Digestive, Urinary, Skeletal, Muscular, and Developmental Systems Flashcards
Alimentary Canal
Muscular tube that begins at the mouth and ends at the anus.
Peristalsis
Rhythmic contractions that push food down the alimentary canal.
Journey of food through the organs
Food goes from the mouth, to the esophagus, stomach, small intestine, large intestine/colon, rectum.
Accessory Organs of the digestive system
- Organs that play a role in digestion but aren’t part of the alimentary canal
- Includes the teeth, tongue, salivary glands, liver, gallbladder, and pancreas
Exocrine Secretions
Released into body cavities such as the mouth or stomach or onto the body surface, such as digestive enzymes, saliva, or sweat.
Where is the pancreas located?
Tucked into a loop of small intestine on its left and extends to the right behind the stomach. Involved in the exocrine system.
The Mouth
- Ingestion of food is accomplished
- Teeth and tongue grind food into a lump (bolus) and salivary glands secrete saliva
- Saliva contains digestive enzyme amylase which helps to digest starch
The Stomach
- Acidic (1-2 pH) due to gastric glands secreting HCl. Helps to break up food and kill germs.
- Gastric glands secrete enzyme pepsin to help digest protein. HCl helps pepsin to work and activates pepsinogen into pepsin to digest proteins.
- The stomach secretes mucus to protect the lining from acid.
Gallbladder
Stores bile produced by the liver.
Liver
- Produces bile
- Stores glycogen, produces glucose, metabolizes fat, and detoxes the blood.
- Nutrient molecules are absorbed into the blood and brought to the liver for processing through portal veins.
Small intestine
- Site of the most digestion and absorption of nutrients
2. Bile is released to break down fats into chyme, but does not digest them.
Amylase
Enzyme that helps digest carbs
Protease
Enzyme that helps digest protein.
Lipase
Enzyme that helps digest fat.
Pancreas
- Secretes enzymes for each type of food for the small intestine
- Enzymes from the pancreas don’t work well in an acidic environment, so it secretes bicarbonate to neutralize acid in the intestines.
Where does digestion happen?
The stomach doesn’t really help with digestion, it mostly occurs in the small intestine.
Large intestine
- No digestion occurs, water is just reabsorbed
- Chyme becomes solid and turns into feces
- Large intestine contains a large amount of non pathogenic e. coli bacteria that prevents pathogenic bacteria from growing and supplies us with vitamin K.
6 kinds of nutrients
- Carbs, lipids, proteins, vitamins, minerals, and water
2. Vitamins, minerals, and water are small and don’t need digestion
Digestion
Breaking of large molecules into molecules small enough to cross cell membranes and enter the bloodstream. Small molecules are known as end products.
What are lipids broken down into?
Fatty acids and glycerol.
Vitamin A
- Needed to make retinal, a chemical necessary for sight
2. Deficiency would cause night blindness
Vitamin B
- Needed for cellular respiration and DNA replication
2. Deficiency can cause skin disorders, mental confusion, or anemia.
Vitamin C
- Needed to make a fiber in connective tissue (collagen)
2. Deficiency causes wounds that don’t heal or scurvy
Vitamin D
- Needed for calcium absorption
2. Deficiency causes weak bones and teeth or rickets
Vitamin E
- Needed to protect cell membranes from damage
2. Deficiency causes anemia
Vitamin K
- Needed for blood clotting
2. Deficiency causes easy bruising and excessive bleeding
Iron
- Mineral needed to make hemoglobin
2. Deficiency causes anemia
Calcium
- Mineral needed for strong bones and teeth
2. Deficiency causes rickets in children and osteomalacia in adults.
Iodine
- Mineral needed to make thyroxine
2. Deficiency causes decreased metabolic rate (hypothyroidism)
Main waste products of the body
- Urea from breakdown of amino acids, uric acid from breakdown of nucleic acids, creatinine from muscle matabolism
- All waste products other than water and CO2 are eliminated by the kidneys as urine.
What is the functional unit of the kidney?
The nephron
How does blood enter the kidney?
Through renal arteries that branch into capillaries.
Glomerulus
Knot of capillaries at the beginning of nephron, inside Bowman’s capsule.