Musculo - Anatomy & Physiology Flashcards
What layer is found directly below the epidermis?
Dermis
How many layers are found in the epidermis?
5
What is the name of the most superficial layer of the epidermis?
Stratum corneum
What is the name of the deepest layer of the epidermis?
What is the name of the deepest layer of the epidermis?
Stratum basalis
What layer of the epidermis is found just superficial to the stratum basalis?
Stratum spinosum
What layer of the epidermis is found just deep to the stratum corneum?
Stratum lucidum
What layer of the epidermis is found between the stratum spinosum and the stratum lucidum?
Stratum granulosum
Name the layers of the epidermis from the surface to the base.
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basalis (remember: Californians Like Girls in String Bikinis)
Which epithelial cell junction prevents diffusion across the paracellular space?
Zona occludens
What is another name for the zona occludens?
Tight junctions
Which epithelial cell junction surrounds the perimeter just below the zona occludens?
Zona adherens
Cadherins depend on what ion for their function?
Calcium
Which epithelial cell junctions are small, discrete sites of attachment?
Macula adherens
Which epithelial cell junctions allow adjacent cells to communicate for electric and metabolic functions?
Gap junctions
Which epithelial cell junction connects cells with the underlying extracellular matrix?
Hemidesmosome
The zona occludens is composed of what two substances?
Occludins and claudins
The zona adherens contains which kind of filaments?
Actin filaments
In the zona adherens, _____ molecules attach to _____ molecules in the cell to form a perimeter just below the zona occludens.
Cadherins; actin
Which protein anchors macula adherens within the epithelial cell?
Keratin
What is another name for zona adherens?
Intermediate junction
What is another name for the macula adherens?
Desmosome
Gap junctions are formed from ______ that have a central channel that allow adjacent cells to communicate for electric and metabolic functions.
Connexons
A hemidesmosome is formed from ______ in the cell binding to ______ in the basement membrane to keep cells connected to the underlying extracellular matrix.
Integrin; lamin
The medial collateral, medial meniscus, and anterior cruciate ligaments are commonly injured when a person plays which sport?
Football
The terms anterior and posterior with regard to the cruciate ligaments refer to the sites of ______ attachment.
Tibial
The positive anterior drawer sign is an indication of the tearing of which knee ligament?
Anterior cruciate ligament
Abnormal passive abduction of the knee indicates that what ligament is torn?
Medial collateral ligament
What ligament attaches the lateral condyle of the femur to the anterior aspect of the tibia?
Anterior cruciate ligament
What ligament attaches the medial condyle of the femur to the posterior aspect of the tibia?
Posterior cruciate ligament
What ligament attaches the medial condyle of the femur to the medial aspect of the tibia?
Medial collateral ligament
What ligament attaches the lateral condyle of the femur to the lateral aspect of the tibia and fibula?
Lateral collateral ligament
Name the cartilage that cushions the area between the medial condyle of the femur and the medial aspect of the tibia.
Medial meniscus
Name the cartilage that cushions the area between the lateral condyle of the femur and the lateral aspect of the tibia.
Lateral meniscus
Sensation from which nerve can be blocked by injection of local anesthetic near the ischial spine?
Pudendal nerve
Pudendal nerve blocks are used to relieve pain in what clinical situation?
Childbirth
Describe the location of McBurneys point.
Two thirds of the way from the umbilicus to the anterior superior iliac spine
What is located at McBurneys point?
Pain due to appendicitis localizes to McBurneys point
Where is the needle inserted during a lumbar puncture?
Between vertebrae at the level of the iliac crest
Name the muscles that make up the rotator cuff.
Supraspinatus, infraspinatus, teres minor, subscapularis (remember: SItS; small t is for teres minor)
Which rotator cuff muscle helps the deltoid abduct the arm?
Supraspinatus
Which rotator cuff muscle laterally rotates the arm?
Infraspinatus
Which rotator cuff muscle adducts and laterally rotates the arm?
Teres minor
Which rotator cuff muscle medially rotates and adducts the arm?
Subscapularis
Which muscles insert on the posterior aspect of the humerus?
Infraspinatus and teres minor
Which muscle of the rotator cuff is found on the anterior aspect of the humerus?
Subscapularis
Which muscle of the rotator cuff is found on the superior aspect of the humerus?
Supraspinatus
Fracture of the surgical neck or dislocation of the humerus can traumatize which nerve?
Axillary nerve
Midshaft fracture of the humerus damages what nerve?
Radial nerve
Sublaxation of the radius causes trauma to which nerve?
Deep branch of the radial nerve
The recurrent branch of the medial nerve can be damaged by a superficial laceration to what surface?
The palm of the hand
What nerve root is commonly compressed by a cervical disk lesion?
C7
A Pancoasts tumor can compress what trunk of the brachial plexus?
Lower trunk
Compression of the lower trunk of the brachial plexus can lead to nerve injury known as what?
Klumpkes palsy
Improper use of crutches can compress what nerve?
Radial nerve
Supracondylar fracture of humerus can compress what nerve causing what syndrome?
Median nerve; pronator teres syndrome
Fracture of what specific part of the humerus can cause ulnar nerve trauma?
Medial epicondyle
The anterior interosseous nerve is at risk for compression where?
The deep forearm
Name the nerve compressed in carpal tunnel syndrome.
Median nerve
A dislocated lunate will affect which nerve?
Median nerve
Trauma to the heel of the hand can cause damage to which nerve?
Ulnar nerve
Fracture of hook of hamate can disrupt which nerve?
Ulnar nerve
A patient presents with a waiters tip deformity after being thrown from a motorcycle. What cervical roots have been injured?
C5 and C6
A lesion of the lower trunk of the brachial plexus would cause what notable sign on physical exam?
A total claw hand (Klumpkes palsy)
A lesion at what cord of the brachial plexus would cause damage to the axillary and radial nerves?
Posterior cord
Injury to the posterior cord of the brachial plexus would produce what sign on physical exam?
Wrist drop
A patient presents with a winged scapula. What nerve has been injured?
Long thoracic nerve
Deltoid paralysis is caused by injury to what nerve?
Axillary nerve
A patient presents with Saturday night palsy, which consists of a wrist drop. What nerve was most likely injured?
Radial nerve
A solitary lesion of what nerve within the brachial plexus might make it difficult to flex the elbow?
Musculocutaneous nerve
A patient is unable to move his thumb. Physical exam reveals a Popes blessing sign. If the cause is nerve damage, what is the principal nerve that is involved?
Ulnar nerve
What muscle protects the brachial plexus during a clavicle fracture?
Subclavius muscle
A waiters tip results from lesions at what two nerve roots?
C5 and C6
Name the order in which the brachial plexus divides.
The order is Roots, Trunks, Divisions, Cords, and Branches (remember: Randy Travis Drinks Cold Beer)
A patient with a fractured surgical neck of the humerus could demonstrate what sensory and motor deficits?
Inability to abduct the arm at the shoulder, lack of sensation over the deltoid muscle
A patient presents with a flattened deltoid. Name the two injuries that could result in this finding.
Fractured surgical neck of the humerus and dislocation of the humeral head resulting in axillary nerve injury
A patient suffers a midshaft humerus fracture damaging the extensor compartment. He has a wrist drop. What sensory deficit is expected?
Deficit over the posterior arm and dorsal hand
What is the cause of Saturday night palsy?
Extended compression of the axilla by the back of a chair or crutches resulting in radial nerve injury
A patient presents with inability to extend his wrist, fingers (at the metacarpophalangeal joint), and thumb. What nerve is damaged?
Radial nerve
Injury to the radial nerve may result in what sign on physical exam?
Wrist drop
A patient presents with a loss of sensation over the lateral palm, the thumb, and the radial two and one half fingers. What fracture may have caused the deficit?
Supracondylar fracture of the humerus
A patient has a supracondylar fracture of the humerus that affects the flexors of the hand. What sensory deficit is expected?
Decreased sensation in the palmar aspect of the thumb, index finger, middle finger, and half of the ring finger
A patient has carpal tunnel syndrome involving swelling of the wrist that affects the flexors of the hand. What motor deficit is expected on physical exam of the hand? Of the thumb?
Cannot flex fingers; cannot abduct/oppose thumb
A patient has carpal tunnel syndrome involving swelling of the wrist that affects the flexors of the hand. What sensory deficit is expected?
Decreased sensation in the palmar aspect of the thumb, index finger, middle finger, and half of the ring finger
A patient has a fracture at the medial condyle of the humerus that affects the flexors of the hand. What motor deficits are expected on physical exam?
Cannot abduct thumb or abduct or adduct fingers; claw hand
A patient has a fracture at the medial condyle of the humerus that affects the flexors of the hand. What sensory deficit is expected on physical exam?
Decreased sensation in palmar and dorsal sides of fifth digit and half of fourth digit
A patient presents with Popes blessing/hand of benediction. What physical injury causes this finding?
Fracture of the hook of hamate, likely from falling onto an outstretched hand, affecting the ulnar nerve
Name the two muscle groups affected in a patient with ulnar claw hand.
Interossei and lumbricals
A patient presents with decreased sensation over the lateral forearm and an inability to flex the arm at the elbow. What nerve is damaged?
Musculocutaneous nerve
Name six causes of mononeuropathy.
Compression, trauma, diabetes, vasculitis, radiation, and inflammation
The loss of innervation in what muscle causes pronation of the forearm in Erb palsy?
Biceps
Erb-Duchenne palsy is caused by the traction/tear of what two nerve roots?
C5 and C6
A patient presents with his left arm hanging to the side, medially rotated, with pronation of the forearm. What type of palsy does he have?
Erb-Duchenne palsy
Name the four components of thoracic outlet syndrome.
- Atrophy of the thenar and hypothenar eminences; 2. Atrophy of the interosseous muscles; 3. Sensory deficits on the medial side of the forearm and hand; 4. Disappearance of the radial pulse upon moving the head toward the opposite side
Thoracic outlet syndrome results from compression of the _____ artery and the _____ trunk of the brachial plexus by a cervical rib.
Subclavian; inferior
What nerve of the upper extremity is known as the great extensor nerve?
Radial nerve
Name the muscles innervated by the radial nerve.
Brachioradialis, Extensors of the wrist and fingers, Supinator, and Triceps (remember: radial nerve innervates the BEST)
After supination, is the palm or dorsum of the hand facing up?
Palm (remember: to supinate is to move as if carrying a bowl of soup)
What three muscles compose the thenar eminence?
The opponens pollicis, the abductor pollicis, and the flexor pollicis brevis, remember: Oppose, Abduct, and Flex (OAF)
What three muscles compose the hypothenar eminence?
The opponens digiti minimi, the abductor digiti minimi, and the flexor digiti minimi (remember: Oppose, Abduct, and Flex (OAF))
What muscle group in the hand adducts the fingers?
Palmar interosseous muscles (remember: PAD= Palmars ADduct)
What muscle group in the hand abducts the fingers?
Dorsal interosseous muscles (remember: DAB= Dorsals ABduct)
What muscle group in the hand flexes the fingers at the metacarpophalangeal joint?
Lumbrical muscles
Name two specific injuries caused by repetitive elbow trauma.
Lateral epicondylitis (tennis elbow), medial epicondylitis (golf elbow)
A patient has an anterior hip dislocation and can no longer adduct the thigh. She has a sensory deficit along the medial thigh. What nerve has been damaged?
Obturator nerve
A patient has a pelvic fracture. He can no longer flex his thigh or extend his leg. He has a sensory deficit along the anterior thigh and medial leg. What nerve has been damaged?
Femoral nerve
A patient experiences trauma to his lateral leg and can no longer evert or dorsiflex his foot, nor can he extend his toes. What nerve has been injured?
Common peroneal nerve, causing foot drop
A patient has a fibula neck fracture and can no longer evert or dorsiflex his foot, nor can he extend his toes. What nerve has been injured, and what sign is evident on physical exam?
The common peroneal nerve; foot drop (remember: PED= Peroneal Everts and Dorsiflexes; if injured, foot dropPED)
A patient has had trauma to his knee and can no longer invert or plantar flex his foot, nor can he flex his toes. He has decreased sensation in the sole of his foot. What nerve has been damaged?
Tibial nerve
A patient has had trauma to his knee and damaged his tibial nerve. What motor deficits would be expected on physical exam?
Cannot invert foot, cannot plantar flex foot, and cannot flex toes (remember: TIP = Tibial Inverts and Plantarflexes; if injured, cant stand on TIPtoes)
A patient has a posterior hip dislocation. He has a positive Trendelenburg sign. What motor deficit is present?
Inability to abduct thigh
A patient has a posterior hip dislocation and cannot abduct his thigh (positive Trendelenburg sign). What nerve has been damaged?
Superior gluteal nerve
A patient has a posterior hip dislocation. She cannot jump, climb stairs, or rise from a seated position. What nerve has been damaged?
Inferior gluteal nerve
What two nerves may be damaged if a patient sustains a posterior hip dislocation?
Inferior gluteal nerve and superior gluteal nerve
Loss of foot eversion is due to damage of the _____ nerve, while loss of foot inversion is due to damage of the _____ nerve.
Common peroneal; tibial
Loss of dorsiflexion of the foot is due to damage of the _____ nerve, while loss of plantar flexion of the foot is due to damage of the _____ nerve.
Common peroneal; tibial
If a patient has foot drop, his ______ nerve is damaged; but if a patient cannot stand on his tiptoes, then the _____ nerve is damaged.
Common peroneal; tibial
During the conduction of an action potential to muscle, the action potential causes the opening of which voltage-gated channels in the nerve terminal?
Voltage-gated calcium channels, causing release of neurotransmitter
During skeletal muscle signal conduction, postsynaptic ligand binding leads to the depolarization of which membrane?
The motor end plate of the muscle cell
During skeletal muscle signal conduction, the action potential travels down into invaginations in the membrane that are called what?
T-tubules
_____ receptors release calcium from the sarcoplasmic reticulum.
Ryanodine
Name the specific receptors on the skeletal muscle cell membrane that are voltage sensitive.
Dihydropyridine
What term describes the process by which calcium entering a muscle cell through voltage-gated calcium channels on the cell membrane is able to increase the intracellular calcium content of the muscle cell by releasing more calcium from the sarcoplasmic reticulum?
Calcium-induced calcium release
During skeletal muscle contraction, released calcium binds to troponin C, thereby causing a conformational change to move tropomyosin out of what area of the actin filament?
The myosin-binding groove
During skeletal muscle contraction, which bands of the sarcomere shorten in length?
H-band and I-band
During skeletal muscle contraction, what band of the sarcomere remains the same length?
A-band (remember: Aband is Always the same length; HIZ shrinkage)
In the sarcomere, does the A-band correspond to the length of actin or myosin?
Myosin
In the sarcomere, does the I- band correspond to the area that is only actin or only myosin?
Only actin
In the sarcomere, does the H-band correspond to the area that is only actin or only myosin?
Only myosin
In the sarcomere, is the Z line the site of actin or myosin attachment?
Actin
In the sarcomere, is the M line the site of actin or myosin attachment?
Myosin
A sarcomere is defined as the area between one ______ to the next ______.
Z line; Z line
Type I muscle fibers are _____ (fast/slow) twitch.
Slow
Type II muscle fibers are _____ (fast/slow) twitch.
Fast
Type I muscle fibers are red secondary to what?
Increased mitochondria and myoglobin concentration
Type II muscle fibers are white secondary to what?
Decreased mitochondria and myoglobin concentration
In type I muscle fibers, there is a(n) _____ (increase;decrease) in oxidative phosphorylation.
Increase
True or False? Type I muscle fibers create a sustained contraction.
True (remember: one slow red ox)
Weight training results in hypertrophy of what type of muscle fibers?
Fast-twitch muscle fibers
In type II muscle fibers, there is a(n) _____ (increase; decrease) in anaerobic glycolysis.
Increase
In skeletal muscle contraction, ATP binds to what molecule?
Myosin head
In skeletal muscle contraction, calcium binds to what substance, thereby causing a conformational change?
Troponin C
What process causes cocking of the myosin head?
Hydrolysis of ATP
The absence of ATP binding to the myosin head in skeletal muscle may cause what finding?
Rigor mortis
The binding of ATP allows for what process in actin/myosin cross-bridging?
Release
After a smooth muscle membrane is depolarized, voltage-gated _____ _____ will open.
Calcium channels
In the process of smooth muscle cell contraction, calcium binds to what?
Calmodulin
With the binding of calcium to calmodulin in smooth muscle contraction, the activation of _____ _____-_____ kinase takes place.
Myosin light-chain
Myosin light-chain kinase is an enzyme that adds a _____ group to the _____-_____ complex during _____ muscle contraction.
Phosphate, actin-myosin; smooth
In smooth muscle contraction, dephosphorylation of the myosin-actin complex is carried out by what enzyme?
Myosin light-chain phosphatase
Dephosphorylation of the myosin-actin complex leads to what response by smooth muscle?
Relaxation
In bone formation, _____ (endochondral/membranous) ossification is responsible for longitudinal bone growth, while _____ (endochondral/membranous) ossification is responsible for flat bone growth.
Endochondral; membranous
The skull, facial bones, and axial skeleton are examples of bones formed as a result of what type of ossification pattern?
Membranous ossification
In endochondral ossification, what two type of cells replace the cartilaginous model with woven and later lamellar bone?
Osteoclasts and osteoblasts
Osteoblasts are derived from _____ stem cells in the periosteum.
Mesenchymal
_____ (Endochondral/Membranous) ossification involves the production a cartilaginous model that is remodeled into lamellar bone, while _____ (endochondral/membranous) ossification involves the direct production of woven bone that is remodeled into lamellar bone.
Endochondral; membranous
C4 innervates what dermatome?
Shoulder
The dermatome of the lateral aspect of the upper arm is innervated by what nerve root?
C5
Which dermatome covers the thumb?
C6
The C7 nerve root innervates which dermatome?
The middle finger
The dermatome of the pinky is innervated by which nerve root?
C8
The dermatome of the medial aspect of the forearm is innervated by what nerve root?
T1
The dermatome of the axilla is innervated by what nerve root?
T2
The palmar surface of the first three digits is innervated by what branch of the median nerve?
Cutaneous branches of the median nerve
The interossei and adductor polliois muscles are innervated by what nerve?
Branches of the deep ulnar nerve
The thenar muscles are innervated by what branch of the median nerve?
The recurrent branch of the median nerve
The flexor retinaculum is anchored between what three bones?
Trapezium, hook of hamate, and scaphoid
How many tendons run through the carpal tunnel?
Nine
Tendons from which two muscles anchor on the pisiform bone?
Abductor digiti minimi and flexor carpi ulnaris
Describe the dermatomal distribution of the ulnar nerve on the hand.
Medial palmar and dorsal surfaces of the hand
The dermatome of the thumb is innervated by what nerve(s)?
Radial and median nerves
Name the function of the lumbrical muscles of the hand.
The lumbricals flex the metacarpophalangeal joints and extend both the distal interphalangeal and proximal interphalangeal joints
Ulnar claw or “Pope& blessing” is caused by a lesion of what nerve?
A distal lesion of the ulnar nerve
What digits are affected in a distal ulnar nerve lesion?
Fourth and fifth digits
Median claw is caused by a lesion of the distal median nerve. Specify the exact location of the lesion.
The lesion is located after the branch containing C5-C7 brances off to feed forearm flexors
A proximal median nerve lesion causes loss of what muscle function?
It causes loss of opponens polliois muscle function
How does a proximal median nerve lesion affect the thumb?
It causes an inability to abduct thumb, know as “ape hand”
Klumpke & total claw hand is caused by a lesion of what trunk of the brachial plexus affecting what nerve roots?
Lower trunk and nerve roots C8, T1