BIO 189- Chapter 27: Circulatory & Respiratory Systems

What do red blood cells specialize in?

Carrying oxygen

Red blood cells are the only cells in the body that express what?

Cytosolic hemoglobin protein

What is cytosolic hemoglobin protein?

A protein that binds up to 4 O2 molecules

Where do red blood cells develop from?

Stem cells in bones

What are mature RBCs called?

Anucleate (no nucleus)

What are white blood cells?

Cells in the immune system that fight disease and foreign pathogens

What are the unique functions of white blood cells?

Provoke inflammation, stimulate fevers, destroy microbes, store information on past infections for future challenges

What are the three immune dysfunction diseases?

Leukemia, HIV, Autoimmune diseases

What does leukemia do?

Bone marrow cancers overproducing WBC

What does HIV do?

Targets and kills T cells which reduced ability to fight general infections

What do autoimmune diseases do?

Immune cells attack host cells as if they were foreign

What are platelets?

Circulating cell fragments released from mother cells that initiate blood clotting upon vessels being out

What happens wounded epithelial cells release damage signals?

It activates platelets and forms a temporary plug to quickly stop blood loss

What do activate clotting factors form?

Protein fibers

What do protein fibers do?

Trap more platelets and RBCs

What are passive circulatory systems?

Gases and wastes can diffuse directly across body surfaces

What are the two active circulatory systems?

Open and Closed

What is an open circulatory system?

Muscular hearts move body fluid from short vessels into open internal cavities where nutrients and waste exchange occur with tissues

What are examples of open system circulatory systems?

Spiders, insects, crustaceans, and many mollusks

What is a closed circulatory system?

Blood is moved with muscular heart and stays in vessels, exchanges occurs in extremely thin vessels

What are examples of closed circulatory system?

Fish, birds, reptiles, amphibians, squids and octopus

What are vertebrate hearts?

Muscular pumps with internal cavities/hollow chambers

What are the heart chamber names?

Atrium (atria) and Ventricle

What is an atrium?

Receives blood from the body

What are ventricles?

Pumps blood out of heart and to any part of the body

What are two chambered hearts and what does that mean?

1 atrium and 1 ventricle= low pressure

What are examples of two chambered hearts?

Animals with gills such as fishes and larval amphibians

What are single circuit circulatory systems?

A lower blood pressure system that requires less energy

What are four chambered hearts?

2 atria + 2 ventricles

What are examples of animals with four chambered hearts

Birds, crocodiles and mammals

What are the two double circuit circulation?

Pulmonary and Systemic

What is pulmonary circuit (low pressure)?

O2- poor blood returning from tissues pumped from heart to lungs for gas exchange and back to heart as O2-rich blood

What is systemic circuit (high pressure)?

O2-rich blood returns to heart then pumped out to body, delivers O2 to tissues before returning to heart as O2-poor blood

What does higher pressure circuit allow blood to do?

Perfuse to the tissues of the entire body

What is the order of the systemic vessel path?

Heart, artery, arterioles, capillaries, venules, veins, heart

Identify the appropriate level of bio-organizational hierarchy?

What are the types of tissue within the heart?

Connective (exterior pericardium), cardiac (myocardium), endothelium (endocardium)

What is the first step of the pathway of blood within the four chambers?

Blood enters right atrium from venous system (superior and inferior vena cava)

What is the second step of the pathway of blood within the four chambers?

Moves through valve into right ventricle when atria contract

What is the third step of the pathway of blood within the four chambers?

Then pumped through valve to lungs when ventricle contracts

What is the fourth step of the pathway of blood within the four chambers?

Blood returns to left atrium

What is the fiifth step of the pathway of blood within the four chambers?

Blood moves through valve into the left ventricle when atria contracts

What is the sixth step of the pathway of blood within the four chambers?

Then pumped through valve to the rest of the body (via aorta) when ventricle contracts

What controls the heartbeat rate?

The cardiac cycle

What is the cardiac cycle?

The typical events (electrical and muscular) during a single complete heartbeat

Why is cardiac muscle unique?

Self-excitable (myogenic); cells establish a beat and contract in unison without needing neuron signals

What is the sinoatrial (SA) node?

“The Pacemaker”, a region of specialized cardiac cells in the upper wall of the right atrium begins the heartbeat

What is the atrioventricular (AV) node?

“Electrical relay station” and conducts the electrical signal down throughout the ventricle walls

Where does the heartbeat sound come from?

Cardiac valves closing from pressure changes

What does the “lub” sound mean?

Atrioventricular valves closing as ventricles contract (high pressure)

What does the “dub” sound mean?

Pulmonary and aortic valves closing as ventricles relax

What is blood pressure?

The level of internal force placed on internal vessel walls by the blood during contractions

Where is blood pressure the highest?

Aorta and arteries near heart

Veins have a very thin layer of smooth muscle and?

Low blood pressure

Since blood pressure in veins is so low what will happen if they’re not filled with blood?

They’ll collapse

What do valves do?

Ensure no backflow in veins

What are the two blood pressure measurements?

Systolic and diastolic

What do the blood pressure measurements do?

Measure the force blood exerts on the vessel walls at distinct time points

What is systole pressure?

The highest pressure experienced during ventricular contraction

What is diastole pressure?

The point of lowest pressure seen during ventricular relaxation

What is blood pressure measured with?

Sphygmomanometer

What does the medulla do in regards to blood pressure?

Adjust both heart rate and the diameter of arterioles

What is vasoconstriction?

Narrowing of blood vessels by smooth muscle contractions in arteriole walls

What is vasodilation?

Widening of blood vessels when the smooth muscles relax and decreases pressure

What is external respiration?

Gases exchanged between environment and tissues

What are the three similarities all respiratory surfaces have?

Large surface area maximizes exchange efficiency

Contact with exchange medium (air or water)

Moist

What does the upper respiratory tract consist of?

Nose, mouth and pharynx

What does the lower respiratory tract consist of?

Trachea, bronchi, bronchioles, and alveoli

Where does gas exchange occur?

Alveoli

What are alveolus?

Tiny dead end air sac in the lungs

What does breathing require?

Internal pressure changes

How does air move?

Through pressure gradient; from high pressure to low pressure

O2 and CO2 diffuse in _____ directions

opposite

At alveoli, ___ O2 in alveoli air; ___ O2 in blood

high and low

At alveoli __ CO2 in blood and _ CO2 in air

High and Low

At tissues ___ O2 in blood and ___ O2 in tissues

high and low

At tissues ___ CO2 in tissues and ___ CO2 in blood

high and low

What is the main mechanism of O2 transport

Hemoglobin in red blood cells is the protein that binds to O2

What are the 3 CO2 mechanisms of transport

Some CO2 dissolves directly in plasma

Hemoglobin can bind very limited amount of CO2

Carbonic anhydrase enzymes in RBS convert most CO2 to bicarbonate ions

What triggers an increase in breathing rate?

Blood pH dropping (too acidic too much CO2)

What triggers a decrease in breathing rate?

Blood pH increasing (too basic too little CO2)

What is hyperventilation?

Extremely fast breathing, unloads too much carbon dioxide triggering respiratory alkalosis

What is hypoventiltion?

Breathing rate too slow, causes retention of CO2 in blood triggering acidosis