Anatomy Flashcards
How is the thorax arranged?
flexible containing segmentally arranged vertebrae, ribs, muscles and sternum
What protects the heart?
ribs and sternum and pleural cavity
In terms of ribs, where does the heart lie?
between ribs 2-5 - comes just below rib 4. apex lies in the 5th intercostal space in the midclavicular line
what is the pericardium?
fibroserous sac surrounding the heart and roots of great vessels
What are the two types of pericardium?
fibrous pericardium and serous pericardium
What are the features of fibrous pericardium?
- inelastic/ no stretch
- made up of deep connective tissue
fuses inferiorly with diaphram
How does fibrous pericardium fuse to the diaphragm?
central tendons of diaphragm
What is the the function of fibrous pericardium?
prevents overfilling
anchors in position
defines boundaries of middle medistinium
What makes up serous pericardium?
parietal and visceral pericardium (double layered)
What does the parietal layer line?
inner surface of fibrous pericardium?
what is the visceral layer also known as?
epicardium
what does the visceral layer adhere to?
surface of the heart
what is the pericardial cavity?
potential space between parietal and visceral layer for pericardial fluid to allow for movement and prevents friction
in order of proximity to heart, which pericardium layers are closest?
closest - visceral
parietal
distal - fibrous
what three layers make up the heart wall?
endocardium
myocardium
epicardium
what is the inner layer of the heart wall
endocardium
what makes up endocardium?
simple square epithelial cells
what makes up the middle layer of the heart wall?
myocardium
what is unique about myocardium in the heart?
the thickest layer - makes up cardiac muscle
what is epicardium?
outer layer of the heart layer - visceral pericardium
what is closest to heart itself the heart wall or pericardium?
heart wall is closet, last layer is visceral pericardium (epicardium), which makes up start of pericardium
where does the superior vena cava bring blood in from?
head, neck, upper limbs
where does the inferior Vena cava bring blood in from?
anything lower than the heart
what are the three branches on the aortic branch?
- brachiocephalic trunk
- left common carotid artery
- left subclavian artery
What is an auricle?
prominent structures on right and left atrium
looks like a dogs ear
What does trabeculae carnea mean?
meaty ridges
What is the function of trabeculae carnea?
keeps valves the correct way, prevent back flow - like papillary msucles
what is the structure of trabeculae carnea?
numerous, irregular forming ridges and bridges
what is the smallest naturally arising myocyte?
trabeculae carnea
in latin what are pectinate muscles?
pecten - teeth of a comb
where are trabeculae carnea?
inner surface of ventricles
where are pectinate muscles?
parallel muscular ridges in the walls of atria
what are the function of pectinate muscles?
develops large and stable forces of contraction
what is the septum?
divides the heart
what is the muscular section of the heart?
thick and makes up majority - lower sections
what is the membranous part of septum?
thinner and upper section
what does the interventricular septum form?
anterior wall between between ventricles
what are the differences between the right and left trabeculae carnea?
left ventricle has more finer and delicate ridges
which ventricle wall is more thick and why?
left - this side pumps blood to all of body, right is pulomary
which ventricle is longer?
left
what type of connective tissue bands is between atria and ventricles?
fibrous making up fibrous skeleton
what is the function of the fibrous skeleton?
electrically separate atria from ventricles - manages conduction
where is the fibrous skeleton located?
between atria and ventricles encircles pulmonary trunk and aorta and suspends heart valves
what is the function of heart valves?
to prevent backflow
what are the two types of AV valves?
tricuspid and bicuspid
what are the differences between tricuspid and bicuspid?
- tricuspid has three leafleats, bicuspid has 2
- bicuspid is the left
- tricuspid is the right
what is another name for bicuspid valve?
mitral valve
why is the tricuspid valve on the right
there is less pressure than the left and still need to maintain the amount of blood flow - more tunnels of access
how do the AV valves open?
by blood flowing from atria to valves - chordae tendinae relax
how are the AV valves anchored between atria and ventricles?
chordae tendinae to papillary muscles
how do AV valves close?
contraction of papillary muscles to prevent valve eversion
where are semi lunar valves?
in pulmonary artery and aorta
how many cusps are there within the SL valve?
3
what is the function of SL valves?
prevents back flow from aorta/ pulmonary artery
how does SL valve open?
force of blood when ventricles contract
how does SL valves close?
when the ventricles relax, arterial pressure exceeds ventricular and the SL valves snap shut
what surrounds heart valves?
anulus fibrosus - 4 rings of cardiac skeleton
what type of innervation does the vagus nerve provide?
parasympathetic to thoracic viscera
what is the result of stimulated vagus nerve?
reduce heart rate
reduce force of contractions
NO PAIN sensation
where does the phrenic nerve arise form?
cervical region (4th mainly) via somatic afferent fibres
what is the result of phrenic nerve being stimulated?
motor and sensory innervation to diaphragm
how much blood does the heart receive to itself?
250ml/ min
when does the heart receive blood during coronary circulation?
blood is delivered to myocardium during ventricular relaxation - valves are shut
what does the left coronary artery bifurcate into?
anterior interventricular artery and circumflex
describe the route of the LCA?
straight down the front and around the edge of top of heart
what does the right coronary artery bifurcate into?
posterior interventricular artery and marginal artery
describe the route of RCA?
straight down the back and down the edge on the bottom
where does the LCA supply?
most of LA, LV, septum, AV bundle and branches
where does RCA originate?
right aortic sinus of ascending aorta
what does RCA supply?
RA, RV and AV nodes
what are coronary artery paired with?
veins for drainage
where does great, middle and small cardiac veins drain to?
coronary sinus and empties into RA
where does anterior cardiac veins drain?
directly to RA
what is meant by anastomosis?
connections between vessels - ensures supply
what is the great cardiac vein paired to?
anterior interventricular artery
what is the small cardiac vein paired to?
marginal artery
what is the middle cardiac vein paired with?
posterior interventricular artery
what is paired with circumflex?
coronary sinus
what does a angiography do?
visualises patency of coronary vessels
what can occur if there are blockages within the coronary circulation
fatal - heart tissue is deprived of oxygen and nutrients
how is effective heart contraction managed?
coordination by cardiac conduction
what makes up the cardiac conducting system?
non contractile cells that initiate electrical impulses
1. SAN
2. AVN
3. AV bundle/ bundle of His
4. right and left branches
5. purkinje fibres
how is foetal circulation different to adults?
oxygen and nutrients are received from filtered blood from placenta via umbilical cord and can bypass lungs
Does blood bypass lungs in foetal circulation?
majority of it does
what is the foramen ovale?
a connection between right and left atria
what is the purpose of the foramen ovale?
bypass RV and pulmonary system
where is the ductus aterious?
connects pulmoary trunk to aorta
what is the function of ductus arterious?
bypass left side of heart and pulmonary system
where is the ductus venous?
connects umbilical cord to inferior VC
what is the function of ductus venous?
bypass the liver - blood as already been filtered by mother
what occurs at birth affecting foramen ovale?
- newborn takes first breath
- LA pressure increases
- foramen ovale closes
- fossa ovalis is formed
what happens to ductus arterious at birth?
- newborn takes first breath
- lungs expand
- blood rushes to pulmonary circulation
- O2 levels rise
- constricts ductus arterious
- forms ligamentum venosum
what happens to ductus venous?
- newbron takes first breath
- umbilical cord tied
- umbilical vessels close
- ductus venous fibroses
- forms ligamentum venosum
where is fossa ovalis seen?
clear depression in the inferior aspect of the right interatrial septum
how many lymph nodes are there within the body?
500-600 nodes
how does lymph move round the body?
movement forced through in lymphatic system - moves round during times of skeletal contraction
what is the function of the lymphatic system?
body’s defence mechanism
provide mechanism for interstitial fluid - prevents oedema
what is interstitial fluid?
fluid that baths cells.
how does the fluid move in and out of the capillaries?
fluid moves out of arterial end taking nutrients and O2. fluid moves from interstitial space back to capillary at venous end.
at the arterial end of the capillaries, how much interstitial fluid leaves daily?
20L
how much interstitial fluid comes back into capillaries from venule end?
17L daily is reabsorbed
where are the lymph vessels located?
every tissue except CNS, bone marrow, cornea of eye and teeth
what is interstitial fluid named inside the capillary?
plasma
what is the function of capillary blood pressure?
pushes fluid out into interstitial
usually 10.5-22.5 mmHg
pressure decreases with progression
what is the function of colloid osmotic pressure?
pulls fluid back into capillary, bring wastes, gases (reabsorption)
BCOP due to plasma proteins - albumin
remains relatively constant
how much lymph fluid is reabsorbed back into capillaries?
85%
what is lymphedema?
inappropriate accumulation of interstitial fluid
how much fluid does lymphatic capillaries pick up?
15% - prevents oedema
what is the drainage pathway of lymph vessels?
lymphatic capillaries - lymphatic vessels - lymph nodes - lymph trunks - thoracic duct or right lymphatic duct
how does lymph nodes link to cancer?
lymph nodes filter lymph - collect anything that should not be there - collects cancerous cells - can see if cancer has metasized
what does the right lymphatic duct drain?
drains lymph from right side of head, thorax, right upper limb and goes right subclavian vein
what are the layers of the blood vessels?
LIMA
lumen, tunica intima, tunica media, tunica adventitia
