Anatomy Flashcards
How is the mediastinum divided?
Superior - Above heart Inferior divided into; Anterior Middle (Location of heart) Posterior
How is the pericardium divided?
Fibrous - Outer, thick, tough layer
Prevents overfilling and protective
Serous - Visceral and parietal
Secretes serous fluid
Tissue layers of the heart
external – Epicardium visceral serous pericardium middle – Myocardium muscle layer internal – Endocardium internal lining continuous with endothelium of blood vessels connecting with the heart
What forms the majority of the anterior surface of the heart?
The right ventricle
What is the inferior surface of the heart also known as?
Diaphragmatic surface - Rests on the diaphragm
What forms the majority of the posterior surface of the heart?
Right and left atrium
What forms the majority of the right border of the heart?
Right atrium
What forms the majority of the left border of the heart?
Left venticle
What are the four valves?
Tricuspid valve (between right atrium and right ventricle) Pulmonary valve (between right ventricle and pulmonary trunk) Mitral (bicuspid) valve (between left atrium and left ventricle) Aortic valve (between left ventricle and aorta)
What travels through the intraventricular septum?
The left and right bundle branch
The thoracolumbar nerves can be divided into
Cardiopulmonary splanchnic nerves
Abdominopelvic splanchnic nerves
What does the cardiac plexus consists of
sympathetic fibres
parasympathetic fibres
visceral afferent fibres
What nerves constitute the sympathetic nerves
L1 to T2/3
What nerves constitute the parasympathetic nerves
CN III (oculomotor nerve) CN VII (facial nerve) CN IX (glossopharyngeal nerve) CN X (vagus nerve) Sacral spinal nerves
What division of the ANS are pelvic splanchnic nerves
PELvic splanchnic nerves are PARAsympathetic
Pain associated with viscera such as heart, great vessels, oesophagus
Nature is more typically dull, aching, nauseating, poorly localised. Route visceral afferents take from heart via neck & upper thoracic regions of trunk/cord leads to radiating and referred pain from the heart – due to lack of precision in route taken by visceral afferents to the spinal cord
Somatic pain such as muscular, joint, bone
Nature is typically sharp, stabbing, well localised
Why is somatic pain sharp and well localised?
Somatic pain sharp and well-localised due to precisely (somatotopically) organised pathways from periphery and projections to cerebral cortex.
APs arriving at the parietal lobe cause? (Postcentral gyrus)
APs arriving here bring body wall (somatic) sensations into “consciousness” (Somatosensory)
APs originating at the frontal lobe (Precentral gyrus)
APs originating here bring about contractions of body wall (somatic) skeletal muscle (Somatomotor)
What is the sensory homunculus?
The sensory homunculus illustrates the areas of the cerebral neocortex (the outermost layer of the cerebral hemispheres) where sensations from different body wall structures (soma) reach consciousness.
Patient presents with pain preceeding blisters. Sharp central chest pain in T4/T5 dermatone
Herpes Zoster “Shingles”
Location of heart in mediastinum
Inferomedially
What is the ligamentum arteriosum
It is the remnant of ductus arteriosus connecting pulmonary trunk to arch of aorta
How do visceral afferent AP pass onto the cortex
Visceral afferent APs pass bilaterally to thalamus & hypothalamus then diffuse areas of the cortex
What do the cardiopulmonary splanchnic nerves carry
Sympathetic nerves to chest organs plus pain afferents from chest organs (which enter spinal cord which posterior rootlets)
The levels at which the visceral afferent enter the sympathetic trunks & spinal cord from the heart
Cervical ganglia and T1-T5 spinal nerves respectively
Cause of radiating pain
The radiation is to the dermatomes supplied by the spinal cord levels at which the cardiac visceral afferents enter the sympathetic chain/spinal cord i.e. BILATERALLY to cervical and upper thoracic dermatomes
What is referred pain?
In REFERRED PAIN, the sensation of pain is “felt” only at a site remote from the actual area of injury or disease. Due to afferent (sensory) fibres from soma and afferent (sensory) fibres from viscera (visceral afferents) entering the spinal cord at the same levels
The brain chooses to believe that the pain signals coming from the organ, are actually coming from the soma
What layer(s) of the heart do the coronary vessels supply
Epicardium and myocardium
Where do coronary arteries arise from
Ascending aorta, right and left sinuses
The left anterior descending artery is also known as
Anterior interventricular artery
Left coronary artery is also known as
Main stem coronary artery
Most common coronary artery affected by atherosclerosis
Left Anterior Descending (LAD; 40-50%)
Right Coronary Artery ; 30-50%
Circumflex branch of left coronary artery; 15-20%
Longest vein in the body
The great saphenous vein (GSV, alternately “long saphenous vein”) is a large, subcutaneous, superficial vein of the leg. It is the longest vein in the body, running along the length of the lower limb.
Features of coronary artery bypass
Grafts anastomosed proximally to the ascending aorta
Grafts anastomosed to coronary artery distal to narrowing hence the narrowing is “bypassed”
Commonly used grafts for coronary bypass
Radial artery Internal thoracic (internal mammary) artery (by pedicle)
What artery generally supplies the conducting system
Right coronary artery; has AV nodal and SA nodal branches off the RCA
Arterial blood supply of the interventricular septum
Left anterior descending supplies left side
Posterior interventricular artery supplies right side
Also supplies left and right bundle branches
What is Dysphagia?
Difficulty swallowing
What is the transverse thoracic plate
The thoracic or transthoracic plane is defined as a horizontal line that runs from the manubriosternal joint (sternal angle or angle of Louis) to the inferior endplate of T4
Where does lymph from the left inferior lobe drain to?
In some patients the lymph from the left inferior lobe drains into the right lymphatic duct
What are the common nodes enlarged in pulmonary diseases?
Tracheobronchial lymphnodes
Bronchopulmonary lymphnodes
What is the Cisterna Chyli
The cisterna chyli is a dilated sac at the lower end of the thoracic duct in most mammals into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow. It receives fatty chyle from the intestines and thus acts as a conduit for the lipid products of digestion. Located at L1 and L2
How does the Vagus nerve get through the diaphragm
The vagus nerve passes through the diaphragm along with the oesophagus through the oesophageal hiatus
How does the right Phrenic nerve get through the diaphragm
The Phrenic nerve passes through the diaphragm with the IVC to supply the diaphragm from inferior aspect. The left Phrenic nerve pierces the diaphragm
What causes the double pulsation seen in JVP
Atrial contraction then filling of the right atrium against a closed tricuspid valve cause a “double pulsation” (pressure wave)
Which of the recurrent laryngeal nerve enters the chest?
The left recurrent laryngeal nerve enters the chest; hooks under arch of aorta. The right recurrent laryngeal nerve hooks under subclavian artery and doesn’t enter the chest
What are recurrent laryngeal nerves?
Branches of the vagus nerve that supply the pharynx and larynx, once the vagus nerves have given off their recurrent laryngeal branches they contain only parasympathetic fibres
What is endochondral ossification?
Process in which an initial small hyaline cartilage grows and turns into bones (ossifies)
Parts of a growing bone
From top down - Epiphysis Epiphyseal growth plate Metaphysis Diaphysis
Structure of bone
Outer Cortex - dense, heavy, compact bone
Inner Medulla - porous, lighter, spongy bone
What is the periosteum
Fibrous connective tissue sleeve on bone
Bones of the cranial vault (neurocranium)
Frontal, Temporal, Parietal, Sphenoid and Occipital
Bones of facial skeleton (viscerocranium)
Nasal bone, Zygoma, Maxilla, Mandible
Where is the temperomandibular joint?
At the condylar process
Parts of vertebra column
Cervical - 7 Thoracic - 12 Lumbar - 5 Sacral - 5 Coccygeal - 4
What joint is present between vertebrae?
Facet joint b/w two adjacent vertebrae
What is the transverse foramen used for in vertebrae?
Passage of vertebral arteries
Which cervial vertebrae has no body or spinous process?
C1 - Atlast
Significance of the Atlanto-Axial joint
Consists of Atlas on top of Axis; allows rotation of the head
Bones of upper limb
Humerus, Radius, Ulna, Carpals, Metacarpals, Phalanges
Bones of lower limbs
Femur, Tibia, Fibula, Tarsals, Metatarsals, Phalanges
Structure of skeletal muscles
Skeletal muscles - Fascicles - Muscle fibres - Myofibrils - Actin and Myosin
Types of skeletal muscles
Circular - Orbicularis oculi Pennate - Deltoid Quadrate - Rectus abdominus Flat with aponeurosis - External oblique Fusiform - Biceps brachii
What is a tendon. How’s it different form aponeurosis?
Attach muscle to bone. Aponeurosis attaches muscle to soft tissue instead.
2 main reflexes involving skeletal muscles
Stretch reflex
Flexion withdrawal reflex
Muscle paralysis vs spasticity
Paralysis is when the motor nerve isn’t functioning whereas spasticity is when the muscle has an intact motor nerve. Paralysed muscles have a reduced tone whereas spastic muscles have an increased tone
Which fascia are skeletal muscles found in
Deep fascia
How is compartment syndrome treated?
Using fasciotomy; fascia is cut to relieve pressure
Where does transition to smooth muscle happen and end?
Trachea and middle third of oesophagus is where skeletal muscles transition to smooth
Diaphragm is skeletal muscle
Perineum is the transition back to skeletal muscle
