Respiratory System: Gas Exchange and Cellular Respiration

What is the main purpose of gas exchange in the respiratory system?

To convert sugars into ATP

To acquire O2 for cellular respiration (correct)

To release energy stored in sugars

To dispose of CO2

Which process involves the movement of air or water through a specialized gas-exchange organ?

Cellular respiration

Ventilation (correct)

Diffusion at the respiratory surface

Gas exchange down pressure gradients

According to Fick's Law of Diffusion, what does the rate of diffusion of a gas depend on?

The partial pressure of the gas within the total gas mixture (correct)

The temperature of the surrounding environment

The number of oxygen molecules in the atmosphere

The concentration of ATP in the cells

In gas exchange, where do O2 and CO2 diffuse to and from?

From regions with higher partial pressure to regions with lower partial pressure Signup and view all the answers

Why is gas exchange essential for aerobic organisms?

To acquire O2 for cellular respiration and dispose of CO2 Signup and view all the answers

What characteristic allows oxygen and other gases to easily cross cell membranes?

They are hydrophobic molecules Signup and view all the answers

What is the main purpose of sensors in the aorta and carotid arteries?

To monitor O2 and CO2 concentrations in the blood Signup and view all the answers

Why do respiratory pigments like hemoglobin increase the oxygen-carrying capacity of blood?

By combining reversibly with oxygen Signup and view all the answers

Why does hemoglobin exhibit a sigmoidal shape on the oxygen-hemoglobin equilibrium curve?

As a result of cooperative binding of oxygen Signup and view all the answers

How does a small change in the partial pressure of oxygen affect the delivery of oxygen according to the oxygen-hemoglobin equilibrium curve?

It results in a large change in oxygen delivery Signup and view all the answers

Which factor does NOT influence hemoglobin's binding affinity to O2?

Blood flow rate Signup and view all the answers

What happens to the color of blood when hemoglobin is fully deoxygenated?

It turns dark red Signup and view all the answers

What is the function of cilia in the trachea, bronchi, and bronchioles?

Line the walls and move mucus and particles towards the throat Signup and view all the answers

Which lung volume refers to the normal volume of air inhaled with each breath?

Tidal volume Signup and view all the answers

Where are the main breathing control centers located in humans?

Medulla oblongata and pons Signup and view all the answers

What does the medulla oblongata regulate in relation to breathing?

Rate and depth of breathing Signup and view all the answers

What is the maximum amount of air a person can expel from the lungs after maximum inhalation?

Vital capacity Signup and view all the answers

How is residual volume of air described after exhalation?

Prevents collapse of lungs Signup and view all the answers

Which of the following statements is correct regarding the size of the lungs in humans?

The right lung is larger and has three lobes, while the left lung is smaller and has two lobes. Signup and view all the answers

What is the primary function of the intercostal muscles and diaphragm during breathing?

To contract and relax, causing air to be drawn into the lungs. Signup and view all the answers

According to Boyle's Law, what is the relationship between the pressure and volume of a gas in a closed space?

Pressure and volume are inversely related, such that an increase in one leads to a decrease in the other. Signup and view all the answers

Which of the following statements accurately describes the mechanics of breathing in humans?

Humans use negative pressure breathing to pull air into the lungs. Signup and view all the answers

What is the primary role of the diaphragm in the process of breathing?

To separate the thorax from the abdomen and aid in the expansion and contraction of the lungs. Signup and view all the answers

According to the information provided, which of the following statements is incorrect?

Boyle's Law states that pressure and volume are directly proportional in a closed space. Signup and view all the answers

During inhalation, what happens to the air pressure inside the lungs compared to the atmospheric pressure?

The air pressure inside the lungs decreases below atmospheric pressure Signup and view all the answers

Which of the following statements is true regarding the diaphragm during exhalation?

The diaphragm relaxes, increasing the volume of the lung cavity Signup and view all the answers

What is the primary mechanism that drives air into the lungs during inhalation?

Contraction of the diaphragm and intercostal muscles, expanding the thoracic cavity Signup and view all the answers

During exhalation, what happens to the air pressure inside the lungs compared to the atmospheric pressure?

The air pressure inside the lungs increases above atmospheric pressure Signup and view all the answers

Which of the following statements correctly describes the relationship between the thoracic cavity volume and lung volume during inhalation and exhalation?

During inhalation, thoracic cavity volume increases, and lung volume increases Signup and view all the answers

What is the primary driving force that causes air to be expelled from the lungs during exhalation?

Relaxation of the diaphragm and intercostal muscles, contracting the thoracic cavity Signup and view all the answers

Gas exchange is the mechanism where aerobic organism acquire O2 for cellular respiration and disposes of ______

CO2 Signup and view all the answers

Partial pressure is a measure of the concentration of individual components in a mixture of gases…the rate of diffusion of a gas is proportional to its partial pressure within the total gas mixture. A gas diffuses from a region of higher partial pressure to a region of lower partial ______

pressure Signup and view all the answers

Gases diffuse down pressure gradients in the lungs and other organs as a result of differences in partial ______

pressure Signup and view all the answers

Gas Exchange Involves five major steps: Ventilation is the movement of air or water through a specialized gas-exchange organ such as a lung or ______

gill Signup and view all the answers

Diffusion at the respiratory surface where O2 moves from the air or water into the blood and CO2 moves from the blood into the air or ______

water Signup and view all the answers

Oxygen and other gases are hydrophobic molecules that easily cross cell membranes through simple ______

diffusion Signup and view all the answers

Alveoli are wrapped by ______

capillaries Signup and view all the answers

Surfactant is a complex liquid mixture of lipids and ______ secreted by Type II alveolar cells

proteins Signup and view all the answers

Production of surfactants starts after 20 weeks of ______

gestation Signup and view all the answers

Preterm infants do not produce enough ______

surfactant Signup and view all the answers

Infants are treated with exogenous ______

surfactants Signup and view all the answers

Lack of surfactant can lead to respiratory distress ______

syndrome Signup and view all the answers

Air inhaled through the ______ à pharynx à larynx (voice box) à trachea (windpipe) à bronchi à bronchioles à alveolar ducts à alveolar sacs = site of gas exchange

nostrils Signup and view all the answers

Human respiratory system is dived in two parts: Upper Respiratory System Nasal ______

cavity Signup and view all the answers

Mucus and cilia prevent particulate matter from entering the ______

lung Signup and view all the answers

Pharynx ✓ Region shared by digestive and respiratory system.✓ Connects the nasal cavity with ______

larynx Signup and view all the answers

Trachea is fairly rigid since its walls have about 16 to 20 C-shaped hyaline cartilaginous ______

rings Signup and view all the answers

These rings have two main purposes: Keep trachea open (i.e., prevent collapsing) during breathing so that oxygen can reach alveoli deep in the lungs ✓Cartilaginous rings are incomplete (or C-shaped) instead of complete (or O-shaped) so that expansion of esophagus occurs during ______ as food or liquids move through it

peristalsis Signup and view all the answers

Bohr shift to left means O2 binds strongly to ______

hemoglobin Signup and view all the answers

Bohr shift to right means O2 is released readily by ______

hemoglobin Signup and view all the answers

In humans, the oxygen association/dissociation curve of fetal hemoglobin is found to the ______ of the oxygen association/dissociation curve adult hemoglobin

left Signup and view all the answers

Carbon dioxide is carried by hemoglobin, it does not compete with oxygen for the iron-binding positions but is bound to the protein chains of the ______ structure

hemoglobin Signup and view all the answers

Three ways CO2 is transported in the blood: Dissolved in plasma = 7%, Bound to hemoglobin (which becomes carbaminohemoglobin) = 23%, As bicarbonate ions – (HCO3 ) = ______%

70 Signup and view all the answers

Respiratory pigments help in carrying oxygen around throughout the circulatory system. Respiratory pigments are metal-containing proteins which combine reversibly with oxygen, increasing the oxygen-carrying capacity of blood. Most vertebrates and some invertebrates use ______ as their main respiratory pigment.

hemoglobin Signup and view all the answers

A single hemoglobin molecule can carry ______ molecules of O2.

four Signup and view all the answers

The oxygen-hemoglobin equilibrium curve representing hemoglobin's affinity to oxygen shows that a small change in the partial pressure of oxygen can result in a large change in the delivery of O2. The sigmoidal shape of the curve is the result of ______ binding of oxygen to hemoglobin.

co-operative Signup and view all the answers

Hemoglobin exhibits cooperative binding, in which oxygen binding to the active site of one subunit increases the affinity of hemoglobin to bind more oxygen at the remaining active sites of the other subunits. Hemoglobin binding affinity to O2 varies with pH, temperature, and ______ concentration.

CO2 Signup and view all the answers

Blood is bright red when hemoglobin is fully oxygenated, and dark red when hemoglobin is fully ______.

deoxygenated Signup and view all the answers

Sensors in the aorta and carotid arteries monitor O2 and CO2 concentrations in the blood. These sensors exert secondary control over breathing by sending signals to the breathing control center. These sensors are known as ______.

chemoreceptors Signup and view all the answers

Humans excrete nitrogen through ______ like many other mammals.

urea Signup and view all the answers

Kidneys are the main excretory organ in humans. The kidney osmoregulates the body’s internal environment by controlling the amount of water and salts excreted through the ______.

urine Signup and view all the answers

Water and electrolytes are lost through sweat glands in the ______.

skin Signup and view all the answers

Lungs are in charge of removing ______.

carbon dioxide Signup and view all the answers

Liver breaks down toxic substances in the blood, as well as produces ______.

urea Signup and view all the answers

Large intestine (colon) removes solid waste and some water in the form of ______.

feces Signup and view all the answers

The nephron is the functional unit of the ______

kidney Signup and view all the answers

Kidneys use filtration, reabsorption, and secretion to produce ______

urine Signup and view all the answers

The primary function of the intercostal muscles and diaphragm during breathing is ______

ventilation Signup and view all the answers

Surfactant is a complex liquid mixture of lipids and ______ secreted by Type II alveolar cells

proteins Signup and view all the answers

According to Fick's Law of Diffusion, the rate of diffusion of a gas depends on the difference in its partial ______

pressure Signup and view all the answers

Where does reabsorption of glucose occur in the nephron? A. Bowman’s capsule B. Proximal convoluted tubule C. Loop of Henle D. Distal convoluted tubule E. Collecting duct Where does reabsorption of glucose occur in the nephron? A. Bowman’s capsule B. Proximal convoluted tubule C. Loop of Henle D. Distal convoluted tubule E. Collecting duct The descending loop of Henle in the nephron is permeable to which of the following substances? A. Potassium ions B. Sodium ions C. Water D. + H ions The descending loop of Henle in the nephron is permeable to which of the following substances? A. Potassium ions B. Sodium ions C. Water D. + H ions Numbers represent osmolarity [milliosmoles of solute (mOsm) per liter] Which parts of the nephron are mainly found in the renal medulla of the kidney? A. The entire nephron can be found within the renal medulla B. The loop of Henle and the collecting duct C. The proximal and distal convoluted tubules D. The loop of Henle and Bowman’s capsule Which parts of the nephron are mainly found in the renal medulla of the kidney? A. The entire nephron can be found within the renal medulla B. The loop of Henle and the collecting duct C. The proximal and distal convoluted tubules D. The loop of Henle and Bowman’s capsule Urine passes through all the following structures except the ____? A. ureters B. vasa recta C. urethra D.

renal pelvis Signup and view all the answers

The renal corpuscle consists of the ______ and Bowman’s capsule

glomerulus Signup and view all the answers

Filtration, reabsorption, and secretion are the three processes involved in kidney's production of ______

urine Signup and view all the answers

The two parts of the nephron responsible for reabsorption and secretion are the proximal and distal convoluted ______

tubule Signup and view all the answers

Reabsorption of urea in the collecting duct helps maintain the high osmolarity of the inner ______

medulla Signup and view all the answers

The part of the loop of Henle responsible for reabsorption of water and ions is the ______ arm

descending Signup and view all the answers

The part of the loop of Henle responsible for reabsorption of ions without water is the thin segment of the ______ arm

ascending Signup and view all the answers

During the ascending limb of ______ of Henle, NaCl is reabsorbed without water movement, first through diffusion (thin portion), then through active transport (thick portion) (0.5 marks).This decreases urine osmolarity until it reaches around 100 mOsm, making the urine hypo-osmotic compared to blood (0.5 marks).In the distal convoluted tubule, active secretion of hydrogen and potassium ions into the urine and reabsorption of water and NaCl back into the blood (0.5 mark).This results in iso-osmotic urine compared to blood (300 mOS) (0.5 mark).In the collector duct, water reabsorption can vary depending on the system's water balance (0.5 mark).Therefore, urine osmolarity can also vary from 300 to 1200 mOS, being iso-osmotic or hyper-osmotic compared to blood (0.5 mark).

loop Signup and view all the answers

In the distal convoluted ______, active secretion of hydrogen and potassium ions into the urine and reabsorption of water and NaCl back into the blood (0.5 mark).This results in iso-osmotic urine compared to blood (300 mOS) (0.5 mark).In the collector duct, water reabsorption can vary depending on the system's water balance (0.5 mark).Therefore, urine osmolarity can also vary from 300 to 1200 mOS, being iso-osmotic or hyper-osmotic compared to blood (0.5 mark).

tubule Signup and view all the answers

In the collector ______, water reabsorption can vary depending on the system's water balance (0.5 mark).Therefore, urine osmolarity can also vary from 300 to 1200 mOS, being iso-osmotic or hyper-osmotic compared to blood (0.5 mark).

duct Signup and view all the answers

During the ascending limb of loop of Henle, ______ is reabsorbed without water movement, first through diffusion (thin portion), then through active transport (thick portion) (0.5 marks).This decreases urine osmolarity until it reaches around 100 mOsm, making the urine hypo-osmotic compared to blood (0.5 marks).

NaCl Signup and view all the answers

This decreases urine osmolarity until it reaches around 100 mOsm, making the urine hypo-osmotic compared to blood (0.5 marks).

water Signup and view all the answers

The smallest blood vessels of the body are about 5 to 10 micrometres in diameter and are called ______

capillaries Signup and view all the answers

Blood pressure is higher in arteries compared to ______

veins Signup and view all the answers

Cardiac output is the volume of blood pumped by the heart per unit of time, usually measured in ml per minute or litres per min. It is calculated as Cardiac Output (CO) = Heart Rate (HR) X Stroke Volume (SV). HR is the number of beats per unit of time, usually measured in beats per minute (bpm), while SV is Stroke Volume (SV) = End-Diastolic Volume (EDV) – End-Systolic Volume (ESV). EDV stands for End-Diastolic Volume, which is the volume of blood after left ventricle relaxation. The volume of blood ejected during the contraction of the left ventricle is ______

stroke Signup and view all the answers

Peripheral resistance is the resistance to blood flow resulting from friction of blood against the walls of the vessels, usually measured in mmHg. Cardiac output (CO) is calculated as Cardiac Output (CO) = Cardiac Output (CO) X ______ (PR)

peripheral Signup and view all the answers

In humans, blood pressure is measured in the ______

arteries Signup and view all the answers

The force of blood on the wall of the blood vessel is known as ______

blood pressure Signup and view all the answers

Humans have a circulatory system to transport O2, CO2, nutrients, water, wastes, heat, hormones, and defence cells through the ______

body Signup and view all the answers

The three basic components of the human cardiovascular system are circulatory fluid, blood vessels, and a muscular ______

pump Signup and view all the answers

The pulmonary circuit oxygenates the blood by sending it to the ______

lungs Signup and view all the answers

The main blood vessels of the pulmonary circuit are the artery and vein

pulmonary, pulmonary Signup and view all the answers

The systemic circuit brings nutrients and oxygen to the entire ______

body Signup and view all the answers

The right lung receives deoxygenated blood from the ______ pulmonary artery

right Signup and view all the answers

The left atrium pumps oxygenated blood to the ______

body Signup and view all the answers

The coronary circuit brings nutrients and oxygen to the ______

heart Signup and view all the answers

Gas exchange involves the movement of air or water through a specialized gas-exchange organ such as a lung or ______

gill Signup and view all the answers

The function of capillary beds in the pulmonary circuit is to bring blood for ______ exchange

gas Signup and view all the answers

The main blood vessels of the systemic circuit are the aorta and ______ cava

vena Signup and view all the answers

The left ventricle pumps oxygenated blood to the ______

body Signup and view all the answers

The main blood vessel that leaves the heart is the ______

Aorta Signup and view all the answers

The blood vessels responsible for supplying blood to the head are the R & L ______ arteries

Carotid Signup and view all the answers

The organ responsible for removing solid waste and some water is the large intestine (colon) which removes waste in the form of ______

feces Signup and view all the answers

The region shared by the digestive and respiratory system that connects the nasal cavity is the ______

pharynx Signup and view all the answers

The blood vessel that returns blood to the heart is the superior ______ cava

vena Signup and view all the answers

The main excretory organ in humans is the ______

kidney Signup and view all the answers

Aneurysm occurs when the connective tissue surrounding a blood vessel weakens and the smooth muscle bulges outwards. It can affect any part of the body, including the brain and heart. If this bulge bursts, it can be lethal; for example, an aneurysm in the brain can lead to a stroke. Arteries are more likely to be affected than ______.

veins Signup and view all the answers

In the Inferior limb (legs) circuit, the R & L Iliac arteries and veins are found in the hip, while the R & L Femoral arteries and veins are located in the ______.

leg Signup and view all the answers

The Renal (kidney) Circuit includes the R & L Renal artereis and veins. The R & L Renal artereis and veins are part of the circuit involving the ______.

kidney Signup and view all the answers

In the Major blood vessels, the Aorta is described as the start, the blood vessel that leaves the heart. The Inferior vena cava is mentioned as the common end, the return to the heart. The Systemic Circuit Main Blood Vessels in the Lower Body deal with deoxygenated blood from the Aorta and oxygenated blood from the ______.

arteries Signup and view all the answers

Common cardiovascular and blood diseases include a Stroke, a medical emergency that occurs when there is a ruptured blood vessel in the brain, or when blood supply to the brain has been blocked. Arteries and veins can be affected. There are two main types of strokes: Ischemic stroke due to lack of blood flow to the brain, and Hemorrhagic stroke due to rupture of a blood vessel that leads to bleeding in the brain. Ischemic stroke results from lack of blood flow to the brain, while Hemorrhagic stroke results from rupture of a blood vessel that causes bleeding in the brain. Both types of strokes can have severe consequences as they lead to cell death due to brain tissue being deprived of oxygen and nutrients. Hemorrhagic stroke is specifically due to the rupture of a blood vessel that causes bleeding in the brain, while Ischemic stroke results from a lack of blood flow to the brain. Common cardiovascular and blood diseases also include an Aneurysm, which occurs when the connective tissue surrounding a blood vessel weakens and the smooth muscle bulges outwards. Aneurysms can affect any part of the body, including the brain and heart. If an aneurysm bursts, it can be lethal, for example, an aneurysm in the brain can lead to a stroke. Arteries are more likely to be affected than ______.

veins Signup and view all the answers

The main purpose of sensors in the aorta and carotid arteries is to monitor O2 and CO2 concentrations in the blood. These sensors exert secondary control over breathing by sending signals to the breathing control center. These sensors are known as ______.

chemoreceptors Signup and view all the answers