Cardiovascular sytem and blood

What is the heart?

a hollow, muscular organ the size of a fist

where is the heart located?

between the lungs

What is the apex?

the "tip" of the heart

where is the apex pointed?

towards the left hip

what is the outer covering of the heart called?

the pericardium

What is the space between the heart and pericardium called?

the cavity

What is the middle/thickest layer of the inside of the heart called?

myocardium

What is the function of the pericardium?

to protect and lubricate heart while it pumps

why is the myocardium the yhickest layer of the heart?

responsible for pumping the heart, made of muscle

What are the two loops that circulate blood back to the heart?

1. Pulmonary Circuit
2. Systemic Circuit

What does the pulmonary circuit do?

it carries blood to the lungs (picks up oxygen and drops carbon dioxide)

What does the systemic circuit do?

it carries blood to the body and back (drops off oxygen and picks up carbon dioxide)

what color is oxygenated blood?

red

what color is deoxygenated blood?

blue

what are the 4 chambers of the heart?

1. right and left atria
2. right and left ventricles

which two chambers contain oxygenated blood?

left atrium and left ventricle

which two chambers contain deoxygenated blood?

right atrium and right ventricle

what structure separates the two sides of the heart?

septum

what structures cover the atria?

auricles

what do the auricles do?

hold extra blood

what is the function of valves within the heart?

to stop blood flowing backwards

what are the 2 sets of valves?

1. atrioventricular valves (between atria and ventricles)
2. semilunar valves (between ventricles and major blood vessels.

what are the different atrioventricular valves?

1. tricuspid valves (between right atrium and right ventricle)
2. bicuspid valve (between left atrium and left ventricle)

what are the 2 different semilunar valves?

1. pulmonary valves (from pulmonary artery)
2. aortic valve (from the aorta)

what is the path of the deoxygenated blood in the body?

body tissues - vena cavae - right atrium - right ventricle - pulmonary artery - lungs

what is the path of the oxygenated blood in the body?

lungs - pulmonary veins - left atrium - left ventricle - aorta - body tissues

what is the intrinsic conduction system?

sets the basic rhythm of the beating heart by generating impulses which stimulate the heart to contract.

what is the path of the intrinsic conduction system?

SA node - AV node - AV bundle - bundle branches - Purkinje fibers

what is another name for the SA node?

the cardiac pacemaker

what is it called when the heart relaxes while beating?

diastole

what is it called when the heart contracts while beating?

systole

what happens during diastole?

- atrial contraction (ventricles fill)
- AV valves close causing lub sound

what happens during systole?

- ventricles contract
- semilunar valves close causing dub sound
- isovolumetric relaxation

what is cardiac output?

how much blood is pumped out by each ventricle

how do you calculate cardiac output?

heart rate x stroke volume

what is stroke volume?

the volume of blood being pumped out by a ventricle in a heartbeat.

what is stroke volume affected by?

rapid blood loss and exercise

what is heart rate?

number of times your heart beats in a minute

what is heart rate affected by?

stress, hormones, ion concentration and physical factors

what are the three different types of blood vessels?

arteries, veins and capillaries

what do arteries do?

- pump away from the heart
- carry oxygenated blood (except pulmonary)

what do veins do?

- carry blood to the heart
- carry deoxygenated blood (except for pulmonary)w

what do capillaries do?

location of gas exchange

describe the flow of blood from artery to a vein.

artery - aterioles - capillaries - venuoles - vein

why is it helpful for capillaries to only have one cell layer?

gas exchange is more effective

what are the layers of the artery?

thick layer of muscle, lumen (where the blood flows)

what are the layers of the vein?

thin layer of muscle, lumen (where the blood flows)

which type of blood vessel receives high pressure blood?

arteries

which type of blood vessel receives low pressure blood?

veins

how do veins maintain blood pressure?

1. muscular pumping - muscles contract, squeeze blood through veins
2. one way valves

how can capillary sphincters restrict blood flow?

sphincters can close off different parts and slow down blood flow.

what are the functions of blood?

1. transport oxygen waste and hormones/nutrients
2. regualte body temperature, pH and fluid volume
3. prevent infections and blood loss

what is blood?

it is connective tissue made of cells suspended in a fluid matrix

what are the suspended cells known as?

formed elements

what is the fluid matrix known as?

plasma

what is hematocrit?

percentage of red blood cells in blood

what is the pH range of blood?

7.35 to 7.45

how many litres of blood do you have in your body?

5-6 litres

what is the composition of blood?

90% water and 10% dissolved gases, salts, minerals, nutrients, enzymes, hormones, waste and proteins

what are the three basic types of proteins found in plasma?

1. albumin - regulates osmosis between blood and tissues
2. globins - transports substances and fights infections
3. fibrinogens - used in blood clotting

what regulates the composition of plasma?

homeostasis

what are erythrocytes?

red blood cells

what is the function of erythrocyte?

transporting oxygen around the body via hemoglobin molecules

what is the structure of a erythrocyte and how does it help its function?

- bioconcave shape allows for greater surface area
- round sides make for efficient flow through blood vessels.
- no nucleus & few organelles so they don't use up the oxygen while transporting it.

why must oxygen be carried by erythrocytes?

oxygen is non-polar so it can't diffuse into the blood.

what is hemoglobin?

a protein that is composed of 4 chains called globins

what does each globin contain?

a flat molecule called a hemew

what does a heme hold?

an iron atom, which can bind to one O2 molecule

how many O2 molecules can one hemoglobin hold?

four

what is a leukocyte?

white blood cell

what is the funciton of leukocytes?

to protect the body from pathogens

how is an erythrocyte different from a leukocyte?

- very numerous
- does not contain a nucleus
- can live 100-120 days
- confined to blood
- consistent concentration

how is a leukocyte different from an erythrocyte?

- less numerous
- has a nucleus
- can live for few days to years
- can pass out of blood vessels (diapedesis)
- concentration fluctuates

how are erythrocytes and leukocytes the same?

they are both formed elements

what is granulocyte?

they are a type of leukocyte that have low shaped nuclei and visible granuoles

what are some examples of granulocytes?

neutrophils, basophils, eosinophils

what are agranulocytes?

they are leukocytes that have spherical/kidney shaped nuclei and no visible granuoles

what are examples of agranulocyte?

lymphocyte and monocyte

neutrophils (function, shape, abundance)

- they engulf and destroy bacteria
- granuoles with lobe shaped nuclei
- most common leukocyte and more are produced during infection
- 41-75% out of white blood cells

eosinophils (function, shape, abundance)

- kill parasitic worms ingested in food
- lessen allergic reactions
- granuoles with two-lobed nuclei
- 1-5% out of white blood cells

basophils (function, shape, abundance)

- release histamines which dialate blood vessels so that other leukocytes can rush in to fight infection or allergen
-granuole
- 0-1% out of white blood cells

lymphocytes (location, shape, abundance, types)

- usually found in lymphnodes instead of blood stream
- two types T cells and B cells
- agranuoles with large spherical nuclei
- 20-45% out of white blood cells

monocytes (function, shape, abundance)

- leave blood, enter surrounding tissues, become macrophages
- agranuoles with kidney shaped nuclei
- 3-8% out of white blood cells

what is the mneumonic device for leukocytes?

Never Let Monkeys Eat Bananas
Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils

what are thrombocytes?

they are platelets

what are thrombocytes made of?

tiny fragments of other cells

what is the function of thrombocytes?

responsible for blood clotting

what is the stimulating factor for producing blood cells?

hormones

what is hemostasis?

when a blood vessel is injured, platelets begin the process of forming a blood clot

what are the steps of hemostasis?

1. blood vessels contract to reduce blood loss
2. platelets chemically attract to the wound and stick together
3. injured tissue releases tissue factor (cause production of thrombin)

what does thrombin and fibronogen create?

fibrin mesh

what is a thrombus?

an abnormal clot that forms within a blood vessel

what is a thrombus called if it dislodges and floats through the blood?

embolus

how does an abnormal clot affect the body?

restricts the blood flow and can cause stroke, heart attack and death

what is an antigen?

a protein, peptide or polysaccharide that the body recognizes as friend or foe.

what does the immune system produce in the presence of an antigen?

antibodies

what does an antibody do to the antigens?

antibodies bind to the antigen and they clump together

what is it called when antibodies clump together?

agglutination

type A antigen and antibody

A antigens with anti-B antibody

type B antigen and antibody

B antigens with anti-A antibody