BPK 326 Head & Neck

sulci function

separate lobes

sulci vs gyri vs fissures

• sulci: grooves/lines separating gyri

• gyri: ridges of cortex

• fissures: deep sulci

what’s the longest sulci

central sulcus (superior sagittal sulcus to lateral/sylvian sulcus)

where in the brain do directions change

@ midbrain (midbrain diencephalic junction)

nucleus vs ganglia

collection of neuronal cell bodies in CNS vs in PNS

what’s the exception to ganglia location

basal ganglia lies within CNS

tract vs nerve

collection of axons in CNS vs PNS

commissure vs decussation

tract crosses singular rostral/caudal level vs crosses obliquely over many levels

precentral and postcentral gyrus function

• precentral: contralateral voluntary motor control; medial starts at the toes

• postcentral: contralateral sensory processing; medial starts at genitals

what areas in brain does precentral and postcentral gyrus refer to

• precentral: primary motor cortex

• postcentral: primary somatosensory cortex

frontal lobe structures & functions

1. primary motor cortex: voluntary movements

2. prefrontal cortex: planning, actions, attention, memory

3. broca’s area: speech production

parietal lobe structures and functions

1. primary somatosensory cortex: touch, pain, temp

what lobe is responsible for decision making, problem solving, personality, social behaviour, emotions

frontal

what lobe is responsible for integrating visual and auditory info?

parietal

what lobe is responsible for spatial awareness and mathematical reasoning?

parietal

temporal lobe structures and functions

1. primary auditory cortex: processing and interpreting auditory info

2. wernicke’s area: speech comprehension

what lobe is responsible for long-term memories?

temporal

occipital lobe structures and functions

1. primary visual cortex: initial visual processing

what lobe is responsible for coordinating eye movements and visual attention?

occipital

limbic lobe function

emotional processing

cingulate sulcus

separates cingulate gyrus from frontal and parietal lobes

calcarine sulcus

in occipital lobe and connects to medial parieto-occipital sulcus

paracentral lobule

U-shaped medial extension of pre and post-central sulci that controls lower limb movement

why is there contralateral control in the medulla even though it’s posterior to the midbrain?

pyramidal decussation at caudal part of medulla where most of motor fibres cross over

brainstem structures and functions

1. midbrain: sensory processing, motor movement, reflexes

2. pons: relays info between cerebellum and cerebral cortex

3. medulla oblongata: autonomic functions (ie heart rate, respiration)

4. cerebellum: balance, posture, coordination

white matter tracts and functions

1. internal capsule

2. corona radiata

^both carries motor/sensory signals between cerebral cortex and brainstem/spinal cord

3. corpus callosum: relays info between left/right hemispheres

what are the projection fibres?

internal capsule and corona radiata

describe position of internal capsule

divides caudate and thalamus from lentiform (putamen & globus pallidus) and sits posteriorlly in the brain

what structure would you not be able to see in a scan if the internal capsule is visible?

head of caudate cause it’s anterior and internal capsule is posterior

what area is first targetted with Parkinson’s

basal ganglia

what area is first targetted with Alzheimer’s

hippocampus

deep brain nuclei functions

1. thalmus: sensory relay station

2. basal ganglia: movement & reward

3. caudate nucli, putamen, globus pallidus: voluntary movements

4. amygdala: emotions

5. hypothalamus: homeostatis

6. hippocampus: memory

cortico injuries vs nerve injuries

contralateral deficits vs ipsilateral deficits

damage to primary motor cortex/corticobulbar tract results in what

• upper motor neuron lesion

• tongue deviates contralaterally

damage to hypoglossal nerve/CN 12 results in what

• lower motor neuron lesion

• tongue deviates ipsilaterally

damage to facial area of primary somatosensory cortex results in what

lower half of contralateral face (stroke)

damage to trigeminal nerve results in what

whole ipsilateral face (Bell’s Palsy)

motor control of body vs head structures

corticospinal tract vs corticobulbar tract

what detects fine touch, proprioception, and vibration?

dorsal column-medial lemniscus system (ipsilateral)

what detects pain and temp

spinothalamic tract (contralateral)

what does the lateral corticospinal tract control

limbs

ischemic stroke vs peripheral lesion of facial nerve (CN 7)

contralateral facial weakness of lower face vs ipsilateral facial weakness

comparing ischemic stroke and peripheral lesion

• older vs younger

• onset: sec-min vs hrs-days

• upper face always affected for peripheral

• both lower face affected

what contains CSF

subarachnoid space surrounding brain and ventricles

blood pathway in sinuses

superior sagittal/inferior sagittal → straight → torcular herophili/confluence → occipital OR transverse

• ends at occipital

• from transverse → sigmoid → internal jugular vein

anatomy is the setting in which…

the events of life occur

studying anatomy approaches

1. systemic anatomy: broken up by organ systems

2. regional anatomy: by region/areas of body

3. clinical anatomy: application of treatment/diagnosis

4. comparative anatomy: inter-individual, populations, species

anatomical regions of the body

1. head

2. neck

3. thorax

4. back

5. abdomen

6. upper limb

7. pelvis

8. lower limb

what does cephalic refer to

head

what does cervical refer to

neck

what does otic refer to

ear

what foes orbital refer to

eye

crural vs sural

crural = leg

sural = calf

acromial vs scapular

acromial = shoulder

scapular = shoulder blade

pedal vs plantar

pedal = foot

plantar = sole

what does antecubital refer to

anterior elbow

what are colloquial terms, give example

informal/casual words used, ie collar bone or abs

what are eponyms, give example

incorporate name of anatomist that discovered the structure, ie fallopian tube, or eustachian tube

what are common terms, give example

incorporate literature names or other, ie adam’s apple or achilles tendon

what does anatomical position mean?

• erect posture

• hands at side and palms face forward

• feet shoulder width apart and parallel, toes forward

• gaze forward

supine & prone positions describe the position of the ____

torso

anatomical planes & axes + how they divide the body + movements

1. sagittal/longitudinal plane (left/right) - frontal axis (medial/lateral) - flex/extend

2. frontal/coronal plane (front/back) - sagittal axis (anterior/posterior) - adduction/abduction, lateral flexion

3. transverse/axial/horizontal plane (top/bottom) - longitudinal axis (superior/inferior) - rotations

movements occur within ____ and about ____

a plane, an axis

describe midsagittal/medial plane

equal left and right halves of body

describe parasagittal

unequal left and right halves of the body

why is the top of the brainstem a crucial point for directional terms

because the bending of the neuraxis makes rostral/caudal become anterior/posterior instead of top/bottom below and dorsal/ventral become superior/inferior instead of posterior/anterior below

cranial definition

a position higher than another part of the body

where does ankle movement occur

• between tibia and talus = dorsi/plantar

• at subtalar joint = inversion/eversion

describe IR and ER

rotation of anterior surface toward/away from midline

rank x-ray densities

1. metal

2. bone

3. soft tissue

4. fat

5. air

describe terms of brightness/darkness in x-rays

1. opaque: tendency of structure blocking x-rays from passing through and reaching detector (bright)

2. lucent: tendency of structure to allow x-rays to pass through and reach detector (dark)

why wouldn’t a lung be totally lucent on x-ray

because there’s soft tissue and skin surrounding it, which the x-rays pass thru

what can improve soft tissue resolution on x-rays

contrast agents

pros of CT scans

• faster and less expensive than MRI

• better tissue resolution than conventional x-rays

• metal implants are fine

CT terms

• hyperdense & hypodense

MRI terms

hyperintense & hypointense

describe brightness/darkness in MRI

not a form of x-ray so it’s not based on densities. rather its based on proton behaviour (fat and water content)

pros to MRI

• best anatomical resolution (being able to see tissues, organs, structures)

• but…slow, expensive, and dangerous for metal implants/devices

describe density of congealed blood in CT and why

• opaque

• hyperdense

• blood clots are red blood cells packed together tightly and therefore are rich in hemoglobin, making it harder for x-rays to pass through & appearing brighter on scan

what makes up skeletal system

axial skeleton (skull, vertebral column, thoracic cage) + appendicular skeleton (limbs)

endochondral ossification

process of bone developement from cartilage

what degenerates as bone develops and why

the bone growth outpaces ability of cartilage to receive O2 which causes cartilage degeneration and room for ossification

why is it hard to treat cartilage medically

because there’s a lack of vascular supply so it’s hard to heal or grow

types of joints

1. fibrous, connective, synovial

2. synarthrosis (immovable), amphiarthrosis (slightly moveable) , diarthrosis (freely moveable)

histological parts of functional joints

1. synarthrosis → fibrous joints

2. amphiarthrosis → cartilaginous joints

3. diarthrosis → synovial

describe synarthroses joints and types

• bones connected by fibrous tissue

• little to no movement

• types: skull sutures, syndesmoses (longer fibres), gomphoses (teeth socket)

describe amphiarthoses joints and types

• bones connected by cartilage

• slightly moveable

• types: synchondroses (hyaline cartilage), symphyses (fibrocartilage), primary/temporary (becomes synarthrosis), secondary/permanent

type of joint connecting radius & ulna or tibia & fibula

synarthrosis, fibrous, syndesmoses

examples of synchondroses, symphyses, primary, secondary joints

• epiphyseal plate = synchondroses

• between intervertebral discs & pubic symphysis = symphyses

• pubic symphysis = secondary

periodontal ligament

tissue connecting teeth to sockets

what is part of a diarthroses/synovial joint?

joint capsule: synovial membrane + fluid, articular cartilage

arthroscopy vs arthroplasty

surgical procedure on a joint vs replace of a joint

examples of synovial joints for multiaxial, uniaxial, biaxial movements

• multiaxial = ball + socket

• uniaxial = hinge

• biaxial = saddle

during muscle contraction, what moves toward the origin?

distal attachment/insertion

muscle injury typically occurs at the ______

myotendinous junction (MTJ)

why are hamstrings prone to injury

extremely vulnerable when fully extended because there’s a long myotendinous junction

what anchors muscle to skeleton/deep fascia

aponeurosis (flat sheets)

plexus

collection of peripheral nerves with functional activity

where does spinal cord end

L1/L2

pathways of motor & sensory neurons

• motor neurons = ventral root

• sensory neurons = dorsal root