The Remarkable Body Flashcards
1
Q
The Body’s Cells
A
- Cells need energy, oxygen, water, and nutrients to do their work
- Genes determine nature of cells’ work
- Affect how nutrients are handled
- Cells → Tissues → Organs → Body System
- Affect how nutrients are handled
2
Q
Transport of Nutrients
(Body fluids supply tissues with nutrients)
A
- Blood
- Carries water-soluble nutrients
- Goes from small intestine to liver to heart
- Cardiovascular System
- Lymph
- Carries fat-soluble nutrients
- Goes from small intestine via the lymphatic system to the thoracic duct where lymph enters the bloodstream near the heart (“mixing oil with water”)
3
Q
Transport of Nutrients
(Arteries carry oxygen and nutrients to the tissues)
A
- Blood circulates among cells by capillaries
- Exchange of materials between the cell fluid and the extracellular fluid
- How the Body Fluids Circulate Around Cells
- Delivery of oxygen an nutrients
- picks up carbon dioxide and wastes
4
Q
Transport of Nutrients
(Blood returns to the heart via veins)
A
- Carbon dioxide is removed by the lungs in exchange for oxygen
- Blood circulates to the kidneys where wastes are removed (filtered by nephrons) and excreted in the urine
5
Q
Regulation
(Communication between organs and cells)
A
- Hormones
- e.g insulin and glucagon regulate blood glucose
- Nervous System
- e.g responds to need for food (hunger), regulates digestion (gastric juices)
- Combination of hormones and nervous system
- e.g. fight or flight reaction: epinephrine (hormone) and body responses/movements
6
Q
Digestion
A
- Breakdown of nutrients into their smallest subunits for absorption into the body
- CHO: monosaccharides
- Protein: Amino Acids
- Fat: fatty acids and glycerides
- Digestive System
- Summary of Chemical digestion
7
Q
Digestion
(Mouth)
A
- Taste buds guide food acceptability
- Mechanical digestion: chew and mix food with saliva (mucus and enzymes)
- Chemical digestion: saliva contains salivary amylase enzyme to begin breakdown of CHO
8
Q
Digestion
(Esophagus)
A
- Passes food to the stomach via peristalsis (wave-like muscular squeezing along digestive tract)
9
Q
Digestion
(Stomach)
A
- Mechanical digestion: churns and mixes food to a liquid mass (chyme)
- Movement within stomach aided by 3 layers of muscle
- Movement of food along GI tract controlled by
- Cardiac sphincter (into stomach)
- Pyloric Valve (into small intestine)
- Heartburn
- Antacids for temporary heartburn relief
9
Q
Heartburn
A
Burning sensation in the chest caused by backflow of stomach acid into the esophagus
10
Q
Digestion
(Stomach - 2)
A
- Chemical digestion: adds hydrochloric acid and enzymes (pepsin to breakdown proteins), and fluids (gastric juice)
- Gastric juice is pH ~2
- Denatures proteins
- Kills microorganisms
- Mucus protects the stomach wall
- Gastric juice is pH ~2
11
Q
Digestion
(Small Intestine)
A
- Major site of digestions
- 20 feet long
- Pancreas secretes bicarbonate that neutralizes the acidic contents from the stomach
12
Q
Digestion
(Small Intestine - 2)
A
- Chemical digestion: enzymes from pancreas and small intestine digest CHO, protein and fat
- Pancreatic amylase (CHO); pancreatic lipase (fat); trypsin and chymotrypsin (protein)
- Enzymes enter via pancreas → Pancreatic duct → small intestine
- Mechanical digestion: segmentation
- Hormones from pancreas: insulin and glucagon
13
Q
Digestion
(Small Intestine - 3)
A
- Bile emulsifies fat to assist digestion
- Synthesized in the liver
- Stored in the gall bladder
- Enters small intestine via bile duct
14
Q
Microbes in the Digestive Tract
A
- A healthy digestive tract contains trillions of microbes (microbiota)
- These bacteria do many activities within our digestive tract, and can effect our bodies in many ways