NEET MDS Lessons
Anatomy
Appendicular Skeleton
Upper extremity
• Shoulder-clavicle and scapula
Clavicle
Articulates with the manubrium at the sternal end
Articulates with the scapula at the lateral end
Slender S-shaped bone that extends horizontally across the upper part of the thorax
Scapula
Triangular bone with the base upward and the apex downward
Lateral aspect contains the glenoid cavity that articulates with the head of the humerus
Spine extends across the upper part of the posterior surface; expands laterally and
forms the acromion (forms point of shoulder)
Coracoid process projects anteriorly from the upper part of the neck of the scapula
Arm (humerus)
Consists of a shaft (diaphysis) and two ends (epiphyses)
Proximal end has a head that articulates with the glenoid fossa of the scapula
Greater and lesser tubercles lie below the head
Intertubercular groove is located between them; long tendon of the biceps attaches here
Surgical neck is located below the tubercles
o Radial groove runs obliquely on the posterior surface; radial nerve is located here
o Deltoid muscles attaches in a V-shaped area in the middle of the shaft. called the deltoid tuberosity
Distal end has two projections. the medial and lateral epicondyles
Capitulum-articulates with the radius
Trochlea-articulates with the ulqa
Forearm
Radius
Lateral bone of the forearm
Radial tuberosity is located below the head on the medial side
Distal end is broad for articulation with the wrist: has a styloid process on its lateral side
Ulna
Medial side of the forearm
Conspicuous part of the elbow joint (olecranon)
Curved surface that articulates with the trochlea of the humerus is the trochlearnotch
Lateral ide is concave (radial notch); articulates with the head of the radius Distal end contains the styloid process
Distal end contains the styloid process
Hand
Carpal bones (8)
Aranged in two rows of four
Scaphoid. lunate. triquetral. and pisiform proximal row); trapezium. trapezoid.
capitate. and hamate (distal row)
Metacarpal bones (5)
Framework of the hand
Numbered 1 to 5 beginning on the lateral side
Phalanges (14)
Fingers
Three phalanges in each finger; two phalanges in the thumb
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First pouch |
Auditory tube, which comes in contact with epithelial line of first pharyngeal cleft, where future external acoustic meatus will form. Distal portion will form tympanic cavity (lining will become eardrum) Proximal portion will become auditory tube |
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Second pouch |
Forms buds that penetrate surrounding mesenchyme, which together form the palatine tonsils |
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Third pouch |
Forms thymus and inferior parathyroid glands |
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Fourth pouch |
Forms superior parathyroid glands |
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Fifth pouch |
Forms utlimobranchial body |
Nerve Supply of the Muscles of the Orbit (pp. 715-6)
- Three cranial nerves supply the muscles of the eyeball; the oculomotor (CN III), trochlear (CN IV) and abducent (CN IV) nerves.
- All three enter the orbit via the superior orbital fissure.
- The trochlear nerve supplies the superior oblique muscle.
- The abducent nerve supplies the lateral rectus muscle.
- The oculomotor nerve supplies everything else.
- A mnemonic that is used is this formula for this strange sulfate: SO4(LR6)3
The Oral Cavity
- The oral cavity (mouth) consists of two parts: the vestibule and the mouth proper.
- The vestibule is the slit-like spaced between the cheeks and the lips and the teeth and gingivae.
- It is the entrance of the digestive tract and is also used for breathing.
- The vestibule communicates with the exterior through the orifice of the mouth.
- The oral cavity is bounded:
- Externally: by the cheeks and lips.
- Roof of oral cavity: formed by the palate.
- Posteriorly: the oral cavity communicates with the oropharynx.
Sternum
o Forms the medial part of the anterior chest wall
o Manubrium (upper part)-clavicle and first rib articulate with the manubrium .
o Body (middle blade)-second and tenth ribs articulate with the body via the costal cartilages
o Xiphoid (blunt cartilaginous tip)
Ribs (12 pairs)
o Each rib articulates with both the body and the transverse process of its corresponding
o thoracic vertebra
o The second to ninth ribs articulate with the body of the vertebra above'
o Ribs curve outward, forward, and then downward
o Anteriorly, each of the first seven ribs joins a costal cartilage that attaches to the sternum
o Next three ribs (eighth to tenth) join the cartilage of the rib above
o Eleventh and twelfth ribs do not attach to the sternum; are called "floating ribs"
Veins of the Face
The Supratrochlear Vein
- This vessel begins on the forehead from a network of veins connected to the frontal tributaries of the superficial temporal vein.
- It descends near the medial plane with its fellow on the other side.
- These veins diverge near the orbits, each joining a supraorbital vein to form the facial vein near the medial canthus (angle of the eye).
The Supraorbital Vein
- This vessel begins near the zygomatic process of the temporal bone.
- It joins the tributaries of the superficial and middle temporal veins.
- It passes medially and joins the supratrochlear vein to form the facial vein near the medial canthus.
The Facial Vein
- This vein provides the major venous drainage of the face.
- It begins at the medial canthus of the eye by the union of the supraorbital and supratrochlear veins.
- It runs inferoposteriorly through the face, posterior to the facial artery, but takes a more superficial and straighter course than the artery.
- Inferior to the margin of the mandible, the facial vein is joined by the anterior branch of the retromandibular vein.
- The facial veins ends by draining into the internal jugular vein.
The Superficial Temporal Vein
- This vein drains the forehead and scalp and receives tributaries from the veins of the temple and face.
- In the region of the temporomandibular joint, this vein enters the parotid gland.
The Retromandibular Vein
- The union of the superficial temporal and maxillary veins forms this vessel, posterior to the neck of the mandible.
- It descends within the parotid gland, superficial to the external carotid artery but deep to the facial nerve.
- It divides into an anterior branch that unites with the facial vein, and a posterior branch that joins the posterior auricular vein to form the external jugular vein.
- U-shaped bone
- Body
- Greater horn
- Lesser horn
- Suspended by ligaments from the styloid process