human anatomy

SHC 4113 Human Anatomy

Lecture 1 Anatomical terminologies

Anatomy definition: study of the structure of living organisms: part of the body, form, position and relationship among structures

Anatomical position

Standing erect (upright position)

Eyes are level, directed forwards

Arms at the side with the palms facing forward

Legs are parallel with feet on the floor

Directional terms: Anterior (ventral), Posterior (dorsal), superior (cranial or cephalad), inferior (caudal), medial, lateral, proximal, distal, superficial (external), deep (internal), parietal, visceral, ipsilateral, contralateral

Body planes and sections: sagittal section, frontal (coronal) section, transverse (cross) section

Body movement: flexion (bending), extension, abduction, adduction, circumduction, rotation, elevation, depression, protraction, retraction, pronation, supination

Special movement of the body

Head and trunk: lateral flexion, rotation, mandible (lateral excursion, medial excursion)

Hand and digits: ulnar flexion, radial flexion, radial abduction, palmar abduction of thumb, opposition of thumb, reposition

Foot: dorsiflexion, plantar flexion (inversion, eversion)

Bone marking

Muscle and ligaments: Tuberosity, crest, trochanter, line, tubercle, epicondyle, spine, process

Joints: head, facet, condyle, ramus

Depression and opening

For passage of blood vessels and nerves: groove, fissure, foramen, notch

Others: meatus, sinus, fossa

Lecture 2 Bone: an overview

The skeletal system is the framework of bone and cartilage that protects our organs and allows us to move

Bone is the hardest tissue of the body composed of:

Water: 20% organic matter: 30-40%, give toughness

inorganic matter: 40-50%, calcium phosphate and carbonate, give hardness

Functions of the skeleton

Support: form internal framework, support body, cradles soft organs, give size and shape

Protection: protect soft organs, vital organs, e.g.

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Figure 3

Cranium bones protect the brain

Movement: skeletal muscles attached to bones by tendons, to move the body

Storage: provide storage of mineral salts, e.g. Calcium, phosphorus

Blood cell formation: red bone marrow in cancellous bone makes red blood cells, platelets

Macroscopic structure of bone

Diaphysis: compact bone, give the length of the bone

Periosteum: cover and protect the diaphysis by a fibrous connective tissue membrane

Epiphyses: end of long bone, thin layer of compact bone with an area filled with spongy bone

Articular cartilage: cover the external surface of the bone, smooth, slippery surface to decrease the friction

Epiphyseal line: thin line of bony tissue, remnant of the epiphyseal plate (initial bone development site)

Yellow marrow/ medullary cavity: center of the long bone, high fat content, yellow in color

Medullary canal: hollow space within the diaphysis, contains yellow marrow

Red marrow: fill in the spaces in cancellous bone, rich blood supply, formation of platelets and blood cells

Type of bone tissues (adult skeleton--206 bones)

Compact bone: dense outer layer, solid, hard, ivory in color, covered with fibrous tissue called periosteum

Cancellous bone: found in the extremities of long bones & the interior of small bones, spongy, red marrow filled

Microscopic structure of bone tissue

Compact bone tissue: circular pattern structure, found in the diaphysis of long bone

Haversian canal--containing blood vessels, lymphatics & nerve

Lamellae--concentric plates of bone surrounding the Haversian canal

Lacunae--filled in the spaces of lamellae containing lymph and bone cell

Canaliculi--bring nutrients and oxygen to bone cell and remove waste products

Cancellous (spongy) bone

--red bone marrow is present, red bone marrow is a type of tissue in which blood cells are found & matured before entering the blood vessels

-found in extremities of the long bone (epiphysis) and the inner mass of flat bone

Bone formation (ossification, osteogenesis)

As the cartilage enlarges through appositional and interstitial growth, chondrocytes near the centre of the shaft increase greatly in size. The matrix is reduced to a series of small struts that soon begin to calcify the enlarged chondrocyte then die and disintegrate, leaving cavities within the cartilage.

Blood vessels grow around the edges of the cartilage and the cells of the perichondrium convert to osteoblasts. The shaft of the cartilage then becomes ensheathed in a superficial layer of bone.

Blood vessels penetrate the cartilage and invade the central region. Fibroblasts migrating with the blood vessels differentiate into osteoblasts and begin producing spongy bone at a primary center of ossification. Bone formation then spreads along the shaft toward both ends.

Remodeling occurs as growth continues, creating a marrow cavity. The bone of the shaft becomes thicker, and the cartilage near each epiphysis is replaced by shafts of bone. Further growth involves increase in length.

Capillaries and osteoblasts migrate into the epiphyses, creating secondary ossification centers.

The epiphyses are filled with spongy bone. An articular cartilage remains exposed to the joint cavity; over time it will be reduced to a thin superficial layer. At each metaphysis, an epiphyseal cartilage separates the epiphysis from the diaphysis.

Bone remodeling-old bone is constantly destroyed by osteoclasts, while new bone is formed by osteoblasts

Factors affecting bone growth

Genetic factors-size and shape of bone

Mechanical factors-osteoblast activity increases by muscle contraction(bone tissue thicken, strengthen; osteoclast become active by not enough exercise( bone tissue thinner, weaker

Nutrition-vitamin A necessary for osteoblast, osteoclasts to function; -vitamin C for collagen synthesis and matrix mineralization by osteoblasts, deficiency(growth retard, osteoporosis; -vitamin D for absorbing calcium from intestine, deficiency( rickets, osteomalacia

Hormones --growth hormone: from pituitary gland, increase protein synthesis, promote cell division; increase(gigantism; decrease(dwarfism --thyroid hormone: from thyroid gland, increase rate of replacement of cartilage bon in the growth plate --sex hormone: oestrogen, testosterone stimulate bone growth, and ossification of epiphyseal plate --parathyroid hormone: from parathyroid gland, stimulate osteoclast to breakdown bone, and increased blood calcium levels --calcitonin: from thyroid gland, stop effects of PTH, stop osteoclasts, help calcium absorption by bones

Lecture 3: bones: classification and position

Classification of bones

Long bone

Short bone (cube shape)

Flat bone

Irregular bone

Sesamoid bone (small bone developed from tendon)

Skeleton divided into 2 parts: axial skeleton, appendicular skeleton

Whole body 206 bones; 80 from axial skeleton, 126 from appendicular skeleton

Skull bones-cranium (8), face(14)

Frontal bone, parietal bones, temporal bones (styloid process, mastoid process, jugular foremen), occipital bone, sphenoid bone, ethmoid bone

Foramen magnum allows spinal cord to connect with the brain

Facial bones:14 irregular bones, 12 are paired, only mandible and vomer are single

Maxillae (maxillary bone)

Zygomatic bones (cheekbones)

Lacrimal bones (tears)

Nasal bones

Vertebral column

Structure of intervertebral discs

Cervical vertebrae (7) (C1-C7) atlas and axis are different because they perform functions not shared by the other cervical vertebrae Atlas (C1)-no vertebral body, nod "yes" Axis (C2)-act as a pivot for rotation of the atlas joint between atlas and axis, nod "no" C3- C7 : have small bodies with articular facets for articulation with one another All (C1-C7) have transverse foramina in their transverse processes for the passage of vertebral blood vessels

Thoracic vertebrae (12)-all typical, larger than cervical vertebrae, form a joint with the ribs

Lumbar vertebrae-largest and strongest vertebrae

Sacrum (5)-winglike shape bone

Coccyx (3-5)-tiny, irregular shaped, human "tailbone"

Thoracic cage(bony thorax)-made up of sternum, ribs, thoracic vertebrae, costal cartilages --protective, cone-shaped cage for the organs inside the cavity (heart, lungs, major blood vessels)

Sternum-flat, consists of 3 bones (manubrium, body, xiphoid process)

Ribs-12 pairs true ribs-first 7 pairs, connect to sternum directly by costal cartilages false ribs-next 5 pairs floating ribs--last 2 pairs of ribs, no sternal attachment

Appendicular skeleton

Shoulder girdle (pectoral girdle), consists of 2 bones: clavicle, scapula

--Scapulae (shoulder blades): triangular in shape

Bones of the upper limbs

Arm-humerus

Forearm-radius and ulna

Hand-carpals (8), metacarpals(5), phalanges(14)

Bones of the pelvic girdle

Pelvic girdle: bear the weight of upper body; protect vital organs e.g. reproductive organs, urinary bladder, intestine

Hip bone: ilium, ischium, pubis

Bones of the lower limbs

Lecture 4: Different types of joints

Joints classification

26 irregular bones, called vertebrae

Spinal nerve pass

33 vertebrae in 2 groups:

True vertebrae separated by intervertebral discs�cervical (7), thoracic (12), lumbar vertebrae (5)

False vertebrae are fixed to one another

Sacrum: 5 sacral vertebrae�coccyx: 4 fused coccygeal vertebrae

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Fixed joints/ fibrous joints

Held by fibrous tissue

Cartilaginous joints/ slightly movable joint

A pad of white fibrocartilage between the ends of bones making up the joint

Freely moveable joints/ synovial joint

Presence of synovial membrane

Synovial joints-with synovial fluid

Structure of a synovial joint

Capsular ligament/ joint capsule

Articular cartilage

Synovial membrane

Extra-capsular structure

Intra-capsular structure