Cardio, Lymphatic, Defence/immunity Flashcards
What is cardiac output?
The amount of blood pumped out by each ventricle in 1 minute (measured as volume/minute)
It is the product of heart rate and stroke volume
What is heart rate?
The number of times the heart beats (contracts in a minute (measured as beats per minute)
What is stroke volume?
The volume of blood pumped out by one ventricle with each beat (Volume per beat).
What is the sinoatrial node? Where is it located and what does it do?
It is a pacemaker cell located in the superior right atrium and it generates impulses and sets the heart rate
Impulses spread from the sinoatrial (SA) node to the ____________ node, located in the inferior interatrial septum.
Atrioventricular
Impulses pause at the _____________ node to allow the atria to finish contracting before ________ start contraction
Atrioventricular (AV)
Ventricles
The perkinje fibres do what?
Depolarise the contractile cells of both ventricles
The mechanism that facilitates venous return is intrinsic (true or false?)
False, the mechanism is extrinsic because the pressure is generally too low to promote blood flow back to the heart.
Which extrinsic mechanisms exist to facilitate venous return?
- Respiratory pump (inhalation) - abdominal pressure squeezes vessels
- Muscular pump: skeletal muscle milks the blood vessels squeezing the blood back toward heart
- Sympathetic activity: causes contracting of lumen smooth muscle (vasoconstriction) pushing blood towards the heart
What are the functions of lymph nodes?
Filter lymph: macrophages remove and destroy microorganisms and other tissue debris
Activate the immune system: location where lymphocytes encounter antigens and activate to attack them
What is innate (non-specific) immunity?
- involves defences against any pathogen regardless of species
- refers to defences that are present at birth
- it is always present but there is no ‘memory’ component
What is adaptive (acquired) specific immunity?
It is based on a response to a specific microbe
It is slow to respond but contained a memory component
Involves B- cells (Antibody mediated immunity - AMI)
And T- cells (Cell mediated immunity - CMI)
It is acquired via vaccine or breast milk
What are some first line (non-specific) defence mechanisms?
- intact skin
- mucous membranes and their secretions
- normal microbiota
What are some second line (non-specific) defences?
- natural killer cells and phagocytic white blood cells
- inflammation
- fever
- antimicrobial substances (complement proteins an interferons)
What are the characteristics and signs of inflammation?
- Redness
- Pain
- Heat
- Swelling
(5. Sometimes loss of function depending on site and extent of damage)
What are the four main components of the lymphatic system?
Lymph vessels
Lymph fluid
Lymph nodes
Lymph organs/tissues
What are antigens?
Substances that the body recognises as foreign and mounts an immune response to. Most are proteins or polysaccharide molecules.
Blood enters the right atrium via the ________ and _________ vena cava
Superior, Inferior
Blood then moves through the ________ valve and into the _________ _________
Tricuspid , right ventricle
Blood then travels to the lungs via the _________ trunk and the left and right _____________ arteries
Pulmonary , Pulmonary
Oxygenated blood return to the left ___________ via _________ veins
Atrium , Pulmonary
From here the blood flows through the __________ valve into the ______ ____________
Bicuspid , Left ventricle
Blood is then pumped out through the ________ valve into the _________ and around the entire body.
Aortic . Aorta
Which ventricle has a thicker layer of cardiac muscle
The left one
