Basic Anatomy

Question 1

What are the roles of the skeletal system?

Answer 1

1. support soft tissues- provide attachment sites
2. movements at joints/articulations where muscles contract
3. protection from vital organs and bones themselves house Ca+, Protein, Fat, Na+, K+
4. form new blood cells (RBCs, some white, platelets) via hemopoiesis

Question 2

What are the 3 types of bones?

Answer 2

Long, Flat, Irregular

Question 3

What is compact/cortical bone?

Answer 3

75% of skeleton, strength, tendon attachment, light weight

Question 4

What is trabecular bone?

Answer 4

spongy! 25% of skeleton–> large SA for mineral exchange, maintains skeletal strength and integrity (bones w/ more Trabecular (like hip bones) are more suseptible to fracture caused by osteoporosis

Question 5

Describe the layers of bone

Answer 5

Medullary- yellow, fatty cavity
Endosteum is the thin layer than lines the medullary
Periosteum- vascular layer of connective tissue cover bones (but not joints)

Question 6

Osteoclasts vs. Osteoblasts

Answer 6

blast- bone building
clasts= break donw (Calcium and protein are removed when diet is poor/female is pregnant)
*we have a new skeleton every 10 years

Question 7

What is Wolff’s Law?

Answer 7

form follows function–> skeleton will lay down more bone tissue in response to stress to make it more dense (why weight bearing activity is important)

Question 8

The importance of Girdles?

Answer 8

that is where axial and appendicular skeletons meet: should girdle, pelvic girdle

Question 9

What are the 3 types of joints?

Answer 9

1. Fibrous- synarthroidal, immovable (skull, Tibia/Fibula)
2. Cartilagenous- pad or disk, little movement (pubic symphysis, vertebrae)
3. Synovial- diarthroses

Question 10

What are the components of a Synovial Joint?

Answer 10

1. Articular cartilage (Hyaline cartilage covers the end of bone)
2. Articular Capsule (dbl layered dense fiber/membrane)
3. Synovial membrane (contains capillaries and synovial fluid)
4. Synovial Fluid

Question 11

What are the types of Synovial movements?

Answer 11

1. Uniaxial/hinge= ankles, elbows
2. Biaxial= foot, knee, hand, wrist
3. multiplanar (triaxial)= hip, thumb, shoulder
   Synovial movements are gliding, angular (flexion, extension, ab/adduction), circumduction

Question 12

What is circumduction?

Answer 12

“cone” that combines flexion, extension, abduction, adduction

Question 13

What is opposition?

Answer 13

thumb movement unique to humans and primates

Question 14

Shoulder girdle: functions and compartments

Answer 14

Function: stabilize the scapula
Posterior:
Anterior: Pec Minor and Serratus Anterior
Posterior: Levator Scapulae, Rhomboids, Trapezius

Question 15

What does the Trapezius do?

Answer 15

helps neck extension IF scapula is fixed, as a whole will pull up and adduct the scapula, can stabilize scapula for Deltoid action

Question 16

What do the Rhomboids do?

Answer 16

adduct and downwardly rotate Scapula (use in pull-ups, at start, they draw medial borders down and back toward spine)

Question 17

What does the Levator Scapulae do?

Answer 17

elevates superior medial scapula- assists upper Traps, also helps w/ bilateral extension and unilateral flexion of neck

Question 18

What do Serratus and Pec Minor do?

Answer 18

adduct scapula during pushing movements with the hands

Question 19

What are the rotator cuff muscles and what do they do?

Answer 19

SITS (all have scapular insertion/connection)
Supraspinatus- holds it from superior position and helps the Deltoid abduct the arm
Infraspinatus
Teres Minor (w/ infraspinatus) can externally rotate shoulder when scapula are stabilized by the rhomboids
Subscapularis (the only anterior scap muscle) will medially rotate arm if Rhomboids stabilize scapula
surround the humeral head, keep it stable in the Glenoid fossa to prevent subluxation

Question 20

What are the other shoulder muscles?

Answer 20

Deltoid- forms a shoulder cap w/ diff actions depending on placement (requires traps to stabilize scapula and any movement of humerus on scapula): anterior fibers flex and internally rotate, posterior extend and laterally rotate humerus
Teres Major- if rhomboids stabilize scapula, assists as the little lat, and internally rotates humerus
Coracobrachialis- front of shoulder, flexion and adduction of humerus

Question 21

Describe the muscles of the axial skeleton

Answer 21

1. latisimuss dorsi- widest muscle of post trunk, one of the most powerful extensors of the humerus, adducts and internally rotates humerus, when it is fixed (hanging) it can anteriorly tilt pelvis and/laterally flex spine
2. Pec Major- works with lats to adduct humerus from a raised, abducted position, and can internally rotate humerus, twisted fibers allow for this movement:
   clavicular portion flexes and extended shoulder, sternocostal portion extends a flexed shoulder

Question 22

Describe the muscles that act on the elbow

Answer 22

Upper Arm Anterior:
1. Biceps Brachii (two heads attach to scapula)- weak shoulder flexor, strong elbow flexor when forearm is supinated, can also supinate forearm from pronation because it inserts on radius
2. Brachialis- only pure elbow flexor
Upper Arm posterior (triceps brachii)- one head on scapula, weak should extensor, primary elbow extensor
Lateral? Brachioradialis- flexes elbow, favored when forearm is in mid position (between supination/pronation)

Question 23

What are the anterior wrist muscles and what do they do?

Answer 23

Wrist flexion, forearm pronation:
Flexor Carpi Radialis
Flexor Carpi Ulnaris
Pronator Teres
Pronator Quadratus

Question 24

What are the posterior wrist muscles and what do they do?

Answer 24

Wrist extension, forearm supination:
Extensor Carpi Radialis Longus
Extensor Carpi Ulnaris
Extensor Carpi Radialis Brevis
Supinator

Question 25

What are the trunk muscles of the abdominal wall?

Answer 25

1. Rectus Abdominis- pubis to rib cage, spinal flexion, controls pelvic tilt by pulling pelvis up to prevent anterior pelvic tilt 2. External Obliques- fibers run diagonal/toward midline like hands in front pockets, rotation, bilateral flexion 3. Internal Obliques- If you rotate trunk to the right, simultaneous contraction of R int. obliques and L ext. obliques 4. Transverse Abdominis 5. Transverse Abdominis- horizontal fibers, deepest mcle of abdominal wall, compresses cavity, stabilizes lumbar and pelvic regions, assists in forced expiration, tightens thoracolumbar fascia, stabilize sacroiliac joints (can reduce diameter of abdomen by sucking in)

Question 26

What are the trunk muscles of the posterior surface of the spine?

Answer 26

``` Erector Spinal (sacrum to skull)- bilateral spinal extension, unilateral lateral flexion Multifidi- spinal stability, not a prime mover ```

Question 27

Describe the anterior hip muscles

Answer 27

1. Iliopsoas (combo of Iliacus and Psoas Major which share a tendon and insert on the femur) main functions are flexion and external rotation of the femur, can flex pelvis/spine to femur or femur to pelvis *When flexing the femur to pelvis (example, leg lifts off the floor), Iliopsoas can cause excessive lordosis so it is important to flatten spine to floor 2. Sartorius- longest muscle, cross both hip and knee joint, flexion at both when activated 3. Rectus Femoris- part of the quad muscle group, but is the only one that acts on hip, flexion at hip, extension at knee 4. Tensor Fascia Latae- stabilize knee by tightening to IT tract, to activate you can lay in a supine position, raise one leg and internally rotate it 5. Pectineus- flexor, strong adductor, external rotator 6-8. Adductor Brevis, longus, magnus 9. gracilis- hip adduction (and knee flexion)

Question 28

Describe the posterior muscles that act on the hip

Answer 28

Posterior muscles mainly extend the hip/externally rotate femur 1. glut max- does this once femur/pelvis have extended 15 degrees 2. glut medius- hip abduction 3. glut min- internal rotation of femur (min/med important for walking to stabilize hip) 4. Piriformis- where sciatic nerve passes through or just inferior to 5. hamstrings- extend the hip (semitendinosus, semimembranosis, Biceps femoris) 6. 6 Deep Lateral Rotators: Inf/Sup Gemellus, Obturator Externus/Inferus, Quadratus Femoris, Piriformis

Question 29

Describe the mucles that act on the knee

Answer 29

Anterior (extensor) Quads- vastus lateralis, vastus medialis, rectus femoris, vastus intermedius) which all converge onto patellar tendon + sartorius Posterior (flexor) hamstrings Medial (adduction) Adductors + Pectineus and Gracilis (hip adduction and knee flexion)

Question 30

Describe the muscles that act on the ankle and foot

Answer 30

Anterior (extend toes, dorsiflex and invert foot) are just lateral to tibia: Anterior Tibialis, Extensor Hallucis Longus, Extensor Digitorum Longus, Peroneus Tertius Posterior (plantarflex the foot and/or flex toes: Soleus, Gastocnemius, Plantaris, Popliteus, Flexor Hallucis Longus, Flexor Digitorum Longus, Posterior Tibialis Gastrocnemius is a powerful plantar flexor (also flexes knee) with soleus Lateral compartment- Peroneus Longus and Brevis

Question 31

What is the subtalar joint?

Answer 31

articulation of the talus and calcaneus (allows inversion/eversion of foot)