Tuesday, 19 February 2019

Anatomy Revisited #1



Q. Which of the following is true of the anatomical position?
(A) The humerus is proximal to the scapula.
(B) The radius is medial to the ulna.
(C) The vertebral arch is ventral to the vertebral body.
(D) The femur is superior to the fi bula.
(E) The phalanges of the foot are cranial to the metatarsals

Ans: The answer is D:
The femur is superior to the fibula. In theanatomical position, a person is standing erect, facing anterior(forward), with the upper limbs by the sides, the palms facing anterior, the lower limbs placed together with the soles on the ground, and the toes pointing anterior. In this position, the thigh is superior to (above) the lower leg. Thus, the femur is superior to both the tibia and fi bula. Choice A (The humerus is proximal to the scapula) is incorrect. The humerus hangs from the lateral corner of the scapula; thus, it is lateral and inferior to the scapula. The humerus also may be described as distal to the scapula because it is further away from the attachment of the upper limb to the trunk. Choice B (Theradius is medial to the ulna) is incorrect. The radius is the bone in the forearm located further away from the midline. Therefore, the radius is located lateral to the ulna. Choice C (The vertebral arch is ventral to the vertebral body) is incorrect.
The vertebral arch, which is composed of the paired pedicles and laminae, is located dorsal (posterior; behind) to the body of the vertebra. Choice E (The phalanges of the foot are cranial to the metatarsals) is incorrect. The phalanges (toes) are positioned anterior to (or in front of) the metatarsals, which are located in the body of the foot. The phalanges also can be described as being distal to the metatarsals in that they are further away from the attachment/origin of the foot.

Q. A radiologist wishes to image the body in a plane parallel to both scapulae. Which of the following choices best describes the desired sectioning?
(A) Horizontal section
(B) Transverse section
(C) Frontal section
(D) Sagittal section
(E) Oblique section

The answer is C: Frontal section.
The scapulae (shoulder blades) lie across the back. An imaging plane passing parallel
to both these bones divides the body into anterior (front) and posterior (back) parts. A frontal (coronal) section divides the body into anterior (front) and posterior (back) portions.
It runs perpendicular to the median and horizontal planes. Choice A (Horizontal section) is incorrect. A horizontal section passes at right angles to both the median and coronal planes, dividing the body into superior (upper) and inferior (lower) parts. Choice B (Transverse section) is incorrect. A transverse section (cross section) passes perpendicular to the long axis of a structure. While often the same as a horizontal section, it is not always equivalent. For example, a transverse section through the foot is equivalent to a coronal (frontal) section, dividing the foot into anterior and posterior parts. However, a horizontal section of the foot divides it into superior and inferior parts, as shown in the given illustration. Choice D (Sagittal section) is incorrect. A sagittal section runs parallel to the median plane of the body, dividing it into unequal right and left parts. Choice E (Oblique section) is incorrect. Oblique sections run at offset angles from the median, coronal, and horizontal planes. Horizontal sections of the abdomen produce mostly oblique (not transverse) sections of the small intestine because of the coiled nature of the bowel.


Q.Screwing in movement of forearm is?
 (A) Flexion
(B) Abduction
(C) Pronation
(D) Adduction
(E) Supination
The answer is E: Supination.
The screw-home movement is the clockwise motion that drives a screw into its receptacle,
in this case the bulb into the socket. When using the right hand, the palm and forearm turn laterally and the palm moves from facing posterior to facing anterior, which is supination. Choice A (Flexion) is incorrect. Flexion is the action of decreasing the angle between parts while moving through the median or sagittal planes. Choice B (Abduction) is incorrect. Abduction refers to movements going away from the midline in the coronal plane. Choice C (Pronation) is incorrect. Pronation is the opposite of supination. When pronating the right hand, the palm and forearm turn medially so that the palm moves from facing anterior to facing posterior. In this case, right-handed pronation is a counter-clockwise movement that would unscrew the light bulb. However, when using the left hand, pronation produces the screw-home movement. Choice D (Adduction) is incorrect. Adduction refers to movements going toward the midline in the coronal plane.



Source: lipincotts illustrated anatomy and embryology