Respiratory Cardio-Vascular (RCV) I

Question 1

Describe the heart

Answer 1

12cm long, 9cm wide, weighs between 8-10oz, lies on diaphragm in 2/3 to left of midline in thoracic cavity, apex = anterior and inferior, base = posterior and superior

Question 2

Describe the 3 different layers of the heart

Answer 2

pericardium - parietal and visceral layers, myocardium - muscular middle layer, endocardium - inner endothelial layer

Question 3

Describe the pericardium layer of the heart

Answer 3

outermost parietal layer is fibrous - protects the heart and keeps it in position, inner layer of visceral pericardium is a serous layer, pericardial fluid lies between the parietal and visceral layers in the pericardial cavity - reduces friction between the membranes

Question 4

Describe the myocardium layer of the heart

Answer 4

muscle fibres arranged diagonally as interlacing bundles - involuntary smooth muscle

Question 5

Describe the endocardium layer of the heart

Answer 5

smooth lining for chambers of the heart, continuous with linings of blood vessels - made of endothelium and connective tissue

Question 6

Sulci

Answer 6

the grooves on the exterior surface of the heart, they carry the coronary arteries which are the heart’s blood supply

Question 7

4 chambers of the heart

Answer 7

2 superior atria, 2 inferior ventricles

Question 8

Atrial septum

Answer 8

divides the atrial chambers into left and right atrium

Question 9

Interventricular Septum

Answer 9

divides the ventricles into left and right

Question 10

Describe the flow of blood in the heart from the RA to the RV

Answer 10

RA receives blood from IVC/SVC & coronary sinus (this is blood returning from the coronary supply to the heart tissue), blood passes through the RA to the RV through the tricuspid valve (3 cusps)

Question 11

Describe the tricuspid valve

Answer 11

made of dense connective tissue covered in endocardium, these connective tissue rings of valves helps prevent them from overstretching

Question 12

Coronary Sinus

Answer 12

brings blood back to the RA from the coronary arteries supplying the heart tissue

Question 13

Describe the flow of blood in the heart from the RV to the LV

Answer 13

Blood passes from the RV through the pulmonary valve into the pulmonary trunk where it then divides into 2 arteries - left/right pulmonary arteries, the LA then receives the blood from the pulmonary veins after its passed through the lungs, blood then passes from the LA to the LV through the bicuspid (mitral) valve (2 cusps)

Question 14

Describe what happens with the blood after it has left the LV

Answer 14

blood passes from the LV into the ascending aorta (AA) through the aortic valve, as blood is pushed from the heart the pressure increases within the aorta driving blood into the coronary circulation to supply the heart tissue, eventually this drains back through the coronary veins into the coronary sinus, the remainder continues through the AA and onto the descending (thoracic/abdominal) aorta, branches come off the aorta to supply the rest of the body

Question 15

Describe the muscle distribution between the atrium and the ventricles

Answer 15

thicker muscle in the ventricles than atria because the blood has to be pumped further - assisted by the muscular covering of myocardium, RV & LV pump blood at the same time but LV has to push the blood a greater distance

Question 16

Describe what the valves respond to

Answer 16

respond to pressure changes in the chambers and open to allow this blood flow but close accordingly preventing back flow

Question 17

Name the 2 atrioventricular valves

Answer 17

tricuspid and bicuspid (mitral)

Question 18

Describe the role of valves in the blood flow of the heart

Answer 18

when the atrioventricular valves open the cusps point into the ventricles allowing blood flow from atria to ventricle, as blood moves from RV to pulmonary trunk, its upward movement closes the AV valve and opens the pulmonary valve (same from LV into aorta with the aortic valve), as ventricles relax the blood flows back towards the heart filling the cusps of the valves and forcing them to close preventing back flow

Question 19

Describe the pulmonary circulation that occurs

Answer 19

The RA receives dark red, de-oxygenated blood from IVC & SVC, this blood then travels from RA to RV and up into the pulmonary trunk where it then travels through the left & right pulmonary arteries into the right & left lungs where these arteries then become arterioles & capillaries, it does this for gaseous exchange, once it reaches the capillaries it unloads CO2 (exhaled) and picks up O2 (inhaled) via diffusion across thin membranes of blood capillaries and alveoli, blood then continues through venules which become veins and onto pulmonary vein returning to the RA

Question 20

Describe the role of the autorhythmic fibres - 3 points

Answer 20

these trigger a heart contraction and cause it to beat, can still trigger contractions without a nervous system, specialised cardiac fibres act as a pacemaker creating an effective pump

Question 21

Describe the pathway of the contraction of the heart - 5 points

Answer 21

sino-atrial node (found just inferior to the opening of the SVC), stimulation of the SAN reaches the atrioventricular node (AVN) which affects the AV bundle known as the Bundle of His, this therefore activates the ventricular fibres and the inter-ventricular septum, the wave then reaches the Purkinje Fibres sending contractions upwards form the apex of the heart

Question 22

Describe the cardiac output and under what circumstances it differs and why - 3 points

Answer 22

SA node initiates contraction, set rate of approximately 72 beats per minute, however this differs under different conditions (e.g. exercise/rest/stress) - requires cardiac rate to change, chemicals (e.g. hormones) & O2 levels alter output, Age/Gender/Temperature also effect the cardiac ouput

Question 23

Describe the cardiovascular centre

Answer 23

its in the medulla oblongata of the brain, receives input from a variety of sensory receptors and directs appropriate output by increasing/decreasing nerve impulses

Question 24

The Respiratory System consists of … - 6 points

Answer 24

nose, pharynx, larynx, trachea, bronchi, lungs

Question 25

Respiratory portion of the lungs consist of … - 3 points

Answer 25

respiratory bronchioles, alveolar ducts and alveolar sacs

Question 26

Describe the nose - description and purpose

Answer 26

mainly cartilaginous with an opening via the naris (nostrils), warms & moistens air by secretions of mucus from goblet cells within the inner lining of the nasal cavity

Question 27

Describe the role of the mucus in the nose - 3 points

Answer 27

filter the air as it passes through the course hairs of the nasal cavity, adds resonance to the voice, detects olfactory stimulus in sense of smell

Question 28

Describe the nasal cavity - 4 points

Answer 28

the space within the internal nose, subdivided, cavity consists of hyaline cartilage and is divided by nasal septum, ducts from the sinuses and tear ducts interconnect with the nasal cavity

Question 29

Describe the nasal conchae - description and role - 4 points

Answer 29

subdivide the nasal conchae (formed by Turbinate bones) into the superior/middle/inferior meatuses forming groove-like passages, these conchae increase surface area, prevent dehydration by trapping water droplets during exhalation

Question 30

Describe the pharynx - 4 points

Answer 30

lies posterior to nasal & oval cavities, lined with mucus membrane, provides passageway for food and air, divided into nasa/oro/laryngo pharynx

Question 31

Nasal Pharynx - 1 point

Answer 31

lined with cilia (hair-like projections) to sweep dust particles towards lower pharynx

Question 32

Oro-pharynx - 2 points

Answer 32

this is from the soft palette to the hyoid bone, lined with stratified squamous epithelium to help protect it from abrasive foods

Question 33

Stratified squamous epithelium

Answer 33

flattened epithelial cells arranged in layers upon a basal membrane

Question 34

Laryngo-pharynx - 2 points

Answer 34

same lining as oro-pharynx (stratified squamous epithelium) and opens into oesophagus posteriorly and voice box anteriorly

Question 35

Describe the larynx

Answer 35

passageway to join pharynx to the trachea, C4-C6, consists of thyroid & cricoid cartilage, epiglottis and vocal folds

Question 36

Describe how food is prevented from entering the trachea during swallowing

Answer 36

as the pharynx widens to accept food, the epiglottis moves down to form a ‘lid’

Question 37

Describe and explain the lining of the larynx - 4 points

Answer 37

stratified squamous epithelium, for protection against abrasive foods, ciliated to waft dust particles, goblet cells secreting mucus to moisten air or food

Question 38

Describe the trachea - size, position - 4 points

Answer 38

12cm long, 2.5cm in diameter, anterior to oesophagus, runs from larynx to T4/T5

Question 39

Name the 4 layers of the trachea and describe its lining - 3 points

Answer 39

layers include mucosa, submucosa, hyaline cartilage, areolar connective tissue, lined with epithelium for protection, goblet cells secrete mucus, ciliated to help expel any dust particles

Question 40

Describe the structure of the trachea - 3 points

Answer 40

16-20 incomplete rings made of hyaline cartilage, incomplete posteriorly because in contact with the oesophagus therefore accommodates swallowing, cartilaginous rings prevents the trachea collapsing

Question 41

Describe the bronchi

Answer 41

trachea splits into right/left main bronchi at T4/T5, right bronchus is more vertical/straighter/wider, internal ridge is known as the carina at this division

Question 42

Describe the lining of the bronci

Answer 42

lined with mucus membrane which is sensitive and will trigger a cough reflex if needed - minimises the number of particles entering lungs