Lecture 1 Flashcards
(40 cards)
What is pericardius
Swollen bit on heart that puts pressure on it, need a pericardecromy which is removal of the sac
Features of the heart
Pumps blood one way
Leakproof
Regular and automatic
Able to chance output when required
Where is the heart located ?
In mediastinum ( between 2 lungs ) and in the Thoracic Cavity in rib cage . 5th intercostal space of ribs = apex (bottom of the heart) 3rd = base
Diaphragm function
Between chest and ribs, expands to push chest up and down
What are the two systems pumping blood
Pulmonary circulation ( carry’s Blood low in oxygen to lungs then to heart)
Systemic Circulation (oxygen rich blood to body )
Heart structure from right side top to bottom
Superior vena cava (blood from body to heart)
Right pulmonary artery ( blood to right lung)
Right pulmonary veins ( blood back from lungs to heart )
Right atrium ( top chamber of heart)
Inferior vena cava (blood from lower body to heart)
Right ventricle (lower chamber of heart)
Heart structure from left side top to bottom
Aorta (carries blood to body)
Left pulmonary artery (blood to left lung)
Left pulmonary veins (back from left lung)
Left atrium (top chamber)
Left ventricle (bottom chamber)
What is the circulation of blood (deoxygenated blood to oxygenated blood)
Low 02 blood enters the vena cave from body then leaves the R AND L pulmonary arteries to lungs.
High 02 blood enters the R AND L pulmonary veins from lungs and leaves through the aorta to body.
What are the layers of tissue in the heart
- Pericardial sac
- parietal pericardium
- pericardial cavity
- epicardium
- myocardium
- endocardium ;
- loose connective tissue
- squamous epithelium
What is pericardial cavity filled with and what function
Pericardial fluid and reduces friction as the heart beats
What is the sac called where the heart is contained
Pericardial sac (made of collagen fibres)
What lines the pericardial sac and what is it made off
Outer parietal pericardium and inner visceral pericardium separates by the pericardial cavity
What is the fluid called in the pericardial cavity
Pericardial fluid that acts as lubricant
What is the heart wall made of
Thick myocardium composed of cardiac muscle cells
Heart chambers lined by endocardium ( thin layer of AEOLAR connective tissue covered by SIMPLE SQUAMOUS epithelium )
What is the different between skeletal muscle cells and cardiac muscle cells
Cardiac muscle cells=
Short ( not long )
Branched ( allows link neighbour cells )
Single nucleus because short
Striated like skeletal
Involuntary control by the autonomic nervous system
What are intercalculated discs
Allow all cardiac cells to perform as one unit
What are the cells that physically join adjacent cells together
Desmosomes
What electrically links cells together in heart
GAP junctions
What is the conduction system in the heart
Sino-Atrial Node in the wall of right Atrium (“pacemaker”) passes signal onto Atrio-Ventricular Node passes to Atrio-Ventricular Bundle (between R and L ventricles) which branches in 2 down to apex then travels to Purkinje fibres which delivers signal to muscle cells in wall by diffusing up sides.
How does Sa node initiate signal?
Specialised cardiac muscle cells that can become spontaneously active without any outside influence, 75x per min approx
What are the valves in the heart?
-prevent back flow of blood Right tricuspid atrio -ventricular valve Right Semilunar valve Left bicuspid atrio ventricular valve Left semilunar valve
What is attached to left and right tricuspid and bicuspid valves
Chordae Tendinea (threads of connective tissue attach valve to Papillary muscles which contract to pull on tendons and o prevent back flow of blood Bi cuspid = 2 flaps of connective tissue Tri cuspid = 3
What are the two types of control of heart activity?
Intrinsic control and extrinsic control
I= hearts own in-built processes e.g. can control rhythm without outside factors
E= nervous system and endocrine system affect on heart activity
What is the main thing that controls the heart activity ?
Sino Atrial Node = specialised cardiac muscle cells at the back of the right atrium near superior vena cava which become spontaneously active (generate its own action potential)
