What are the 3 types of Articulations?
- - Fibrous (3)
- - Cartilaginous (2)
- - Synovial (Majority)
What does Synarthroses mean?
No Movement within a joint
What does Amphiarthroses mean?
Slight movement within a joint
What does Diarthroses mean?
Huge range of movement within a joint (All synovial joints are diarthroses)
Name the 3 types of Fibrous articulations.
- - Suture- ex. skull bones (Synarthroses)
- - Syndesmosis- ex. fibula/tibia (Amphiarthroses)
- - Gomphosis- ex. tooth (Synarthroses)
Name the 2 types of Cartilaginous articulations.
- - Synchondrosis- ex. Hyalin Cartilage; becomes Synostosis by the fusion of two centers of occification to form solid bone (Synarthroses)
- -Symphysis- ex. vertebral column (Amphiarthroses)
What are Synovial joints?
- Majority (Diarthroses)- contain synovial fluid which
- - lubricates
- - feeds chondrocytes
- - absorbs shock
What are the different types of joint movement?
- 1. Linear Motion (Gliding)
- 2. Rotation
- 3. Angular Motion (Tilting)
- 4. Circumduction
What are the different types of Angular Movements?
- Abduction- take away from the body
- Adduction- take in towards the body
- Flexion- take from anatomical position adn place into the fetal position
- Extension- Bring back to anatomical position
- Pronation/Supination- take your soup and "pro" it on the floor
- Medial- rotate inward (internal)
- Lateral- rotate outward (external)
What limits movement at synovial joints?
- Articular discs (menisci)- ex. knee or jaw
- Ligaments- Intracapsular: inside joint cavity; Extracapsular: outside joint cavity
- Tendons & Muscles- muscles contract and tendons prevent movement
- Articular Surface Contour- shape of atricular surface
Which type of joint in the body allows the greatest range of motion?
The joint of the body tend to follow a pattern of increased strength causing less motion at the joint. Which of the following joints are the strongest:
-The pubis symphysis
-The articulation between the frontal bone and a parietal bone
The articulation between a frontal and a parietal bone
What is an Ellipsoidal joint?
(Condylar Joint)An oval articular surface nestles within a depression on the opposing surface. ex.connect the fingers/toes to meta-carpal/tarsals
What are Plane Joints?
(Gliding) the relatively flat articular surfaces slide across one another, but the amount of movement is very slight. ex. between carpal/tarsal bones
What are Hinge Joints?
Permit angular movement in a single plane; like opening/closing a door. (monaxial) ex. elbow
What is a Pivot Joint?
(monaxial) permit only rotation. ex. between the atlas/axis
What is a Saddle Joint?
Resembles a saddle because it's concave on one end and convex on the other. Extremely Mobile.(biaxial) ex. twiddling your thumbs
What is a Ball-and-socket joint?
The round head of a bone rests in the cup-shaped depression in another. (Triaxial) ex. Shoulder/Hip
What does a Glenoid Labrum do?
Enlarges the joint cavity
Which of the following ligaments is partially or completely dislocated during a shoulder separation?
What statement correctly describes the shoulder joint?
Articular cartilage covers the head of the humerus and the glenoid cavity.
What contributes the most to the stabilization of a shoulder joint?
- Rotator Cuff muscles
- Ligaments & muscles that move the humerus
The function of a bursa is to
- Reduce friction between a bone & tendon
- Smooth the surface outline of a joint
What are the 3 main functions of the Muscular System?
- 1. Produce Macroscopic movements
- 2. Produce Forces that Prevent movement
- 3. Produce Heat
What are the 3 types of Muscle Tissue?
What are common properties associated with the Muscular System?
- Cells are elongated into "fibers"
- Plasma membranes are electrically 'excited'
- Muscle fibers produce Contractile Force
- Muscle fibers are extensible & elastic
How are muscles and connective tissues "blended" in skeletal muscles?
- Skeletal Muscle (Organ)
- Muscle Fascicle (Bundle of cells)
- Muscle Fiber (Cell)
How to Muscle Fibers develope?
- 1.Through the fusion of Myoblasts
- 2. Myosatellite cells bind to the immature muscle fiber which is surrounded my numerous nuclei
What is the function of the Myosin head?
it acts as a motor that pulls the Z line in to shorten the sarcomere by 'sliding' between thick and thin filaments
What is the Z line made of?
What is the H band?
The area of non-overlap between thick and thin filaments
What happens as the Z line gets closer to the the A band?
The overlap shrinks
What keeps the Z line centered?
what is the role of Titin filamants?
Titin anchors thick filaments to the Z line (Stretch the sarcomere- strectch titin = Resistance)
What happens when the zone of overlap is reduced to zero?
- Thick/thin filaments cannot interact at all
- Muscle fibers cannot produce any active tension
- Contraction cannot occur
What happens if you increase the sarcomere length?
- Reduces tension
- Reduces the size of the zone of overlap
- Reduces the number of potential cross-bridge interactions
What happens in the Optimal Resting range?
- Produce Greatest tension/force
- Maximum number of cross-bridges can form
What happens in a decrease in sarcomere length?
- Reduces tension
- Sarcomeres cannot shorten much more
- Thin filaments meet at the M line and overlap the thin filaments on the other side
- Still produce 100% force
What happens when the resting sarcomere is as short as it can be?
- Tension production falls to zero
- Thick filaments are jammed against the Z line (they overlap too much)
- Sarcomere cannot shorten anymore
- Interferance with cross-bridges
- Don't want to be here (Delta State)-disruptive & breaks down
What is the cross-bridge cycle?
A series of molecular events that occur after the excitation of the sarcolemma.
What is a Cross-bridge?
A Myosin head bound to Actin
What structure is the functional unit of contraction in skeletal muscle fiber?
Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are calcium ions stored within the fiber?
The Sarcoplasmic Reticulum
After a power stroke, the myosin head must detach from actin before another power stroke can occur. What causes cross bridge detachment?
ATP binds to the myosin head
How does the myosin head obtain the energy required for activation?
Hydrolysis of ATP
What specific event triggers the uncovering of the myosin binding site on actin?
Calcium ions bind to troponin and change its shape
When does cross bridge cycling end?
Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin.
How is Contraction regulated?
- Binding sites are covered by Tropomyosin to keep from contracting
- To turn ON-Put Calcium ions in and bind to Troponin (this causes a change in the shape and rolls Tropomyosin out of the way to make it capable of turning ON)
- To turn OFF- Take away the Calcium ions and Tropomyosin rolls back in and keeps from forming cross-bridges
Explain Excitation-Contraction Coupling.
- Excitation- A signal from the nervous system travels to every sarcomere simultaniously
- Starts the signal at the Sarcolemma and spread rapidily
- Signal comes from the Sarcolemma to the inside of the cell by Transverse tubules (T tubules)
- then travels through the Terminal cisternae to the triad and transmits an action potential to the rest of the cell and gets transduced into another signal
- The Sarcoplasmic reticulum is jammed full of calcium and the signal flows out creating a "Twitch"
How do you initiate muscle contraction "Twitch"?
- 1. Action Potential reaches T tubule
- 2. SR releases Calcium
- 3. Active-site exposure, cross-bridge formation
- 4. Contraction begins
How do you achieve muscle relaxation?
- 1. SR recaptures Calcium ions
- 2. Active sites covered, No cross-bridge interactions
- 3. Contraction Ends
- 4. Relaxation occurs, Passive return to resting length
True or False?
All skeletal muscle fibers produce "twitches"?
True; But the amount of time it takes to produce "twitches" varies.
What are Slow fibers?
- Smaller in diameter
- Darker color due to Myoglobin
- Fatigue Resistant
What are Fast fibers?
- Larger in diameter
- Paler in color
- Easily Fatigued (Shorten more rapid and contract faster)
*Larger Diameter = More Force Produced*
What are Parallel Muscles?
- Fascicles are parallel to longitudinal axis. (ex. Biceps)
- Parallel muscles w/ Tendinous bands (ex. Rectus abdominus)
- Wrapping (ex. Supinator)
What are Convergent Muscles?
Fibers are based over broad area but come together at a common attachment site (ex. Pectoralis)
What are Pennate Muscles?
- 1+ tendons run through the body of the muscle, & fascicles form oblique angles
- Unipennate-all muscles found on same side of the tendon (ex. Extensor digitorum)
- Bipennate- muscles on both sides of the tendon (ex. Rectus femoris)
- Multipennate- The tendon branches in all directions within the muscle (ex. Deltoid)
What are Circular Muscles?
(Sphincter) fibers concentrically arranged around and opening (ex. Orbicularis Oris-Mouth)
What are the three Classes of Levers?
- First-class: The applied force and resistance are on opposite sides of the fulcrum (ex. muscles that extend the neck)
- Second-class: resistance lies between the applied force and fulcrum (ex. plantar flexion)
- Third-class: force is applied between the resistance and fulcrum (ex. biceps brachii-flexes the elbow)
What is the Central Nervous System (CNS)?
- Consists of the brain and spinal chord
- Integrating, Processing, & Coordinating: Sensory input & Motor output
What is the Peripheral Nervous System (PNC)?
- Consists of all of the neural tissue outside the CNS.
- Provides Sensory info. to the CNS and carries Motor commands from the CNS to peripheral tissues/systems
- Subdivided into two divisions: Afferent- brings sensory info to the CNS; Efferent- carries motor commands to muscles/glands
Where does the Afferent division begin in the PNS?
- Receptors: dendrites, speciallized cell/cluster of cells, complex sense organ
- Provide info. to be carried to the CNS
- Have both Somatic and Visceral components
Where does the Efferent division begin?
- Begins inside of the CNS
- Ends in the effector: a muscle cell, gland cell, etc.
- Includes both Somatic Nervous System (SNS) and Autonomis Nervous System (ANS)
What are Neurons? What do they consist of?
- Neurons are responsible for the transfer/processing of info. in the nervous system
- They are composed of: a cell body, dendrited, axon, and synaptic terminals
What are Neuroglia?
(Glial cells) which are supporting cells in the nervous system
When looking at a cross sectional view of the Central Canal, what is present?
- Ependymal cells- participate in the movement and production of cerebrospinal fluid (CSF)
- Glial cells surround the Ependymal cells
- The central canal has basal cell processes that go out in the gray matter (The surface of the Ependymal of the canal is Cilliated)
Do do you tell the difference in an axon and a dendrite when staining a cell body of a neuron?
- Granular staining in cell body (Nissl bodies) project into dendrites a little bit. However, It Does NOT project into the axon hillock or axon itself.
- Nissl bodies-(stain dark) Rough ER; Ribosomes!
In a neuron, where does DNA Transcription happen? Where does Translation happen?
- DNA transcription-Nucleus
- Translation into proteins- cell body
In what direction can an Action Potential travel in a nuron?
In One Direction
What happens if you have a site of injury on an axon?
- 1. Degeneration on the distal part (Proximal part is OK)
- 2. Invaded by phagocytes and clear they clear the way
- 3. Proximal stump spreads/grows; If one contacts the original site, it recognizes it and all of the other go away
- 4. Schwann cells go in and line the stumps. The sprout finds the Schwann cells and crawls along it. If it recognizes it, it starts Regeneration
Neurons can be classified on the basis of the number of processes that project from their cell body.
- Anaxonic- No distinguishable axon
- Bipolar- 1 dendrite & 1 axon
- Pseudounipolar- dendrite and axon are continuous at one side of the cell body
- Multipolar- several dendrites and 1 axon (Most common)
What is the function of Myelinated axons?
Increase Action Potential transmissions
Neurotranmitters can either be Excitatory or Inhibitory.
- The fusion of secretory vessicles and the presynaptic membrane secrete Neurotransmitters that diffuse rapidly and bind to receptors either:
- Excitatory- open and allow depolarization of the membrane to fire off its action potential;OR
- Inhibitory- Increase polarization so it is less likely to fire off an action potential
(Whether or not a postsynaptic cell fires its own action potential is the sum
of the both excitatory and inhibitory inputs)
Neuron Organization and Processing
- Divergence- spread of information over a wide target (multiple) neurons on one postsynaptic neuron
- Convergence- A single postsynaptic neuron receives input from multiple presynaptic neurons
- Serial Processing- (simplest) a pattern of stepwise info. processing from neuorn to the next (single neurons in a line)
- Parallel Processing- Processes info. by several neurons at one time (Many different responses occur at the same time)
- Reverberation- When neural circuits use Positive feedback to continue activity of the circuit by means of Collateral Axons stimulating presynaptic neurons
Which neuronal tissue cell type is likely to be mafunctioning if the blood-brain barrier is no longer adequately protecting the brain?
In what location would you find a somatic sensory receptor?
A skeletal muscle
What does the Myelin Sheath do?
Increases the speed of an impulse
Which cells produce the myelin sheath?
- Oligodendrocytes produce the myelin sheath in the CNS
- Schwann cells produce it in the PNS
Myelinated tissue is known as white matter. Why do Myelinated Axons appear white?
The abundance of phospholipids
What makes up the Cervical Enlargement? What does it do?
- It is made of both Gray matter and White matter
- It supplies nerves to the upper extremity
Where does the spinal chord end?
(There is No more CNS at this pt., only spinal nerves)
How many spinal nerves does the Cervical region have?
How many spinal nerves does the Thoracic region have?
How many spinal nerves does the Lumbar region have?
How many spinal nerves does the Sacral region have?
To avoid damaging the spinal cord during a spinal tap, the needle should be inserted _____.
Below L1– L2
Where would you be likely to find the motor nuclei that control the extensors of the forearm?
Lateral side of the Anterior gray horn
The ulnar nerve, which we refer to as our "funny bone" when we strike it, comes from what structure?
Brachial plexus, Medial Cord
The specific regions of enlargment on the spinal cord are due from
- increased number of neurons
- increased amount of gray/white matter
Where do the spinal nerves start? where do they exit?
What forms the spinal nerve?
The dorsal/ventral roots
What are the 3 Protective Membranes surrounding the spinal cord?
- (Meninges) Protect, support, absorb shock
- Dura Mater- outermost covering (dense irregular connective tissue) "Tough Mother"
- Arachnoid Mater- (middle meningeal layer) thin layer of epith. cells that adhear to the inside surface of the Dura Mater; is separated from the Pia mater from a gap called the Subaracnoid space
- Pia Mater- inner most meningeal layer taht is in direct contact with the neural tissue (carries the blood supply)
The Dorsal roots contain? the Ventral roots?
- Dorsal- Sensory neurons in the ganglia
- Ventral- Motor neurons only
What is Somatotopy?
The mapping of somatic functions in different regions
What are the Connective Tissue Layers of the Peripheral Nerve?
- Epineurium- covering peripheral nerve (outtermost layer)
- Perineurium- (around one fascicle) Carries the blood supply
- Endoneurium- individual axon covering all of the way down to Schwann cells that act as a basal lamina
Look at Page 376 in textbook and study the chart
What is a Dermatome?
Somatic sensory nerve distribution to the body surface
Name the different Nerve Plexuses
- Cervical: (C1-C5)
- Brachial: (C5-T1) split into Superior Trunk, Middle Trunk, & Inferior Trunk. Which then branch into the Lateral, Posterior, and Medial cords.
- Lumbar: (T12-L4)
- Sacral: (L4-S4)