Exam 3 Review and Introduction to Skeletal System

Exam 3 Results

  • The average on Exam 3 was 81%.
  • This is an increase from Exam 2, which had an average of 80%.
  • The summer classes typically perform well due to student dedication.
  • A Kahoot quiz on the integumentary system was available for extra credit.
  • Earning all points on the Kahoot could add up to 3.65% to the final score.
  • Students should take advantage of extra credit opportunities.
  • Another extra credit opportunity will be provided at the end of today's class.

Exam 3 - Questions Students struggled with

Skin Color and Melanocytes

  • Question: Whether skin color is classified as light or dark is primarily based on differences in the number of melanocytes present. True or false?
  • Answer: False.
  • Skin color differences are primarily based on the kinds of pigments produced by melanocytes, not the number of melanocytes.
  • Freckles are formed by a crowding of melanocytes.

Parathyroid Hormone (PTH) and Bone

  • Question: If a tumor secreted excessive amounts of parathyroid hormone, one would expect excessive bone dissolving or bone building.
  • To answer, consider: What is PTH's effect on the bone?
  • PTH, along with Vitamin D, increases blood calcium levels.
  • To increase blood calcium levels, PTH stimulates bone dissolving (breakdown) to release calcium into the blood.
  • Therefore, excessive PTH secretion would cause excessive bone dissolving.

Exam 4

  • Exam 4 will cover the skeletal system and joints.
  • The skeletal system will be divided into the axial and appendicular divisions.
  • Axial skeleton: bones of the skull, vertebrae, and torso (rib cage).
  • Appendicular skeleton: bones of the appendages (upper and lower limbs) and the bones where those limbs attach to the torso.
  • Joints will be covered in a separate chapter.

Lab Assignments

  • All lab assignments have been posted and are due Monday morning.
  • Assignments are organized logically, corresponding to the lecture material.
  • Assignments include:
    • Skull tour
    • Axial skeleton practice
    • Quiz over axial skeleton material (review questions from Exercise 8 in the lab manual)
    • Appendicular click to ID practice
    • Lab manual Exercise 9
    • Joints tour and click to ID
    • Exercise number 10
    • Mega overview of the skeleton
  • The lab assignments focus on anatomical identification, naming bones, and identifying surface features and associated joint structures, tendons, etc.
  • This week is anatomy-heavy, with less physiology.

Additional Practice Items

  • Additional practice items have been posted on Moodle.
  • Quizlets and matching games are available.
  • Handouts with diagrams of the thorax, elbow, shoulder, forearm, and full skeleton are available.
  • It is recommended to print off the unlabeled versions of the diagrams and practice labeling them.
  • Use the answer keys to check your work, and start from scratch with a fresh diagram for repeated practice.

Chapter 7 Lecture Overview

  • Chapter 7 covers the axial versus appendicular parts of the skeleton.
  • The axial skeleton includes the bones that form the skull, the vertebra, and the thoracic (rib) cage.
  • The appendicular skeleton includes all the bones of the upper and lower appendages.
  • The appendicular skeleton also includes the pectoral girdle (clavicle and scapula) and the pelvic girdle (hip bones or os coxae).
  • The left and right os coxae together form the pelvic girdle.

Skull Bones

  • There are 22 bones in the skull.
  • Most skull bones are joined together by sutures (tight, immovable joints).
  • 8 cranial bones come in contact with the meninges.
  • 14 facial bones, do not come in contact with the meninges, underlying the facial muscles.
  • Skull bones create important spaces, including the cranial cavity, orbital cavities (eye sockets), nasal cavities, and the buccal cavity (oral cavity).
Skull Bone Review
  • Bones come in pairs (Left and Right sides) Except for frontal bones.
  • Parietal Bone
  • Temporal Bone
  • Frontal Bone
  • Occipital Bone
  • Sphenoid Bone
  • Ethmoid Bone
  • Nasal Bone
  • Lacrimal Bone
  • Zygomatic
  • Maxillary
  • Mandible
Sutures
  • Coronal Suture, joins at the singular frontal bone, to both the left and right Parietal Bones.
  • Sagittal Suture, joins the left and right parietal bones.
  • Squamous Suture, joins the Parietal Bone to the Temporal Bone.
  • Lamboid Suture, joins the Occipital bone to both the right and left Parietal Bone.
Temporal bone features
  • External Acoustic Meatus: the ear hole/passageway leading to the middle and inner ear structures (for hearing).
  • Mastoid Process: a bony protrusion behind the ear.
  • Styloid Process: for attachment of important neck muscles and muscles of swallowing.
  • Zygomatic Process: part of the temporal bone that joins to the zygomatic (cheekbone).
Sphenoid bone features
  • Butterfly-shaped bone that extends the entire width of the head.
  • Sella Turcica: an indentation that houses the pituitary gland.
Ethmoid bone features
  • Forms a vertical portion between the eyes and a horizontal portion forming the roof of the nasal cavity.
Nasal bone features
  • Two nasal bones that fuse together roughly down the center. Forms the bridge of the nose.
Lacrimal bone features
  • Very tiny lacrimal bones in each eye socket. Where tears are produced.
Lower jaw features
  • Mandible: the only really movable bone of the skull.
  • TMJ: Temporomandibular joint, where the mandible connects to the temporal bone.
Temporal bone features
  • Mandibular Foramen: passage of blood and nerve supply to feed the superficial soft tissues.
Skull Openings
  • Foramen: Meaning smaller holes in bone pass blood and nerve supply.
  • Meatuses: Meaning Larger holes for passage way.
Other Skull bone features
  • Mental Protuberance: forms the anatomical chin.

Bottom of the Skull

  • When looking up at the bottom of the skull, note the Occipital bone and cartilage pads.
    Occipital Condyles: This is where the connection between the skull and vertebrae is made.
  • Foramen Magnum: Large hole also at the bottom, where the spinal cord attaches to the brain. posterior extension is the brain stem that connects to the spinal cord.

autopsy photos

  • Shown were several autopsy photos of the cranium with various parts shown in detail.

Bones forming the nasal septum

  • Vomer: forms the inferior half of the septum.
  • Ethmoid bone: forms the superior half of the septum.
  • Septal cartilages (quadrangular cartilage): forms the anterior end of the septum.

Hyoid Bone

  • Positioned just behind the lower jaw (mandible).
  • Unique because it does not articulate with any other bone.
  • Suspended by muscles in the upper throat region.
  • Connects to the styloid process, larynx, and trachea.

Vertebrae and Rib Cage

Typical Vertebra

  • Body: Weight-bearing portion of the vertebra.
  • Spinous Process: Projects from the back, for muscle attachment.
  • Transverse Processes: Extend off to the sides, for muscle attachment.
  • Vertebral Foramen: Space behind the body, containing the spinal cord.

Classes of Vertebrae - Mnemonic using "Eating Times".

  • Cervical (C1-C7): Breakfast at 7:00 AM.
  • Thoracic (T1-T12): Lunch at 12:00 PM.
  • Lumbar (L1-L5): 5:00 PM Dinner.
  • Sacral (S1-S5): Snack time at 10:00 PM.
  • Coccygeal (Co1-Co4): Late night, Taco Bell run at 2 am.
Cervical Vertebrae Features
  • C1 (Atlas) and C2 (Axis) are unique in shape.
  • C1 (Atlas): Triangular shaped bone with no body, large vertebral foramen. Allows head movement in yes gesture.
  • C2 (Axis): Semi-triangular with a prominent point (dens or odontoid process) that projects through the atlas. Allows head movement in no gesture.
  • C3-C7: Small bodies, forked spinous processes, and transverse foramen (holes in transverse processes).
  • Transverse foramen houses the vertebral arteries and veins, providing blood supply to and from the head.
Thoracic Vertebrae Features
  • Larger bodies than cervical vertebrae.
  • Articulate with rib pairs (12 rib pairs total).
Lumbar Vertebrae Features
  • Even larger bodies.
  • Blunt and squarish spinous processes.
Sacral and Coccygeal Vertebrae Features
  • Fuse with age, forming part of the pelvic girdle and tailbone, respectively.
  • Sacral fuses at approximately 26 years old.
  • Coccyx fuses at approximately 30 years old.
  • Site of attachment of some muscles of the pelvic floor.

Rib Cage

  • Protects the vital organs in the chest.
  • Consists of the sternum (breastbone) and 12 rib pairs.
  • Sternum: Composed of the manubrium, body, and xiphoid process.
  • Ribs connect to the sternum via costal cartilage.
  • Posteriorly, ribs connect to the thoracic vertebrae.
Rib connections to vertebrae
  • Typically two connections:
    Rib to the body of the vertebrae.
    Rib to the transverse process of the vertebra.
    head to vertebral body and the elbow of the rib, the tubercle to the transverse process.
Rib Types
  • True Ribs (1-7): Connect directly to the sternum via their own independent costal cartilage.
  • False Ribs (8-12):
    • Ribs 8-10 connect indirectly, via another costal cartilage.
    • Ribs 11-12 (floating ribs) do not have any connection ventrally towards the front of the body.

Appendicular Preview + Mnemonics

Appendicular Skeleton

*   The appendicular skeleton includes all of the wrist bones and ankle bones.
Tarsals of the Foot - Mnemonic "Tiger Cubs Need Milk"
*   Ankle bones are collectively referred to as tarsals.
*   Tiger cubs need and then milk.
*   Tiger cubs: The proximal row.
*   Is talus
*   calcaneus
*   Navicular
*   Milk, the distal row.
*   Medial
*   Intermediate
*   Lateral
*   Is all Cuneiforms. The second C which is the cuboid.
Scapula (Shoulder Blade)
*   The shoulder is attached to the torso.
*   Feel for your shoulder blade and orientate yourself with the spine.
*    The spine extends to the Acromion process
  • View Details:
    • Back is, posterior.
    • Front, a anterior view.
    • Medial towards.
Hip bone
  • Llium, the upper superior largest part off the bone.
  • The obturator with the other two parts.
    Ischium.
    Pubis.
    With the ischium, this is your butt bone,
    This is where the pubic bone comes together from the left and right and it forms the pubic Symphysis.
Carpals of the Hand - Sally Left the Party to Take Charlie Home or Straight Line to Pinky. Here Comes the Thumb.
    Carpals are the wrist bones.
  • Sally left the party, and that is, proximals: Scaphoid, Lunate, Triquetrum, Pisiform.
  • There are two mnemonics one of kinesiology majors, Duke University: straight line to pinky, hear comes a thump.
  • 2 Mnemonics:
    straight line to the pinky: scaphoid, lunate, triquetrum, and the pisiform.
  • then flipped to: Hamate, cataptale, trpezipaid, and trapezium
  • Here comes the thumb: :Hamate, capitate, trapezoid, and trapezium.
  • the hook of Hamate, know which feel when in the computer. Where your pinky is