Circulatory System

electrocardiogram

(ECG) procedure of hooking up skin electrodes to your skin in order to record the electrical activities of the heart.

Sympathetic Nervous System categorized by and are triggered when? what does it do to the heart rate?

(fight or flight) under the autonomic nervous system and is triggered under stressful situations which involve cardiovascular muscle. This is where the brain tells the heart to increase its heart rate.

intercalated disc

An intercalated disc is an undulating double membrane separating adjacent cells in cardiac muscle fibers. Intercalated discs support synchronized contraction of cardiac tissue. They can easily be visualized by a longitudinal section of the tissue. Three types of membrane junctions exist within an intercalated discs -- two of which are desmosomes and gap junctions.

Fig 3.9, g

Aortic semilunar valve is between the left ventricle and the aorta

Pulmonary Valve

Between the right ventricle and the pulmonary trunk

Fig 3.9, d

Bicuspid valve between the left atrium and the left ventricle

Give the types and rout of the pathway from the heart in the vessels and back to the heart.

Blood goes from the heart to the arteries (strong and elastic vessels that always take blood from the heart) into the arterioles, then the capillaries, then the venules, then the veins

Cardiac muscle

Cardiac muscle is a type of involuntary striated muscle found in the walls of the heart. Cardiac muscle shares similarities with skeletal muscle with regard to its striated appearance and contraction, with both differing significantly from smooth muscle cells. These cells are also excitable and contain the actin (muscle fiber), myosin (thicker muscle filaments), and tropomyosin (bound to actin) used in skeletal muslces.

Describe the Systemic Circuit

It is the longer traveling of the two circuits which provides nutrients from the blood to the body as the heart pumps. It delivers oxygenated blood from the heart (pumped from the left atrium into the aorta) to the body and then allows for the diffusion of nutrients through the capillaries, then brings back the deoxygenated blood through the veins into the right atrium via the superior vena cava (from structures above the diaphragm) and inferior vena cava (from structures below the diaphragm).

Describe the Pulmonary Circuit

It is the shorter traveling of the two circuits which sends deoxygenated blood from the heart to the lungs in order to be replenished. The blood is pumped from the right ventricle through the pulmonary trunk to the lungs where they are replenished with oxygen via diffusion and then are sent back to the left atrium via the pulmonary veins.

Fig 3.9, b

Pulmonary Veins which bring back oxygenated blood from the lungs to the left atrium

What is the blood composed of? give a brief description of each component.

Red blood cells (carry the nutrients such as O2 and CO2); White blood cells (immune cells; platelets (help with clotting); all suspended in a plasma fluid that contains water and proteins

Parasympathetic Nervous System categorized by and is triggered when? what does it do to the heart rate?

Relaxed state of muscles under the autonomic nervous system and is the state where metabolism still occurs and cleaning of you body. This is where the brain tells the heart to slow its heart rate

Give the areas stimulated in a heart contraction and in order of firing and their location

Sinatoatrial Node (SA) located in the right atrium, Atrioventricular node (AV) located on the interatrial septum, then down the bundle of His located on the interventricular septum, then the bundle of branches, purkinje fibers located on the ventricular walls.

Compare and Contrast the Arteries and the Veins

The Arteries are strong elastic vessels that carry blood away from the heart and branch into smaller arterioles. The Veins carry blood back to the heart and have thinner walls than arteries but they are much more elastic and developed from smaller branches called venules. The veins also hold the majority of the blood at one time and have a lower pressure so they use valves to stop blood from flowing backwards. Veins are also surrounded partly by skeletal muscles, unlike arteries which are surrounded by smooth muscles.

Fig 3.10, 1

The P wave represents the depolarization of the SA node in the right atria that leads to their contratction. The reason why it is smaller than the QRS is b/c the muscle mass that is contracting is less. The P wave represents the lub sound in the heart beat or the ventricle diastole.

Fig 3.10, 2

The QRS complex represents the dub sound in the heart beat or the ventricular systole. This represents the ventricles contracting from the AV node depolarizing. The complex is so large because there is a large muscle mass contracting in order to pump the blood throughout the body.

Fig 3.10, 3

The T wave represents the ventricular repolarization and has no sound with it because all it represents is everything in the heart returning back to normal

Ventricle Diastole

The first part of a heart beat and the more quite one. In this state, the ventricles are relaxed as the blood is poring in from the contracting atriums, therefore the bicuspid and the tricuspid valves are open. The pulmonary valve and aortic valve are open. Following is the Ventricular Systole.

Ventricle Systole

The second part of a heart beat which is the more loud one. In this state, the atriums relaxes and fill with blood and the ventricles contract, leading to the closing of the bicuspid and the tricuspid valve and the opening of the pulmonary valve and the aortic valve which allows the passage of blood into the aorta and the pulmonary trunk.

What are the two important circuits of the Cardiovascular System?

The two are the pulmonary circuit (lungs and heart) and the systemic circuit (heart to the body).

What is special about the connection between the Sinoatrial node (SA) and the atrioventricular node (AV). How do they relate to Ventricular Systole and Diastole?

They are not connected. They are in close proximity so that when the SA nod is triggered, eventually it reaches the AV node to induce an action potential. There are no gap junction to link the SA and AV node like how there are between the AV and the rest of the areas that conduct electrical signals. Because of the separation, the SA node is in charge of inducing the Ventricular Diastole and the AV node is in charge of the Ventricular Systole.

Fig 3.9, J

Tricuspid valve which is between the right atrium and the right ventricle.

erythrocytes

another name for red blood cells. they transport the nutrients and contain a lot of hemoglobin (Iron metal protein in the form of heme) to do so. They have a biconcave disc shape that increases surface area to aid in the diffusion of O2 and CO2. They also contain polysaccharides on their membrane (act as a marker) and are produced in the bone marrow (blood cells formation depend on folic acid (B9) and B12). Important: red blood cells do not contain mitochondria or nucleuses so they do not use oxygen, only carry it. Every blood cell lasts about 120 days and is then trashed in the spleen.

Fig 3.9, f

aorta is the largest vessel in the body that delivers oxygenated blood to the body from the left ventricle

Fig 3.11, b

areriole

what vessels usually take oxygenated blood away from the heart

arteries

Fig 3.11, a

artery

What animals have an open circulatory system?

arthropods

Bicuspid valve

between the left atrium and the left ventricle

Aortic valve

between the left ventricle and the aorta

Tricuspid valve

between the right atrium and the right ventricle

pulmonary veins

bring back oxygenated blood from lungs to left atrium

superior vena cava

brings deoxygenated blood from all structures above the diaphragm

inferior vena cava

brings deoxygenated blood from all structures below diaphragm

Fig 3.11, c

capillaries

Tunica externa

composed of connective tissue with elastic and collagen fibers. This forms the outside of the vessels that helps protect them and provides elasticity

Blood plasma

composed primarily of water (90%), mineral, electrolytes, and contains proteins that exert osmotic pressure. The three major proteins are albumins, globulins, fibrinogens.

Aorta

delivers oxygenated blood from the left ventricle to the body (the biggest blood vessel in the body)

Fig 3.9, 1

deoxygenated blood

What do gap junctions do? What are they made of?

facilitate the exchange of compounds between the cells (small molecules) to help organs to work together. They have gates that open and close where half is found in either side of the cell. They are made of connexon (each is made of 6 connexon). They also allow cations to go from one cell to the next to propagate an electrical signal

albuins

found in the blood plasma that serve as transport proteins

fibrinogen

found in the blood plasma that serve in the clotting function

globulins

found in the blood plasma that serve the immune function as antibodies

In what cells would desmosomes most likely be found?

in skin and muscle

Cardiovascular system

it is a closed system (so blood is always found inside of the vessels, not soaking tissue) that consists of the heart, blood vessels, and the blood. The heart pumps the blood and the vessels proved the pathway for the blood

Fig 3.9, c

left atrium which pumps blood into the left ventricle

Fig 3.9, e

left ventricle delivers oxygenated blood to the aorta

Fig 3.11, i

lumen

Tunica interna

made of simple squamous epithelium (endothelium) that provide a smooth surface for blood to pass through (minimize friction)

Tunica media

made of smooth muscles that help mediate vasoconstriction (constriction) and vasodialation (relaxation). Controls the diameter of the vessel.

In what cells would gap junctions most likely be found?

organs where cells need to work together such as the heart or brain (electrical activity)

Fig 3.9, 2

oxygenated blood

what do desmosomes do?

provide anchorage between cells to prevent them from being pulled apart

Fig 3.9, L

pulmonary semilunar valve which is between the right ventricle and the pulmonary trunk

Fig 3.9, K

pulmonary trunk that takes blood from the right ventricle to the lungs

Fig 3.9, h

right atrium which receives the blood from the superior vena cava (above the diaphragm); inferior vena cava (below the diaphragm); and the coronary sinus (small blood vessels that bring blood from the heart). it delivers the blood to the right ventricle

Fig 3.9, I

right ventricle gets blood from the right atrium and delivers it to the pulmonary trunk

how does the heart contract? (general)

specialized cells called pacemaker cells that generate their own electrical activities

Fig 3.9, a

superior vena cava (above the diaphragm); inferior vena cava (below the diaphragm); and the coronary sinus (small blood vessels that bring blood from the heart)

pulmonary trunk

takes deoxygenated blood from the right ventricle to the lungs

capillaries

the blood vessels with the smallest diameter that are only made of endothelial layer of cells to aid in diffusion of nutrients through the slits in between the cells. The capilaries are the site of exchange of nutrients, providing glucose and O2 and obtaining CO2 from the cells. They are the most abundant vessels yet only contain 5% of all the blood at a give time b/c blood cells slow down and travel in a single file fashion (facilitates the diffusion).

What is the relationship between the heart and the brain?

the heart initiates its own electrical activity; the brain does not initiate contractions, only regulates the rate of contractions.

What connects the lymphatic system and the blood vessels in the circulatory system?

the superior vena cava

Fig 3.11, f

tunica externa

Fig 3.11, h

tunica intima

Fig 3.11, g

tunica media

Fig 3.11, J

valve in the veins

Fig 3.11, e

veins

what vessels usually take deoxygenated blood to the heart

veins

Fig 3.11, d

venule

When do the bicuspid and the tricuspid valves close?

when the ventricles contract