected to the stomach, the site of chemical digestion and nutrients absorption
Finger like projections that line the inside of the small intestine, contains small blood vessels through which nutrients diffuse into the blood stream (villi plural)
Large Intestine
Water is absorbed here, materials that pass through are waste products, peristalsis is used to force the semi-solid waste into the last section of it
Rectum and Anus
Muscles here control the release of feces