Science - Ch3: Body Systems

NOTE: This only has 3.1 + 3.2

What happens when you consume less energy than your body requires?

You use up fat stores and may start using muscle tissue for energy, leading to loss of mass.

What is the consequence of not having fat stores when energy intake is low?

The body begins to use muscle tissue, including heart muscle, leading to weakness.

How does the body respond to increased energy demands?

The heart muscles strengthen to pump more blood, and breathing muscles become more efficient.

What is the chemical reaction for respiration?

Oxygen + Glucose → Carbon Dioxide + Water + Energy.

What are reactants in a chemical reaction?

The substances that undergo change, found on the left side of a word equation.

What are products in a chemical reaction?

The substances produced from the reaction, found on the right side of a word equation.

What happens when you consume more energy than your body requires?

Excess nutrients are converted to fat and stored, potentially leading to overweight or obesity.

What health problems can arise from being overweight?

Joint strain, increased heart workload, and potential blockage of blood vessels by cholesterol.

What is the role of red blood cells in respiration?

They carry oxygen from the lungs to the cells and transport carbon dioxide back to the lungs.

How do the diaphragm and rib muscles work during inhalation?

The diaphragm contracts and flattens, while rib muscles pull the rib cage up and out.

What happens during exhalation?

The diaphragm relaxes and arches upwards, while rib muscles move down and in, increasing chest pressure.

What is the function of mucus in the respiratory system?

It traps fine particles and bacteria, which are then swallowed or expelled.

What is the role of the trachea in respiration?

It serves as the windpipe, allowing air to pass from the throat to the lungs.

What is the significance of the alveoli's thin walls?

They facilitate efficient gas exchange between the air and blood.

What is the involuntary nature of breathing?

Breathing occurs automatically without conscious thought, although it can be controlled temporarily.

How does the body eliminate carbon dioxide?

Carbon dioxide moves from cells into the blood and is expelled from the body during exhalation.

What is the relationship between energy consumption and body mass?

Energy intake must balance energy expenditure to maintain body mass; imbalance can lead to weight gain or loss.

What is the function of the trachea?

The trachea conducts air to the lungs and is reinforced with cartilage rings to prevent collapse.

What structures do the trachea divide into?

The trachea divides into two bronchi, which further divide into smaller tubes called bronchioles.

What are alveoli and their function?

Alveoli are microscopic sacs in the lungs that provide a large surface area for gas exchange between the lungs and bloodstream.

What is respiration?

Respiration refers to the series of chemical changes in cells that release energy, involving the intake and expulsion of air.

What is the role of the respiratory system?

The respiratory system takes in air, extracts oxygen, and makes it available to the cells for respiration.

What is the length and diameter of the large intestine?

The large intestine is about 1.5 meters long and 6 to 7 cm in diameter.

What happens in the large intestine?

Water and remaining nutrients are reabsorbed, and waste forms into feces, which are expelled through the anus.

What is the function of the anus?

The anus is a sphincter muscle that expels feces from the body.

What is vomiting and its purpose?

Vomiting is the expulsion of stomach contents to rid the body of unwanted bacteria and is caused by contractions of the stomach and intestines.

What causes diarrhea?

Diarrhea occurs when the small intestine becomes inflamed and cannot absorb water, leading to loose stools and risk of dehydration.

What is heartburn?

Heartburn is a burning sensation caused by stomach acid rising up into the esophagus due to pressure on the stomach.

What is appendicitis?

Appendicitis is the inflammation of the appendix, which can occur if its opening is blocked, requiring surgical removal.

What is the function of the liver?

The liver performs over 500 chemical processes, including the production of bile for fat digestion and detoxifying substances.

What is bile and its role in digestion?

Bile is a greenish liquid produced by the liver that aids in the mechanical digestion of fats by breaking them into smaller droplets.

What are villi and their function in the small intestine?

Villi are microscopic projections in the small intestine that increase surface area for nutrient absorption.

What nutrients are absorbed in the ileum?

The ileum absorbs fatty acids, glycerol, amino acids, and glucose from digested food.

What is the main source of energy for the body?

Glucose, produced from the digestion of carbohydrates, is the main source of energy for the body.

What is the role of the diaphragm in respiration?

The diaphragm is a muscle that contracts and relaxes to help draw air into and push air out of the lungs.

What is peristalsis?

Peristalsis is the wave-like muscle contractions that move food through the digestive tract.

How does the body respond to harmful bacteria in the digestive system?

The body may induce vomiting or diarrhea to expel harmful bacteria and viruses.

What is the significance of the appendix in the human body?

The appendix may house beneficial bacteria and play a role in the immune system's development.

What is the primary function of the respiratory system?

To facilitate the exchange of oxygen and carbon dioxide between the body and the environment.

How does the structure of the trachea support its function?

The trachea's cartilage rings provide structural support to keep it open during breathing.

What is the relationship between the liver and the digestive system?

The liver processes nutrients absorbed from the digestive system and detoxifies harmful substances.

What are villi and their function in the digestive system?

Villi are tiny projections in the digestive system that contain capillaries for nutrient absorption.

What is the shape and primary function of the stomach?

The stomach is bag-shaped and stores food for 1-6 hours while mechanically and chemically digesting it.

What is the role of gastric juice in the stomach?

Gastric juice contains hydrochloric acid to kill bacteria, mucus to protect the stomach lining, and digestive juices to start protein digestion.

How long is the small intestine and what is its diameter?

The small intestine is up to 6 meters long and has a diameter of 3 cm.

What are the two main types of digestion?

Mechanical digestion, which breaks food into smaller pieces, and chemical digestion, which breaks down food into simpler chemicals.

What is the function of saliva in digestion?

Saliva moistens food and contains enzymes that begin breaking down starch into glucose.

What is the process of peristalsis?

Peristalsis is the contraction and relaxation of muscles in the esophagus that pushes food down to the stomach.

What is the role of the epiglottis during swallowing?

The epiglottis closes the windpipe to ensure food goes into the stomach and not the lungs.

What separates the esophagus from the stomach?

A sphincter muscle separates the esophagus from the stomach, preventing backflow.

What is the function of the pancreas in digestion?

The pancreas produces digestive enzymes that are released into the duodenum for chemical digestion.

What is the role of nutrients in the body?

Nutrients provide energy, support growth, and aid in repair of tissues.

What is mechanical digestion?

Mechanical digestion involves physically breaking down food into smaller pieces without changing its chemical structure.

What is chemical digestion?

Chemical digestion involves breaking down food into simpler substances through chemical reactions.

What are the four types of teeth in humans?

Incisors, canines, premolars, and molars.

What is the function of incisors?

Incisors are used to bite off pieces of food.

What is the function of molars?

Molars grind food into smaller pieces during chewing.

What is the role of the tongue in digestion?

The tongue helps mix food with saliva and pushes it into the esophagus as a bolus.

What happens to food in the stomach?

Food is churned and mixed with gastric juice for further digestion.

What is the function of the liver in digestion?

The liver produces bile, which helps in the digestion and absorption of fats.

What is the role of the large intestine?

The large intestine absorbs water and forms waste for excretion.

How do cells in the body obtain nutrients?

Cells obtain nutrients through the bloodstream after digestion breaks food down into usable forms.

What is the significance of the digestive tract?

The digestive tract is the pathway through which food passes and is processed into nutrients.

What is the function of the sphincter between the stomach and small intestine?

The sphincter controls the passage of food from the stomach to the small intestine.

What is the role of the appendix in the digestive system?

The appendix is thought to play a role in gut flora and immune function, though its exact function is not fully understood.