march 20 bone review

Nasal Conchae

  • Nasal Conchae Overview

    • The nasal conchae consist of three pairs: superior, middle, and inferior.

    • Inferior Nasal Concha: This is a separate bone.

    • Middle and Superior Nasal Conchae: Parts of the ethmoid bone, not standalone bones, hence they are not bolded.

  • Identification

    • For identification questions:

      • Ethmoid bone = answer for bone identification.

      • Middle nasal concha or superior concha = answer for structure identification.

    • Superior nasal conchae are fragile; often broken out in human skulls, unlikely to be asked to identify these.

Hyoid Bone

  • Overview

    • The hyoid bone is not a skull bone; it is located near the skull.

    • It does not connect with any other bones, providing support to structures like the larynx and tongue muscles.

    • The only specimens available for study are attached to cervical vertebrae in skeletons.

  • Key Functions

    • Forms the upper edge of the larynx (voice box).

Thoracic Cage (Rib Cage)

  • Components

    • Composed of 12 pairs of ribs numbered from top to bottom.

  • True Ribs (7 pairs)

    • Connection: Each attaches directly to the sternum via its own costal cartilage.

    • Also known as vertebrosternal ribs.

  • False Ribs (5 pairs)

    • Connection: Last three pairs link to the cartilage of the rib above, not directly to the sternum.

    • Known as vertebrochondral ribs.

    • The last two pairs do not attach anteriorly, referred to as floating ribs or vertebral ribs.

  • Identifying Ribs

    • Know how to recognize true vs. false ribs in intact skeletons; remember 7 true, 5 false.

Clavicle

  • Identification

    • The clavicle (collarbone) is easily identifiable due to its S-shape.

    • Identification of its ends will occur in the context of the complete skeleton.

Vertebrae Structures

  • General Structure

    • Each vertebra has two main parts:

      • Body (large cylindrical structure)

      • Vertebral arch (which includes processes: transverse and spinous processes, and other structures).

  • Vertebral Foramen

    • The neural opening through which the spinal cord passes.

    • The collective openings of vertebrae create the vertebral canal.

  • Intervertebral Foramen

    • Holes between vertebrae, through which spinal nerves exit.

Types of Vertebrae

  • Main Types

    • Cervical Vertebrae (7)

      • Identified by the presence of transverse foramina.

      • Atlas (C1): No body, ring-shaped.

      • Axis (C2): Features a tooth-like structure called dens.

    • Thoracic Vertebrae (12)

      • Key feature: facets for rib articulation on transverse processes.

    • Lumbar Vertebrae (5)

      • Largest vertebrae; differentiated by lack of transverse foramina and rib articulation facets.

Long Limb Bones

  • Presentation

    • Upper and lower limb include six large long bones; identification required at stations.

  • Upper Limb

    • Humerus: Rounded head, no narrow neck.

    • Femur: Largest bone, rounded head connected via a narrow neck.

    • Forearm Bones:

      • Ulna: Shaped like a pipe wrench or ice cream scooper.

      • Radius: Head shaped like a golf tee.

  • Lower Limb

    • Tibia: Thick bone with a medial malleolus (inner ankle bump).

    • Fibula: Thinner bone with lateral malleolus (outer ankle bump).

Bones of the Hand and Wrist

  • Carpals

    • Eight wrist bones, arranged in two rows.

    • Remember with the mnemonic: "Some Lovers Try Positions That They Can't Handle".

      • Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate.

  • Metacarpals and Phalanges

    • Metacarpals: Bones of the palm.

    • Phalanges: Order as proximal, middle (not for the thumb), and distal.

Bones of the Foot and Ankle

  • Tarsals

    • Like wrist; bones are called tarsals.

  • Mnemonic for Tarsals

    • Talus, Calcaneus, Navicular, and three Cuneiforms, plus Cuboid.

  • Metatarsals and Phalanges

    • Same terminology applies as in hands; toes also have proximal, middle, and distal phalanges.

Pelvis Structure

  • Components

    • Comprised of two coxae, a sacrum, and a coccyx.

    • Each coxa consists of three fused bones: ilium, ischium, and pubis.

  • Key Terminology

    • Pelvic girdle: The structure made by the two coxae.

    • Pubic symphysis: Joint where the pubic bones meet.

    • Sacroiliac joint: Connection between ilium and sacrum.