Cardiovascular and Respiratory System Flashcards
What does the mediastinum refer to?
The chest in the middle but not including the lungs
What are the 4 different sections of the mediastinum?
Superior
Anterior
Middle
Posterior
What are the superior and inferior borders of the superior mediastinum?
Superior border: Top of the manubrium to T1
Inferior border: Sternal angle to T4/5
What is found in the superior mediastinum?
Thymus tissue, aortic arch, pulmonary vessels
What makes up the inferior mediastinum?
Anterior, middle and posterior mediastinum
What are the borders and what makes up the anterior mediastunum?
Borders: below sternal angle, around anterior surface of heart up to IVC, above diaphragm
Fat and thymus
What makes up the middle mediastinum?
Comprised entirely of the heart
What are the borders of and what structures are found in the posterior mediastinum?
Borders: inferior of T5, posterior to the heart, superior to diaphragm
Structures: aorta and oesophagus
Describe the microscopic structure of the heart:(different layers from out to in)
Pericardium: comprised of two layers
- Fibrous: tough outer layer, anchors heart to diaphragm, prevents rapid overfilling
- Serous: consists of 2 layers (outer visceral layer/ epicardium and the inner parietal layer/ pericardium)
- Pericardial space: between serous layers, lubricating serous fluid decreases friction
Myocardium: heart muscle, trabeculae are ridges and bridges of muscle that create turbulence
Describe the gross anatomy of the heart:
- image
What are the 3 branches coming of the aorta from right to left (anatomical position)?
Brachiocephalic trunk: splits into right subclavian artery and right common carotid artery
Left Common carotid artery
Left Subclavian artery
What do the subclavian arteries provide blood to?
Upper limb
What do common carotid arteries supply blood to?
head and neck
What is different in foetal circulation?
Ductus venous: bypasses liver from umbilical cord to inferior vena cava (becomes ligamentum venosum)
Foramen ovale: blood flows from RA to LA (becomes fossa ovalis)
Ductus Arteriosus: vessel from pulmonary artery to to aorta (becomes ligamentum arteriosum)
What features are visable in right atria?
- Orifice of coronary sinus
- Right atrial appendage
- Crista terminalis (origin for pectinate muscles)
- Musculi pectani
How much thicker is left ventrical wall than right ventricle?
3x
What are the 4 valves in the heart?
Atrioventricular valves:
- Tricuspid (right AV valve)
- Bicuspid/ mitral (left AV valve)
Semilunar valves (both 3 leaflets):
- Pulmonary valve
- Aortic valve
What causes the heart sounds?
Atrioventricular valves closing cause first ‘lub’ sound
Aortic and pulmonary valves falling back after ventricular contraction causes ‘dub’
What supplies the heart muscle with blood?
Right and left coronary artery from the aortic sinuses.
Venous return of cornary arteries?
Great cardiac vein, middle cardiac vein, small cardiac vein and anterior cardiac veins drain into coronary sinus -> drains into RA
What is the conducting system of the heart?
SAN (generates signal) -> AVN (secondary pacemaker, delays signal) -> bundle of his -> right and left bundles -> Septomarginal trabecula/ moderator band (rapid conduction)
-> Purkinje fibres
What 4 structures form the upper respiratory tract?
Nasal cavity, paranasal sinuses, pharynx and larynx
What 3 parts are the pharynx divided into?
Nasopharynx = base of skull to palate
Oropharynx = sopft palate/ uvula to epiglottis (elastic cartilage)
Laryngopharynx = epiglottis to bifurification occurs to oesophagus and trachea
What forms the lower respiratory tract?
Right bronchus (vertical, greater diameter, shorter than left main bronchus), left bronchus, primary bronchi (additional middle lobe bronchus in right lung), lungs
How many lobes does each lung have?
Left = 2
Right = 3
What is contained within the hilum?
bronchus, pulmonary artery, pulmonary vein
What are the names of the lobes in the right lung?
superior
middle
Inferior
What are the fissures separating lobes of lung called?
Obllique fissure separates superior and inferior lobe in both lung
Horizontal feature separates superior and middle lobe in right lung
What type of cells are present in respiratory epithelium?
Pseudostratified ciliated columnar epithelium with goblet cells
What are the cells of the alveoli?
Type 1 pneumocytes: site of gas exchange
TYpe II pneumocytes: make up 5% all cells and produce surfactant
Purpose of surfactant:
increases lung compliance and prevents collapse or atelectasis of lungs at end of experation
Function of respiratory tract
Upper - conduction of air (warms and humidifies)
Respiration (gas exchange)
Protection against pathogens (mucous)
What is percussion?
Tapping out where something is in someones lungs
What is auscultation?
Listening to lungs (avoid scapula)
