Body Functions Flashcards
Define digestion
Digestion is the process of digesting foods.
List the parts of the digestive system
The Mouth
The Esophagus
The Stomach
The Small Intestine
The Large Intestine
The rectums
The anus
The Liver
The Gallbladder
The Pancreas
What is the function of the mouth in the digestive system?
The Mouth is where digestion begins through chewing and the action of saliva.
What is the function of the esophagus in the digestive system?
The Esophagus transports food from the mouth to the stomach.
What is the function of the stomach in the digestive system?
The Stomach temporarily stores food and begins protein digestion.
What is the function of the small intestine in the digestive system?
The Small Intestine is where the most digestion and nutrient absorption occurs.
4What is the function of the large intestine in the digestive system?
The Large Intestine absorbs water and forms feces.
What is the function of the rectums and anus in the digestive system?
The rectums and anus store and eliminate feces.
What is the function of the liver in the digestive system?
The Liver produces bile for fat digestion.
What is the function of the gallbladder in the digestive system?
The Gallbladder stores and concentrates bile.
What is the function of the pancreas in the digestive system?
The Pancreas produces digestive enzymes and hormones
Define mechanical digestion
The physical breakdown of food into smaller peices.
Define chemical digestion
Chemical digestion is the chemical breakdown of food into simpler, absorbable molecules.
Describe the function of mechanical digestion
it increases the surface area of food making it easier for enzymes to act on it.
For example, chewing in the mouth and churning in the stomach.
Describe the function of chemical digestion
It converts complex food molecules into nutrients that can be absorbed by the body.
For example, the action of enzymes in saliva, stomach acids and intestinal juices are all examples of chemical digestion.
Define respiration
Respiration is a series of chemical reactions occurring inside cells.
Compare respiration and breathing
Respiration is a series of chemical reactions occurring inside cells whereas breathing is the physical process by which air enters and leaves the body.
Identify the main organs in the human respiratory system
- Nose and nasal cavity
- Pharynx (throat)
- Larynx (voice box)
- Trachea (windpipe)
- Bronchi and bronchioles
- Lungs
- Alveoli
- Diaphragm
What is the first step in the respiratory system?
Inhalation
What is the second step in the respiratory system?
Air passage
What is the third step in the respiratory system?
Branching
What is the fourth step in the respiratory system?
Gas exchange
What is the fifth step in the respiratory system?
Exhalation
Explain Inhalation (first step in the respiratory system).
The diaphragm contracts and moves downward, expanding in the chest cavity. This contraction creates negative pressure which draws air into the lungs through the nose or mouth.
Explain Air Passage (second step in the respiratory system).
This is where air travels through the pharynx, larynx and trachea.
Explain Branching (third step in the respiratory system).
The trachea branches into two bronchi, which further dived into smaller bronchioles within the lungs
Explain Gas exchange (fourth step in the respiratory system).
Air reaches the alveoli (tiny air sacks in the lungs) and oxygen from the air diffuses into the bloodstream, whilst carbon dioxide from the blood diffuses into the alveoli.
Explain Exhalation (fifth step in the respiratory system).
The diaphragm relaxes, moving upward. This reduces the volume of the chest cavity, creating positive pressure that pushes air out of the lungs.
What are the four steps of oxygen diffusion?
- Oxygen-rich air enters the alveoli when inhaling.
- It diffuses from the alveoli (high concentration) to the bloodstream (low concentration).
- The Oxygen molecules pass through the thin alveolar walls and capillary membranes.
- The Oxygen binds to hemoglobin in red blood cells.
What are the four steps of carbon dioxide diffusion?
- Dioxide-rich blood flows into the pulmonary capillaries.
- The Carbon dioxide diffuses from the bloodstream (high concentration) to the alveoli (low concentration).
- The carbon dioxide molecules pass through the capillary and alveolar membranes
- They are expelled from the body during exhalation.
How is breathing rate linked to respiration rate?
Breathing rate and respiration rate are closely linked, as breathing supplies oxygen for cellular respiration.
When the body’s demand for energy increases (e.g. during exercise), the rate of cellular respiration increases.
This leads to a higher demand for oxygen and a greater need to expel carbon dioxide, resulting in an increased breathing rate.
This is the same during rest as the demand for energy is lower and breathing rates decrease.
List the components of the circulatory system.
- Heart
- Blood vessels
- Blood
- Lymphatic system
Describe the function of the Heart
The central pump of the circulatory system.
Describe the function of the Arteries
Carry oxygenated blood away from the heart to the body’s tissues.
Describe the function of the Veins
Return deoxygenated blood from the body back to the heart.
Describe the function of the Capillaries
Allow for the exchange of nutrients, oxygen, and waste products between blood and body tissues.
Describe the structure of the Heart
It has four chambers - two atria and two ventricles.
Describe the structure of the Arteries
Thick, elastic walls to withstand high pressure that progressively branch into smaller vessels
Describe the structure of the Veins
Thinner walls with valves to prevent backflow.
Merge into larger vessels as they approach the heart
Describe the structure of the Capillaries
Microscopic vessels with very thin walls that connect arteries and veins. They form extensive networks to maximize surface area for exchange
Define excretion
Excretion is the way the body gets rid of wastes it has produced.
Describe the excretory role of the lungs
Carbon dioxide removal and water vapor excretion.
Describe the excretory role of the kidneys
The removal of urea, salt and water.
What is the function of Ligaments
Provide stability to joints and limit excessive movement
What is the function of Tendons
Transfer force from muscles to bones, enabling movement
What is the function of Muscles
Generate force and movement through contraction and relaxation
