AP I Lab Exam 3 Review: Bones, Joints, Muscles, and Integumentary System

Bone Terminology and Landmarks

Key Bone Terms

Understanding bone terminology is essential for identifying skeletal structures and their functions.

• Condyle: A rounded end of a bone that articulates with another bone. Example: The mandible has a condyle that forms the temporomandibular joint.

• Foramen: A hole in a bone, typically allowing the passage of nerves and blood vessels. Example: The foramen magnum in the occipital bone allows the spinal cord to pass through.

Bone Identification and Sidedness

Recognizing bones and determining their right or left orientation is a fundamental skill in anatomy.

• Scapula: The shoulder blade; the image provided is a right scapula.

• Tibia and Fibula: The two bones of the lower leg. The image provided is of the right tibia and fibula, with labeled landmarks such as the medial condyle, lateral condyle, and medial malleolus.

• Vertebrae: The lumbar vertebrae are identified by their large, robust bodies and short, thick spinous processes, suitable for supporting the weight of the lower back.

Joint Movements

Types of Movements

Joint movements describe how bones move relative to each other at articulations.

• Supination: The rotation of the forearm and hand laterally so that the palm faces anteriorly (upward in anatomical position).

• Extension: Increasing the angle between two bones, such as straightening the elbow.

Pelvic Anatomy: Male vs. Female

Comparative Features of the Pelvis

The pelvis differs between males and females due to functional requirements such as childbirth.

Characteristic	Female Pelvis	Male Pelvis
General Build	Lighter, thinner	Heavier, thicker
Greater Sciatic Notch	Wide	Narrow
Pubic Arch Angle	Broader (90-100°)	Acute (60-70°)
Sacrum	Wider, shorter	Narrower, longer
Coccyx	More movable, straighter	Less movable, curves anteriorly
Pelvic Inlet	Wider, more oval	Narrower, heart-shaped

Muscle Anatomy

Major Muscles: Origins, Insertions, and Actions

Knowing the origin, insertion, and action of muscles is crucial for understanding movement and function.

• Quadriceps Muscles:

  • Rectus femoris

  • Vastus lateralis

  • Vastus medialis

  • Vastus intermedius

  Insertion for all: Patella and tibial tuberosity Action: Extends the knee; rectus femoris also flexes the thigh; vastus lateralis and vastus medialis stabilize the patella.

• Orbicularis oculi:

  • Origin: Orbital portions of the frontal bone and maxilla

  • Insertion: Skin of the orbital area and eyelids

  • Action: Closes the eye, blinking/winking

• Other muscles to know: buccinator, pectoralis major, deltoid, diaphragm, latissimus dorsi, triceps brachii, hamstrings, sternocleidomastoid, external intercostals, internal oblique, trapezius, biceps brachii, teres major

Integumentary System

Layers of the Skin

The skin consists of several layers, each with distinct functions.

• Stratum lucidum: A clear layer found only in thick skin, such as the palms of the hands and soles of the feet.

• Thick skin: Located on the palms and soles, contains the stratum lucidum and has a thicker epidermis compared to thin skin.

Sweat Glands: Eccrine vs. Apocrine

Sweat glands play a role in thermoregulation and excretion.

Feature	Eccrine Sweat Glands	Apocrine Sweat Glands
Distribution	All over the body	Confined to axillae, areola, and anogenital areas
Function	Temperature regulation	Activated at puberty; respond to pain, stress, sexual stimulation
Secretion	Primarily water	Contains proteins
Structure	Smaller, superficial in dermis	Larger, deeper in dermis
Associated Structures	Opens directly onto skin surface	Empties into hair follicles

Additional info:

• Students should review diagrams and labeled images as referenced in the notes for visual identification of bones, muscles, and skin structures.

• Understanding anatomical terminology and being able to apply it to practical identification is essential for lab exams.