Anatomy Lecture Anatomy Lecture ReviewReview

Anatomical Position

• The body standing erect, facing forward, feet together, toes pointed slightly apart, hands at one’s side, palms facing forward.

• Once the body is in this position (or imagined to be in this position,) the positional terms can be used correctly.

• Left and Right: yours or the patient’s?

Positional Terms

AnteriorPosterior

VentralDorsal

SuperiorInferior

MedialLateral

SuperficialDeep

ProximalDistal

SupineProne

Body Planes

• Frontal (Coronal)• Sagittal• Transverse

Sagittal plane

Para-Sagittal plane

Histology

• Histology is the study of normal tissues under a microscope.

• Be able to recognize a description of all the structures seen in compact bone under a microscope:– Lacunae, perforating canal, osteon (functional

unit of compact bone), central canal, canaliculi, lamellae, osteocytes, osteoblasts, osteoclasts, periosteum, hydroxyapatite.

Compact Bone

Compact Bone Structures• Osteon: functional unit of compact bone.• hydroxyapatite The crystalline structure of calcium and phosphate

that make up bone matrix• lamellae The circular and concentric layers of collagen fibers• lacunae The pockets or cavities in which the cells are trapped• Haversian (or central) canal The large channels containing a

blood vessel which run longitudinally down the center of each unit• canaliculi The “tiny channels” which run transversely through the

layers of bone and allow for diffusion of nutrients and wastes to the cells

• perforating canal: connects one Haversian canal to another• osteocytes The mature bone cells which are trapped in the matrix

and help to maintain it• Osteoblasts: bone cells that lay down new bone• Osteoclasts: bone cells that reabsorb bone

Bone Terms to Know• Periosteum (secured to the bone by Sharpey’s

fibers)• Sharpey’s fibers (anchor the outer wrapping to

the bony matrix below it)• Articular Cartilage (cap around long bone)• Tendon (attaches muscle to bone)• Ligament (attaches bone-to-bone)• Aponeurosis (modified tendon)• Epiphysis (ends of long bones)• Diaphysis (shaft of long bone)• Medullary Cavity (hollow area inside long bone)• Spongy Bone (contains trabeculae instead of

osteons and lamellae)• Trabeculae

Spongy Bone

• Instead of osteons, spongy bone has trebeculae.

Histology

• Tendons and ligaments are made from what type of connective tissue?– Dense Regular Connective Tissue

The Axial Skeleton

• Skull • Sternum • Vertebrae

– 7 Cervical– 12 thoracic– 5 lumbar– 5 sacral– 5 fused coccygeal

• Ribs

Pelvic Girdles • Os Coxae (Innominate

bone)– Ilium– Ischium– Pubis (Os pubis, pubic bone)

Pectoral Girdles • Clavicle • Scapula

Appendicular Skeleton• Humerus• Radius • Ulna• Carpals

– Metacarpals– Phalanges (pollicis refers to the thumb)

• Femur• Patella• Tibia• Fibula• Tarsals

– Metatarsals– Phalanges (hallux is the big toe)

Bone Characteristics

• Vascular (has own blood supply)

• Regenerates well

• Contains calcium and hydroxyapatite

• Forms mostly after birth

• Is not flexible

Bone Cells

• Osteoblast (makes bone)

• Osteocyte (mature bone cell)

• Osteoclast (reabsorbs bone)

Formation of Endochondral Bone

• Hyaline cartilage develops in the general shape of the future bone.

• Periosteum forms on the outside of the developing bone.

• Osteoblasts deposit bony tissue in place of disintegrating cartilage.

Types of Ossification

• Primary– starts in diaphysis from cartilage

• Secondary– starts in epiphysis from cartilage

Types of Bones

• Long Bones– Arms and legs

• Sesamoid Bones– Develop inside tendons and near joints

• Flat Bones– Skull bones and scapula

• Irregular Bones– vertebrae

Cartilage

• What are the three types of cartilage?– Hyaline cartilage (most of the joints)– Fibrocartilage (vertebral discs, pubic symphysis)– Elastic cartilage (ears)

• Where in the body can each of these three types of cartilage be found?

• What type of cartilage does an embryonic skeleton have?– Hyaline

Cartilage Characteristics

• Avascular (no blood supply)

• Does not regenerate well

• Contains no calcium or hydroxyapatite

• Begins conversion to bone before birth

• Is flexible

Stages of Healing a Fracture

Figure 6.14

Blood escapes

Fibrous callous

Spongy Bone callous

Osteoclasts remove excess bone

Categories of Fractures

• Simple: Skin is not broken• Compound: Bone sticks out through skin, often

gets infected

• Complete: Both sides of diaphysis broken through

• Incomplete: One side of diaphysis is broken

• Stress: Just a crack in the surface

Types of Fractures

• Comminuted

• Compression

• Spiral

• Epiphyseal

• Depressed

• Greenstick

Types of Fractures

Table 6.1

Table 6.1

Table 6.1

Table 6.1

Table 6.1

Table 6.1

About Joints

• Tendons– bind a muscle to bone

• Ligaments– bind bone to bone

• Both are dense regular connective tissue• About Muscles (acting at a joint)

– origin– insertion– action

Joint Movement

• Synarthrotic

– immoveable, allows no movement

• Amphiarthrotic

– allows only limited movement

• Diarthrotic

– freely moveable

Fibrous Joints

A fibrous joint is two bones joined by fibrous connective tissue.

It is immovable so it is categorized as a synarthrotic joint.

No joint cavity

Cartilaginous Joints

A cartilaginous joint is two bones joined by cartilage. The cartilage is either fibrocartilage (a symphysis joint) or hyaline cartilage (a synchondrosis).

Fibrocartilage joints (symphyses) are amphiarthrotic (slightly moveable). Examples are intervertebral discs and the pubic

symphysis Hyaline cartilage joints (synchondroses) are synarthrotic

(immovable). Examples are epiphyseal plates and costal cartilages

SynchondrosisA synchondrosis is a joint in which the bones are bound by hyaline cartilage (A synchondrosis is synarthrotic: not moveable)

A synchondrosis is a synarthrosis

Synovial Joints

• The most familiar type of joint and the most common. It allows a wide range of motion so it is functionally classified as a diarthrotic joint

• Examples include the elbow, knee, knuckles, the joints between the wrist and ankle bones

• Synovial joints are the most structurally complex type of joint, (having a joint cavity) and are the most likely to develop uncomfortable and crippling dysfunctions

Bursae

A bursa is a fibrous sac filled with synovial fluid, located between adjacent muscles or where a tendon passes over a bone.

Bursae cushion muscles, help tendons slide more easily over the joints, and sometimes enhance the mechanical effect of a muscle by modifying the direction in which its tendon pulls.

Condyloid Joints

Metacarpal-phalangeal joints: these arebiaxial condyloid joints

Ball and Socket Joints

Shoulder and hip joints are ball and socket. This type of joint is multiaxial.

The Knee Joint

• Tibiofemoral joint and patellofemoral joint• The largest and most complex diarthrosis • of the body• Hinge joint, but has movements of gliding, rolling and

rotation• 3 articulations: lateral and medial articulations of

femur and tibia; intermediate articulation of patella and femur. Note: Fibula does not articulate with the femur, only with the tibia.

10 pt Essay Question: Label this

Essay Answer: ½ pt each

10 pt Essay Question: Label this

Essay Answer: 1 pt each

Anterior Posterior

10 pt Essay Question: Label this(1/2 point each)

Essay Answer (a)

Essay Answer (b)

Muscle Types

• Smooth: spindle shaped– no striations– involuntary

• Cardiac: cylindrical shaped– striated– involuntary (only responds to direct electrical

stimulation)

• Skeletal: elongated– striated– voluntary

MOTION TERMS• FLEXION: reduces the angle of the joint from the anatomical

position. Flex elbow• EXTENSION: movement that returns you to anatomical position.

Extend elbow.• All these terms refer to either a body part or a joint. Can flex elbow

or flex joint.• HYPEREXTENSION: extension beyond anatomical position; wrist,

neck.• Some terms relate only to certain areas, such as the ankle:• DORSIFLEXTION: lift up toes• PLANTARFLEXION: move toes down• INVERSION: when sole of foot points inward• EVERSION: sole of foot points outward.• ABDUCTION: move body part away from midline; arm, fingers,

thumb• ADDUCTION: bring back to midline; arms, fingers, thumb

MOTION TERMS

• ROTATION: pivot on an axis; shake head “no”; can rotate head and shoulder

• CIRCUMDUCTION: to draw a circle with body part; shoulder, head

• PRONATION (to lie prone is on stomach). Turn hands downward.

• SUPINATION: refers to arms; want a bowl of soup, supinate• PROTRACTION: to move anteriorily; shoulders, mandible• RETRACTION: to move part posteriorly; shoulders• ELEVATION: to raise part superiorly; shoulders• DEPRESSION: to lower part; open mouth.

Muscle Terms

• Prime mover

• Synergist (helps prime mover)

• Antagonist (does opposite of prime mover)

• Fixator (holds bone in place so prime mover can move a body part better)

Gluteus Maximus

• When sitting and going to a standing position, this is the primary muscle responsible for straightening the hip

Hip Flexors

• When one foot is on the ground, these muscles contract to lift the opposite foot off the ground

The Reflex Arc

Dorsal root ganglia contain cell bodies of sensory neurons

Order of Nerves Firing

• To pick up an object, you wrap your hand around the object. This gives you a sensory input as you feel the object.

• The sensory neuron sends the impulse to the spinal cord where it synapses on an interneuron.

• The interneuron synapses on a motor neuron

• The motor neuron tells your muscles to contract so you can pick up the object.

Spinal Nerve Plexi

• A network of ventral rami

• Interlacing network• Gives redundancy in

case of nerve damage

C1-C4- Cervical plexus

C5-T1- Brachial plexus

L1-L4- Lumbar Plexus

L4-S4- Sacral Plexus

Brachial Plexus

ROOTS

TRUNKS

DIVISIONS

CORDS NERVES

Damage to the Brachial Plexus

Major Nerves of the Upper

Extremity

Axillary

Musculocutaneus

Axillary Nerve

• Deltoid

• Teres minor

Musculocutaneus Nerve

• Supplies anterior muscles of the arm

Median Nerve

• Carpal Tunnel Syndrome

• Supplies no muscles of the arm

• Supplies anterior forearm (except flexor carpi ulnaris)

Ulnar Nerve

• “Funny Bone”

• Supplies flexor carpi ulnaris

Radial Nerve

• Supplies muscles on the posterior arm and forearm– Triceps brachii– Extensor carpi radialis– Extensor digitorum communis

Nerves of the Lower

ExtremityFemoral

Obturator

Obturator Nerve

• Supplies adductor muscles

Sciatic Nerve

• Supplies back of thigh– Biceps femoris– Semimembranosis– Semitendonosis

• Supplies leg and foot

Femoral Nerve

• Anterior Thigh– Quadriceps femoris

Tibial Nerve

• Posterior leg and foot– Gastrocnemius– Soleus– Tibialis Posterior

Common Peroneal Nerve

• Superficial branch – Lateral side of leg– Supplies peroneal muscles

• Deep branch– Supplies anterior leg muscles– Injury causes “Foot Drop”

Dermatomes

• The area of skin innervated by a cutaneous branch of a spinal nerve at a particular level.

Arteries of the Upper Extremity

Arteries of the Upper Extremity

• Subclavian (becomes axillary artery in armpit)

• Axillary (becomes brachial artery in arm)– Supplies triceps brachii

• Brachial (divides into radial and ulnar arteries when it reaches the elbow)– Supplies arm muscles except triceps brachii

• Radial• Ulnar

Arteries of the Lower Extremity

External Iliac artery

Arteries of the Lower Extremity

• External iliac (becomes femoral artery)

• Femoral (becomes popliteal artery at knee)– Muscles of thigh

• Popliteal (becomes tibial artery in leg)

• Tibal– Leg muscles