Random Flashcards
What is concentric, isometric and eccentric contraction?
Concentric contraction is the shortening of muscle to cause movement.
Isometric keeping a limb elevated in space, prevent moving.
Eccentric contraction is slowly lengthening.
What would use fast anterograde and retrograde transports?
What would use slow anterograde transport?
Fast: vesicles, endosomes mitochondria
Slow: cytoskeleton, proteins,
Describe the exocytosis of neurotransmitter.
When an action potential reaches the terminal, it opens calcium channels leading to calcium influx.
Neurotransmitter is in vesicles bound to the terminal web (actin filaments) through synapsin I.
Camodulin dependent protein kinase phosphorylates synapsin I which releases the vesicles and they move into the ACTIVE ZONE.
Then Vsnares (VAMP) and T snares are the fusion process but calcium is what stimulates fusion.
These are thought to be regulated by synaptotagmins.
Describe the 4 support cells in the CNS.
Ependymal cells = line ventricles of brain and spinal canal. Most of them are bound together by adhering junctions but in the choroid plexus they are tight junctions. (Choroid plexus is a vascularized, secretory structure that produces cerebrospinal fluid and the ependymal cells will regulate transfer of material and transfer of ions from blood stream. Protruding into the ventricle are cilia that move cerebrospinal throughout the body.
Microglia does not have a CNS origin and they clear dying cells from neural damage, eliminate inactive synapses, neurons, and useless glial, and lastly IMMUNE function by recruiting leukocytes past the blood brain barrier to interact with astrocytes.
Astrocytes: unique structures featuring GFAP (intermediate filament) that link capillaries to neurons.
1-they provide structural support
2-potassium sinks at nodes of ranvier and initial segment (sent to each other via gap junctions
3-segregate synapses, if inactive they move away and allow NT to diffuse, if active they tightly associate.
4-they can be signaled by NT (change their shape, their membrane permeability, their tropic factors)
5-blood brain barrier: although the tight junctions at endothelial cells is what is segregating blood and neurons, the astrocytes release factors to influence the tightness and passage of materials and regulate blood flow to brain.
6. Immune response, they also clean up neuronal debris.
Oligodendrocytes: form myelin sheath (INITIAL SEGMENT IS NOT MYELINATED). One oligodendrocyte wraps like 40-50 axons.
Major dense lines - cytoplasmic faces to one other
Intraperiod lines are the extracellular faces to one another linked by PLP.
Paranodal region: separation of myelin at the major dense lines exposing the cytoplasm allowing for communication with the axon from oligodendrocyte to axon.
What is the adhesion protein of intraperiod lines for schwann cell wrapping around on internode.
Po protein.
Describe the organization of a nerve in the PNS.
The nerve is wrapped by the epineurium.
Each nerve contains multiple fascicles, each wrapped by the perineurium.
Within the fascicle are a bunch of nerve fibers.
Each nerve fiber is wrapped by endoneurium, then BM, then Schwann cell then axon.
For X-rays what is radiopaque and radiolucent?
What is the order of material?
Besides material, what else effects X-rays?
What does a left lateral projection mean?
How does distance from film affect the xray?
Radiopaque refers to brighter items (white)…because it is absorbing all the light.
Radiolucent means the xray goes right through.
From radiopaque to most radiolucent,
Heavy metal, enamel, bone, water density (muscle, cartilage, tendon, blood, nerve, connective tissue), fat, air.
The thickness because the thicker an object is, the more radiopaque. Less light gets through to film.
left lateral projection means the left side is facing the film.
Distance: the farther away from the film, the more light refracts onto the film. So larger and blurrier (lower resolution).
What inserts to the radial tuberosity?
What are the origins of the biceps brachi and coracobrachiales?
What does brachiales attach to?
Where do each of the triceps originate and attach.
Where does the latissimus dorsi attach and what is its action?
The biceps brachi inserts into radial tuberosity.
Biceps long head originates in superglenoid tubercle.
Short head originates from the coracoid process.
Coracobrachiales originates from coracoid process.
Brachiales insert into the coronoid process of the ulna.
Triceps long head originates from infraglenoid tubercle and attaches to olecron process of the ulna (elbow)
Triceps lateral and medial head goes from posterior (above and then below radial groove) of humerus to olecron. All three triceps head share a common tendon to olecron.
Latissimus dorsi is interesting. Its huge, attaches to inferior scapula, spine, and iliac crest but it only inserts into the anterior arm. All actions are on arm. Extension, adduction, and internal/medial rotation of arm.
What are the walls of the axilla?
Lateral wall is the humerus with bicipital groove.
Medial wall is the serratus anterior (innervated by the thoracoacromial nerve)
Anterior is the pecs
Posterior is the lats, teres major, and subscapularis.
Where does the teres minor and major originate and attach.
And what are their movements and innervations?
Teres major originates lateral to the inferior angle and attaches to front part of the humerus (aligned with the lesser tubercle and just superior to the latissimus dorsi attachment)
Innervation: lower subscapular
Teres minor originates from lateral scapula and inserts into GREATER tubercle.
Important for external rotation and adduction of the arm.
Innervation: axillary.
What composes the anatomic snuffbox?
Hint: all originate form the posterior forearm.
Anterior wall: tendon of abductor policies longus
Tendon of extensor policis brevis
Tendon of extensor policis longus
Posterior wall: tendon of extensor policis longus.
Medial wall: scaphoid
*You can find the radial artery
(SANDWICH: extensor policis brevis is between extensor longus and abductor policis longus)
Where does the subscapular attach. What are its movements and innervations?
Subscapular attaches to the LESSER TUBERCLE. It is aligned with the attachments of the teres major and lats. This is why they all together form the posterior wall of the axilla.
Motion: internal rotation
Nerve: lower and upper subscapular nerves
Arteries: circumflex scapular artery, dorsal scapular artery, suprascapular artery
What does pec minor attach to, actions, innervations.
Pec minor originates from the coracoid process.
Nerve: medial pectoral nerve (C8-T1)
Artery: lateral thoracic artery
what do the dorsal scapular nerve and artery innervate?
Nerve and artery: rhomboids minor, major and levator scapulae.
Artery: also subscapular anastomosis.
what does autonomic neurons supply and what is its path?
Where do you find prevertebral ganglion.
How about parasympathetic efferents?
Autonomic supplies cardiac muscle, smooth muscle, and glands.
To reach a gland in the trunk, leaves lateral horn (T1-L2), leaves ventral root, enters spinal nerve, enters ventral rami, enters the white communicans, synapses on postganglion and then postganglion axon exits the grey communicans into the spinal and then ventral ramus.
Gland of cervix would be same (has to be T1) until you reach the paravertebral, your axon will shoot up, synapse on postganglion in the corresponding segment, then axon will exit gray and exit spinal nerve.
Parasympathetic: cranial and sacral preganglion, synapses really distal at the terminal ganglia of the wall of the organ they innervate.
What sensations are conveyed by somatic and visceral afferents.
Where are their cell bodies located?
How would visceral afferents travel? (Referred pain)
Somatic: pain, temperature, touch, propioception
Visceral: hunger, nausea, dissension
Locations:
Somatic: dorsal root ganglia from C2 to coccyx.
Visceral: dorsal root ganglia from T1 and L2
They’d come from the organ and travel down the paravertebral until they reach like T1 or T2, exit via the white communicans and then they synapse at the dorsal horn.
Referred pain: where the visceral afferent synapses, you can feel pain in the dermatome region of the corresponding somatic afferents which also synapse at that dorsal horn.
Which muscles are rotators of the arm?
Lateral rotation:
- Infraspinatus (greater tubercle)
- Teres minor (greater tubercle)
Medial rotation:
Teres major
Latissimus dorsi
1. Subscapular (lesser tubercle).
Deltoids do both rotation.
What are the 4 abductors of the shoulder?
Deltoid, upper and lower trapezius, supraspinatus, serratus anterior.
Describe the elbow joint.
Lateral epicondyle is smaller and features your extensors.
Medial epicondyle is larger and features your flexors.
The medial part is your trochlea (groove) which your coronoid process of the ulna fits into (ulna articulates best)
Capitulum is your ball.
Ulna has the olecranon which your triceps tendon) attaches to.
Radial tuberosity is the insertion site for the biceps brachi.
what is titin and what is nebulin
What is desmin?
Titin goes from Z line to M line and generates passive tension and prevents overstretching
Nebulin goes from Z band until the end of actin filaments. This is used to regulate thin filament length.
Desmin is an IF that wraps around the Z disk and connects neighboring myofibrils. So there is coordinated contraction of adjacent myofibrils.
What does the fibular nerve innervate?
The common fibular nerve: innervates the short head of the biceps femoris directly.
The other branches supplies lateral and anterior compartment of the leg. (Deep and superficial branches).
How does hyperkalemia reduce excitability of neurons and muscle cells?
Depolarization will inactivate voltage gated sodium channels
Which of the muscles are likely hurt by a nerve injury via a glenohumeral joint dislocation
It would be directed inferioy and affect the axillary nerve which innervates deltoid and teres minor
What functional deficit can occur from lesion of the lateral cord with reduced sensation of lateral forearm?
It means there is likely damage to the nerve fibers that become the musculocutaneous. So itll likely affect supination as the biceps are good supinators
Person has buldge in anterior arm and popping sound in upper arm when flexing. He has weak flexors and supination.
Avulsion fracture of supraglenoid tubercle which attaches to biceps long head
GTO
Only detects tension, not rate. So it may be for contraction but it can also detect passive stretch.
Describe the organization of skeletal muscle.
Filaments make up organized sarcomeres. Sarcomeres one after another form the myofilaments. Myofilaments surrounded by sarcoplasmic reticulum become myofibrils. Many myofibrils surrounded by a endomysium become the muscle fiber/cell.
Bundles of myofibers surrounded by the perimysium become a muscle fascicle. Epimysium surrounds many fascicles and this is the muscle
How is cardiac muscle different from skeletal muscle?
Skeletal muscle has peripheral nuclei
Cardiac muscle has one or two centrally located nuclei.
Skeletal: fascicles, has connective tissue
Cardiac: no organized connective tissue, so there is more disorganized CT between cells.
Skeletal: T tubule at A I bands line
Cardiac: T tubule at Z line
Cardiac has special purkinje fibers, spontaneous rhythmic contraction under involuntary control. (They have larger and paler cells)
Specific cell to cell boundaries: intercalated discs, belt desmosomes, spot desmosomes, gap junctions.
Various shapes.
How is smooth muscle unique?
indistinguishable cell borders, spindle shapes, almost no CT between cells
One centrally located nuclei
No striations
No t-tubules
Looks like dense connective much many more nuclei.
Surrounds a blood vessel.
They have invaginations called caveolae which has an accumulation of vesicles. Feature gap junctions.
What are the only three muscles innervated by the anterior interroseus.
What are the only two muscles innervated by the radial nerve?
What does the radial artery and ulnar artery become distally?
Anterior interosseus nerve: deep anterior forearm:
- pronator quadratis,
- medial half of digitorum profundus,
- flexor pollicis longus
Radial nerve:
- Brachioradialis
- Extensor Carpi radialis longus.
Ulnar artery is the main supplier of blood to the hand. It forms the superficial palmar arch.
The radial artery becomes the deep palmar arch.
What does the circumflex scapular artery innervate?
The circumflex scapular innervates the teres major, minor and the infraspinatus.
It is a branch of the subscapular artery/
What is Erbs palsy and Klumpke’s palsy?
Erb’s is upper trunk injury due primary to forceful separation between shoulder and neck. Proximal limb structures are affected, intrinsic shoulder muscles, axillary wall muscles.
Limb is held in an extended, adducted, medially rotated, hand is probated (waiter sign) Sensory loss along lateral side of distal arm and proximal forearm (C5-C6) dermatome.
Klumpke’s is a lower trunk injury. Caused by upward traction on the upper limb or compression of the thoracic outlet via a cervical rib. Affects the intrinsic muscles of the hand. Thenar, hypothenar and interossei are atrophied. Clawing of digits 2-5, loss of abduction and adduction of fingers and sensory loss along the medial side of forearm and proximal forearm. (C8-T1)
Describe a median nerve injury. How it happens, symptoms, variability.
Median injury can be caused by laceration to the wrist, injury to the cubita fossa (supracondylar fracture), inflammation in the carpel tunnel, hypertrophy of the pronator teres it runs under/through.
Symptoms:
Cutaneous sensory loss on lateral side of palm (ulnar is the medial side)
Injury at wrist level: flexion and abduction of thumb is still possible because of flexor pollicis longus (anterior interosseous) and abductor pollicis longus (posterior interosseous). Thenar atrophy, clawing of digits 2 and 3,
loss of opposition - this is the best test for median nerve injury proximal or distal because both would have this symptom.
More proximally: loss of flexor digitorum superficiales, flexor pollicis longus and brevis, radial half of flexor profundas, flexor carpi radiales. Inability to flex fingers 1-3 (Hand of benediction) and wrist flexion would tilt to the ulnar side.
What are the medical terms you should know for sensory and muscle weakness?
Paresis: partial weakness of muscle
Paresthesia: numbness and tingling
Hypoesthesia: reduced sensation.
Write your presentation for axillary and musculocutaneous nerve.
The musculocutaneous nerve is arises from the lateral cord and contains rami (C5-C7). It innervates the muscles of the anterior arm such as the biceps brachi, the coracobrachiales and the brachiales. A branch of the musculocutaneous is the lateral antebrachial cutaneous nerve and as the name implies, it serves the sensory information for the lateral forearm. Injury to this nerve is uncommon and the most likely cause is a penetrating wound. With weakness of the anterior arm muscles you will get weakness of shoulder flexion, elbow flexion and supination. The brachioradialis will still function as an elbow flexor since it is innervated by the radial nerve.
The axillary nerve arises from the posterior cord and it contains the rami C5-C6. It is found with the posterior humeral circumflex in the quadrangular space which boundaries are the long head of the triceps, teres major and minor, subscapularis and the humerus. It supplies the deltoid and teres minor. Injury to this nerve can occur by glenohumeral dislocation or fracture of the surgical neck of the humerus. Teres minor is a weak lateral rotator compared to other lateral rotators such as the deltoids, infraspinatus. The best test for a nerve injury to the axillary nerve would be abduction as that is the strongest movement for the delts. You would also get sensory of the skin overlying the deltoids. The long term effect would also be atrophy of the deltoids.
How would you test flexor digitorum superificiales versus flexor digitorum profundas?
Pull three fingers back. Since the profundas share a common tendon, they’re effectively all stretched so if you flex it is only the superficial at work.
What composes the femoral triangle?
Lateral: medial border of sartorius (attachment is iliac spine, abduction and flexion of hip, medial rotation at knee, lateral rotation at hip)
Medial: adductor longus (attaches the femur)
Superior: inguinal ligament
The triangle contains the femoral vein, artery, nerve.
Females need a virtuous love. (Nerve is most lateral)
Describe the nerves of the thigh
The femoral is a posterior division but innervates the anterior compartment (hip flexors and knee extensors)
The Obturator is a anterior division and innervates the medial thigh. This is for hip adduction
The tibial nerve is an anterior division and innervates the posterior compartment of the thigh (hip extension, knee flexion).
What are the ANTERIOR muscles of the thigh and their attachments plus actions, and innervations
Hip flexion:
- Iliopsoas attaches to lesser trochanter (L2, L3 + femoral)
- Tensor fascia lata - iliac spine > iliotibial tract (superior gluteal nerve)
- Sartorius attaches iliac spine>medial tibia (femoral)
- Rectus femoris - femur > patella, femoral nerve
Knee extension
Vastus intermedius
Vastus lateralis
Vastus medialies
All three originate from the femur to attach to the patella.
