Axial and Appendicular Skeleton: Bones and Functions
The axial skeleton is the centerpiece of the bony framework. It consists of 69 bones, including the skull, spine, and rib cage. Inside the skull are the cranial bones, facial bones, and small auditory ossicles. Below is the backbone, which is the pillar of bone structure, and consists of the cervical, thoracic, and lumbar vertebrae, besides the sacrum and coccyx. Between the spine and sternum, surrounded by the ribs, is the rib cage, which is an essential part of the axial skeleton, protecting
Read MoreLower Limb Muscles: Anatomy and Function
Gluteal Muscles
- Gluteus Maximus:
- Origin: Upper coccyx, sacrum, and posterior ilium.
- Insertion: Posterior femur.
- Action: Extension and external rotation of the thigh; helps maintain an upright posture. The sciatic nerve passes beneath it.
- Gluteus Medius:
- Origin: Middle coccyx.
- Insertion: Greater trochanter of the femur.
- Action: Abduction and internal rotation of the thigh.
- Gluteus Minimus:
- Origin: Iliac crest.
- Insertion: Greater trochanter of the femur.
- Action: Abduction and internal rotation of the thigh.
- Piriformis:
Common Musculoskeletal Conditions: Symptoms and Causes
Common Musculoskeletal Conditions
Muscle Atrophy: Muscle atrophy is the wasting or loss of muscle tissue. It can result from disuse, degeneration, or congenital nerve defects.
Backache: Back pain often stems from strain or lack of exercise. Individuals who are overweight are at higher risk. Proper lifting techniques, such as bending your knees, are crucial.
Bone Cancer: Osteosarcoma is the most common primary bone cancer, resulting from the malignant transformation of bone-forming cells.
Cramps: Muscle
Read MoreSkull Sutures, Temporomandibular Joint, and Neck Muscles Anatomy
Skull Sutures and the Temporomandibular Joint
Skull sutures are toothed, scaly, harmonica-like (the nose), and esquindélesis (between the underside of the body of the sphenoid and vomer).
Temporomandibular Joint (TMJ)
The temporomandibular joint (TMJ) is located among the temporal fossa, in front of the ear canal, and the condyle of the mandible or lower jaw (synovial condyle). It has a joint capsule and articular surfaces between the two, providing a fibrocartilaginous disc. The joint capsule is
Read MoreHuman Anatomy: Skeleton, Muscles, and Reproductive Systems
The Human Body: A Concise Overview
The Skeletal System
Axial Skeleton
- Skull
- Thorax
- Spinal Column
Appendicular Skeleton
- Upper Limbs
- Lower Limbs
Cartilage
Softer than bone, composed of cartilaginous tissue. Found in the nose, ears, intervertebral discs, joints, and embryonic skeleton.
Joints
Structures that connect two bones.
Parts of a Joint:
- Ligaments: Connect bones.
- Cartilage: Covers and prevents friction.
- Synovial Cavity: Space filled with a viscous lubricant fluid.
Muscle Structure
- Muscle Fascicle: Structure formed
Understanding Neuronal Function and Synaptic Transmission
SOL.II
- Neurons are polarized cells because they present a dendritic domain and an axonal domain.
- With respect to the Action Potential (AP): It is the electrical signal for the propagation of neuronal information.
- Regarding myelin: Its function (F(X)) is to accelerate the speed of nerve impulse propagation.
- Neuronal circuits: Endings are formed by axons and dendrites/synapses and glial cell prolongations. A simple example of a neuronal circuit is the patellar reflex.
- The Nervous System (NS): This is formed