anatomy exam 1 Flashcards
how does regional anatomy organize the body?
by major segments or parts
how does systemic anatomy organize the body?
focuses on the body’s organ systems
what types of anatomy does clinical anatomy include?
regional and systemic anatomy (to describe function)
describe anatomical position
head (eyes) and toes directed anteriorly
arms adjacent to the sides with palms facing forward
lower limbs close together with feet parallel
how does the median plane divide the body?
divides the body into two halves
how does the sagittal plane divide the body?
divides the half into two other halves
how does the frontal (coronal) divide the body?
divides the body into front and back halves
how does the transverse plane divide the body?
divides body into superior and inferior parts
what are the four terms of laterality (and what do they mean)?
bilateral - both sides
unilateral - on one side
ipsilateral - same side
contralateral - opposite sides
what two components make up the central nervous system?
brain and spina cord
what connects the spinal cord to the brain?
brain stem (medulla oblongata and pons)
what is contained within gray matter in the spinal cord?
neuron cell bodies
what types of signals come into the dorsal root / dorsal horn?
sensory / afferent signals
what types of signals come out of the ventral horn?
motor / efferent signals
what is the outermost layer of meninges?
dura mater
what is the middle layer of meninges?
arachnoid mater
what is the inner most layer of meninges?
pia mater (adhered to tissue of spinal cord)
what is the order of spaces and meninges around the spinal cord? (outer to inner)
epidural space
dura mater
subdural space (potential space)
arachnoid mater
subarachnoid space (CSF found here)
pia mater
what are denticulate ligaments made up of and what is their clinical significance?
paired extensions of pia mater than attach to the arachnoid and dura mater (run between ventral and dorsal rootlets of the spinal cord)
helps to prevent lateral shifting of the spinal cord within the dural sac
what can be found within the epidural space?
adipose tissue, internal vertebral plexus
what can be found within the subarachnoid space?
spinal veins and arteries, cerebrospinal fluid, arachnoid trabeculae
what levels of the spinal cord makeup the cervical enlargement and what does it give rise to?
C5-T1
cervical plexus and brachial plexus
what levels of the spinal cord makeup the lumbar enlargement and what does it give rise to?
L1-S2
lumbar plexus and sacral plexus
how many spinal nerves are there within each segment of the spinal cord? (bilateral, paired)
cervical (8)
thoracic (12)
lumbar (5)
sacral (5)
coccygeal (1)
another term for conus medullaris (which level does it usually end at)?
terminal end of spinal cord
usually around L1-L2
significance of filum terminale (internum / externum)
extensions of pia mater that anchor the spinal cord inferiorly in dura sac (function is same way as denticulate ligaments)
significance of lumbar cistern
enlargement of subarachnoid space from L2-S2 (CSF pools here)
significance of cauda equina
L2-S5 spinal nerve roots (forms as a result of differential growth of spinal cord and vertebral column)
segmental spinal arteries arise from: (subclavian aa)
vertebral aa
ascending cervical aa
deep cervical aa
segmental spinal arteries arise from: (descending aorta)
posterior intercostal aa
lumbar aa
segmental spinal arteries arise from: (internal iliac aa)
lateral sacral aa
what artery does the anterior spinal artery arise from?
(located in subarachnoid space along spinal cord)
vertebral aa
what artery does the paired posterior spinal aa arise from?
(located in subarachnoid space along spinal cord)
vertebral aa or cerebellar aa
what types of arteries do segmental arteries give rise to and where do they go?
radicular - anterior and posterior
medullary - anterior
what is the largest of the segmental medullary arteries?
artery of ademkiewicz (supplies lower spinal cord)
order of venous drainage of spinal cord
anterior / posterior spinal veins
anterior / posterior medullary veins and radicular veins
internal vertebral venous plexus
segmental veins
other major systemic routes of venous drainage
what is a significance difference of veins within the internal vertebral venous plexus compared to veins found in other parts of the body?
these veins DO NOT have valves
clinical significance of internal vertebral venous plexus
cancer metastases (has many connections to systemic venous circulation)
what are the two sensory (afferent) tracts and what kind of stimulus do they perceive? (lateral and posterior)
dorsal columns - fine touch and proprioception
spinothalamic pathway - lateral - pain and temperature and anterior - touch and pressure
where do ascending tracts (sensory pathways) originate and where do they travel to? (
originate - peripheral body
travel to - primary sensory cortex
where do descending tracts (motor pathways) originate and where do they travel to?
originate - cerebral cortex and brainstem
travel to - muscle
what is the motor (efferent) tract? (lateral and anterior)
corticospinal tract (somatic motor - voluntary movement)
lateral - 85-90% to limbs
anterior - 10-15% to trunk
what does the peripheral nervous consist of?
cranial nerves, spinal nerves, and ganglia
what direction does sensory innervation get to the body?
brings information to the CNS from the environment
what direction does motor innervation come from the body?
sends instructions from the CNS to muscle and glands
where are the parts of a motor neuron located?
(one axon)
cell body - CNS
axon - comes out as part of a spinal nerve
where are the parts of a sensory neuron located?
(bipolar - two axons)
cell body - found outside of CNS, in ganglion
axon branches into peripheral tissue to pick up information and other branch goes to CNS to relay information
what does somatic innervation concern? (voluntary)
body wall (skeletal muscle or skin)
what does visceral innervation concern? (involuntary)
internal organs (innervation of the heart)
different types of:
body wall (somatic)
internal organs (visceral)
somatic sensory (skin)
somatic motor (skeletal muscle)
visceral sensory (brain regulation of internal organ function)
visceral motor (heart, digestive system)
what is the target tissue of somatic motor innervation and is it voluntary or involuntary control?
target tissue - skeletal muscle
voluntary control
ONE neuron connects the CNS to the target muscle
how does somatic sensory innervation carry sensory information and is perceived consciously or unconsciousy?
carries sensory information from skin and musculoskeletal system
perceived consciously
ONE neuron connects site of stimulus to CNS
examples of somatic sensory stimuli
pain from cutting, tearing, crushing, inflammation, burning
temperature
touch
pressure
vibration
THINK STIMULI THAT CAN BE FELT BY SKIN
importance of notochord
fiber of tissue that is important in regulating development of surrounding tissues (control segmentation)
importance of paraxial mesoderm
columns of tissue along either side of notochord that segments and becomes somite pairs (gives rise to bone, skeletal muscle, dermis - below the head)
what does dermamyotome give rise to?
population of somites that gives rise to dermis and muscle
what does sclerotome give rise to?
gives rise to axial skeleton (becomes bone)
what does exaxial dermamytomes give rise to?
all intrinsic (deep) back muscles and dermis that covers them
what does hypaxial dermamytomes give rise to?
all other skeletal muscle and dermis below the neck, including the limbs
what rami supples epaxial dermamytomes?
dorsal rami
what rami supples hypaxial dermamytomes?
ventral rami
what is the target tissue of visceral motor innervation and are they under conscious or unconscious control?
target tissue - smooth muscle, cardiac muscle, glands
under unconscious control (involuntary)
TWO neurons connect the CNS to target tissue
what are visceral structures located within the body wall?
sweat glands, arrector pili muscles, smooth muscle in skin and vessel walls
what types of innervation do most internal organs receive?
both sympathetic and parasympathetics
what type of innervation do most visceral structures in the body wall receive?
sympathetic innervation only