The circulatory system is a/an (blank) transport system

internal

An internal transport system (the circulatory system) assists diffusion because it ensures what?

No substance has to diffuse very far to enter or leave a cell

What is the name of the sac that encloses the human heart? What is it's function?

The pericardium

Restricts heart movement: no bouncing in thoracic cavity

Prevents heard from overfilling

The pericardium has 2 layers which contain a small amount of fluid. What does this do?

Lubricates surfaces and prevents inflammation

The human heart is formed by 4 chambers:

2 Atria

2 Ventricles

What distinguishes the Atria, and what are their function?

Collection chambers for blood returning to heart

They are much thinner than ventricles

only pump short distances to the ventricles

What distinguishes the ventricles, and what is their function?

Pump blood around great distances

Left pumps to entire body (is thicker)

Right pumps to the lungs

Both are much thicker than atria

What are the heart valves made from, and what are the two main types?

Connective tissue

2 Atrioventricular

2 Semilunar Valves

Where are the atrioventricular valves?

Between atria and ventricles

Mitral valve- left side

Tricuspid valve- right side

Where are the semilunar valves?

In the arteries leaving the heart

Aortic valve- left side (BODY)

Pulmonary valve- right side (LUNGS)

Blood draining from the body goes through which part(s) of the circulatory system? Where does it flow next?

Superior Vena Cava (Head/arms)

Inferior Vena Cava (lower trunk/legs)

Both lead into the right atrium

Blood that has been pumped out of the right ventricle goes through which "tube" to which organ?

The pulmonary artery carries this blood to the lungs

Oxygenated blood comes out of the lungs and goes through which "tube" to which organ?

Pulmonary vein to the left atrium, and then pumped into the right ventricle (which goes back to through the body again)

Coronary arteries and veins do what?

Coronary arteries deliver nutrient rich blood to the heart, and coronary veins remove waste

The repeated contraction and relaxation of pumping blood is called the what?

Cardiac cycle

The cardiac cycle consists of which two main phases? Describe each one.

Diastole: heart is relaxed and blood flows into all 4 chambers. AV valves (between atria and ventricles) open (0.4) sec

Systole:

a) Atria briefly contract to fill ventricles with blood (0.1s)

b) Ventricles contract and pump out blood

Av valves close and semilunar vales open

What is the difference between the SA node and the AV node?

SA node: is the pacemaker which generates electrical signals in atria, setting rate of heart contractions

AV node: Relays the signals to the ventricles and this causes ventricles to contract

Arteries and veins are made of which 3 layers of tissue?

Endothelium- lined by a single layer of epithelial cells

Smooth muscle- regulates blood flow by constriction

Connective tissue- elastic and allows stretching

Veins have valves to prevent backflow

Capillaries are what? What do they form?

Microscopic blood vessels that form an intricate network among cells in tissues

Formed by thin walls which are formed by a single layer of epithelial cells

How do capillaries help the body?

They increase surface area for gas and fluid exchange with the interstitial fluid

Specialized for chemical exchange

What is the difference between systolic and diastolic blood pressure?

Systolic: caused by contraction of ventricles

Diastolic: low pressure between contraction

How is the distribution of blood to parts of the body controlled?

How many capillaries open at once?

5-10% of capillaries are open at once

Blood flow through capillaries is controlled by:

1) Contraction and relaxation of smooth muscle layer

-Under influence of hormones and nerves

2) Opening and closing of precapillary sphincters

(tiny "caps" that squeeze the capillaries shut or loosen to open)

Cholesterol does what in animal cell's membrane?

Controls the fluidity

What is the 'good' cholesterol, and what is the 'bad' cholesterol?

'good' is called HDL (high density lipoprotein)

'bad' is called LDL (low density lipoprotein)

Atherosclerosis is what?

What is the result of complications?

Fatty deposits that develop in the inner wall of arteries, narrowing the passage to which blood can flow

Plaques might rupture and form blood clots

How does a myocardial infraction occur?

When a coronary artery feeding the heart is blocked

Hypertension is what? What does it cause?

When blood pressure is constantly above 140/90

Causes

-heart has to work harder, which causes it to weaken over time

-tiny ruptures in vessels, which leads to increased plaque formation

-increased risk of blood clot formation

What is the only liquid tissue?

Blood

What does plasma consist of?

water, plasma proteins, ions, other substances; maintains osmotic balance

Where does the cellular component of blood originate? What makes these cells different?

hematopoietic stem cells in red bone marrow

(stem cells)

they are unspecialized

What are the functions and features of red blood cells?

Transport O2 and CO2

(In mammals) they lack nuclei, meaning no repair, no ATP generation

due to lack of nuclei they are "bioconcave disk" shaped:

-increased surface area to volume ratio

-flexible passage shape for narrow passages

How do red blood cells carry oxygen?

They contain the protein hemoglobin:

The hemoglobin molecule can carry 4 oxygen molecules from the lungs to tissue cells

has 4 heme pigments attached to 4 polypeptide chains, each can hold one molecule of O2

What ion does the heme pigment contain that holds oxygen?

Fe2+, can combine reversibly with oxygen

Red blood cell production is regulated by what kind of feedback loop that does what?

Negative feedback loop: senses O2 levels reaching tissues

When tissues lack O2 what hormone is released, and what does it do?

Eythropoietin, it is released by kidneys to stimulate bone marrow to produce more RBC's

What do Leukocytes do?

White blood cells, they function in defense and immunity

-fight infections and cancer; function in and out of circulatory system

What are the 5 types of leukocytes?

Monocytes, Eosinophils, Basophils, Lymphocytes, Neutrophils

What does changes in numbers of circulating WBC's indicate?

Infection, leukemia, chemotherapy, parasites, or allergic reaction

What are platelets, what is their lifespan?

Circulating cell fragments which form a temporary plug at the site of injury

Lifespan- 5-9 days

When you get a cut, what are the three phases that occur to stop the bleeding?

1) platelets rapidly adhere to the exposed tissue and release chemicals that make nearby platelets sticky

2) Platelets aggregate and form a sticky plug

3) Blood clotting occurs through coagulation, the formation of a threadlike protein called fibrinogin which reinforces the plug

Describe fibinogen and its processes

Fibrinogen becomes fibrin, this traps platelets and WBCs, and reinforces the clot

Stops any leaks until connective tissue forms a permanent patch

What are antibodies?

Proteins which recognize and bind to a specific antigen

What is the antigen-binding site?

What is special about its shape?

a region of the molecule responsible for the antibody's recognition and binding function

Tip of each arm has a variable region

(only specific amino acids codes can interact)

What is the antigenic determinant?

Region of the antigen that binds to the antigen binding site of the antibody (have complementary shapes)

-One same antigen can have many antigenic determinants

Which blood types contain which antigens?

Differentiate antibody and antigen

Antigens: found on molecules (from allergens to blood) and have specifically shaped attachment points

Antibodies: fit the attachment points on the antigens, have two arms that can attach

People who are RH+ have what antigen on the surface of their RBC's?

Have the D antigen (normal plasma does NOT contain this)

What happens if an RH- person receives blood from and RH+ person?

anti-RH antibodies will be formed: this is okay on the first transfusion, but any follow ups will be dangerous

What is the main processing center of the excretory system?

The 2 kidneys

What is the overall process of excretion?

Urine from kidneys moves into the urinary bladder for storage via the ureter duct, and is expelled by the urethra

Describe the 3 steps of filtration

1) Filtration: pressure of blood in renal artery forces water and small molecules into excretory organ= filtrate

2) a) Reabsoption of water and valuable solute (varies by need of organism)

b) secretion of unneeded or toxic substances from blood capillaries to collecting tubules

3) Excretion of urine

What are nephrons?

Single folded tubule and associated blood vessels, extending from the renal cortext into the renal medula

Preform the kidney's functions in miniature

Reabsorption reclaims which things and how?

water, glucose, ammino acids, salt etc through active transport, diffusion, and osmosis

High (blank) in interstitual fluid in medulla promotes (blank) by (blank)

NaCl

Water reabsoption

Osmosis

How is blood pH maintained by kidneys?

Secretion of excess H+ into tubules and reabsoption of HCO3- maintains blood pH

Capillaries leaving nephron converge into (blank) leading to (blank) vein

venule

renal vein

What controls urination?

Sphincter muscles near junction of urethra