ANHS308 Ex. Phys. Chapter 3 Resp. System O2 from AIr to Blood

The higher the elevation the

lower pressure of O2

low O2 pressure can lead to

fatigue and lethargy, nausea, fluid in brain and lungs, fatal conditions.

External respiration

exchange of oxygen and carbon dioxide between air and blood.

Ventilation

moving air in and out of the lungs (breathing)

Total Lung Capacity

the maximum volume of air the lungs can hold after maximal inhalation, at rest in 5 L

Tidal Volume

the volume of air inhaled or exhaled during a normal, resting breath, 0.5 L at rest

Minute Ventilation

the total volume of air moved in or out of the lungs per minute

Minute Ventilation Equation

Ve=TvxRR

True or False: The internal intercostals assist inhalation during heavy exercise.

False during exhaling

Identify the mechanism of breathing of each; inspiration vs expiration.

Inspiration:

the diaphragm contracts and the intercostals contract, rib cage pulls down, during heavy breathing the sternocleidomastoid, scalene, pectoralis minor assist. The thoracic cavity volume increases and lung pressure decreases to move air into the lungs.

Expiration:

When at rest the diaphragm relaxes, the external intercostals relax, and the thoracic volume decreases. Pressure inside the lungs increases and pushes the air out. During exercise the internal intercostals contract to pull ribs down and in, abdominal muscles contract pushing diaphragm up, which forces air out quickly.

Gas moves from areas of ______ concentration to ______ concentration.

high to low

At sea level, PO₂ ≈ ______ mmHg.

159

Tidal volume = 0.8 L, Respiratory rate = 20 breaths/min. What is VE?

16 L/min

What Statement is correct about oxygen in the blood?

a.        exists in solution as a dissolved gas

b.       is bound to hemoglobin as oxyhemoglobin

c.        is in the form of carboxyhemoglobin

d.       is in the form of deoxyhemoglobin

B

True or False: The respiratory control center is located within the Carotid Bodies.

False it is located in the medulla oblongata and the pons

What is the response to the central chemoreceptors that control breathing?

Respond to an increase in PCO2 and a decrease in pH. Your body responds by breathing quicker, so that you can get rid of that CO2, so your blood does not become acidic.

Identify the oxyhemoglobin curve. What does it represent/express when the curve shifts?

When the curve shifts to the right it means that hemoglobin has a lower affinity for oxygen, so it releases O2 into the tissue. Tissues get more oxygen during exercise. CO2, H+, and temperature increase. Affinity and pH decrease.

When the curve shifts to the left it means that hemoglobin has a higher affinity for oxygen, so it holds onto the O2. It is caused by lower CO2, H+, and temperature. pH and affinity are increased.

During exercise, the oxyhemoglobin curve shifts to the right because:

1. pH decreases

2. Temperature increases

3. CO2 increases

4. H+ increases

5. affinity increases

Define the following term: Diffusion. What effects Diffusion rate?

Diffusion: movement of molecules or ions from an area of high to low concentration

Answer:

pressure gradient, surface area, distance/thickness of membrane

Identify exercise-induced hypoxemia in elite endurance athletes.

They have such high pulmonary blood flow rates during maximal exercise that their transit time becomes so fast that the blood cannot saturate with oxygen. In simpler terms the blood moves to fast through the body so the body cannot get enough oxygen into the blood.

What’s the difference between steady state and homeostasis?

Steady state: the body’s ability to adapt after homeostasis, ex. Heart rate increases during running and then hits that constant rate

 

Homeostasis: it is a system that requires energy to maintain an steady internal environment

Explain each concept feedback system. Identify an example of each feedback system seen in the human body.

Positive Feedback: continues the stimulus for a positive outcome/restore balance

Childbirth and breast feeding.

Negative Feedback: counters the stimulus to restore balance

Body temperature regulation

Air passes in and out of the lungs through

conducting passages

the respiratory tract ends at the

alveoli

Trachea divides into

two bronchi and further down into bronchioles

Air inhaled is

warmed from body heat and humidified

Inspired air is

filtered by mucus and cilia

upper respiratory tract consists of

mouth, nasal cavity, pharynx, larynx

lower respiratory tract consists of

conducting passages from the trachea and below

Lobes of the right lung

upper, middle, and lower

Lobes of left lung

upper and lower

Pleural membrane in to out consists of

Visceral membrane, intrapleural space, parietal pleura

what is the visceral membrane

pleural membrane surrounding each lung

what is the intrapleural space

keeps lungs and thoracic wall from touching

Parietal pleura

covers inside of thoracic wall

Where are O2 and CO2 exchanged between air and blood

alveoli

the gases have to cross the

blood-gas barrier

The blood gas barrier is

extremely thin, short diffusion distance in healthy lungs allows for easy and fast gas exchange

capillaries surround

80-90% of alveoli

Boyle’s Law of gases

air pressure changes as lung volume changes

negative pressure

inhalation, air rushes into the lungs

positive pressure

exhalation, air rushes out

Inspiratory reserve volume (IRV)

air inspired beyond resting tidal volume

expiratory reserve volume (ERV)

air expired beyond tidal exhalation

Vital Capacity equation

Vc=Vt + IRV + ERV

Respiratory Rate

number of breaths taken per minute

Alveolar ventilation rate (VA)

affects only air that reaches the alveoli not the anatomical dead space

Ventilation-Perfusion (V/Q)

ratio of these two rates: efficacy of blood oxygenation

Speed is dependent on

pressure

Transit time

time it takes a red blood cell to travel the distance of the capillary

during vigorous exercise

pulmonary blood flow increases, decreasing transit time

Bohr Effect

What happens when there is a curve between oxygen-hemoglobin dissociation

most CO2 in red blood cells is converted

into bicarbonate

Central Chemoreceptors

monitor Po2 and H concentration in cerebrospinal fluid

peripheral chemoreceptors

monitor changes in arterial blood

During vigorous exercise, additional mechanisms are required to raise ventilation

neural input from motor cortex, feedback from exercising muscles, control of carbon dioxide flow to lungs