Anatomy Structures & Functions Flashcards
Rapid review of anatomy terms for neuroanatomy and musculoskeletal anatomy
Nerve that innervates lateral rectus muscle of eye
CN VI - abducens nerve
Nervous system cell with long cellular processes
Neuron
What are the three fundamental types of neurons?
Motor, Sensory, Interneurons
___ neurons send signals away from the CNS.
Motor
Cranial nerves originating in the midbrain
CN III (oculomotor); CN IV (trochlear)
Section of the midbrain involved in coordination of movement and dopamine production
Substantia nigra
Function of fusiform gyrus
Processing color, and facial and word recognition
___ neurons are located within the CNS and mediate communication among other neurons.
Interneurons
Function of pineal gland
Produces melatonin
This portion of the neuron receives signals from other cells.
Dendrites
Location of primary somatosensory cortex
Post-central gyrus
Nerve that innervates superior oblique muscle of eye
CN IV - trochlear nerve
Location of primary motor cortex
Precentral gyrus
Function of supramarginal gyrus
Visual, auditory, and somatosensory association
Function of angular gyrus
Language and number processing, memory, attention
Nervous system cell with short cellular processes
Glial cells
This structure is lined by the primary visual cortex
Calcarine sulcus
Location of primary gustatory cortex
Insular cortex
Function of flocculonodular lobe of cerebellum
Helps with balance
___ neurons send signals to the CNS.
Sensory
This portion of the neuron transmits a signal to a target.
Axon and axon terminals
Functions of the insular cortex
Primary gustatory cortex; balance and vision integration
Structure that connects cerebellar hemispheres
Vermis
Which type of nervous system cell transmits impulses?
Neurons
Function of caudate and putamen
Communicates with cerebral cortex to prohibit/inhibit movement
List the structures that connect the cerebral hemispheres
Corpus callosum and fornix
These cerebellar structures sit just superiorly to the foramen magnum
Cerebellar tonsils
Function of anterior lobe of cerebellum
Proprioception and posture
Key structure involved in processing fear
Amygdala
White matter tract running between caudate and putamen
Internal capsule
Function of posterior lobe of cerebellum
Inhibit involuntary movement, and fine motor control
Function of dentate nucleus
Planning voluntary movement
White matter tracts communicating between cerebellum and cerebrum/brainstem
Cerebellar peduncles
Section of the midbrain that controls body posture and gait
Red nucleus
What kind of nerve fibers run through the crus cerebri?
Motor fibers running from the primary motor cortex to the trunk and limbs
The tectum is directly superior to:
The cerebral aqueduct
What cranial nerve and nucleus is found at the level of the inferior colliculi?
CN IV
Locations of enlargement of the spinal cord
Cervical enlargement for upper limb (C4-T1), lumbosacral enlargement for lower limb (T11-S1)
At what vertebral level does the spinal cord end?
Around L1-L2
Conus medullaris
End of the spinal cord, before the cauda equina
What makes up the white matter of the spinal cord?
Myelinated axons
What neurons come off of the lateral horn (T1-L2, S2-S4)?
Sympathetic (T1-L2) and parasympathetic (S2-S4) autonomic fibers
Longitudinal arteries of the spinal column
1 anterior spinal artery, two posterior spinal arteries, and vertebral arteries branching off from the subclavian
What gives collateral circulation to the spinal column?
Segmental arteries branching off from intercostal and lumbar arteries
Artery of Adamkiewicz
Only named segmental artery, for the lumbar enlargement. If you cut that off, you lose blood supply to leg innervation
How are nerves without segmental arteries supplied with blood?
Radicular arteries going to the spinal nerve roots, entering through intervertebral foramena
What targets are innervated by dorsal rami?
intrinsic back muscles, skin on the back
What targets are innervated by ventral rami?
External back muscles, and trunk, limbs, etc
Which spinal nerve does not have an associated named vertebra?
C8 - there is no C8 vertebra.
All cervical spinal nerves exit ___ to their associated vertebra
Superior
All thoracic/lumbar/sacral spinal nerves exit ___ to their associated vertebra
Inferior
Landmark for T4 dermatome
Nipple
Landmark for T10 dermatome
Umbilicus
Landmark for T12 dermatome
Suprapubic region
Landmark for C6 dermatome
Thumb
Landmark for L5 dermatome
Big toe
Interior of an intervertebral disc
Nucleus pulposus
Exterior of an intervertebral disc
Annulus fibrosus
What is the phenomenon called when the jelly of the nucleus pulposus compresses spinal nerve roots?
Intervertebral disc herniation, with pain, numbness, and tingling
Where does the spinal dura open up?
At the cauda equina, around S2
What fills the epidural space in the spinal column?
Fat, and the epidural venous plexus
What space is the target in an epidural?
The epidural space - go through skin but not through dura
What space is the target in a lumbar puncture?
Subarachnoid space - go through skin, dura, and arachnoid
Is the subdural space an actual space or a potential space in the spinal column?
Potential space
Is the subarachnoid space an actual space or a potential space in the spinal column
Actual
Is the epidural space a potential space or an actual space in the spinal column?
Actual
Where is CSF located in the spinal column?
In the subarachnoid space
What structures cross the subarachnoid space?
Arachnoid trabeculae
What structures stabilize the pia mater?
Denticulate ligaments and the film terminale
At what vertebral level do you perform a lumbar puncture?
Inferior to L3/L4
Which cranial nerves pass through the cavernous sinus?
III, IV, V1, V2, VI
Exteroreceptors
Respond to stimuli outside the body
Interoreceptors/visceroreceptors
Respond to stimuli within body (BP, proprioception)
Cranial nerves that contribute to sensation of taste
CN VII, IX, X
Where do sensations of taste enter the brainstem?
Solitary tract nuclei - from there, go on to the thalamus and then to the gustatory cortex of the insula
Rod cells
Have rhodopsin, very photosensitive, good for vision in low light, no color differentiation
Cone cells
Have photopsin, important for color vision, good in bright light
Where are rods and cones located in the eye?
Rods are in the peripheral retina, and cones are in the macula and fovea.
Where do vision signals pass through the thalamus?
Lateral geniculate nucleus
Where does hearing information enter the brainstem?
CN VIII at pronto medullary junction, go through cochlear nucleus bilaterally
What type of free nerve endings sense pain/nociception?
Myelinated A-delta fibers for fast pain, C fibers for slow, aching pain
Meissner’s corpuscle
light touch, fast-adapting, small sharp borders
Merkel disc
Light touch, slow-adapting, small sharp borders
Lamellated corpuscles
Fast-adapting, vibration and pressure, large vague borders
Ruffini corpuscles
Pressure and skin stretch, slow-adapting, large vague borders, signal changes in joint position
Root hair plexus
Light touch, fast-adapting
What kinds of innervation are lost if you damage the roots of the brachial plexus?
Somatomotor, somatosensory, sympathetic
Innervation of pre-axial muscle mass
C5, C6, C7
Innervation of post-axial muscle mass
C8, T1
Do the roots of the brachial plexus contain anterior division fibers, posterior division fibers, or both?
Both
What roots contribute to the upper trunk of the brachial plexus?
C5, C6
What roots contribute to the middle trunk of the brachial plexus?
C7
What roots contribute to the lower trunk of the brachial plexus?
C8, T1
What roots contribute to the posterior cord of the brachial plexus?
C5, C6, C7, C8, T1
What fibers are in the lateral cord of the brachial plexus?
Anterior division fibers from C5, C6, C7
What kind of fibers are in the posterior cord of the brachial plexus?
Posterior division fibers
What fibers are in the medial cord of the brachial plexus?
Anterior division fibers from C8, T1
Distal to the divisions, what changes with regard to composition of the nerves of the brachial plexus?
They contain either anterior or posterior division fibers, not both
Name the three components of the “M” of the brachial plexus, from lateral to medial.
Musculocutaneous, Median, Ulnar
Damage to C5/C6 will most likely result in problems with which joint of the arm?
Shoulder
Damage to C6/C7 will most likely result in problems with which joint of the arm?
Elbow
Damage to C7/C8 will most likely result in problems with which joint of the arm?
Wrist
Damage to C8/T1 will most likely result in problems with which joint of the arm?
Joints within the hand/digits
This nerve branches off of the C5 root of the brachial plexus.
Dorsal scapular nerve
This nerve branches off of the C5, C6, and C7 roots of the brachial plexus.
Long thoracic nerve
These two nerves branch off of the upper trunk of the brachial plexus.
Suprascapular nerve, Nerve to the subclavius
This nerve branches off the lateral cord of the brachial plexus.
Lateral pectoral nerve
This nerve branches off of the medial cord of the brachial plexus and innervates the same targets as a nerve off of the lateral cord.
Medial pectoral nerve
These three nerves branch off of the medial cord of the brachial plexus.
Medial pectoral nerve, medial brachial cutaneous nerve, medial antebrachial cutaneous nerve
These five nerves come from the posterior cord of the brachial plexus.
Upper subscapular nerve, middle subscapular (thoracodorsal) nerve, lower subscapular nerve, axillary nerve, radial nerve
What are the five muscles that can move the sternoclavicular joint?
Trapezius, levator scapulae, rhomboids, pectoralis minor, serratus anterior
Innervation of the trapezius
CN XI - spinal accessory nerve
What action do the upper fibers of the trapezius perform around the AP axis?
Elevation
What action do the lower fibers of the trapezius perform around the AP axis?
Depression
List the actions that the trapezius performs, and their respective axes.
Upper fibers: elevation (AP), retraction (vertical), upward rotation of glenoid fossa (oblique)
Middle fibers: retraction (vertical), upward rotation of glenoid fossa (oblique)
Lower fibers: depression (AP), retraction (vertical), upward rotation of glenoid fossa (oblique)
What portion of the trapezius muscle is most efficient at retraction?
Middle fibers
At what joint do all movements of the pectoral girdle occur?
Sternoclavicular joint
Describe the attachments of the trapezius.
Proximal attachments at the base of the skull and the spinous processes of thoracic and cervical vertebrae.
Distal attachments at the lateral third of the clavicle, medial margin of the acromion, and spine of the scapula.
Clinical finding in weakness of the trapezius
Shoulder droop
Innervation of the rhomboids
Dorsal scapular nerve
Describe the attachments of the rhomboids
Proximal: thoracic and cervical vertebrae
Distal: medial border of scapula
What actions can the rhomboids perform at the sternoclavicular joint? List actions and respective axes.
Elevation (AP), retraction (vertical), downward rotation of glenoid fossa/medial rotation of inferior angle (oblique axis)
Primary function of levator scapulae
Elevate the scapula
Innervation of levator scapulae
Dorsal scapular nerve
Muscle targets of dorsal scapular nerve
Levator scapulae and rhomboids
Actions (and axes) of levator scapulae at the sternoclavicular joint
Elevation (AP) - primary function, downward rotation of glenoid fossa/medial rotation of inferior angle (oblique axis), some retraction (assists rhomboids)
Innervation of serratus anterior
Long thoracic nerve
What spinal nerve roots contribute to the innervation of serratus anterior?
C5, C6, C7
Attachments of serratus anterior
Proximal: ribs 1-9
Distal: medial border of scapula
Note that the muscle actually runs between the ribs and the scapula.
Actions (and axes) of serratus anterior at the sternoclavicular joint
Protraction (vertical), depression (AP), upward rotation of glenoid fossa/lateral rotation of inferior angle (oblique axis)
What are the key muscles that act on the sternoclavicular joint in full flexion and abduction of the arm?
Trapezius and serratus anterior
Clinical finding in weakness/paralysis of serratus anterior
“winging” of the scapula, especially prominent on flexion and abduction of the arm
What is the primary action of serratus anterior during a push-up?
Protraction
What is the primary action of trapezius during a push-up?
Retraction
Innervation of pectoralis minor
Medial and lateral pectoral nerves
What kind of nerve fibers innervate pectoralis minor?
Anterior division fibers from C5-T1
Attachments of pectoralis minor
Proximal: ribs 3-5
Distal: coracoid process
Actions (and axes) of pectoralis minor at sternoclavicular joint
Depression (AP), protraction (vertical), downward rotation of glenoid fossa/medial rotation of inferior angle (oblique axis)
What muscles elevate the sternoclavicular joint?
Upper fibers of trapezius; rhomboids; levator scapulae
What muscles depress the sternoclavicular joint?
Lower fibers of trapezius; pectoralis minor; serratus anterior
What muscles protract the sternoclavicular joint?
Pectoralis minor and serratus anterior
What muscles retract the sternoclavicular joint?
Trapezius; rhomboids; a small contribution from the levator scapulae
What muscles cause upward rotation of the glenoid fossa?
Trapezius; serratus anterior
What muscles cause downward rotation of the glenoid fossa?
Pectoralis minor, rhomboids; levator scapulae
What are the muscles of the rotator cuff?
Supraspinatus; infraspinatus; teres minor; subscapularis
Which of the muscles that move the glenohumeral joint are located in the shoulder?
Deltoid; pectoralis major; latissimus dorsi; teres major; supraspinatus; infraspinatus; teres minor; subscapularis
Which of the muscles that move the glenohumeral joint are located in the arm?
Biceps brachii; triceps brachii; coracobrachialis
Innervation of deltoid
Axillary nerve
Which actions (and their respective axes) can be produced by the deltoid?
All of them!
AP axis: abduction (all except posterior-inferior fibers); adduction (posterior-inferior fibers only)
Transverse axis: flexion (anterior fibers), extension (posterior fibers)
Vertical axis: lateral rotation (posterior fibers), medial rotation (anterior fibers)
Attachments of the deltoid
Proximal: entire length of the spine of the scapula, lateral border of the acromion process, and lateral third of the clavicle
Distal: deltoid tuberosity of the humerus
This is the most superficial of the lateral extensor muscles of the forearm, and originates proximal to the lateral epicondyle
Brachioradialis
These two lateral extensor muscles originate proximal to the lateral epicondyle, and extend the wrist.
Extensor carpi radialis longus, extensor carpi radialis brevis
These three muscles extend the wrist and flex the elbow
Brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis
This muscle originates from the lateral epicondyle and extends the wrist as its primary function
Extensor carpi ulnaris
These three extensor compartment muscles originate from the lateral epicondyle
Extensor digitorum, extensor digiti minimi, extensor carpi ulnaris
This structure binds down extensor tendons at the wrist
Extensor retinaculum
These 3 deep extensor muscles move the thumb
Extensor pollicis longus, extensor pollicis brevis, abductor pollicis longus
List the five deep extensor muscles
Supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis
Around which axis does flexion/extension of the thumb take place?
AP axis
Around which axis does adduction/abduction of the thumb take place?
Transverse axis
Around which axis does medial/lateral rotation of the thumb take place?
Vertical axis
What secondary action can extensor pollicis longus do?
extend the wrist (in addition to extending the thumb)
What secondary actions can extensor pollicis brevis and abductor pollicis longus do?
Both of them can weakly flex the wrist.
Which artery passes through the anatomical snuffbox?
Radial artery
How many muscles move the thumb?
8
These four muscles are in the superficial layer of the flexor compartment of the forearm, and are anchored to the medial epicondyle.
Pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
This muscle forms the second layer of the flexor compartment of the forearm.
Flexor digitorum superficialis
This muscle is the only one that can move the DIP joint
Flexor digitorum profundus
These three muscles are located in the deep two layers of the flexor compartment of the forearm
Flexor digitorum profundus, Flexor pollicis longus, Pronator quadratus
This structure binds down tendons of the flexor compartment
Flexor retinaculum
Which structures pass through the carpal tunnel?
4 flexor digitorum superficialis tendons, flexor pollicis longus tendon, 4 flexor digitorum profundus tendons, median nerve
Where do the ulnar nerve and artery pass through the wrist?
Guyon’s canal, which is outside the carpal tunnel
What are the muscles of the thenar compartment?
Opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
What are the muscles of the hypothenar compartment?
Opponens digiti minimi, abductor digiti minimi, flexor digiti minimi
What actions do dorsal interosseous muscles perform?
Abduction of the digits
What actions do palmar interosseous muscles perform?
Adduction of the digits
Where do the lumbrical muscles originate and attach?
Originate at flexor digitorum profundus tendons, attach to the extensor head (no bony attachments)
What is the reference point for abduction/adduction of the fingers?
The middle finger
What is the name for the fluid-filled lubricating structure around the flexor digitorum tendons in the fingers?
Synovial tendon sheaths
What synovial sheath surrounds flexor pollicis longus in the wrist?
Radial bursa
What synovial sheath surrounds the flexor digitorum tendons as they pass through the wrist?
Ulnar bursa