Skeletal System Lecture: Bones of Lower Limbs PDF

School of Medicine and life science Department of surgical discipline Bones of free extremities. Lecture for I course students EP “General Medicine» Lector Professor Kiselev A.Yu.  The purpose of the lecture: – Study the upper and lower limb anatomy Objective...

School of Medicine and life science Department of surgical discipline Bones of free extremities. Lecture for I course students EP “General Medicine» Lector Professor Kiselev A.Yu.  The purpose of the lecture: – Study the upper and lower limb anatomy Objectives of the lecture: – Parts appendicular skeleton – The pectoral girdle – Clavicle – Scapula – Upper limb – Pelvis – Lover limb  The Appendicular Skeleton Pectoral girdle – Attaches the upper limbs to the trunk Pelvic girdle – Attaches the lower limbs to the trunk Upper and lower limbs differ in function – Share the same structural plan  The Pectoral Girdle Consists of the clavicle and the scapula Pectoral girdles do not quite encircle the body completely – Medial end of each clavicle articulates with the manubrium and first rib – Laterally – the ends of the clavicles join the scapulae – Scapulae do not join each other or the axial skeleton  The Pectoral Girdle Provides attachment for many muscles that move the upper limb Girdle is very light and upper limbs are mobile – Only clavicle articulates with the axial skeleton – Socket of the shoulder joint (glenoid cavity) is shallow Good for flexibility – bad for stability Articulated Pectoral Girdle Clavicles  Clavicles Provide attachment for muscles Hold the scapulae and arms laterally Transmit compression forces from the upper limbs to the axial skeleton  Scapulae Lie on the dorsal surface of the rib cage Located between ribs 2 – 7 Have three borders – Superior – Medial (vertebral) – Lateral (axillary) Have three angles – Lateral, superior, and inferior Structures of the Scapula Structures of the Scapula Structures of the Scapula The Scapula Scapula  The Upper Limb 30 bones form each upper limb Grouped into bones of the – Arm – Forearm – Hand  Arm Region of the upper limb between the shoulder and elbow Humerus – The only bone of the arm – Longest and strongest bone of the upper limb – Articulates with the scapula at the shoulder – Articulates with the radius and ulna at the elbow  Arm Humerus – Many structures of the humerus provide sites for muscle attachment – Other structures of the humerus provide articulation sites for other bones Structures of the Humerus of the Right Arm The Humerus: Anterior Humerus Head medial epicondyle anatomical neck surgical neck olecranon fossa lateral epicondyle Capitulum greater tubercle Trochlea lesser tubercle coronoid fossa deltoid tuberosity intertubercular groove The Humerus: Posterior  Forearm Formed from the radius and ulna Proximal ends articulate with the humerus Distal ends articulate with carpals  Forearm Radius and ulna articulate with each other – At the proximal and distal radioulnar joints The interosseous membrane – Interconnects radius and ulna In anatomical position – The radius is lateral and the ulna is medial  The Ulna and Radius: Posterior Ulna Radius Olecranon Head styloid process Radial tuberosity trochlear notch coronoid process styloid process radial notch ulnar notch The Ulna and Radius: Anterior Details of Arm and Forearm  Ulna Main bone responsible for forming the elbow joint with the humerus Hinge joint allows forearm to bend on arm Distal end is separated from carpals by fibrocartilage Plays little to no role in hand movement Proximal Part of the Ulna Radius and Ulna  Radius Superior surface of the head of the radius articulates with the capitulum Medially – the head of the radius articulates with the radial notch of the ulna Contributes heavily to the wrist joint – Distal radius articulates with carpal bones – When radius moves, the hand moves with it Distal Ends of the Radius and Ulna  Hand Includes the following bones – Carpus – wrist – Metacarpals – palm – Phalanges – fingers  The Wrist and Hand The carpal bones are the eight bones of the wrist. The five metacarpal bones articulate with the distal carpal bones and make up the palm of the hand. The fourteen phalanges of the hand make up the finger bones.  SLTPTTCH Hand  Carpus Forms the true wrist – the proximal region of the hand Gliding movements occur between carpals Composed of eight marble-sized bones  Carpus Carpal bones – Are arranged in two irregular rows – Proximal row from lateral to medial Scaphoid, lunate, triquetral, and pisiform – Distal row from lateral to medial Trapezium, trapezoid, capitate, and hamate – A mnemonic to help remember carpals Sally left the party to take Carmen home Bones of the Hand  Metacarpus Five metacarpals radiate distally from the wrist Metacarpals form the palm – Numbered 1–5, beginning with the pollex (thumb) – Articulate proximally with the distal row of carpals – Articulate distally with the proximal phalanges  Phalanges Numbered 1–5, beginning with the pollex (thumb) Except for the thumb, each finger has three phalanges – Proximal, middle, and distal Bones of the Appendicular Skeleton  Pelvic Girdle Attaches lower limbs to the spine Supports visceral organs Attaches to the axial skeleton by strong ligaments Acetabulum is a deep cup that holds the head of the femur – Lower limbs have less freedom of movement Are more stable than the arm  Pelvic Girdle Consists of paired hip bones (coxal bones) Hip bones unite anteriorly with each other Articulates posteriorly with the sacrum  Bony Pelvis A deep, basin-like structure Formed by – Coxal bones, sacrum, and coccyx Bony Pelvis  Coxal Bones Consist of three separate bones in childhood – Ilium, ischium, and pubis Bones fuse – retain separate names to regions of the coxal bones Acetabulum – A deep hemispherical socket on lateral pelvic surface  Ilium Large, flaring bone Forms the superior region of the coxal bone Site of attachment for many muscles Articulation with the sacrum forms sacroiliac joint  Ischium Forms posteroinferior region of the coxal bone Anteriorly – joins the pubis Ischial tuberosities – Are the strongest part of the hip bone  Pubis Forms the anterior region of the coxal bone Lies horizontally in anatomical position Pubic symphysis – The two pubic bones are joined by fibrocartilage at the midline Lateral and Medial Views of the Hip Bone  True and False Pelves Bony pelvis is divided into two regions – False (greater) pelvis – bounded by alae of the iliac bones – True (lesser) pelvis – inferior to pelvic brim Forms a bowl containing the pelvic organs True and False Pelves  The Lower Limb Carries the entire weight of the erect body Bones of lower limb are thicker and stronger than those of upper limb Divided into three segments – Thigh, leg (Shin), and foot  Thigh The region of the lower limb between the hip and the knee Femur – the single bone of the thigh – Longest and strongest bone of the body – Ball-shaped head articulates with the acetabulum The Femur: Anterior Femur Head Neck greater trochanter lesser trochanter intercondylar fossa patellar surface linea aspera fovea capitis medial condyle lateral condyle intertrochanteric line intertrochanteric crest The Femur: Posterior Structures of the Femur  Patella Triangular sesamoid bone Imbedded in the tendon that secures the quadriceps muscles Protects the knee anteriorly Improves leverage of the thigh muscles across the knee The Patella  Leg (Shin) Refers to the region of the lower limb between the knee and the ankle Composed of the tibia and fibula – Tibia – more massive medial bone of the leg Receives weight of the body from the femur – Fibula – stick-like lateral bone of the leg Interosseous membrane – Connects the tibia and fibula  Leg Tibia articulates with femur at superior end – Forms the knee joint Tibia articulates with talus at the inferior end – Forms the ankle joint Fibula does not contribute to the knee joint – Stabilizes the ankle joint Structures of the Tibia and Fibula The Tibia and Fibula: Posterior  The Foot Foot is composed of – Tarsus, metatarsus, and the phalanges Important functions – Supports body weight – Acts as a lever to propel body forward when walking – Segmentation makes foot pliable and adapted to uneven ground FootTarsals Talus Calcaneus Cuboid navicular cuneiforms - 1st, 2nd, 3rd  Tarsus Makes up the posterior half of the foot Contains seven bones called tarsals Body weight is primarily borne by the talus and calcaneus  Metatarsus Consists of five small long bones called metatarsals Numbered 1–5 beginning with the hallux (great toe) First metatarsal supports body weight  Phalanges of the Toes 14 phalanges of the toes – Smaller and less nimble than those of the fingers – Structure and arrangement are similar to phalanges of fingers – Except for the great toe, each toe has three phalanges Proximal, middle, and distal Bones of the Foot Bones of the Foot Figure 8.12b  Bones of the Foot PLAY Bones of the Foot Figure 8.12c  Arches of the Foot Foot has three important arches – Medial and lateral longitudinal arch – Transverse arch Arches are maintained by – Interlocking shapes of tarsals – Ligaments and tendons Arches of the Foot 3 Arches Lower Limb and Pelvis  Any questions? Questions for students 1. Name the all upper limb bones 2. Name the all pelvic bones 3. Name the all lower limb bones 4. Which bones does the patella belong?? 5. How many arches of foot? Named it.