5/29/25 Intro to Anatomy

Introduction to Anatomy

Objectives

  • Identify and apply anatomicomedical terminology clinically.
  • Identify primary anatomic systems relevant this semester.
  • Describe clinical applications for examples of anatomic systems.

Questions

  • Email questions or ask in class during the lecture debrief.

Approaches to Anatomy

  • Regional: Study by body regions (e.g., head, neck).
  • Systemic: Study by body systems (e.g., skeletal, nervous).
  • Clinical: Study as related to health sciences; synthesizes regional and systemic approaches.

Regional Anatomy

Surface Anatomy

  • Study of relationships of structures beneath the skin.
  • Emphasizes observation and palpation of tendons, muscles, bones, arteries.

Anatomicomedical Terminology

Anatomical Position

  • Head and toes facing anteriorly.
  • Arms adjacent to side, palms anterior.

Anatomical Planes

  • Median: Vertical plane passing longitudinally, dividing into right and left halves.
  • Sagittal: Vertical planes parallel to the median plane.
  • Frontal (coronal): Vertical planes at right angles to the median plane, dividing into anterior and posterior.
  • Horizontal (transverse): Horizontal plane at right angles to both median and frontal plane, dividing into superior and inferior.
  • Clinical Application: Spine Motions
    • Flexion/extension.
    • Sidebending.
    • Rotation.

Anatomicomedical Terminology: Relationships

  • Remember anatomical position!
  • Medial / Lateral: Example: forearm.
  • Anterior / Posterior: Example: forearm.
  • Dorsal / Ventral: Hand vs. foot; example: hand.
  • Superior / Inferior, Cranial / Caudal, Proximal / Distal

Terms of Laterality

  • Ipsi/Contra: Same vs. opposite side.
  • Unilaterally vs. bilaterally: One side vs. two sides.
  • Example: Sternocleidomastoid (SCM)
    • Action:
      • Bilaterally: Flexes the neck.
      • Unilaterally: Ipsilateral lateral neck flexion and contralateral rotation.

Anatomicomedical Terminology: Terms of Movement

  • Flexion/Extension
    • Flexion at ankle (dorsiflexion)
    • Extension at ankle (plantarflexion)
  • Thumb movements examples.

Anatomicomedical Terminology: Terms of Movement

  • Abduction/Adduction
    • Horizontal
    • Scapular
    • Humeral
  • Example: Humerus vs. fingers
    • Fingers
      • Axis: 3rd met
  • Thumb abd/add example.

Anatomicomedical Terminology: Terms of Movement

  • Abduction/Adduction
    • Example: femur vs. toes
      • Toes
        • Axis: 2nd met (Netter 537)
  • Rotation:
    • Medial (internal) / Lateral (external)
    • Upward and downward
  • Circumduction
    • Combination of flex/ext, abd/add
  • Opposition/Reposition
    • Thumb
  • Protrusion/Retrusion
    • Mandible, lips, tongue

Anatomicomedical Terminology: Terms of Movement

  • Elevation/Depression: Example: scapula.
  • Inversion/Eversion: Example: ankle.
  • Pronation/Supination: Example: forearm.

Summary: Terminology

  • Anatomical position.
  • Anatomical planes.
  • Relationship and comparison.
  • Terms of movement.

Anatomic Systems

  • Skin and Fascia.
  • Skeletal System.
  • Muscular System.
  • Circulatory System: Vascular/Lymphatic Systems.
  • Nervous System.

Skin

  • Functions:
    • Protection.
    • Containment.
    • Heat regulation.
    • Sensation.
    • Synthesis and storage of Vitamin D.

Skin and Fascia Layers

  • Skin
    • Epidermis
    • Dermis
  • Subcutaneous Tissue
    • Superficial fascia
  • Deep Fascia (Moore COA p 13)

Epidermis

  • No blood vessels (avascular).
  • No lymphatics.
  • Contains some nerve endings (Moore COA p 13).

Dermis

  • Composed of collagen and elastic fibers.
  • Pattern of collagen determines tension and wrinkle lines of the skin (Moore COA p 13).
Langer Lines (Tension Lines)
  • Tend to be longitudinal around limbs, transverse around neck and trunk.
  • At elbows, knees, wrists, ankles: more transverse (Moore COA p14).

Clinical Application

  • Incisions and scars parallel to tension lines heal well due to limited disruption of collagen.
  • Incisions and scars perpendicular to tension lines may gap or have keloid scarring due to disruption of collagen fibers.
  • Note: tension lines are just one consideration for placement of surgical incisions.
  • What are some other considerations?
  • Elastic fibers deteriorate with age/not replaced, increasing wrinkles/skin sagging.

Dermis components:

  • Hair follicles.
  • Arrector pilli muscles (Moore COA p 13).
  • Sebaceous glands (Moore COA p 13).
  • Sweat glands
  • Nerves
  • Blood vessels: Dilation/constriction (Moore COA p13).
  • Lymphatic vessels (Moore COA p13).

Fascia

  • Subcutaneous Tissue (superficial fascia).
  • Deep Fascia (Moore COA p13).

Subcutaneous Tissue (Superficial Fascia)

  • Includes fat in addition to structures of dermis.
  • Skin ligaments: Attach deep fascia to the dermis (Moore COA p 13).
  • Controls the mobility of the skin over the deeper layers.
  • Dorsum vs. palm of hand.
  • Clinically, why is skin mobility important? (Moore COA p 13)

Deep Fascia

  • Dense and organized connective tissue layer that surrounds deeper structures (Moore COA p 13; Netter p 522).
Investing Fascia:
  • Extensions from internal surface that invest deeper structures.
Intermuscular Septa:
  • Thick sheets of deep fascia that typically connect from the surrounding fascia to the bone (Netter p 522).

Deep Fascia

Retinaculum:

  • Thickening of deep fascia around joints.

Deep Fascia Function

  • Divides limbs into compartments.
    • Clinical significance: compartment syndrome (Netter p 522).
    • Contain or direct the spread of infection (Netter p 522).

Deep Fascia Function

  • Limits outward expansion of muscles during contraction (Netter p 522).
  • Compressing veins, returning blood to heart (assisted by one-way valves)(Netter p 522).

Bursae

  • Closed sacs or envelopes of serous membrane.
  • Typically collapsed, containing just a thin layer of fluid.
  • Function of bursae?
  • Identify a few bursae in the body.

Synovial Sheaths

  • Specialized elongated bursae that wrap around tendons (Netter p 463; Netter p 461).

Clinical Application

  • What structures are located in a compartment besides muscle? (Netter p 522)

Clinical Application

  • If pressure builds up in a compartment, what would happen to the vasculature and nerves in the compartment? (Netter p 463)

Clinical Application

  • How would injuries to the anatomical structures translate to signs/symptoms?
  • How would a patient with acute compartment syndrome present – i.e., What are the signs/symptoms of compartment syndrome?

Summary: Skin and Fascia

  • Skin and fascia and selected clinical applications

Skeletal System

Divisions:

  • Axial skeleton: Head, neck, and trunk.
  • Appendicular skeleton: Limbs, including pectoral and pelvic girdles.

Skeletal System

  • Composed of bone and cartilage.
  • Bone: living connective tissue
  • Functions:
    • Protection
    • Support
    • Supply new blood cells
    • Leverage for movement

Skeletal System

  • Medullary (marrow) cavity
  • Blood cell and platelet formation

Skeletal System

Periosteum

  • Fibrous connective tissue membrane covering bone (except where articular cartilage occurs).
  • Highly innervated with pain fibers.
  • Bone itself has limited pain fibers.
  • Clinical Application
    • Fracture Pain
    • Ultrasound

Skeletal System

  • Classification of Bones - examples
    • Long
    • Short
    • Flat
    • Irregular
    • Sesamoid
  • For each of the above types of bone, give an example of each.

Skeletal System

  • Bone markings and formations
    • Condyle
    • Tubercle
    • Crest
    • Fossa
    • Foramen
  • What is the significance of the above structures?

Skeletal System

  • Cartilage
    • White fibrocartilage: IV disks, labrum
    • Yellow elastic cartilage: ears
    • Hyaline articular cartilage: ends of bones

Skeletal System: Joints Classification

  • Joints classified according to the manner / material by which they are united
  • Amount of motion available at a joint varies
  • Amount of motion is influenced by the joint type

Skeletal System: Joints Types

  • Fibrous
  • Cartilaginous
  • Synovial

Skeletal System: Fibrous

  • United by fibrous tissue
    • Sutures: Bones are close together, either interlocking or overlapping. (skull)
    • Syndesmosis: Bones are united with a sheet of fibrous tissue and are partially mobile. (interosseous membrane)
    • Gomphosis: Bones are peg-like processes that fit into a socket (teeth)

Skeletal System: Cartilaginous

  • United by hyaline cartilage or fibrocartilage

Primary cartilaginous (Synchondrosis)

  • Bones are united by hyaline cartilage and are usually temporary. (growth plates)

Secondary cartilaginous (Symphysis)

  • Bones are united by fibrocartilage and joints are slightly mobile. (pubic symphysis)

Skeletal System: Synovial

  • United by articular capsule
    • Capsule lined by synovial membrane
      • Synovial membrane produce synovial fluid
    • Articular cartilage
  • Synovial joints are classified according to their shape and the motions they permit

Skeletal System: Synovial Joints Types

  • Plane
  • Hinge
  • Saddle
  • Condyloid
  • Ball and socket
  • Pivot
  • For each of the above types of joints, give an example of each.

Skeletal System: Synovial Joints - Details

Plane

  • Flat surfaces
  • Usually uniaxial
  • Permit gliding or sliding movements

Hinge

  • Uniaxial: permit flexion and extension
  • Capsule lax A/P; strong M/L ligaments

Skeletal System: Synovial Joints - Details

Saddle

  • Saddle shaped surfaces
  • Biaxial: abduction/adduction, flexion/extension
  • Example: 1st Carpometacarpal (CMC)

Condyloid

  • Biaxial: abduction/adduction, flexion/extension
  • Motion in one plane >> motion in other plane
  • Example: Metacarpophalangeal (MP)

Skeletal System: Synovial Joints - Details

Ball and socket

  • Multiaxial: Flexion/extension, abduction/adduction, medial/lateral rotation

Pivot

  • Uniaxial: rotation around a central axis

Joint Nerve Innervation and Blood Supply

Nerve Supply

  • Joints have rich nerve supply; nerve endings located in the articular capsule
  • Hilton’s Law = nerves supplying a joint also supply the muscles moving the joint and the skin covering the attachments of these muscles
  • Articular nerves transmit sensory impulses from the joint that contribute to proprioception

Arterial Supply

  • Articular arteries provide blood supply to joints
  • Located in the joint capsule
  • Arise from vessels around the joint
  • Often anastomose (communicate) to form peri-articular arterial anastomoses (networks)

Venous drainage

  • Articular veins accompany arteries

Summary: Skeletal System

  • Bone and cartilage
  • Bone shapes
  • Bony landmarks
  • Types of cartilage
  • Types of joints

Muscular System

  • Types of muscle:
    • Skeletal
      • Flat, pennate, fusiform, quadrate, circular
    • Cardiac
    • Smooth (Moore COA p31)

Vascular System

  • Arteries
    • tunica adventitia
    • tunica media
    • tunica intima
  • Veins
  • Capillaries (Moore COA p39)

Clinical Application: Blood Supply

  • Blood supply is very important (but not the only factor to consider) for healing potential.
  • Know the quality of a structure’s blood supply
    • Lateral ankle ligaments, MCL
    • ACL, scaphoid
  • Know the location of a structure’s blood supply
    • Meniscus
  • Know if the blood supply changes with age
    • Meniscus

Muscle Packet

  • Have to know that information cold.
  • The next step will be applying that info – we will be testing the strength of the muscles, and for each muscle, you have to be able to say out loud its origin, insertion, action, primary spinal nerve levels and peripheral nerve levels off the top of your head

Muscle Packet

  • Ask what other muscles are innervated by
    • the same spinal nerve
    • the same peripheral nerve
  • Ask where the muscle originates, inserts
  • You have to know that basic factual info about each muscle cold because we’re going to be adding the psychomotor component of testing the muscle on top of that.

References

  • Moore et al. Clinically Oriented Anatomy 9th edition LWW 2022
  • Netter F. Atlas of Human Anatomy 8th edition Elsevier 2022.