Understanding the Skeletal System: Structure, Function, and Cells
Skeletal System: Bone Tissue and Bones
Bone Classification
Long Bone (e.g., Humerus):
- Longer than they are wide, with one diaphysis and two epiphyses.
- Bones of the limbs: superior (arm, forearm, palm, fingers) and inferior (thigh, leg, sole, toes).
- Mostly compact bone, especially in the epiphysis.
- Plays a role in support.
- Contains a medullary cavity (only type of bone with this feature).
Short Bone (e.g., Talus):
- Small, almost cubic.
- Filled with spongy bone, covered by a thin layer of compact bone.
- Bones of
Muscular System: Anatomy, Function, and Contraction
Muscular System Functions
- Movement: Contraction of skeletal muscles.
- Posture: Maintenance by skeletal muscles.
- Respiration: Movements of thoracic muscles.
- Heat Production: Body heat generation.
- Communication: Muscle actions facilitate communication.
- Organ Constriction: Smooth muscles move substances.
- Heartbeat: Cardiac muscle propels blood.
- Organ Protection: Muscles provide support.
Muscle Connective Tissues
Epimysium
The epimysium is the outermost layer of dense, irregular connective tissue surrounding the
Read MoreAnatomy of the Human Skull: Bones and Structures
Lower Vision of the Skull
Nostril (smaller sphenoid wing), middle cranial fossa (petrous bone), posterior cranial fossa (holds the cerebellum).
Frontal Bone
Form: Most of the anterior cranial fossa, the roof of the orbits, and the forehead. Anatomical Features: Squama, parietal border, brow ridge, supraorbital margin with supraorbital notch, zygomatic process, nasal spine, ethmoidal notch, frontal sinus. Formed from 2 points of ossification, between which is the metopic suture.
Sphenoid Bone
Form: Much
Read MoreMuscle Contraction and Fiber Types: A Cellular Process
Phases of Neuromuscular Transmission
- The action potential originates in the axonal cone and travels along the axon, specifically through the nodes of Ranvier. Upon reaching the presynaptic membrane, it triggers the opening of voltage-gated calcium (Ca) channels.
- Calcium ions enter the neuron, causing the presynaptic membrane to attract vesicles containing acetylcholine (ACh) located in the cytosol of the axon.
- Acetylcholine is released into the synapse.
- Chemical-gated channels open when coupled with
Human Anatomy: Joints, Muscles, and Bones
Joints
Hip Joint
- Which type of joint is the hip?
Ball and socket - Which ligament of the hip joint closes the acetabular notch?
Transverse acetabular ligament or transverse ligament of the acetabulum
Knee Joint
- Choose the correct answer about the knee:
Its medial collateral ligament is firmly attached to the medial meniscus - The inability to extend the leg at the knee joint would indicate paralysis of the muscle:
Quadriceps femoris muscle - Which of these answers about the lateral collateral ligament of the knee
Human Body Systems: Skeletal, Endocrine, Digestive, Respiratory
Skeletal System
The skeletal system provides support, protection, mineral storage, hematopoiesis (blood cell formation), and enables movement.
Types of Bones
- Long bones
- Irregular bones (e.g., vertebrae)
- Short bones (e.g., carpals, tarsals, ossicles)
- Flat bones (e.g., cranial bones, sternum, hip bones)
Bone Structure
- Diaphysis: The shaft of a long bone, composed of hard compact bone.
- Epiphysis: The ends of a long bone, composed of spongy bone.
Internal Structure
- Medullary cavity: A hollow space within the diaphysis,