Exhaustive Human Anatomy Study Guide: Muscles, Connective Tissues, and Lab Protocols

Course Analytics and Performance Overview

• Overall Class Average: $53.6\%$
• Score Variance: Variance spans $32\%$, representing a difference of $3$ letter grades.
• Score Range: Lowest score was $1$; highest score was $97$.
• Grade Distribution Breakdown:
  • A: $1$ student
  • B: $2$ students (plus $1$ additional B recorded)
  • C: $5$ students
  • F: $9$ students (more than half of these scores fell below $25\%$)
• Course Grade Policy: All enrolled students remain on the roll sheet and will receive a final grade at the end of the semester. No students will be dropped automatically.

Schedule, Open Lab, and Assessment Plan

• Upcoming Assessment Timeline:
  • Current Week: Last opportunity to make major strategic changes in study habits.
  • Next Week: Content review and quiz covering assigned material.
  • Following Week: Exam $2$ (marking the $50\%$ midpoint of the semester).
• Open Lab Availability:
  • Open lab is active during the current week.
  • Next week represents the final week of open lab prior to Exam $2$, concluding on that Friday.
• Preparation Requirements: Complete the lab learning activity prior to attending class next week.

Lab Coat and Cadaver Protocol

• Cadaver Utilization: Cadavers will be used continuously in lab from the current session through the end of the semester. Cadaver-based questions will appear on next week's quiz and on Exam $2$.
• Lab Coat Sizing and Fitting: Lab coats range from size extra small to double extra large, extending to approximately arm length.
• Sanitation and Storage Procedure:
  • Lab coats must be sealed inside plastic bags for $10$ minutes to prevent outbreaks of lice or scabies.
  • Label the plastic storage bag with full name using a Sharpie.
  • Create a name tag on a piece of tape using first name and affix it directly to the lab coat.

Scope of Study and Manual Structure

• Lab Assessment Scope:
  • Students are responsible for terminology definitions and muscle identification (names).
  • Muscle actions will not be tested on the lab quiz; actions will be tested during the in-person midterm on October $20$
• Anatomical Landmarks Column: The middle column of the lab manual lists the two landmark bone attachments used to locate each muscle.
• Material Cut-Off: Draw a line on page $11$ directly beneath "muscle of breathing" (diaphragm). The diaphragm is the final muscle included on next week's quiz.

Gluteal Muscle Group

• Gluteus Maximus: The largest and most superficial muscle of the gluteal group.
• Gluteus Medius: Triangular-shaped muscle located deep to the gluteus maximus and anterior to it.
• Gluteus Minimus: The smallest muscle of the gluteal group. Visible on only $3$ lab models:
  1. Plastic Man model (front desk).
  2. Torso models ($2$ identical torso units displaying a cut gluteus medius with gluteus minimus underneath).
  3. Three-quarter hip model: Features the pubis on the anterior side; lacks gluteus maximus on the posterior side, but features a cut gluteus medius with a window displaying gluteus minimus.

Iliopsoas Muscle Group

• Iliacus: Located directly inside the iliac fossa within the abdominal cavity model.
• Psoas Major: Positioned directly medial to the iliacus muscle; attaches to the lumbar vertebrae. Contains a silent initial letter 'p' (Greek origin).
• Cadaver Identification Note: To observe the iliopsoas group on a cadaver, the intestines must be lifted and moved aside.

Adductor Muscle Group

• Adductor Longus: The most anterior of the three adductor muscles; the primary muscle involved in common groin strain injuries.
• Gracilis: The most medial and smallest muscle of the adductor group ("gracile" translates to petite); vulnerable to injury during leg squeezing actions.
• Adductor Magnus: The largest and most posterior adductor muscle; extends down the medial thigh and wraps slightly anteriorly.

Anterior Thigh and Fascial Structures

• Sartorius: The longest muscle in the human body. Runs diagonally from the hip to the medial knee like a sash. Named after Latin sartor (tailor) due to the crossed-leg sitting position used at sewing looms ("crisscross applesauce").
• Tensor Fascia Latae (TFL): Teardrop-shaped muscle located at the front pocket region.
  • Etymology: Tensor = stretcher/puller; Fascia = band/bundle (from Latin fascis); Latae = lateral/side. Literal translation: "side band stretcher".
• Iliotibial Band (IT Band): Aponeurosis pulled by the tensor fascia latae. Name combines ilium and tibia with an 'o' per Greek compound naming conventions.
• Aponeurosis Structure: Broad, flat, tendon-like connective tissue sheet joining muscles. The iliotibial band is the only named aponeurosis required by name. Additional bodily aponeuroses exist on the scalp/head, lower back, and abdominal wall.

Hamstring Muscle Group

• Biceps Femoris: Lateral hamstring muscle (pinky toe side) featuring two heads (long head and short head).
• Semitendinosus: Superficial medial hamstring muscle. Named because half ($50\%$
• Semimembranosus: Deep medial hamstring muscle located directly beneath the semitendinosus; represents the most medial hamstring.

Quadriceps Muscle Group

• Rectus Femoris: Straight muscle running down the midline of the anterior thigh.
• Vastus Medialis: Large muscle on the medial aspect of the anterior thigh (big toe side).
• Vastus Lateralis: Large muscle on the lateral aspect of the anterior thigh.
• Vastus Intermedius: Deep muscle located directly underneath the rectus femoris (inter = between).

Lower Leg Muscle Group

• Tibialis Anterior: Most anterior muscle of the lower leg, positioned adjacent to the tibia. Primary muscle implicated in shin splints due to tissue tearing away from bone during running.
• Extensor Digitorum Longus: Located one muscle width lateral to the tibialis anterior (marked with a screw on lab models). Features a tendon splitting to all toes; performs toe extension and dorsiflexion.
• Functional Definitions:
  • Flexion: Decreasing the angle between two bones.
  • Extension: Increasing the angle between two bones.
• Gastrocnemius: Superficial posterior lower leg muscle ("leg belly").
• Soleus: Deep posterior lower leg muscle situated beneath the gastrocnemius. Named after sole fish ("fillet of sole") due to its flat appearance.
• Calcaneal Tendon: Shared tendon inserting the gastrocnemius and soleus into the calcaneus. Formally designated calcaneal tendon (layman term: Achilles tendon).

Facial and Neck Muscles

• Orbicularis Oculi: Circular muscle encircling the eye orbit; closes eyelids tightly.
• Temporalis: Biting muscle overlying the temporal bone.
• Masseter: Primary chewing muscle located over the ramus of the mandible (masticate = to chew; macerate = to break down/tear up).
• Zygomaticus: Muscle attached to the zygomatic bone (cheekbone); enables smiling. Dimples are caused by a structural variation or partial absence of this muscle.
• Buccinator: Deep muscle of the cheek (buccal region). Named after trumpet playing (buccinator); functions in blowing, trumpet playing, and suction via straws.
• Sternocleidomastoid: Attaches to the sternum, clavicle, and mastoid process (sterno-cleido-mastoid). Enables head rotation and chin flexion. Moved laterally when palpating the carotid pulse.
• Digastric: Hammock-shaped muscle beneath the mandible featuring two bellies (di = two, gastric = belly):
  • Anterior belly: Opens mandible ("ah").
  • Posterior belly: Attaches to hyoid bone; aids swallowing.

Grading Clarifications and Student Dialogues

• Question $29$ Examination Clarification: Adding extraneous anatomical descriptors to correct base terms (such as over-specifying proximal regions) results in point deductions because the added text alters the named structure to a different anatomical feature.
• Terminology Precision: "Medial" denotes a direction, whereas "middle" denotes a structural position (e.g., middle phalanx vs. medial phalanx). Confusing directional and positional terms represents the single most common deduction on laboratory exams.
• Career Path Discussions: Students discussed academic requirements for occupational therapy, speech-language pathology, and child life specialty programs.

Laboratory Field Notes and Cadaver Observations

• Cadaver Pathology: Specimen cause of death was a stroke.
• Cadaver Condition: Fully intact anatomical specimen with skin removed, exposing muscular and skeletal structures.
• Facility Layout: The cadaver storage suite is located through a secured interior side door within the laboratory space.