Lab 2.5 to 2.8 and 3.1 - 3.2

2.5 Appendicular Skeleton

• It contains the pectoral girdle and the pelvis girdle

  • The pectoral girdle consists of the two bones that make up the shoulder scapula nd clavicle bones

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Study t terms

Fossa 2 on back of scapula and front of humorous

Fossa 1 on front of scapula and back of humorous

a before s

• Humerus Bone

• Only bone in the arm and forms the glenohumeral joint

• Head of humerus - ball like structure and fits into the glenoid cavity

• Greater tubercle - biggest “lump” on anterior proximal side of humorous

• Lesser tubercle - smaller “lump” on the anterior proximal side of humorous

• Intertubercular sulcus - grooves formed from the greater and lesser tubercles, on the anterior side

• Deltoid tuberosity - middle “lump” on the humerus

• Radial groove - just above the deltoid tuberosity on the posterior side of the humerus

• Ulna Bone

• Olecranon process - the elbow bone, the most proximal part of ulna

• Coroniod process - on the anterior part of ulna, smaller pointer part

• Trochlear notch - deep curve below the olecranon process

• Ulnar head - most distal pat of the ulna

• Styloid process - pointy part distal of the ulna

• Radius bone

• Radial head - most proximal part of radius bone

• Radial neck - just below the radial head

• radial tuberosity - proximal “lump” on radius

• Syoloid process of radius - most distal part of radius

Gluteal tuberosity - rough lines on the posterior side of bone which allows for muscle connection

Linea aspera - line that runs on the posterior side of femur which allows for hamstring muscle to attach

Popliteal fossa - posterior distal side of femur

Intercondylar fossa - posterior side, middle hole in femur bone

Medial and Lateral supracondylar line - just below the Linea aspera

Medial and lateral epicondyle

Medial and lateral condyle - the blue ball looking parts of the femur

Patellar surface - where the knee joint goes U shaped at the distal part of femur

• Tibia Bone

• Tibial plateau - flat proximal part of tibia

• Lateral tibial condyle - outside tip of tibia

• Medial tibial condyle - inside tip of tibia

• Intercondylar eminence - what forms the pointy parts of the proximal tibia

• Tibial tuberosity - boney part that sticks out the tibia

• Anterior crest (shin) - smooth anterior part of tibia

  • Anterior crest articulates with the talus bone (top part of ankle)

• Medial malleolus - pointy distal part of the tibia

• Fibula Bone

• Lateral malleous - distal part of the fibula (pointy part)

• 2 tibiofibular joints - distal and proximal

• Interosseous membrane - what the fibula and tibia are held together by

• Three paired bones of the pelvic girdle

• ilium bone

• Ischium bone

• Pubis Bone

• The pelvis is made up of the sacrum vertebrae & pelvic girdle

  • While the pelvic girdle is made up of 2 (left & right) coxal bones

Scaphoid and Lunate bones attach to the radius

Lunate attaches to ulna

• So → Scaphoid Attahces to Radius

• Long → Lunate Attaches to Ulna

• To → Triquetrum

• Pinky → Pisform Think Pinky, and is only bone you can see anteriorly

• Here → Hamate Ring finger think hooked for life

• Comes → Capitate Think middle finger is a capital (capitate)

• The → Trapezoid

• Thumb → Trapezium Rymes with thumb (trapezium)

2.6 Synovial Joints

Features of a Synovial Joint

• Synovial Joints

  • are freely movable joints

• Hyaline Cartilage

  • provides smooth frictionless surface

• Joint Capsule

  • dense irregular collagenous connective tissue

  • lined with connective and epithelial tissue called synovial membrane

  Synovial Fluid

  • fills the joint cavity

  • reduces friction

  • exchanges oxygen nutrients, and waters with the cells of articular cartilage

Knee joint

Dense irregular collagenous connective tissue

Shoulder Joint

Dense regular collagenous connective tissue

Ligaments: the bones on a synovial joints are held together by ligaments

• Extrinsic ligaments: are external to the joint capsule

• Intrinsic ligaments: are embedded inside the joint capsule

Tendons: Synvovial joints typically are surrounded by tendons

Bursa: Fluid-filled sacs located between tendons and joints

Range Of Motion of Synovial Joints

• Nonaxial Joints: A nonaxial joint is a type of joint where the bones can slide past each other but do not spin. An example of this is where a rib connects to the bone in your back

  

• Unaxial Joint: Uniaxial joints are like door hinges that only move in one direction, back and forth. The elbow is a great example; it can bend and straighten but not twist.

  

• Biaxial Joint: Biaxial joints are like your fingers. They can move in two directions, like bending up and down, and moving side to side. This is why you can wave your finger and move it back and forth.

  

• Multiaxial Joint: Multiaxial joints are like the shoulder and hip joints. They can move in many directions, like a ball rolling in a cup. This means you can raise your arms, spin them around, and move your legs in lots of different ways.

  

Structural Classification of Synovial Joint

• Plane Joint

  • The ends of the bones that connect at a joint are flat or a little curved. This shape helps the bones slide easily against each other, which is why they're called gliding joints.

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• Condylar Joint

  • A condylar joint is when one bone has a round bump that fits into a round dip on another bone. It's like a ball rolling in a bowl! This shape helps the bones move smoothly together.

  • 

• Saddle Joint

  • Saddle joints are special types of joints in our body. They have two bones that fit together like a saddle on a horse. One side of the saddle is curved in (like the front and back of a saddle) and the other side is curved out (like the sides of a saddle). This helps the bones move in different directions.

  • 

• Hinge Joint

  • A hinge joint is like a door hinge. One part of the bone sticks out a bit, and the other part dips in, just like how a door opens and closes. Good examples of hinge joints are our elbow and knee. They can bend just like how a door can swing open and shut.

  • 

• Pivot Joint

  • A pivot joint is a special kind of joint in our body where one bone can spin around another bone. It works like a door that swings open. This type of joint helps with movements like turning your head or your arm. Two examples of pivot joints are the one near your elbow and the one in your neck that helps you shake your head no.

  • 

• Ball and Socket Joint

  • A ball and socket joint is like a ball fitting into a cup. This special type of joint is found in your shoulder and hip, letting you move your arms and legs in many directions, just like a ball can roll around in a cup.

  • 

2.7 Knee Joint

• The knee joint is a modified hinge joint

• Cruciate Ligaments

  • controls front and back movement of knee joints

• Anterior Cruciate Ligament (ACL)

  • prevents hyperextension of the knee

• Posterior Cruciate ligament (PCL)

  • Stops tibia bone from sliding backwards on the femur bone

• Collateral Ligaments

  • Controls side to side movement of the knee joint

• Medial collateral ligament (MCL)

  • Resists stresses that pull the tibia bone laterally on the femur bone

• Lateral collateral ligament (LCL)

  • Resists stresses that pull the tibia bone medially on the femur bone

• 3 Bursae in the knee

  • Suprapatellar bursae

  • deep infrapatellar burase

  • subcutaneous bursae

2.8 Shoulder Joint

• The shoulder joint is a multiaxial and ball and socket joint

• Glenoid Labrum

  • Fibrocartilaginous ring along the rim of the glenoid cavity

• 3 Glenohumeral ligaments

  • reinforces the anterior joint capsule

• Coracohumeral ligament

  • located in the anterior articular capsule between the greater tubercle and coracoid process

• Coracoacromial ligament

  • Located between the coracoid process and acromion

• Transverse Humeral Ligament

  • extends between the greater and lesser tubercles, and forms a tunnel that houses one of the tendons of the biceps brachii muscle

• Biceps Brachii Tendon

  • found in the anterior arm, this tendons passes through the articular capsule of the shoulder joint

• Rotator Cuff

  • group of 4 muscles and tendons - the 3 posterior muscles

  • supraspinatus (back)

  • infraspinatus (back)

  • teres minor muscles (back)

  • subscapularis muscle (front)

• Bursae

  • 2 that help reduce friction in the joint

• Subacromial bursa

  • largest bursae, located below the acromion

• Subscapular bursa

3.1 Muscle Tissue Histology

• Myology

  • Study of the muscular system

• Actin and Myosin

  • two proteins that help muscles contract

• Three types of muscle tissues

  • Skeletal (long - voluntary)

  • Cardiac (small - involuntary)

  • Smooth (spindle shaped - involuntary)

• Striated

  • overlap of two proteins (actin and myosin)

• Non-striated

  • two proteins not overlapping

• Gap Junctions

  • communication between cells/fibers

• Smooth Muscle Tissue: non-striated and involuntary

• Smooth muscle tissue

  • found in sheets or as individual cells

• Gap Junction

  • allows communication between muscle fibers

• Cardiac muscle tissue: striated and involuntary

• Intercalated disc

  • constitutes border of each muscle fiber and serves as communication between gap junctions

• Skeletal Muscle Tissue: Striated and Voluntary

• The entire skeletal muscle tissue is enclosed by a fibrous sheet called the epimysium (outside inside layer)

• Muscle Fiber

• Edomysium - Where muscle fibers are contained

• Perimysium - What separates each fasicle

• Fasicle - contains groups of muscle fibers

• Epimysium - outside inside layer of muscle tissue

• Fascia - outside outside layer of muscle tissue

• Sarcomere

  • Smallest functional unit of a skeltal muscle tissue

• Mnemonic: ZIMAH

  • Z disc to z disc forms a sarcomere. One way to remember Z discs are their resemblance of the letter Z.

  • I bands are the lighter sections on each end of a sarcomere.

  • M line is the midline in a sarcomere.

  • A band is the darker section in the center of a sarcomere.

    • H zone the lighter region in the middle of the A band.

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• Fusiform

  • Thick in the middle and tapered at the ends

  • ex. biceps brachii

• Parallel

  • ex. rectus abdominis

• Convergent

  • Flarred like a wings

  • ex. pectorallis major

• Unipennate

  • Feather shaped

    • ex.extensor digitorum longus muscle

• Bipennate

  • Think of a leaf tendon in the middle and fibers flare out

  • ex. rectus demoris muscle

• Multipennate

  • think leaf with multiple tendons flaring out

  • ex. deltoid muscle

• Circular

  • arranged in a circle usually around openings (mouth and eye)

  • ex. oblicularis oris or oculi muscles

3.3 Axial Skeletal Muscles

A. Scalp Muscles 

• Galea Aponeurotica: Fibrous connective tissue superficial to the cranium connecting the frontalis & occipitalis muscles 

• Frontalis Muscle: Superficial to frontal bone

  • Action: pulls scalp anteriorly, raises the eyebrows & wrinkles the forehead 

• Occipitalis Muscle: Superficial to occipital bone

  • Action: pulls scalp posteriorly

B. Orbital & Nasal Region Muscles

• Orbicularis Oculi Muscle: Superficial; oculi refers to the area around the eyes

  • Action: closes the eyelids

• Corrugator Supercilii Muscle: Deep; corrugator means to wrinkle & supercilii means eyebrow

  • Action: frowning muscles by wrinkling the eyebrows

• Nasalis Muscle: Superficial to nasal bones

  • Action: flares the nostrils

C. Oral Region Muscles

• Orbicularis Oris Muscle: Superficial; oris refers to the area around mouth; attached to modiolus

  • Action: closes mouth; puckers lips, & uniquely developed in humans for speech

• Zygomaticus Minor Muscle: Superficial; zygomaticus refers to cheekbones; minor means small; located medially to the zygomaticus major muscle, laterally from the levator labii superioris muscle

  • Action: elevates upper lip for smiling or sneering

• Zygomaticus Major Muscle: Superficial; major means big; located superolateral to the orbicularis oris muscle & attached directly to the modiolus

  • Action: draws angle of mouth up & lateral for laughing

• Risorius Muscle: Superficial to masseter muscle; lateral to the lips; attached directly to modiolus

  • Action: draws angle of mouth lateral for laughing, expressing horror or disdain

• Levator Labii Superioris Muscle: Superficial; levator means to elevate, labii superioris refers to upper lip; medially located to the zygomaticus minor muscle & attached superomedial to the orbicularis oris muscle 

  • Action: elevates upper lip

• Depressor Labii Inferioris Muscle: Superficial to the mentalis muscle; depressor means downward movement; attached & located inferiolateral to the orbicularis oris muscle

  • Action: draws lower lip downwards

D. Modiolus

• A fibrous tissue located superficial on the lateral side of the lips where facial muscles intersect, like the superficial orbicularis oris, risorius, zygomaticus major muscles, & the deep buccinator muscle

  • Action: provides stability for mouth movement & facial expression

E. Mental & Buccal Region Muscles

• Buccinator Muscle: Deep to masseter muscle

  • Action: compresses cheeks; aids in food position for chewing or sucking

• Mentalis Muscle: Deep; found by the mental region

  • Action: elevates & wrinkles skin of chin; elevates lower lip as for drinking or pouting

• Platysma Muscle: Superficial on the anterolateral side of the neck

  • Action: creates downward sag of mouth; tenses skin of neck

F. Muscles for Chewing 

• Temporalis Muscle: Superficial to the temporal bone

  • Action: closes jaw; elevates & pulls back the mandible

• Masseter Muscle: Intermediate; deep to the risorius muscle, superficial to the buccinator muscle

  • Action: closes jaw; principal muscle for jaw movement