Exam 2/ Resp, Heart , Blood 🩸

External respiration

Breathing air into the lungs to swap oxygen and carbon dioxide between the lungs and the blood.

Internal respiration

: Swapping oxygen and carbon dioxide between the blood and the rest of the body's tissues.

Conducting zone

: The tubes that move, clean, and warm the air (nose, throat, windpipe). No gas exchange happens here.

Respiratory zone

: The tiny air sacs where oxygen and carbon dioxide actually swap in and out of the blood.

What tissues line the main parts of the breath pathway?

Nasal cavity and Trachea (windpipe): Pseudostratified ciliated columnar tissue (lined with tiny hairs and mucus).

Larynx (voice box): Stratified squamous tissue on top (protects against wear and tear); ciliated tissue underneath.

Alveoli (air sacs): Simple squamous tissue (a single, ultra-thin flat layer so gases pass through easily).

How does the lining of the lungs protect you?

It makes sticky mucus to trap dirt and germs, and tiny hairs (cilia) sweep the dirty mucus up and out of your throat.

What is the epiglottis and what does it do?

It is a flexible flap made of elastic cartilage. It covers your windpipe when you swallow so food and drink go to your stomach, not your lungs

True vocal cords

: The bottom folds that vibrate to make sounds and speech.

False vocal cords

The top folds that do not make sound, but help seal your airway when you hold your breath or swallow.

Which side of the lungs gets blocked by swallowed objects more easily?

The right side (right main bronchus), because it is wider, shorter, and goes more straight down.

How many sections (lobes) does each lung have?

The right lung has 3 lobes, and the left lung has 2 lobes (to leave room for the heart).

What is the respiratory membrane?

The super-thin wall between the air sacs and the tiny blood vessels where oxygen and carbon dioxide trade places.

What is surfactant and what does it do?

It is a slippery fluid inside the air sacs (alveoli) that keeps them from collapsing when you breathe out.

What covers the outside of the lungs?

The pleural membranes (a double-layered protective lining with a tiny space of fluid in between)

Hypoxia

Low oxygen levels in your body tissues.

Anoxia

Zero oxygen in your body tissues.

Boyle’s Law

When space (volume) gets bigger, pressure drops. When space gets smaller, pressure goes up.

Dalton’s Law

The total pressure of mixed gases equals the sum of each gas's individual pressure

Henry’s Law

How easily a gas dissolves into a liquid depends on its pressure and how soluble it is.

Atmospheric pressure

The air pressure outside your body (760 mm Hg).

Positive pressure

Pressure higher than the air outside.

Negative pressure

Pressure lower than the air outside.

Intrapulmonary pressure

The pressure inside your air sacs (changes as you breathe, but balances out with outside air)

Intrapleural pressure

The pressure in the fluid space around your lungs. It is always negative (lower) to keep the lungs pulled open.

What happens if the pressure around the lungs becomes higher than the pressure inside them?

The lung loses its suction and collapses.

Pneumothorax

Air leaking into the space around the lung (often from a chest injury).

Atelectasis

: A collapsed lung (or collapsed part of a lung

How does the main breathing muscle (diaphragm) move?

When you breathe in, the diaphragm contracts and moves downward to flatten out.

Which muscles do you use to breathe in and out?

Normal breathing in: Diaphragm and rib muscles (external intercostals).

Forced breathing in: Neck and upper chest muscles.

Forced breathing out: Abdominal muscles and inner rib muscles (internal intercostals).

Is normal breathing out active or passive?

It is passive—your muscles simply relax, and the lungs naturally spring back into shap

Tidal Volume (TV)

Normal breath in and out (~500 mL

Inspiratory Reserve Volume (IRV

Extra air you can force in after a normal breath (~3,000 mL).

Expiratory Reserve Volume (ERV)

M Extra air you can force out after a normal breath (~1,100 mL).

Residual Volume (RV)

Air left trapped in lungs after breathing out as hard as you can (~1,200 mL).

Vital Capacity (VC)

The total amount of air you can control and move

Total Lung Capacity (TLC)

The total amount of air your lungs can physically hold (VC + RV)

What are the gas pressures (O2 and CO2) in different places?

Outside air: Oxygen is high (159 mm Hg), Carbon Dioxide is low (0.3 mm Hg).

Inside air sacs: Oxygen is 100 mm Hg, Carbon Dioxide is 40 mm Hg.

Deoxygenated blood (entering lungs): Oxygen is low (40 mm Hg), Carbon Dioxide is high (45 mm Hg).

Oxygenated blood (leaving lungs): Oxygen is high (100 mm Hg), Carbon Dioxide is low (40 mm Hg).

How does oxygen travel through the blood?

Almost all of it (~98.5%) hitches a ride on hemoglobin inside red blood cells.

How much oxygen does hemoglobin carry and drop off?

Each hemoglobin holds 4 oxygen molecules.

It usually drops off 1 oxygen molecule during normal resting activity.

It stays about 75% full (saturated) when it returns to the lungs.

How does carbon dioxide travel through the blood?

Most of it (~70%) gets converted into bicarbonate ions floating in the liquid part of blood (plasma), using a helper enzyme called carbonic anhydrase.

What does lung compliance mean?

High compliance: Lungs are stretchy and expand easily (healthy).

Low compliance: Lungs are stiff and hard to expand.

What controls your breathing rate?

The medulla (in the brainstem) sets the basic rhythm.

The pons (in the brainstem) smooths out the switch between breathing in and breathing out

What are hypercapnia and hypocapnia?

Hypercapnia: Too much carbon dioxide in the blood.

Hypocapnia: Too little carbon dioxide in the blood.

What is the main trigger that makes your body take a breath?

High levels of carbon dioxide (CO2) in your blood not low oxygen!

What type of tissue is blood?

Fluid connective tissue.

What are the main physical traits of blood?

pH: 7.35 to 7.45.

Volume: 5 to 6 liters in men, 4 to 5 liters in women.

Temperature: Slightly warm (about 100.4°F).

What are the three main jobs of blood?

Distribution: Carrying oxygen, food nutrients, waste, and hormones.

Regulation: Keeping body temperature, pH, and liquid levels balanced.

Protection: Stopping bleeding with clots and fighting off germs.

What is blood plasma made of?

About 92% water, 7% proteins, and 1% other tiny items like salts and nutrients.

What are the three formed elements and their main jobs?

Red blood cells: Carry oxygen.

White blood cells: Fight off germs and sickness.

Platelets: Help stop bleeding by forming clots.

What do red blood cells do and what is missing inside them?

They carry oxygen throughout the body using hemoglobin. They do not have a nucleus.

What is the name for making new red blood cells?

Erythropoiesis.

What happens to dying red blood cells?

They live about 120 days and get broken down by cleanup cells in the spleen and liver.

What is erythropoiesis and what triggers it?

It is the making of new red blood cells in your bone marrow. It is triggered by a hormone called EPO from the kidneys.

What is anemia and what are some red blood cell problems?

Anemia: Low oxygen in the blood.

Causes: Blood loss, destroyed cells, low iron, or lack of vitamin B12.

Sickle cell: A gene issue that makes red blood cells bend into a crescent shape when oxygen is low.

Polycythemia: Too many red blood cells, making the blood extra thick.

Neutrophils( most common)

Eat and destroy bacteria.

Eosinophils

Attack parasite worms and control allergies.

Basophils( least common)

Release histamine to swell blood vessels and heparin to thin blood

Lymphocytes

Make antibodies (B cells) and fight viruses (T cells).

Monocytes

Turn into large cleanup cells in body tissues.

What do platelets do?

They are small cell pieces that stick together to plug up broken blood vessels.

What are the three steps to stop bleeding?

1. Vascular spasm (the blood vessel squeezes tight).

2. Platelet plug (platelets stick to the hole).

3. Coagulation (a solid mesh clot forms).

What is fibrinolysis?

The body's process of dissolving a clot after the wound heals.

What does thrombin do?

It is a helper enzyme that turns liquid blood proteins into a solid thread mesh to build a clot.

Thrombus

A blood clot stuck inside an unbroken vessel.

Embolus

A blood clot that breaks free and floats down the bloodstream.

Can the liver affect bleeding problems?

Yes. The liver makes most of the proteins needed to clot blood, so liver damage leads to easy bleeding.

What are the blood groups, their antibodies, and universal types?

Type A: Has A markers, anti-B antibodies.

Type B: Has B markers, anti-A antibodies.

Type AB: Has both A and B markers, no antibodies. Can receive any blood type (Universal Recipient).

Type O: Has no markers, both anti-A and anti-B antibodies. Can be given to anyone (Universal Donor).

What is Rh and how do you become Rh positive or negative?

Rh is an extra protein marker on red blood cells. You are Rh positive if you have it, and Rh negative if you do not.

What happens if an Rh-negative mother has an Rh-positive baby?

Her body can build defenses against the baby's blood, which can harm future Rh-positive babies during pregnancy unless treated.

What is leukemia in simple terms?

Bone marrow cancer that makes huge amounts of broken, useless white blood cells that crowd out healthy cells.

What is the protective bag around the heart?

The pericardium (a double-layered membrane with fluid inside to reduce friction).

What are the chambers and valves of the heart?

Chambers: Two top receiving rooms (Right and Left Atria) and two bottom pumping rooms (Right and Left Ventricles).

AV Valves: Tricuspid valve (right side) and Bicuspid/Mitral valve (left side).

SL Valves: Pulmonary valve (leads to lungs) and Aortic valve (leads to body).

Which side of the heart pumps to the lungs vs the body?

Right side: Pumps blood to the lungs (pulmonary route).

Left side: Pumps blood to the rest of the body (systemic route).

Angina Sectors

Temporary chest pain from short-term low blood flow to heart muscle.

Myocardial infarction (heart attack)

Long-term blockage that causes heart muscle cells to die.

What do heart valves do?

They force blood to flow in only one direction and stop it from flowing backward.

What are abnormal heart sounds called and what causes them?

Heart murmurs, caused by leaky or tight valves that make blood swirl around roughly.

What makes normal heart sounds?

The closing of the heart valves (the "lub-dub" sounds).

How is heart muscle different from regular muscle and what is its rest period?

Differences: Heart muscle cells are connected together so they squeeze all at once automatically.

Rest period: Heart muscle stays resting longer between squeezes so it cannot cramp up and has time to fill with blood.

What is the natural pacemaker of the heart and can it beat without nerves?

The SA node. Yes, the heart can beat on its own without outside nerves because it creates its own electrical signals.

How do body signals speed up or slow down the heart?

Sympathetic signals: Speed up the heart rate and make it pump harder.

Parasympathetic signals: Slow down the heart rate.

Fibrillation

Fast, chaotic, out-of-control heart twitching.

Arrhythmia

Any unnatural or irregular heart rhythm.

Ectopic focus

An odd spot in the heart that tries to act like the pacemaker.

Bradycardia

A heart rate that is too slow (under 60 beats a minute).

Tachycardia

A heart rate that is too fast (over 100 beats a minute)

What is cardiac output and how do you calculate it?

It is the total blood pumped by the heart in one minute.

Calculation: Heart Rate x Stroke Volume

What makes up stroke volume?

Stroke volume is the amount of blood pushed out in one squeeze. It depends on how full the heart gets before squeezing and how much blood is left after squeezing.

What is the Frank-Starling law of the heart?

The more blood fills and stretches the heart muscle before a beat, the harder the heart squeezes back.

What are preload and afterload?

Preload: How much the heart stretches as it fills with blood before squeezing.

Afterload: The blood pressure in the main arteries that the heart has to push against to open the valves.

What are some body issues that affect the heart?

Having too much or too little calcium or potassium in the blood, clogged heart arteries, and heart failure.

Harry, a swimmer with the fastest time on the Springfield College swim team, routinely hyperventilates before a meet, as he says, “to get more oxygen into my lungs so I can swim longer without having to breathe.”  First of all, what basic fact about oxygen loading has Harry forgotten?   Is oxygen the most powerful respiratory stimulant?  

Second, how is Harry jeopardizing his life?

Harry is wrong because his red blood cells are already 98% full of oxygen.

Oxygen isn't the main trigger to breathe—carbon dioxide is.

By hyperventilating, Harry blows off too much CO 2While underwater, his oxygen drops dangerously low, but because his CO2 is too low to trigger the urge to breathe, he can pass out underwater without warning (shallow water blackout) and drown.