Chapter 8 - The Skeletal System: The Appendicular Skeleton Flashcards
What is the Appendicular Skeleton?
126 bones
Primarily involved in body movements
Include:
Upper and lower limbs
Girdles attaching them to Axial Skeleton
What is the Pectoral Girdle?
Pectoral Girdle - Shoulder Girdle
2 pectoral girdles
Include:
Clavicle
Scapula
What is the Clavicle?
Clavicle is collarbone
S-shaped
Medial (Sternal) end:
Articulates with Manubrium of Sternum
Lateral (Acromial) end:
Articulates with the Acromion of the Scapula
What are the Clavicle markings?
At Medial (Sternal) end inferiorly:
Impression for the Costoclavicular ligament
At Lateral (Acromial) end inferiorly:
Conoid tubercle
What is the Scapula?
Scapula:
Flat bone located in superior part of posterior thorax
Between ribs 2 and 7
Attaches to Humerus at Glenoid cavity
What are the Scapula markings?
1- Anteriorly:
Lateral (Axillary) Border
Acromion
Coracoid Process
Glenoid Cavity
Superior Angle
Superior Border
Scapular Notch
Subscapular Fossa
Medial (Vertebral) Border
2- Posteriorly:
Supraspinous Fossa
Spine
Infraspinous Fossa
What is the Humerus?
Humerus: Arm bone
Articulates with Scapula proximally
Rounded head fits into Glenoid Cavity of Scapula
Articulates with Radius distally at Capitulum
Articulates with Ulna distally at Trochlea
What are the Humerus Markings?
1- Anteriorly:
Head
Anatomical Neck
Greater Tubercle (lateral)
Intertubercular Sulcus (groove)
Lesser Tubercle (medial)
Deltoid Tuberosity (lateral)
Body (shaft)
Radial Fossa
Coronoid Fossa
Lateral Epicondyle
Medial Epicondyle
Capitulum (w/ Radius)
Trochlea (w/ Ulna)
2- Posteriorly:
Radial Groove
Olecranon Fossa
What is the Ulna and Radius?
Ulna and Radius: the 2 bones of the forearm
Ulna:
Olecranon and Coronoid Process at proximal end of Ulna form Trochlear Notch, which wraps around Trochlea of Humerus making elbow joint
Radius:
Located on lateral side (Thumb)
Articulation of Head of Radius with Capitulum of Humerus and with Ulna allow forearm to rotate
Interosseus Membrane between Radius and Ulna
What are the Radius Markings?
1- Anteriorly:
Head (proximal)
Neck
Radial Tuberosity
Styloid Process (at carpals)
2- Inferiorly at distal end:
Articulation for Scaphoid (lateral)
Articulation for Lunate (medial)
Ulnar notch of Ulna (right next to Ulna)
What are the Ulna Markings?
1- Anteriorly:
Coronoid Process
Ulnar Tuberosity
Head of Ulna (distal)
Styloid Process of Ulna
2- Posteriorly:
Olecranon
3- Laterally:
Trochlear Notch
Radial Notch
What is the Carpal Bones?
Carpal Bones:
8 small bones connected to each other with ligaments
Arranged in 2 rows of 4 bones each
Proximal row:
Scaphoid
Lunate
Triquetrum
Pisiform
Articulate with distal Radius and Ulna
Distal row:
Trapezium
Trapezoid
Capitate
Hamate
Articulate with the Metacarpals
What are Metacarpal Joints?
Metacarpalphalangeal joint: between Metacarpal and Proximal Phalange
First Interphalangeal Joint
Second Interphalangeal Joint
What are Metacarpals?
5 Metacarpals make up palm and back of hand
Numbered 1-5 (I-V) starting with thumb
Bases articulate with distal Carpals
Heads articulate with proximal Phalanges
What are Phalanges?
Phalanges are the bones of digits
14 total
Thumb has 2 (proximal and distal)
Other fingers have 3 (proximal, middle, and distal)
Where are the Carpals?
Sandy Left The Party To Take Cathey Home
Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid Capitate Hamate
Anteriorly from Medial to Lateral up then down
What is the Pelvic Girdle?
Pelvic Girdle: Hip Girdle
Made of 2 Hip Bones (Os Coxa, or Coxal Bones)
Articulate with the Sacrum posteriorly
Each Hip Bone is made of 3 individual bones:
Ilium
Ischium
Pubis
The 2 Hip bones articulate anteriorly at the Pubic Bones (Pubic Symphysis)
There is a disc of Fibrocartilage between the 2 bones
What is the Acetabulum?
The Head of the Femur articulates with the Acetabulum of the Hip Bone as a ball and socket joint
Acetabulum is composed of parts of all 3 of the bones that make up the Hip Bone
What is the Pelvis?
Pelvis is divided into superior and inferior portion by the Pelvic Brim, which is where the abdomen meets the pelvic cavity
Landmarks of the Pelvic Brim:
Sacral Promontory
Arcuate Line
Pectineal Line
Pubic Crest
Pubic Symphysis
What are the 2 Areas of the Pelvis?
1- False (Greater) Pelvis:
Area of bony pelvis superior to Pelvic Brim
2- True (Lesser) Pelvis:
Area of bony pelvis inferior to Pelvic Brim
What are the characteristics of the Male Pelvic Girdles?
Male:
Bones usually larger and heavier
1- General Structure:
Heavy and thick
2- False (Greater) Pelvis:
Deep
3- Pelvic Brim:
Narrow and heart-shaped
4- Acetabulum:
Large and faces laterally
5- Obturator Foramen:
Round
6- Pubic Arch:
Less than 90 degrees
7- Iliac Crest:
More curved
8- Ilium:
More vertical
9- Greater Sciatic Notch:
Narrow (about 70 degrees, inverted V)
10- Sacrum:
Longer, narrower, and more curved anteriorly
11- Pelvic Outlet:
Narrower
12- Ischial Tuberosity:
Longer, closer together, and more laterally projecting
What are the characteristics of the Female Pelvic Girdles?
Female:
Bones structured to meet requirements of pregnancy and childbirth
Wider and shallower than male
1- General Structure:
Light and thin
2- False (Greater) Pelvis:
Shallow
3- Pelvic Brim:
Wide and more oval
4- Acetabulum:
Small and faces anteriorly
5- Obturator Foramen:
Oval
6- Pubic Arch:
Greater than 90 degrees
7- Iliac Crest:
Less curved
8- Ilium:
Less vertical
9- Greater Sciatic Notch:
Wide (almost 90 degrees)
10- Sacrum:
Shorter, wider, and less curved anteriorly
11- Pelvic Outlet:
Wider
12- Ischial Tuberosity:
Shorter, farther apart, and more medially projecting
What are the 3 bones of the Hip Bone?
Ilium
Ischium
Pubis
What are the Ilium Markings?
1- Anterolaterally:
Iliac Crest
Tubercle of the Iliac Crest
Anterior Superior Iliac Spine
Anterior Inferior Iliac Spine
Body of Ilium
Acetabulum
Anterior Gluteal Line
Inferior Gluteal Line
Posterior Gluteal Line
Posterior Superior Iliac Spine
Posterior Inferior Iliac Spine
Greater Sciatic Notch
2- Anteromedially:
Iliac Tuberosity
Auricular Surface
Iliac Fossa
Arcuate Line
What are the Ischium Markings?
1- Anterolaterally:
Body of Ischium
Ischial Spine
Lesser Sciatic Notch
Ischial Tuberosity
Ramus of Ischium
Acetabulum
Acetabular Notch
Obturator Foramen
What are the Pubis Markings?
1- Anterolaterally:
Superior Ramus of Pubis
Pubic Tubercle
Inferior Ramus of Pubis
Acetabulum
Obturator Foramen
2- Anteromedially:
Pectineal Line
Body of Pubis
Pubic Crest
Pubic Symphysis
What is the Femur?
Femur:
Longest, heaviest, and strongest bone in body
Proximal end (Head) inserts into Acetabulum of Hip Bone
Distal end articulates with Tibia and Patella (Not Fibula)
What are the Femur Markings?
1- Anteriorly:
Head
Neck
Greater Trochanter
Intertrochanteric Line
Lesser Trochanter
Body (shaft)
Adductor Tubercle (medially)
Lateral Epicondyle
Medial Epicondyle
Lateral Condyle
Medial Condyle
2- Posteriorly:
Intertrochanteric Crest
Linea Aspera
Intercondylar Fossa
What is the Patella?
Patella is a triangular bone that develops in the Quadriceps tendon
Its posterior surface articulates with the Femur
What are the Patella Markings?
1- Anteriorly:
Base
Apex
2- Posteriorly:
Articular Facet for Medial Femoral Condyle
Articular Facet for Lateral Femoral Condyle
What is the Tibia and Fibula?
Lower leg consists of Tibia and Fibula
Tibia’s proximal end articulates with Femur
Tibia’s distal end articulates with Talus bone of ankle
Tibial Tuberosity on the anterior surface is point of attachment for the Patellar Ligament
What are the Tibia Markings?
1- Anteriorly:
Lateral Condyle
Medial Condyle
Tibial Tuberosity
Anterior Crest (border)
Interosseus Membrane
Medial Malleolus
2- Posteriorly:
Intercondylar Eminence
3- Laterally:
Fibular Notch (at distal end of Tibia)
What are the Fibula Markings?
Head
Interosseus Membrane
Lateral Malleolus
What is the Tarsus?
Tarsus:
Contains 7 Tarsal Bones
Talus
Calcaneus
Navicular
Cuboid
First (Medial) Cuneiform
Second (Intermediate) Cuneiform
Third (Lateral) Cuneiform
Where are the Tarsal Bones?
Tall Centers Never Take Shots From Corners
Talus
Calcaneus
Navicular
Third (Lateral) Cuneiform
Second (Intermediate) Cuneiform
First (Medial) Cuneiform
Cuboid
What is the Matetarsus?
Metatarsus is made of 5 Metatarsal Bones
Metatarsal 1-5 (I-V)
They make up sole and dorsal surface of foot
Proximal ends articulate with the 3 Cuneiform Bones and the Cuboid
Distal ends articulate with the Proximal Phalanges
What is the Lower Limb Phalanges?
Phalanges are arranged like in hand
Big toe (Hallux) has Proximal Phalanx and Distal Phalanx
Other toes have Proximal, Middle, and Distal Phalanges
What are the 2 Arches of the Foot?
The foot has 2 arches that are supported by ligaments and tendons
Purpose:
Allow the foot to support the weight of the body
Provide leverage while walking
Distribute body weight over foot
1- Longitudinal Arch:
Made of one medial portion and one lateral portion
2- Transvers Arch
Where does Skeletal Tissue Develop from?
Most Skeletal Tissue arises from middle primary germ layer Mesoderm
Most of Skull arises from outer layer Ectoderm
Skeleton of Limb Girdles and Limbs derived from Mesoderm
Between Week 4 and 8 after fertilization, extensive growth and development in formation of limbs
How do Skull Bones develop?
Cartilaginous Neurocranium (Hyaline cartilage) undergoes Endochondral Ossification
Membranous Neurocranium undergoes Intramembranous Ossification
What is the Viscerocranium?
The bones of the face form from the Viscerocranium
Cartilaginous Viscerocranium comes from cartilages of the Pharyngeal Arches and this forms the Ear Bones and Hyoid Bone
Membranous Viscerocranium comes from Mesenchyme of the first Pharyngeal Arch, undergoes Intramembranous Ossification, and forms the Facial Bones
