Hubs Flashcards
What is homeostasis?
The state of steady internal physical and chemical conditions maintained by living systems.
What position does the body face in anatomical terminology?
Upright, face forward, feet together, palms face forward.
What does ‘anterior’ refer to?
The front of the body.
What does ‘posterior’ refer to?
The back of the body.
What does ‘superior’ mean?
Closer to the head.
What does ‘inferior’ mean?
Closer to the feet.
What is ‘medial’?
The midpoint of the body.
What does ‘lateral’ mean?
Furthest away from the body.
What is ‘proximal’?
Closest to the trunk of the limb.
What does ‘distal’ refer to?
Furthest from the trunk of the limb.
What does ‘deep’ mean in anatomical terms?
Further from the surface.
What does ‘superficial’ mean?
Closer to the surface.
What is the sagittal plane?
Divides the body into left and right planes.
What does the coronal plane divide?
The body into back and front sections.
What is the transverse plane?
Divides the body into top and bottom sections.
What type of movement occurs in the sagittal plane?
Back and forward movement.
What type of movement occurs in the coronal plane?
Side to side movement.
What type of movement occurs in the transverse plane?
Rotating movement.
Define flexion.
Decreases angles, brings one part of the body closer to another.
What is extension?
Increases the angle.
What is dorsiflexion?
Toes brought up high.
What is plantarflexion?
Toes pointing down (tip toes).
Define abduction.
Movement at joint moves away from midline.
What is adduction?
Movement at joint moves towards midline.
What does inversion refer to?
Sole of foot faces towards midline.
What does eversion mean?
Sole of foot turns away from midline.
What is circumduction?
Combination of four movements: flexion, abduction, extension, and adduction.
What does lateral rotation mean?
External rotation.
What does medial rotation refer to?
Internal rotation.
What is pronation?
Palm faces posterior.
What is supination?
Palm faces anterior.
What are the functions of the skeletal system?
Support, Movement, Protection, Storage, Red blood Cell Formation
Each function plays a vital role in maintaining the body’s structure and health.
Compact bone?
Dense, tightly packed together; all structures line up in one direction; force transmitted in one direction through the bone
Compact bone is crucial for strength and support.
What is the structure of cancellous bone?
Criss crossing fibers; light and spongy; shock absorbing from many directions
Cancellous bone is typically found at joints to handle forces from various angles.
What are the characteristics of long bones?
Longer than they are wide; long thin central diaphysis and wider epiphyses; experience force; act as levers
Examples include limb bones like the femur and humerus.
What are short bones?
Close to equal width and length; mostly cancellous bone; weight bearing
Examples include carpals and tarsals.
What defines flat bones?
Big surface for muscle attachment; not all completely flat; protection bones; thin plates mostly compact bone
The skull is a primary example of flat bones.
What are irregular bones?
Bones that don’t fit into other categories; various functions and shapes
They can include bones with holes or unique shapes.
What is the axial skeleton composed of?
Skull, vertebral column, rib cage
It primarily protects vital organs.
What are the four divisions of the vertebral column?
- Cervical - 7
- Thoracic - 12
- Lumbar - 5
- Sacrum
- Coccyx
Each division has specific functions and characteristics.
What is the composition of the rib cage?
Ribs + Sternum; 12 pairs of ribs
Ribs connect to thoracic vertebrae posteriorly and cartilage anteriorly.
What is the primary function of the appendicular skeleton?
Limb structure
It includes bones of the limbs and girdles connecting them.
Compare the humerus and femur.
Humerus is shorter and lighter for more movement; Femur is more stable but less movement
This pattern is observed in other limb bones as well.
How many carpals are in the human hand? How many phalanges are in each finger?
8, 3 in each finger; thumb has 2
Carpals are the wrist bones, contributing to hand mobility.
How many tarsals are in the human foot?
7
Tarsals form the ankle and contribute to foot stability.
What is the role of the pectoral girdle?
Joins limbs; Clavicle stabilizes; Scapula allows arm movement
It provides flexibility and support for upper limb movement.
What is the primary function of collagen in bone tissue?
To resist tension and provide flexibility
Collagen exists in fibres within the organic extracellular matrix (ECM) of bone.
What are the two main extracellular components of bone?
Organic and inorganic components
Organic components include collagen and ground substance; inorganic components consist of mineral salts and trace elements.
What is the role of osteogenic cells in bone tissue?
To produce osteoblasts
Osteogenic cells are stem cells that contribute to bone formation.
What do osteoblasts do?
Produce new bone matrix
Osteoblasts are responsible for bone formation.
What is the function of osteocytes?
Maintains and recycles proteins and minerals
Osteocytes are mature bone cells that help maintain bone health.
What is the function of osteoclasts?
Removes bone matrix
Osteoclasts are involved in bone resorption.
What is an osteon?
A lengthwise unit within compact bone that provides a pathway for nutrients
Osteons consist of a central canal, lamellae, lacunae, and canaliculi.
What does the central canal of an osteon contain?
Blood vessels and nerves
Central canals are crucial for supplying nutrients to bone cells.
What are trabeculae in cancellous bone?
Struts of lamella bone arranged in a crisscross pattern
Trabeculae help distribute forces in multiple directions.
What is the role of bone remodeling?
To maintain balance between bone formation and destruction
Osteoblasts and osteoclasts work together in this process.
Fill in the blank: Osteoblasts and osteoclasts work together to _______.
Add and remove bone
This process allows bones to adapt to physical forces.
What is homeostasis in the context of bone tissue?
The balance of bone destruction and formation
Homeostasis ensures the amount of bone remains stable.
What are the darker dots found in compact bone called?
Lacunae
Lacunae house osteocytes.
What are canaliculi in bone tissue?
Channels that connect osteocytes to the central canal
Canaliculi facilitate nutrient exchange between osteocytes and the central canal.
What is the main structural difference between compact bone and cancellous bone?
Compact bone is dense, while cancellous bone has a spongy structure
This difference affects their mechanical properties and functions.
What is the initial model for bone growth?
A cartilage model
This occurs 6 weeks after fertilization.
What is the process of turning cartilage into bone called?
Endochondral ossification
What is the primary ossification center in a bone?
Diaphysis
What separates the epiphyses from the diaphysis during bone growth?
Growth plate
What type of growth adds width to bones?
Appositional growth
Name two key soft tissues involved in joints.
- Cartilage
- Dense Fibrous Connective Tissue (DFCT)
What type of cartilage is characterized by high water content and sparse collagen fibers? And whats it’s function
Hyaline (articular) cartilage, To resist compression
What type of cartilage acts as a shock absorber and distributes force?
Fibrocartilage
What type of connective tissue connects bone to bone?
Ligaments
What is the primary function of tendons?
Connect muscle to bones
What does bony congruence refer to?
The sum of bone surfaces that form an articulation
What type of joint allows for small movements and is connected entirely by fibrocartilage?
Cartilaginous joints
What type of tissue primarily makes up Dense Fibrous Connective Tissue (DFCT)?
Collagen
What is the primary cellular component of cartilage?
Chondrocytes
Fill in the blank: The osteoblasts produce bone on the _______.
Lamellae
What is the role of osteoclasts in bone growth?
Mold the bone shape and form the inner cavity
What is a characteristic of fibrous joints?
Ideally no movement, made of DFCT, its structure is a ligament
How does the structure of DFCT affect its healing?
It has little vascularity, leading to slow healing
What is the function of fibrocartilage in joints?
Resist both tension and compression
What type of cartilage degrades with age?
Hyaline cartilage
3 Types of Joints
Fibrous, Cartilaginous, Synovial
Cartilaginous
Tissue is fibrocartilage, structire varies based on joints, small movements
Synovial characteristics
Synovial joints are free-moving joints found in most limb joints, a complex association of tissues and structures that allow for a range of motion determined by joint structure.
Synovial structure
Joint capsule, joint cavity, synovial membrane, ligaments, capsule ligaments, intracapsular movements, fibrocartilaginous pads
Joint capsule + joint cavity in synovial
Made of DFCT holds it all together, supporting on all sides . The joint capsule has potential space in bones for movement and also nutrients
Intracapsular ligaments
within the capsule but seperate to it, helps prevent movement away from itself
Fibrocartilaginous pads
These are there to fill in space Provide cushioning and shock absorption
Planes for joint movement
The three planes coronal, sagittal and transverse
Axis what ones
They have an axis - this goes in the other direction to the plane
- Uniaxial (one axis)
- Biaxial (two axis)
- Multiaxial(many axis)
- Coronal and sagittal go together transverse is different.
Types of joint movements
Plane, Hinge, Pivot, Condylar, Ellipsoid, Saddle, Ball & Socket
Plane
Multiaxial, sliding and gliding
Flat articular surfaces
Hinge
Uniaxial, flexion and extension
Pivot
Uniaxial on the transverse plane, rotation
Condylar
Biaxial, flexion and extension, rotation when knee is flexed
Ellipsoid
Biaxial, circumduction, no rotation
Saddle
Biaxial, Circumduction, obligatory rotation - thumb
Ball and Socket
multiaxial, circumduction, rotation
Osmosis
This is the movement of water across a membrane to equalize solute concentration. The movement of water across a semipermeable membrane to equalize the two sides.
Isotonic
This is when the tonicity of the intracellular fluid and the extracellular fluid are in balance.
Hypertonic
This is when the concentration of H20 is higher outside of the cell, so osmosis causes water to move from inside cell to outside to reinstate isotonic.
Hypotonic
This is when tonicity is low, osmosis will move water from outside the cell to inside to the cell till they are isotonic.
Chemical Gradient
the difference in the concentration of a specific molecule or ion across a semi permeable membrane of a cell on either side
Electrical Gradient
The difference between the charges across a semi permeable membrane of a cell on either side
Passive ion channel
This means that there is an opening in the membrane that things can easily pass through, diffusion.
Sodium-potassium exchange pump
It exchanges sodium and potassium across the membrane. It does it against the gradient, so from low to high conc. So ATP is needed, as it is a active pump. One ATP molecules moves 3 sodium’s out, 3 potassium into the cell. Inside the cell becomes more negative, it affects both chemical and electrical gradient.
Resting membrane potential
Once it reaches a set point it will stop moving ions around. This point is the resting membrane potential.
3 Muscle types
- Smooth muscle - these many line hollow organs and are not under voluntary control
- Cardiac muscle - located only in the heart to generate force to pump blood around body, involuntary movement
- Skeletal muscle - applies force to the bones to control posture and movements, majority is voluntary
Skeletal muscle - jobs
Develop force, Movement and posture, support and protection for organs, voluntary control over major openings, Converts energy to heat to maintain core temp, this in involuntary, shivering.
Skeletal Muscle - tissue level
Individual muscle cells are called fibres. The are long cylinders. These gather into bundles called fascicles, these are all aligned one way to generate the most possible force. These fascicles are then bundled into muscles.
Individual fibres of skeletel muscles
Fibres are comprised of bundles of myofibrils, which are made of repeating units called sarcomeres. This is the part that contracts
Sarcomeres structure
Sarcomeres are made of myofilaments
○ Actin ( thin filaments)
○ Myosin ( thick filaments)
They have a striated appearance ( striped) due to them
Skeletal muscles - electrical signalling
- The fibres are lined by a cell membrane called - sarcolemma
- Transverse tubules (T-tubules) are tube like extension of the membrane that lead to the muscle. Means the whole muscle gets activated at the same time to contract They conduct deep electrical signals into the core of the fibre
- Sarcoplasmic reticulum (SR) they take up and store calcium while the muscle is relaxed then can release it into the cytoplasm when it needs to contract
Excitation-Contraction Coupling (EC-coupling) steps
- The voltage-gated sensor (DHPR)
- The ryanodine receptor (RyR)
- The SR Calcium-ATPas (SERCA)
How Excitation-Contraction Coupling (EC-coupling) steps
- The voltage-gated sensor (DHPR)
○ This receives signals from the T-tubules and interacts with the RyR
○ It changes shape when it receives the signal- The ryanodine receptor (RyR)
○ A passive calcium channel on the Sarcoplasmic Reticulum that gets a signal from the DHPR to release calcium into the cell - The SR Calcium-ATPas (SERCA)
○ An active calcium pump that uses ATP to move calcium back into the SR, against it’s concentration gradient to end the excitation.
- The ryanodine receptor (RyR)
What is myofilament made of?
Actin, the thin filaments and myosin the thick filaments
How does a contraction work
A cross-bridge forms when actin and myosin bind together when Ca is present causing a contraction
The stages in Cross-Bridge Cycling
Attached state, Released state, cocked state, cross-bridge state, power-stroke state
Attached state
The myofilament has just finished a power stroke and you are ready to relax
Released state
ATP binds to the myosin causing it to release the actin
Cocked State
Myosin burns ATP into ADP and stores the energy ready to contract again
Cross-Bridge State
Calcium shows up it now causes the energised myosin to bind to the actin forming a cross bridge
Power-stroke State
The myosin uses it stored energy to pull causing the actin to slide in and the muscle to contract
What muscle tension depends on
No. of muscle fibres recruited and the rate at which the muscle is stimulated
Fast muscle fibres vs slow muscle fibres
Fast muscles can provide more strength put tire quickly, slow muscles less strength but are hard to fatigue
First class lever
- Stabilises joint position, fulcrum between load and effort
Second class lever
Effective at overcoming heavy load, fulcrum then load then force
third class lever
Large range of movement and speed, fulcrum then force then load
