Cardiovascular system III - blood vessel & heart Flashcards
List three types of cardiovascular system:
Pulmonary
Systemic
Coronary
Arteries
Carry blood away from the heart
Veins
Carry blood towards the heart
Can arteries handle pressure?
Yes, high pressure 90mmHg
Arteries structure:
1) Tunica Interna (intima)
2) Tunica Media
3) Tunica externa/adventia
1) Tunica Interna (intima) [A]
Flat layer, smooth Squamous endothelium-
Smooth flow of Blood
2) Tunica Media [A]
Thick layer, smooth muscle, contraction, elastic fibers
3) Tunica externa/adventia [A]
Thick layer, Elastic tissues- stretch in & out- handle the pressure (more in larger arteries)
Which one HAS valves?
Veins - directed flow
Arteries - pressure regulated so doesn’t require valves
Blood in arteries
Deoxygenated; 95% Sat.O2
Bright Red
Veins strutcure:
1) Intima
2) Externa
1) Intima
Endothelial layer
2) Externa
Smooth Muscle and elastic fibres
What is the middle of the arteries and veins called?
Lumen
Blood in veins:
75-80% Sat.O2
Dark Red
Pressure in veins:
Handle low pressure
~8-10 mmHg
Three types of Capillaries?
1) Continuous
2) Fenestrated
3) Sinusoids
1) Continuous
Smooth & skeletal muscle BBB- Very tight junction (restrict toxin exchanges)
2) Fenestrated
Intestinal villi, kidney glomeruli & endocrine cells
Higher permeability of larger biomolecules
3) Sinusoids
Red Bone Marrow & Liver
Huge molecules perfusion
Blood cells, proteins and wastes
Internal vascular structure:
Squamous (flat) endothelial cells is the first layer - close together
1) Continuous
If endothelial cells are close together it means there is less ______ between junctions:
gaps
[Restricted access]
There will only be gaps between junctions, this is called:
Intercellular cleft
2) Fenestrated - pores in cells
ONLY small molecules can pass - not big molecules like red blood cells
3) Sinusoids - Endothelial cells are loosely packed
Red blood cells and metabolic toxins CAN pass
Liver process’ bigger molecules; wrea
Which type of capillaries help this process?
Sinusoids
Capillary Architecture -
can vary depending on type
Diameter or capillary:
200-400um (micrometer)
Capillary walls are lined with endothelial cells
(5-10 um in diameter) for smooth flow
Bundles of smooth muscles spread-out pre-capillaries - used for….
Used as a sponge - regulated by absorbing or releasing blood
Terms used for mechanism of Bundles?
Vasoconstriction
Dilation
Sphincters (precapillary)
Vasotone-dilation - More blood into capillary (metabolic demand - Exercise)
What is the point of blood going through capillary
Exchange of molecules - e.g. losing O2
[if cells outside need O2]
Arteriole/Venule roles:
These are the smaller branches of arterie/vessel where blood come in out of capillary
Types of complex regulation:
a) Metabolic demand
b) Hormonal
c) Temperature and many others
Heart size:
14 cm long; 9 cm wide (fist of your hand)
Heart weight:
300 - 500 grams
Heart / Heartbeats:
70-100/min= 115000/day = ~3.5 billion in lifetime
Volume of blood pumped in a day:
9 L / 9000 mL
The heart structure: 1 Pericardium
Fibrous layer- provide elasticity and protects
The heart structure: 2 Pericardial cavity
filled with fluid shock adsorber
The heart structure: 3 Myocardium
cardiac muscle - contract and relax
What is the inner layer of the heart called?
4 Endocardium
Where do the veins come from?
Lungs
How many pulmonary veins are there?
4
Blood from pulmonary veins to»>
Left atrium
Once heart in cotracted»
Pumped out of left ventricle and out of aorta
What happens in the right ventricle?
pumping blood from your heart to your lungs, where the blood is replenished with oxygen
Vena cava
Superior - drains blood from head, neck
Inferior -
What is the role of the left ventricle?
The left ventricle is responsible for then pumping the oxygenated blood around your body
Once blood is in left ventricle, oxygenated blood is pumped up to aorta through the…
aortic/Semi-lunar valve
Why is the left side of the heart got a thicker muscle tan the right?
The left side needs to pump oxygenated blood around the WHOLE body so needs to regulate a lot of PRESSURE
the right needs to pump blood to lungs which is inferior (under - close) to the heart. Doesn’t require a lot of pressure
1) Atrial kick
a) sideward kick
b) upward kick
2) Cardiac twist
the twist makes sure maximum amount of blood is pumped out of the blood
LUBbDUBb… - heartbeat
it takes around 1-2s for heart to refill with blood
[Delay]
Blood circulation
Blood flow in artery (pulsatile):
Cardiac output
Pressure (high to low)
Gravitational pull
Length & Diameter of artery
Blood viscosity
Hepatic portal system
The venous system that returns blood from the digestive tract and spleen to the liver (where raw nutrients in blood are processed before the blood returns to the heart)
Venous return - flow of the blood back to the heart’s right atrium
1) Calf/skeletal muscle pump
(coordinated contraction of muscle)
2) Pulsatile arteries adjacent to vein complement the muscle pump/pressure and venous return
3) Respiratory (Thoracic) pump
Superficial veins;
are close to the surface of the skin - responsible for carrying blood in periods of intense strength training
Contraction of skeletal muscle and pressure
3) Respiratory (Thoracic) pump - Intrpleural pressure
- Breath in: inspiration
- Breath out: expiration
Breath In (inspiration)
Diaphragm compress abdomen cavity-Increase Pressure -push blood from abdomen cavity to thorax
Reduced pressure in the thorax sucks the blood from the abdominal cavity into the thorax
Breath out (expiration)
Increased pressure in the thorax push the blood back in the heart
Reduced pressure in the abdomen suck the blood from the lower part of the body
Pulmonary embolism is
a blocked blood vessel in your lungs
Varicose vein (chronic vein valve failure)
Swollen and enlarged veins – usually blue or dark purple – that usually occur on the legs
Appearence; lumpy, bumpy and twisted
Coronary circulation:
Two tiny arteries leaving out the aorta
Profuse blood to myocardium
Handles high pressure (irrespective of heart contraction or relaxation)
Blockage leads to the major cardiac problem -
Heart attack
Coronary thrombosis -
Myocardial Infarction (MI)
Capillary Perfusion: Microcirculation
Arterioles carry high hydrostatic pressure = 30mmHg / Low onconic
Venules carry low hydrostatic pressure = 10mmHg / High onconic
What moves out of the lumen?
O2, CO2 and other gases movement
Nutrients
Electrolytes
Metabolic waste
Hormones, Cytokines
Why is the water potential increases within the lumen?
The protein is left in the lumen because t is too large to be defused out.
Water then moves IN
Pressure that is created by a protein is called…
onconic pressure - osmotic pressure (because water tends to move = down gradient)
Autoregulation of perfusion:
- High O2/ Low O2
if O2 was Low;
High levels of:
CO2 , potassium (K+) or
hydrogen (H+) ions (acidic pH)
Lactic acid
(by-products of cell metabolism)
Histamine (Inflammation)
Body temp
Stimulate endothelial cells to release NO
> Vasodilation of precapillary
if O2 was high;
Low levels of:
CO2 , potassium (K+) or hydrogen (H+) ions (acidic pH)
Lactic acid
(by-products of cell metabolism)
Histamine (Inflammation)
Body temp
Stimulate endothelial cells to release endothelin (peptides) + Platelets secretions & prostaglandins
> > > Vasoconstriction of precapillary Sphincters
