MSK Flashcards
Types of bone
Flat, Long, Irregular, Short, Sesamoid
Bone Functions
Protection, Support, Movement, Mineral Storage, Blood Cell Formation (Hematopoiesis)
Bone Composition
Calcium Phosphate, Collagen, Water.
CA++ & PO4 = 80%
Collagen Fibres = 20%
Function of Collagen
Gives strength and slight flexibility.
What is Ca10(PO4)6(OH)2
Hydroxyapatite Crystals.
A matrix of protiens and calcium that bones consist of.
What surrounds this extracellular matrix and spaces known as Lacunae
Osteocytes
Another name for Compact Bone
Cortical Bone
What % of body mass does Compact Bone have?
80%
Formation of Compact Bones?
Osteons (Tube shades units). Has a central canal surrounded by expanding rings (like tree growth rings).
The central canal has nerves, lymphatics and blood vessels.
Another name for Spongy Bone?
Cancellous / Trabecular Bone.
What % of body mass does Spongy Bone have?
20%
Formation of Spongy Bone?
Honey comb structure which contains red bone marrow. This produces Red Blood Cells. It is lighter than Compact Bone.
What is Osteogenesis?
Cells that develop into an Osteoblast cell.
What are Osteoblasts?
Bone building cells.
They remove Ca++ & PO4 from the blood.
What are Osteocytes?
Mature Osteocytes cells.
What are Osteoclasts?
BOne reabsorbing cells. They return Ca++ & PO4 to the circulation. They are merged big groups of dead Osteocytes and other materials. They have many nuclei (5-20, but up to 200).
Complication of Hypercalcemia
Decreases the secretion of parathyroid hormone (PTH), increase in motor neuron excitability, leading to tetanic muscular contractions.
What does a decrease in in PTH secretion cause?
Decrease in Vitamin D activation, a reduction in Ca++ absorption from the gut, increased osetoblast activity and bone growth, excretion of Ca++ in urine.
What may cause bone to be remodelled?
Mechanical stress, endocrine regulation of plasma Ca++, Viatmins A, C & D, minerals, hormones, and weight-beairng excersize.
Do bone stop growing after adolescence?
`No, bones remodel throughout life.
What hormones can affect bone growth/modelling?
Growth hormone, thyroxine, testosterone, oestrogens, calcitonin and parathyroid hormone.
What does Bone Marrow produce?
Stem cells and stem cells.
What are the two types of stem cells that bone marrow produces?
Hemopoietic (Blood cells)
Stromal (Fat, cartilage and bone cells).
What are the two types of bone marrow?
Red or Myeloid.
Yellow.
What is Red Bone Marrow?
Found in Flat bones and in the cancellous (spongy) material at the end of the long bones, they produce red blood & platelets & most white blood cells.
What is Yellow Bone Marrow?
The could is given because of the high number of fat cells. Osteogenesis occurs in this.
Hematopoietic Stem Cells divide into what?
Erythrocytes (RBC)
Leukocytes (WBC)
Megakaryocytes (Platelets - For cloting).
What regulates replication and differentiation?
Thrombopoietin - Platelets.
Erythropoietin - RBC,
Five types of bone fractures?
Comminuted (Enclosed, in more than one place), Impacted (Pressure crushesbone from either end), Incomplete (Greenstick - Partial splintered and common in children), Compound (Open fracture or break in the skin above or near the wound).
How is the Skeletal Muscle attached to the skeleton?
Through Tendons.
What do Ligaments do?
Attach bone to bone.
MAde up of fibrous connective tissue, crisscross bands of tissue, stabalises joints. For example, Anterior Cruciate Ligament - Thigh to shin bone.
What does a tendon look like?
Cylindrical fibres, multi-nucleated, striated, fibrous connective tissue.
What do tendons do?
Contracting cells that provide movement, Cells/Muscle fibres, contains proprioceptors (sensory cells) in spindles that detect muscle status and limb position.
They help muscles to move the bone or structure that they are attached to.
How do muscles move?
Muscle cells composed of smaller segmnents called sacromeres, separated by by Z bands. This is there the actual contraction occurs.
What is reciprocal innervation?
Innervation (Nerve stimulation) so that the contraction of a muscle or set of muscles (as of a joint) is accompanied by the simultaneous inhibition of an antagonistic muscle or set of muscles.
What is an Effector Organ?
A muscle or gland that contracts or secretes, respectively, in direct response to nerve impulses.
Four Key Function of the Skeletal Muscle System?
Body movements - The effector organ of the motor system, stabilises body positions, stores and moves substances within the body like K+, generates heat.
Name the three types of muscular tissue?
Cardiac
Smooth / Visceral
Skeletal / Striated
What is Cardiac Muscle?
Striated muscle, Involuntary. Makes up the wall of the heart.
What is Smooth muscle?
Unstriated Muscle, involuntary. Contained within structure that we don’t control, such as blood vessels, urethra, uterus, internal muscles of the eyes.
What is Skeletal Muscle?
Striated Muscle, voluntary. The muscle attached to our skeletons and allows us to move our body.
What is a Joint?
Points of articulation between 2 or more bones (Made up of connective tissues).
Name the three types of joints?
Fibrous
Cartilaginous
Synovial
Example of a Fibrous Joint?
Tibia - Fibula.
Between the skull bones.
Teeth to Jaw.
Example of a Cartilaginous Joint?
Manubrium - sternum. Intervertebral discs. The pubic symphysis.
Epiphyseal Plates - Area of growth within an immature long bone.
Example of a Synovial Joint?
The most movable type of joint. Ball-and-socket Joint (shoulder joint). Hinge joint (knee) Pivot joint (atlantoaxial joint, between C1 and C2 vertebrae of the neck). Condyloid joint (radiocarpal joint of the wrist) Saddle joint (first carpometacarpal joint, between the trapezium carpal bone and the first metacarpal bone, at the base of the thumb). Planar joint (facet joints of vertebral column, between superior and inferior articular processes).
What is a Fibrous Joint?
No synovial cavity.
Held together by fibrous tissue.
Permits little to no movement.
What is a Cartilaginous Joint?
No synovial cavity.
Held together by cartilage.
Permits little to no movement.
What is a Synovial Joint?
Freely movable. Bones forming joint have synovial cavity.
United by dense articular capsule (Fat layer).
Often untied with ligaments also.
What is Innervation?
The distribution of nerves to or in a part.
What is the difference between Somatic Nervous System and Autonomic Nervous System?
Somatic responses are solely based on skeletal muscle contraction. The autonomic system, however, targets cardiac and smooth muscle, as well as glandular tissue.
Which Nervous System is Voluntary?
The Somatic Nervous System (SNS) within the PNS.
How does movement come about?
Planning/Praxia within the Motor Cortex within the Frontal Lobe.
A lot of movement become automatic after repetition, this involves the cerebellum.
What is Dyspraxia?
Impacts an individual’s ability to plan and process motor tasks.
What is a Reflex Arc?
Short cut via the spinal nerves to the Nervous system = Autonomic Nervous System.
Usually to pain.
What happens in Innervation?
Movements initiated in motor cortex, efferent motor neurons synapse with spinal cord -> action potential in α-motor neuron -> synaptic cleft of motor end plate.
How do Muscle Contract?
Acetylcholine binds a receptor on the skeletal muscle cell -> action potential, increasing Ca++ release -> initiates contraction, ->shortening of the muscle
How do movements occur?
Movements are refined according to sensory information from proprioceptors of joints, skin & muscles. Basal Ganglia of brain (BG - Makes things smoother.
Why should rest periods be built into rehabilitation programs?
Recovery is more energy consuming as movements are less effective and move time consuming.
Movement are refined where?
In the Basal Ganglia of the brain.
What does an action potential do?
Muscles enable movement by initiating an action potential (or impulse) that causes a contraction that moves the limb / body part.
Name 4 MSK conditions?
Connect tie tissue disorders - Rheumatoid Arthritis.
Degenerative Conditiosn - Muscular Dystrophy.
Malignant Conditions - Sarcoma.
Bone Marrow Failure - Aplastic Anaemia.
How bones in the Axial Skeleton?
80 - Central
Crabium/Skill & Veryebrae/Spine
How many bones in the Appendicular?
126 Bones
Shoulder Girdle, Pelvic Girdle, Bones of the Limbs - Appendages.