Lecture 4 Anatomy of Heart Flashcards
• Describe the general organization of the cardiovascular system. • Orientate the heart within the thorax. • Describe the chambered structure of the heart and related this to the pumping action of the organ. • Name the layers of the heart wall.
Cardiovascular system organs. (incl what it does)
Heart (pump), Arteries (supply), Veins/Lymphatics (drainage), Capillaries (Exchange)
what are organs made up of?
Vascular tissue
What is Vascular tissue made up of?
Connective tissue
Cells
Epithelia
What do cells consist of in the cardiovascular system?
Epithelia
Muscle
Blood Vascular System
A closed supply and drainage system.
- a continuous loop
2 loops
1 loop from heart to lungs then to heart.
Another loop from heart going to all other tissues then back to heart.
Supplying and draining capillary beds in the body.
Lymphatic (Vascular) System
- An open-entry drainage system.
- a one-way system
Organisation of the cardiovascular system
Supply side
Exchange network
Heart
Pump
Centre
drives blood through body
Arteries
Supply network - pipes
Capillaries
Exchange surfaces -
bring nutrients, gases in, and wastes out
Veins Lymphatics
Drainage
Epithelial cells
Barriers between environments - barrier between one surface and another
Muscle
Cardiac
Smooth
Blood flow
on right side of heart there is a tubular structure going from capillaries to lungs for gas exchange and going to the left side of the heart.
Pulmonary circulation -
Sending deoxygenated blood from right side of heart to lungs (reoxygenated). The reoxygenated blood returns in veins to the left side of the heart.
Supply side
Organization of the cardiovascular system
(incl what the supply side does, what will happen if damaged?, where situated?)
- Only arteries in supply path
- Major arteries are situated to avoid damage (eg: deep in the trunk; on flexor aspect of limbs).
- Carries blood under high pressure and high velocity, if artery severed you will lose a lot of blood quickly
- Important structures receive blood from two arteriol sources (two separate arteries).
- Arteries change their name at each major branch.
Exchange network - types of capillaries
Organization of the cardiovascular system
Continuous (controlled ~ tight)
Fenestrated (leaky)
Sinusoidal (very leaky)
Exchange network - 3 different types of capillaries with varying degrees of permeability
(How easy to leave the lumen where the blood cells are and cross into the interstitial space surrounding the capillary)
3 pathways for drainage
- Deep veins (Venous)- next to deep supply arteries draining in opposite direction
- Superficial veins (venous) blood loss is less significant and blood travels slower at lower pressure
- Lymphatics
why is Cross-sectional area of veins is at least twice that of arteries?
to shift the same volume of blood / second.
otherwise all peripheral tissues (eg hand) would swell because supply of the arteries wouldn’t match the drainage of the veins.
How do we balance when the supply is under high pressure and velocity, and the drainage is under low pressure and low velocity?
Increase the CSA of the drainage channels to get the same number of ml / second draining back towards the heart as pumping towards the tissue.
Heart shape
Blunt, cone shaped
Pointed end- Apex
Broad end - Base
Rotation and tilt brings ⅔ of heart to the left
PMI
point of maximal impulse
loudest beat
where does the heart sit?
within chest, laterally, behind sternum,
⅔ to left
size of loosely closed fist. Between 2 & 3 ribs is superior aspect of heart,
Midclavicular line of left clavicle between 5 & 6 ribs is the intercostal space Apex beat PMI (point of maximal impulse) against anterior chest wall.
