Podcast Beta
Questions and Answers
Which of the following structures are part of the axial skeleton?
How many cervical vertebrae are present in the vertebral column?
Which bone is considered the only movable bone in the skull?
What type of bones make up the shoulder girdle?
Signup and view all the answers
How many pairs of ribs are typically found in the human body?
Signup and view all the answers
What defines the anatomical position of the human body?
Signup and view all the answers
Which term describes the position of a body part that is nearer to the front?
Signup and view all the answers
How many bones are typically found in the adult human skeleton?
Signup and view all the answers
Which anatomical term describes a position that is away from the median plane of the body?
Signup and view all the answers
Which of the following terms is used to describe a body part closer to the root of a limb?
Signup and view all the answers
Study Notes
Anatomical Position
- Standing erect with eyes looking forward
- Arms straight by the sides with palms facing forwards
- Thumb directed laterally
Anatomical Terms
- Anterior/Ventral: Front of the body
- Posterior/Dorsal: Back of the body
- Superior/Cranial: Nearer the upper end of the body
- Inferior/Caudal: Nearer the lower end of the body
- Median: Exactly in the middle line
- Medial: Nearer to the median plane
- Lateral: Away from the median plane
- Proximal: Nearer to the root of a limb
- Distal: Away from the root of a limb
- Superficial: Towards the skin or the surface of the body
- Deep: Further away from the skin or the surface of the body
Anatomical Planes
- Median Plane: Vertical plane passing through the midline of the body, dividing it into equal right and left halves.
- Paramedian Plane: Parallel to the median plane, dividing the body into right and left parts.
- Horizontal Plane: Runs horizontally, dividing the body into superior and inferior parts.
Classification of the Skeleton
- The skeletal system is composed of 206 bones.
- Axial Skeleton: Bones in the midline of the body (skull, ribs, sternum, vertebral column, hyoid bone).
- Appendicular Skeleton: Bones of the limbs and their girdles (shoulder girdle, free upper limb, pelvic girdle, free lower limb).
Axial Skeleton
- Skull: Composed of 21 immovable bones joined by sutures, including the cranium and face.
- Mandible: The skeleton of the lower jaw, the only movable bone in the head.
- Ribs: 12 pairs.
- Sternum: The breastbone.
-
Vertebral Column: Formed from 33 vertebrae, divided into:
- 7 Cervical vertebrae
- 12 Thoracic vertebrae
- 5 Lumbar vertebrae
- 5 Sacral vertebrae (fused to form the sacrum)
- 2-4 Coccygeal vertebrae (fused to form the coccyx)
Appendicular Skeleton
- Shoulder Girdle: Consists of the scapula (shoulder blade) and clavicle (collarbone).
-
Free Upper Limb:
- Arm: Humerus
- Forearm: Radius and Ulna
- Hand: Carpals, Metacarpals, and Phalanges
- Pelvic Girdle: Hip bone.
-
Free Lower Limb:
- Thigh: Femur
- Leg: Tibia (medially) and Fibula (laterally)
- Foot: Tarsus (ankle bones), Metatarsals (foot bones), and Phalanges (toe bones).
Bone Ossification
- Intramembranous Ossification: Direct development of bone from mesenchyme; found in certain bones like the clavicle, skull cap, and mandible.
- Intracartilaginous Ossification: Cartilage model is formed first from mesenchyme, then replaced with bone; occurs in long bones, vertebrae, ribs, and the base of the skull.
Types of Bones By Shape
- Long Bones: Two ends and a shaft (e.g., femur, humerus, metacarpals, metatarsals, phalanges).
- Short Bones: Cube-shaped (e.g., carpal and tarsal bones).
- Flat Bones: Flat and thin (e.g., bones of the skull cap, sternum, scapula).
- Irregular Bones: Complex shapes (e.g., vertebrae, hip bone).
- Pneumatic Bones: Contain air-filled spaces (e.g., certain skull bones like frontal and maxilla).
- Sesamoid Bones: Develop within tendons, often at sites of friction (e.g., patella).
Structure of a Long Bone
- Epiphysis: Ends of the bone, covered by hyaline cartilage.
- Diaphysis: The shaft, containing compact bone and bone marrow. Covered by periosteum (a fibrous sheath).
- Metaphysis: The area between the epiphysis and diaphysis.
Growth of Long Bones
- Length: Growth occurs at the epiphyseal plate of cartilage.
- Diameter: Growth occurs through the periosteum.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
