Systems Flashcards
What is the primary function of the digestive system?
The digestive system breaks down food into soluble molecules (like glucose, amino acids, and fatty acids) that can pass through cell membranes. These smaller molecules are absorbed into the bloodstream via the small intestine and are then transported by the circulatory system to various parts of the body for energy, growth, repair, and other functions.
What are the four categories of macromolecules (essential nutrients)?
- Carbohydrates
- Lipids
- Proteins
- Nucleic Acids
What are carbohydrates primarily used for?
Provides short/long term energy storage for organisms.
What is the ratio of hydrogen to oxygen in carbohydrates?
2 Hydrogen, 1 Oxygen, per 1 Carbon (2:1:1).
Define monosaccharides.
Simple sugars that contain 1 sugar molecule.
Give two examples of monosaccharides.
- Fructose
- Glucose
What are disaccharides?
Carbohydrates composed of 2 sugar molecules.
List three examples of disaccharides.
- Maltose
- Sucrose
- Lactose
What are polysaccharides?
polysaccharides are large, complex carbohydrates made up of many monosaccharide (simple sugar) units bonded by glycosidic linkages
What is the function of starch in plants?
Stores energy in plants.
What is the primary function of glycogen? And where is it found?
Glycogen is a short-term energy storage molecule. It’s made from excess glucose and stored in the liver and muscles.
- Stores energy in animals
- polysaccharide made
up of glucose units - short term energy
- equivalent to plant’s starch
What are lipids and their solubility?
They are fatty compounds, and they are insoluble in water.
- help form cell membranes
- stores long term ENERGY
What is the basic structure of lipids?
A molecule of glycerol attached to fatty acid chains.
What are the functions of lipids?
- Store long term energy
- Provide materials to build cell membranes
- Cushion/insulate internal organs
What are the main functions of proteins? [5]
- Provide structure and support for blood cells, body tissues and muscles
- Aid in muscle developments, such as contraction
- Act as catalysts to speed up chemical reactions (=enzymes)
- Provide immunity against infection
- Transport ions in cell membranes
List some examples of proteins.
- Hemoglobin
- Insulin
- Collagen
- Antibodies
- Enzymes
What is the role of enzymes in digestion?
They act as catalysts that speed up the rate of chemical reactions
What are nucleic acids responsible for?
Directing growth and development of all organisms using chemical code.
Name the two types of nucleic acids.
- RNA (Ribonucleic acid)
- DNA (Deoxyribonucleic acid)
What process breaks down macromolecules in the body?
Hydrolysis.
What is hydrolysis?
A process where water molecules are added to macromolecules, breaking chemical bonds.
What are the three main types of digestive enzymes?
- Carbohydrase (amylase is a type of carbohydrase)
- Lipase
- Protease
What does carbohydrase do?
Breaks down carbohydrates into simple sugars.
What is the product of lipase digestion?
Glycerol molecules and fatty acids.
What does protease break down?
Proteins into amino acids.
What is the function of nuclease?
Breaks down nucleic acids into nucleotides.
What are the four stages of food processing?
- Ingestion
- Digestion
- Absorption
- Elimination
What is the alimentary canal?
A digestive tract that is a long open tube from mouth to anus.
What is mechanical digestion?
Physically breaking down food into smaller pieces.
What is chemical digestion?
Breakdown of macromolecules by enzymes.
What is bolus?
The soft mass produced after chewing food.
What is peristalsis?
Wave-like muscular contractions that push food down the esophagus.
What is chyme?
A thick semifluid mass of partially digested food and digestive secretions after food is mechanically and chemically digested.
What are gastric glands responsible for?
Secreting gastric juice (mucus, hydrochloric acid, pepsin) in the presence of food.
What is the role of the pyloric sphincter?
- Located at the bottom of the stomach
- Keeps food inside stomach from going into the small intestine.
What does the small intestine do?
Breaks down macromolecules by the enzymes amylase, protease, lipase and absorbs nutrients into the blood stream.
What is the function of villi in the small intestine?
Increase the surface area for nutrient absorption.
What is the role of the liver in digestion?
- liver processes nutrients
Produces bile that emulsifies large fat globules into smaller droplets, increasing surface area for lipase enzymes to break down the fats.
What is bile?
A mixture of bile pigments and bile salts that aids in the digestion of fats.
What is the purpose of the gallbladder?
Stores bile between meals.
What does the pancreas secrete?
Pancreatic juice which contains enzymes to aid digestion of lipids, carbs, and proteins.
What factors affect enzyme reactions?
- Temperature
- pH
What is the optimal temperature for human enzymes?
Around 37°C.
What happens to enzymes at high temperatures?
They may become denatured and not function.
What are the four stages of breathing?
- Inspiration
- Expiration
- Internal Respiration
- Cellular Respiration
What occurs during inspiration?
Breathing in air.
What happens during expiration?
Gas exchange in the lungs.
What is cellular respiration?
The blood brings blood to cells that need it and diffuse CO2 and O2.
What is the equation for cellular respiration?
C6H12O6 + O2 = CO2 + H2O + ATP (energy).
How do earthworms respire?
They use their entire outer skin for respiration.
What is the primary function of the respiratory system?
To provide oxygen for cellular respiration. Gas exchange of oxygen and carbon dioxide .
Cellular respiration is the process by which cells obtain energy from glucose.
What type of respiration do aquatic animals utilize?
Gills
Gills facilitate gas exchange by allowing oxygen from water to diffuse into capillaries.
What is the tracheal system in insects?
An internal system of branching tubes called tracheae
This system connects body cells to the outside environment through spiracles.
What is the primary respiratory organ for most land animals?
Lungs
Lungs allow for a greater intake of oxygen compared to gills or tracheal systems.
What happens to the diaphram, intercostal muscles during inhalation?
Intercostal muscles and diaphragm contract, increasing lung volume
This creates lower pressure in the lungs, causing air to rush in.
What is tidal volume?
The amount of air intake/outtake in normal breathing at rest
It represents the volume of air exchanged with each breath.
What is the function of turbinate bones in the nasal passage?
To increase surface area and help warm, moisten, and clean the air
They also trap bacteria and foreign particles.
What is the pathway air travels through the human respiratory system?
Nasal Passage > pharynx > larynx Trachea > Bronchi > Bronchioles > Alveoli
Gas exchange occurs in the alveoli.
What is the function of the epiglottis?
To control the opening to the glottis
It ensures food goes to the esophagus rather than the trachea.
What is the structure of the heart?
Consists of left atrium, left ventricle, right atrium, and right ventricle
The heart separates oxygenated and deoxygenated blood.
What is the difference between the pulmonary and systemic circuits?
Pulmonary circuit involves deoxygenated blood to the lungs; systemic circuit involves oxygenated blood to the body
The systemic circuit carries blood that is 80-90% oxygenated.
What is hemoglobin?
A protein that carries oxygen in the blood
It releases oxygen in low-oxygen areas and carries some carbon dioxide.
What is the primary function of the circulatory system?
To transport gas, nutrients, and waste
It also regulates internal temperature and protects against blood loss.
What is the difference between open and closed circulatory systems?
Open circulatory systems have blood in direct contact with tissues; closed systems have blood contained in vessels
Open systems are typically found in invertebrates, while closed systems are in vertebrates.
What is the role of platelets in blood?
To form clots to prevent bleeding
Platelets react with plasma to produce fibrin, which forms a mesh over wounds.
What is vasoconstriction?
The constriction of blood vessels to conserve heat
It helps the body conserve heat by reducing blood flow to the skin, which minimizes heat loss. It also increases blood pressure.
What is the sinoatrial node (SA)?
The pacemaker of the heart that stimulates rhythmic contractions
It sends electrical signals to the atria to contract simultaneously.
What causes the ‘lub-DUB’ sounds of the heart?
The closing of heart valves during the cardiac cycle
‘Lub’ is from the AV valves, and ‘DUB’ is from the semilunar valves.
What is systolic pressure?
The maximum blood pressure during ventricular contraction
It occurs during the phase called systole.
What device measures blood pressure?
Sphygmomanometer
It works by temporarily stopping blood flow and measuring pressure against arterial walls.
What is the term for the phase when the heart contracts?
Systole
Systole refers to the contraction phase of the heart cycle.
What is diastolic pressure?
The lowest pressure before ventricular contraction
Diastolic pressure occurs during the diastole phase.
How is blood pressure measured?
Through an artery in the arm using a sphygmomanometer
A sphygmomanometer temporarily stops blood flow and then measures the pressure.
What is the units of blood pressure?
Blood pressure in mmHg
1 mmHg = 0.133 kPa.
What is the equation for blood pressure?
Systolic/diastolic
This represents the highest blood pressure over the lowest blood pressure.
What is the function of valves in veins?
Prevent backflow
Valves work alongside small muscles to aid blood flow towards the heart.
What happens when muscles along veins contract?
A valve at the bottom closes, and a valve in the direction of blood flow opens
This action facilitates the movement of blood towards the heart.
What is cardiac output?
The amount of blood pumped by the heart
Measured in mL/min and indicates oxygen levels in the body.
What factors affect cardiac output?
Heart rate and stroke volume
Heart rate is the number of beats per minute, while stroke volume is the amount of blood ejected with each beat.
What is the equation for calculating cardiac output?
Heart Rate x Stroke Volume
This equation reflects the overall efficiency of the heart in pumping blood.
