Anatomy Flashcards
How many vertebrae does the vertebral column consist of?
33
How long is the average adult’s vertebral column?
71cm (28in)
Why are you 1% shorter in the morning?
Because when upright, the weight of the body against gravity compresses the intervertebral disks, forcing water out of them. When sleeping, the weight of the body is removed from the spine allowing water to be reabsorbed into the intervertebral disks.
How many groups of vertebrae are there? Where are they?
Cervical vertebrae (Neck) Thoracic vertebrae (Chest) Lumbar vertebrae (Lower back) Sacral vertebrae (base of spine) Coccygeal vertebrae (tiny)
How many cervical vertebrae are there and where are they located?
7 (neck)
How many thoracic vertebrae are there and where are they located?
12 (chest)
How many lumbar vertebrae are there and where are they located?
5 (Lower spine)
How many sacral vertebrae are there and where are they located?
5 (Base of spine)
How many coccygeal vertebrae are there?
4 (tiny)
Beyond the age of 3, the spine begins to curve, what are the names of the 4 bends?
Cervical, thoracic, lumbar and pelvic curvatures.
What are the primary curvatures?
The thoracic and pelvic curvatures as they exist from birth.
What are the secondary curvatures?
The Lumbar and cervical curvatures as they develop later on, in the child’s first few years of crawling and walking.
Name two functions of the thoracic cage.
Provides protection to the heart and lungs
Provides attatchment for the pectorial girdle and upper limb
What is the costal margin?
The lower edge of the chest formed by the arch of the lower ribs
What are the three regions of the sternum?
Manubrium, body and xiphoid process
Where is the manubrium of the sternum located? And what level of vertebrae does it lie?
It is the first (broad superior) region, shaped like a know of a necktie. It lies at the level of vertebrae T3 to T4
What is the secondary cartilaginous that articulates the manubrium to the body of the sternum?
Manubrio-sternal joint`
What is the manubrio-sternal joint referred to and why?
The manubrio-sternal joint is the secondary cartilaginous joint which articulates the manubrium to the body of the sternum, this joint is referred to as the Sternal Angle of Louis because of the very small angulation it causes between the manubrium and the body of the sternum.
Why is the Sternal angle of Louis useful?
It can be used to count the ribs. Just lateral to it are the second costal cartilage and to that the second ribs, from then you can count the subsiquent ribs.
Why cant we use the 1st ribs as a starting point for counting the rest of the ribs?
The first ribs are concealed by the clavicles (collarbones) so cannot be felt.
Where and what is the Jugular (superasternal) Notch?
Located at the top of the manubrium and infront of the trachea.
At what joint does the Manubrium articulate with the medial end of the left and right clavicles?
Sterno-clavicular joint (synovial joint)
At what joint does the Manubrium articulate with the first costal cartilage?
This is a primary cartilaginous joint called the 1st chondro-sternal joint.
What is another anatomical name for the body of the sternum?
Gladiolus.
Between which vertebrae does the gladiolus (Body of the sternum) lie?
Between vertebrae T5 to T9
What is a synovial joint?
A joint that joins bones with a fiberous joint capsule that is continuous with the periosteum of the joined bones.
What is the periosteum?
A dense layer of vascular connective tissue enveloping bones, except at joints.
Between which vertebrae does the xiphoid process lie?
T10 and T11
What is the function of the xiphoid process?
Provides attachment for some small abdominal muscles.
Why can cardiopulmonary resuscitation be dangerous because of the xiphoid process?
Improper chest compressions (in the wrong place) can force the Xiphoid process into the liver and cause a fatal hemorrhage.
Describe the distribution of rib size.
Between ribs 1-7 then from 7-12 they get progressively smaller
Describe the distribution of obliqueness of the ribs.
They get increasingly more oblique between ribs 1 to 9. they then decrease from 10-12
Describe rib 1’s structure and location,
use the words - Knobby Head, Neck, Tubercle, shaft, Facet.
Rib 1 lies above the level of the clavicle.
On an articulated skeleton you would look for its vertebral attachment at the bast of the neck. More specifically, at the vertebral end, rib 1 has a KNOBBY HEAD which articulates with the body of vertebra T1 (thoracic).
Immediately distal to the head is a region where the rib narrows to a NECK and then widens again to form a rough region called a TUBERCLE. This is the region where the rib connects to the TRANSVERSE COSTAL FACET.
The rib then flattens and widens into a bladelike structure called the SHAFT. The shaft then becomes squared off, here is where the costal cartilidge begins and spans all the way to the upper sternum.
The upper face of rib 1 has a pair of shallow grooves, these serve as platforms for the subclavian artery and subclavian vein.
What are the subclavian arteries?
There is a left and right subclacian artery, they’re a pair of arteries which supply the upper thorax. Blood is supplied to them from the aortic arch and they supply blood to the left and right arms respectively.
What is the costal groove?
The inferior margin of the rib shafts which marks the path for intercontinental blood vessels and nerve.
What are and what is the difference between true and false ribs?
True ribs each have their own costal cartilage connecting to them. False ribs lack independent cartilaginous connections to the sternum.
Ribs 1-7 are true ribs
Ribs 8-12 are false ribs
What is the alternative to cartilage connecting to the sternum in false ribs?
Instead of connecting to the sternum, the costal cartilage of ribs 8-10 sweep upwards and end on the costal cartilage of rib 7
Why is rib 10 different of ribs 1-9?
Rib 10 attaches to a single vertebrae (T10) as oppose to being between two. So vertebrae T10 has a complete costal facet for rib 10.
Give 3 features of ribs 11-12 that make them floating ribs.
They articulate with vertebrae T11 and T12. Ribs 11 and 12 don’t have tubercles and so these two vertebrae don’t have transverse costal facets.
At the distal end of each rib is a small cartilaginous region, this doesn’t extend up and join with the sternum, or any higher costal cartilage , the ribs are just embedded in lumbar muscle.
What’s the difference in rib anatomy in Japanese people?
Rib 10 is a floating rib.
Where do the clavicle join to the manubrium?
Clavicular notch
What does the pictorial gridle consist of?
Clavicle (collarbone) and scapula (shoulder blade)
What is the mediastinum?
The mediastinum contains all the chest organs apart from the lungs
What is the superior mediastinum?
Spanning posterior to vertebrae 1-4 and anterior of the manubrium is the superior mediastinum
What is the inferior mediastinum?
Split into 3 regions, the inferior mediastinum is the entire region below the superior mediastinum (below the manubrium). This is split into the anterior, middle and posterior mediastinum.
The anterior is in front of the pericardium, just posterior to the manubrium.
The middle contains the pericardium and it’s contents
The posterior is located behind the pericardium
How many pairs of intercostal muscles are there?
22 pairs, 11 internal, 11 external
What is the structure and function of the external intercostal muscles?
The external intercostal muscles aid forced and quiet inhalation, the originate at ribs 1-11 but form insertions are ribs 2-12. They elevate the ribs and bend the ribs open to expand the transverse dimension of the thoracic cavity.
What is the structure and function of the internal intercostal muscles?
The internal intercostal muscles aid forced expiration (quiet is a passive process). They originate at ribs 2-12 but form interiors at ribs 1-11. They depress the ribs and cause the, to bend inwards, decreasing the transverse dimension of the thoracic cavity.
What 3 muscles make the innermost intercostal muscles?
- transverse thoracis
- levatores costarum muscle.
- subcostales muscle
Name the three thoracic muscles outside the ribs.
Serratus Anterior
Serratus posterior -superior
Serratus posterior - inferior.
Describe the serratus posterior superior and it’s function.
Originates from C7 to T3 and inserts on the upper boarders of ribs 2-5 and are innovated by intercostal nerves 2-5.
Describe the serratus posterior inferior and it’s function.
Originates from T11 to L2 and inserts on the upper boarders of ribs 9-11.
Describe the serratus posterior inferior function
The function is to depress through lower ribs so aids FORCED EXPIRATION
Describe the serratus posterior superior function
The function is to elevate the ribs. The angle of the muscles pulls up and elevates the ribs so assists INSPIRATION.
Describe the serratus anterior
Originates at ribs 1-8. Instead itself on the medial border of the scapula on its costal surface.
What is the function of the serratus anterior?
Function is to contract and stabilise the scapula alongside pulling the scapula forwards towards the thorax, keeping it pressed against it.
What nerve mediates the serratus anterior?
Long thoracic nerve.
How are the external intercostal muscles orientated?
They are orientated in the inferior medial direction. Hands in pockEts.
How are the internal and innermost intercostal muscles orientated?
They are orientated in the superior medial direction.
Hands on tIts.
How are the external intercostal muscles attached to the sternum?
Anterior ally, before it meets the sternum the it forms an aponeurosis (fibrous tissue) called the sternal intercostal membrane.
Describe the layers of muscle plura of the thorax, starting either external intercostal muscles and ending with the lungs.
External intercostal muscles ➡ Internal intercostal muscles ➡ innermost intercostal muscles ➡ endothoracic fascia ➡ parietal plura ➡ Pluralcavity ➡ visceral plura ➡ lungs
What is the function of the endothoracic fascia?
It is a fibrous connective tissue which separates the parietal plura from the innermost intercostal muscles.
Which intercostal muscles are important for inspiration?
External intercostal muscles
Which intercostal muscles are important for expiration?
Interact and innermost intercostal muscles. (Due to similar muscle orientation)
Where is the neurovascular bundle located?
Between the internal and innermost intercostal muscles, in the costal groove which lie in the inferior margin of the rib.
What does the neurovascular bundle consist of?
The intercostal artery, nerve and vein
What is the orientation of the neurovascular bundle in the costal groove?
Superior Vein
⬇ Artery
Inferior Nerve
VAN
Describe the how the levatores costarum is positioned.
They attach from the transverse processes (transverse articular facets) of a vertebrae and attaches to the rib below (I.e T4 to rib 5)
What is the function of the levatores costarum muscles.
To assist elevation of the thoracic rib cage.
Describe how the subcostales muscle is positioned.
Attaches from one rib to either the one below or the one below that.
Lies on the internal surface of the ribs
What is the function of the subcostales muscle?
Assists in depressing the ribs.
What is the function of the transverse thoracis muscle?
Assists in depressing the ribs.
Define flexion.
The bending movement of a limb or joint that decreases the angle between the bones of the limb at the joint.
Define extension.
An unbending movement of a limb or joint that increases the angle between the bones of the limb at the joint.
Define abduction.
The movement of a limb away from the midline of the body.
Define adduction.
The movement of a limb towards the midline of the body.
From right to left, name the 3 branches of the aortic arch?
Brachiocephalic artery
left common carotid artery
left subclavian artery.
What are the name of the two branches of the brachicephalic artery? (from right to left)
Right subclavian artery
Right common carotid artery.
What is the ligamentum arteriosum and describe its attachments.
The ligamentum arteriosum is a small ligament. The superior end attaches to the final part of the aortic arch (and beginning of the descending aorta) called the isthmus of aorta. The inferior end is attached to the top of the left pulmonary artery.
What veins does the superior vena cava branch off into?
Left and right branchiocephalic veins.
Describe the heart’s position relative to the ribcage.
The heart is mainly located behind the sternum (T3-T4). The apex of the heart protrudes slightly to the left and can be palpated (felt) in the 5th left intercostal space).
Why does the heart move during respiration?
It is attached to the diaphragm via ligaments protruding from the pericardium so moves during respiration as a result of the contraction and relaxation of the diaphragm. The anterior side of the pericardium is also attached to the sternum.
Where can the apex of the heart be palpated (felt) and why?
It can be palpated in the 5th left intercostal space because the apex of the heart is made up of the tip of the left ventricle - making the apex protrude to the left.
What distinct anatomical feature of the heart indicates the difference between an anterior and a posterior x ray?
Anterior (belly) the apex of the heart will be towards the left whereas in a posterior (back) x ray, the apex will be protruding to the right and the spinal column will be more visible.
What is the name of the partition of which the heart lies?
Mediastinum.
What is the pericardium.
The pericardium is a double walled sac that encloses the heart.
What are the two layers of the pericardium?
Outer layer is the pericardial sac (parietal pericardium) - this is a though, superficial fiberous layer formed of dense connective tissue.
The inner layer is the epicardium (Visceral pericardium) - this is a serous layer.
What is the function of a serous layer?
The serous layer secretes lubricant to reduce friction from muscle movement.
What is the pericardium attached to?
Linked to the diaphragm via ligaments and the anterior section is linked to the posterior region of the sternum.
What is the name of the space between the parietal and visceral pericadium? (Pericardial sac and epicardium)
Pericardial cavity.
Describe how the heart is placed in the pericardial cavity.
The heart isn’t necessarily inside the pericardial sac but rather enclosed in it.
The heart is enclosed in the pericardial sac similar to that of a fist in a deflated balloon. The surface of the balloon in contact with the heart is the Epicardium (visceral pericardium) whist the outer surface of the balloon is the pericardial sac. The air space inside the balloon is the pericardial cavity.
What is inside the pericardial cavity?
Around 5 to 30ml of Pericardial Fluid produced by the serous layer (epicardium) of the pericardial sac.
What is the function of the pericardial fluid?
Acts as a lubricant for the membranes and allows the heart to beat with minimal friction.
What is pericarditis and what are its consequences?
Pericarditis is inflammation of the pericardium. Thge membranes become roughened and produce a painful friction rub between heartbeats.
What is the coronary sinus?
A collection of collecting veins that join together to form a large collecting blood vessel. Located at the Right Atrium.
What is the function of the coronary sinus?
Collects deoxygenated blood from the heart muscle (Myocarium) and delivers it to the right atrium along with the superior and inferior vena cava.
What is pulmonary circulation?
Pulmonary circulation is part of the cardiovascular system which carries deoxygenated blood away from the heart to the lungs and returns oxygenated blood back from the lungs to the heart.
What is the name for the irregular muscle columns lining the ventricles?
Trabeculae Carnae
What are Papillary muscles?
Muscles which attach to the trabeculae carnae and the cordae tendineae of the Bicuspid and Tricuspid valves.
What is one of the main functions of the papillary muscles?
Their main function is to attach to the cusps of the tricuspid and bicuspid valves via the cordae tendineae and prevent the inversion and prolapse of these valves during ventricular systole.
What is the function of the irregular muscle folds (trabeculae carnae) in the ventricles? And what would be the benefit?
It is thought that they prevent the ventricular walls sticking to each other like suction cups, this is due to their ridged nature.
The benefit would be allowing the chambers to expand easily when they refill.
What are the names of the cord like tendos which attach papillary muscles to the tricuspid and bicuspid valves?
Chordae Tendineae
What is the function of the moderator band in the right ventricle?
Prevents over distention (swelling, enlarging due to an increase in internal pressure)
What is a common name for the moderator band?
Septomarginal trabecula.
Where does the moderator band extend from?
Extends from the anterior papillary muscle to the ventricular septum.
What is the name of the wall separating the left and right ventricles?
Interventricular septum
What is systemic circulation?
Systemic circulation is the part of the cardovascular system which carries oxygenated blood away from the heart, to the body and returns deoxygenated blood back to the heart.
Why is the left ventricles the thickest heart chamber?
Because it pumps blood around the systemic circulatory system, which is much further than to the lungs like the right ventricles.
What does the anterior inter-ventricular branch (Left anterior descending) supply?
Both the ventricles and the anterior two-thirds of the interventricular septum.
What two branches does the left coronary artery divide into?
- Anterior interventricular branch (Left anterior descending artery)
- Circumflex branch
What does the right coronary artery supply?
Supplies the right atrium and the Sinoatrial node.