Flashcards in Exam 1 Deck (164):
moving the plantar surface of the sole of the foot towards the ground
moving the dorsum of the foot towards the leg
movement of the plantar surface medially
movement of the plantar surface laterally
What does the CNS consist of?
brain and spinal cord
What does the peripheral nervous system consist of?
12 cranial nerves and 31 spinal nerves
How many cervical nerves are there?
How many thoracic nerves are there?
How many lumbar nerves are there?
How many sacral nerves are there?
How many coccygeal nerves are there?
What is the cell body called outside the CNS?
What is the function of a dendrite?
conducts electrical impulses toward the cell body
What is the function of an axon?
conducts electrical impulses AWAY from the cell body
What is a synapse?
functional contact (microscopic gap) between 2 nerves (axon to dendrite)
What is the function of a synapse?
where chemical neurotransmitters convey electrical impulses
Anterior root function
contains only motor fibers
posterior root function
contains only sensory fibers and associated ganglion
Roots converge to form ______
What are primary rami?
anterior and posterior branches of the spinal nerve that contain motor and sensory fibers
What is the function of posterior primary rami?
They are much smaller and distribute to intrinsic muscles and skin of the back and neck
What is the function of anterior primary rami?
They distribute to the remainder of the anterolateral neck, remainder of the trunk and limbs
What is a plexus?
a structure form by anastomoses of anterior rami of several spinal nerves
Somatic motor spinal nerves innervate what?
To almost all skeletal muscles inferior to head
Somatic sensory spinal nerves innervate what?
From skin of posterior head, neck, trunk, and limbs
Autonomic motor spinal nerves innervate what?
To smooth muscle, cardiac muscle, and glands
autonomic sensory spinal nerves innervate what?
From smooth muscle, cardiac muscle, and glands
What does the sympathetic autonomic nervous system regulate?
"fight or flight;" accelerates heart rate, inhibits intestinal peristalsis, dilates pupils
Describe the sympathetic systems ganglion fibers.
Preganglionic fibers are short and postganglionic fibers are long.
Where do the sympathetic nerves leave the CNS?
At T1-L2 spinal cord levels only
What is the sympathetic trunk?
a longitudinal nerve structure that reaches superior and inferior structures
How many neurons are required to transmit motor impulses to effector structure?
2- first motor neuron synapses with the second neuron
How many neurons are required to transmit sensory impulse from structure?
How many components does the autonomic nervous system have and what are they?
2- motor and sensory components
What does the parasympathetic autonomic nervous system regulate?
"rest and digest;" homeostasis- slows heart rate, increases intestinal peristalsis, constricts pupils
Where do the parasympathetic nerves leave the CNS?
4 cranial nerves and S2-4 spinal cord levels
Describe the parasympathetic systems ganglion fibers.
preganglionic fibers are long and postganglionic fibers are short
What structures does the parasympathetic system innervate?
limited to structures in head, viscera (thoracic, abdominal, and pelvic), and specialized vasculature in genitals. No distribution to limbs or body wall
Where does the spinal cord start and end?
extends from skull (foramen magnum) to 2nd lumbar vertebra
What is the conus medularis?
tapered, inferior end of cord
What is the cauda equina?
consists of lumbar and sacral nerve roots inferior to conus medularis
Where does the spinal cord have enlargements and why?
cervival and lumbosacral; corresponds to large nerve supply for limb muscles
What are the meninges?
Connective tissue surrounding the spinal cord
What are denticulate ligaments?
they anchor the spinal cord to the dura mater
What is the filum terminale?
forms the inferior end of conus medularis to coccoyx
How long does the dura mater extend?
to the 2nd sacral vertebra
What is the epidural space?
the space between the dura and bone of vertebral canal
Where do you complete a lumbar puncture?
from subarachnoid space between L2 and S2
Describe shape and function of body of vertebrae?
cylindrical; weight bearing; connects to adjacent bodies by intervertebral disks
Describe function of vertebral arch.
protects spinal cord
Describe shape of vertebral arch.
Formed posteriorly by pedicles (cylindrical) and laminae(flat) to define the vertebral foramen
Where are the articular processes on vertebrae?
arise from vertebral arch; 2 superior and 2 inferior articular processes located at junctions of pedicles and laminae
What processes on vertebrae are used for muscle attachment?
1 spinous and 2 transverse
Where are notches located on the vertebrae?
between the body anteriorly and articular processes posteriorly
What do the notches of adjacent vertebrae form?
How many cervical, thoracic, lumbar, sacral, and coccygeal vertebrae are there? (in respective order)
7, 12, 5, 5, 4
What makes cervical processes unique and what is its function?
transverse foramen for vertebral arteries
Why are most movements permitted for cervical vertebrae?
because it has relatively thick intervertebral discs and the nuchal ligament
What are the main functions of C1 and C2?
movement and support of skull
What is C1 called and what is its shape?
Atlas; ring-like with no body or spinous process
What movement does C1 allow?
Flexion and extension of head ("yes" movement)
What is C2 called and what is its shape?
Axis; has superiorly directed odontoid process (dens) forming pivot point for rotation of atlas
What movement does C2 allow?
"no" movement of head
Why is movement limited for thoracic vertebrae?
Thoracic vertebrae can only rotate because they have thin intervertebral discs, overlapping spines and attachment of ribs
What makes thoracic vertebrae unique?
facets on body and transverse processes for articulation with heads and tubercles of ribs
What movements are allowed for lumbar vertebrae and why?
flexion, extension and lateral bending with LIMITED rotation due to thick intervertebral discs and orientation of articular processes
What is purpose of sacral vertebrae?
Describe composition of intervertebral discs.
outer anulus fibrosus (dense fibrous tissue that is thinner posteriorly) and inner, softer nucleus pulposus containing 70-80% water
What is the function of intervertebral discs?
Describe dehydration and rehydration of intervertebral discs.
Dehydrate from mechanical pressure (standing/walking) and rehydrate at rest (rehydration becomes less efficient with age)
Which vertebrae are more likely to have a herniated disc?
cervical and lumbar
What is a herniated disc?
extrusion of nucleus pulposus through anulus fibrosus (posteriorly or posterolaterally); the anulus fibrosus is also thinner posteriorly
What is kyphosis?
exaggeration of thoracic curvature and is osteoporosis-related
What is lordosis?
Exaggeration of lumbar curvature; present in morbidly obese people or pregnant women
What is scoliosis?
complex lateral bending and twisting of vertebral column and is usually idopathic
What is the purpose of ligamenta flava?
connects laminae; very elastic and you push through this for CSF sample
What is the purpose of inerspinous and supraspinous ligaments?
What is the nuchal ligament?
thickened supraspinous ligament in cervical region
What is the purpose of longitudinal ligaments?
they are anterior (thicker) and posterior ligaments that connect vertebral bodies
Superficial (except trapezius) and intermediate back muscle groups are innervated by...
Deep back muscles are innervated by....
Which back muscle groups are derived from anterolateral musculature?
superficial and intermediate groups
Which two regions of spine are concave anteriorly?
Which two regions of spine are concave posteriorly?
What forms bony pelvis?
2 hip bones (pubis, ischium, ilium) anterolaterally and by sacrum and coccyx posteriorly
What is the ischium characterized by?
ramus, tuberosity and spine
What separates the tuberosity and spine of the ischium?
lesser sciatic notch
The ischium and pubis form what?
the obturator foramen which is nearly closed by the obturator membrane
What bones contribute to the acetabulum?
pubis, ilium and ischium
What characterizes the ilium?
fan-shaped ala with crest, fossa, anterior (superior and inferior) and posterior (superior and inferior) spines, and greater sciatic notch
What characterizes the pubis?
tubercule, superior pubic ramus and inferior pubic ramus
What is the lumbosacral joint?
strong iliolumbar ligaments unite 5th lumbar vertebra to iliac crest and sacrum
What is the function of the lumbosacral joint?
limit axial rotation of L5 on sacrum and stabilize joint
What is the function of the sacroiliac joint?
transmits weight of body to hip bones
What holds together the sacroiliac joint?
strong sacroiliac ligaments (anterior, interosseous and posterior)
What are the accessory ligaments of the sacroiliac joint?
sacrotuberous and sacrospinous ligaments that convert greater and lesser sciatic notches into greater and lesser sciatic foramina, respectively
has thick interpubic disc of fibrocartilage; has superior and inferior pubic ligaments connecting bones; angle of female pubic arch is greater contributing to wider female pelvis
Describe possible trauma of the pubic joints.
they seldom dislocate because of great strength of surrounding ligaments; bony portions of adjacent pelvic rim (esp pubic bones ) usually fracture
What parts of bony pelvis are in same vertical plane in anatomical position?
anterior superior iliac spines and pubic tubercules
pelvic brim (rim)
ridge of bone from pubis, ilium and sacrum; bounds pelvic inlet and divides pelvis into great and lesser parts
aka false pelvis; superior to pelvic brim and forms inferior part of abdominal cavity; bounded by abdominal wall, iliac alae, L5 and S1
aka true pelvis; inferior to pelvic brim and contains pelvic viscera; bounded by pubis, ilium, ischium, sacrum and coccyx
What does the lesser pelvis contain?
greater sciatic, lesser sciatic and obturator foramina
superior pelvic aperature; bounded by pelvic brim; measured routinely for obstetric reasons during pelvic exam
inferior pelvic aperature; bounded by pubic symphysis, ischiopubic rami, ishial tuberosities, sacrotuberous ligaments, and coccyx; closed by muscular pelvic diaphragm
What is prolapse of viscera?
stretching or tearing of levator ani muscles (esp pubococcygeus)
What is the pelvic diaphragm?
funnel-shaped musculature that closes pelvic outlet and forms floor of pelvic cavity; urethra and vagina pass through gap (urogenital hiatus) btwn anteromedial edges of muscles; consists of levator ani and coccygeus muscles
diamond-shaped region inferior to the pelvic diaphragm
male and female genitals have homologous structures because they develop from what?
the same set of embryonic primordia
What does a line pass between to divide the pelvic diaphragm into the urogenital and anal triangle?
What is the difference between fundamental structures in female versus males?
They have remained bilateral with a midline cleft in the female but they have fused into midline structures in males.
What are the boundaries of the female urogenital triangle?
inferior part of pubic symphysis, ischiopubic rami, and line connecting ischial tuberosities
triangular-shaped fascia between ischiopubic rami that is inferior to pelvic diaphragm
perineal membrane function
provides support for pelvic viscera at urogenital hiatus and separates area into superficial and deep perineal spaces
What are the external genitals of the female attached to?
either bone or perineal membrane
What is the homologous structure of labia majora?
2 prominent longitudinal folds containing fat; blend together anteriorly to form mons pubis
2 small folds medial to labia majora; give rise to prepuce of clitoris
vestibule of vagina
cleft between labia into which urethra, vagina, and ducts of greater vestibular and other glands open
What is the homologous structure of the clitoris?
consists of mobile body and attached root; has glans and NO external urethral orifice; composed of 3 cylindrical bodies of erectile tissue
corpora cavernosa of clitoris
paired structures arranged side by side; expand as crura that are attached to ischiopubic rami in superficial perineal space
clitoris- commissure of the bulbs
unpaired and very small structure that forms glans of clitoris distally; does NOT contain female urethra; expands as 2 vestibular bulbs attached to perineal membrane.
what is the homologous structure of male corpus spongiosum?
commissure of the bulbs of clitoris
location of superficial perineal space
between mobile portion of genitals and perineal membrane
contents of superficial perineal space
crura of clitoris, vestibular bulbs; greater vestibular glands
crura of clitoris
attached to ischiopubic rami; covered by ischiocavernosus muscles that compress erectile tissue and force blood into corpora cavernosa; muscles supplied by the pudendal nerve
attached to perineal membrane; covered by bulbospongiosus muscles that compress erectile tissue and force blood into commissure and glans; muscles supplied by pudendal nerve
greater vestibular glands
associated with inferior ends of vestibular bulbs; secrete mucus; ducts empty into vestibule of vagina
What is the homologous structure in a male for vestibular glands?
location of deep perineal space in male and females
area between perineal membrane and pelvic diaphragm; no communication with superficial perineal space or pelvic cavity
what are the contents of the deep perineal space in a female?
vagina, urethra, external urethral sphincter
What nerve supplies the external urethra sphincter?
cutaneous pouch containing testes, epidiymis and distal parts of spermatic cords; wall contains smooth muscle fibers that contract primarily under influence of cold
What is the name of the smooth muscle in the scrotum?
consists of mobile body and attached root; has prepuce and glans containing external urethral orifice; composed of 3 cylindrical bodies of erectile tissue called corpora
corpora cavernosa of penis
paired structures arranged side by side; expand as crura that are attached to ischiopubic rami in superifical perineal space
unpaired and smaller structure that forms glans penis distally; contains spongy urethra; expands as bulb of penis attached to perineal membrane
What is the homologous structure in a female for corpus spongiosum?
What is the location of the superficial perineal space in the male?
between scrotum/mobile portion of penis and perineal membrane
What are the contents of the superficial perineal space in a male?
crura of penis and penile bulb
crura of penis
attached to ischiopubic rami; covered by ischiocavernosus muscles that compress erectile tissue and force blood into corpora cavernosa; muscles supplied by pudendal nerve
attached to perineal membrane; covered by bulbospongiosus muscles
expels residual urine and semen; help maintain an erection by compressing erectile tissue and forcing blood into corpus spongiosum and glans; supplied by pudendal nerve
contents of male deep perineal space
urethra, external urethral sphincter and bulbourethral glands
what is the male homologous structure to female greater vestibular glands?
bulbourethral glands (these are located in different place than female structure)
What are the boundaries of the anal triangle?
line connecting ischial tuberosities, sacrotuberous ligaments and coccyx
distal 2 inches of GI tract; begins at level of U-shaped rectal sling formed by puborectalis
external anal sphincter
voluntary sphincter of anal canal; has subcutaneous, superficial, and deep parts; supplied by pudendal nerve
wedge-shaped spaces on either side of anal canal; filled with fat that support canal; obturator internus muscle and ischial tuberosity form vertical lateral wall; levator ani and anal canal form sloping superomedial wall
distal part of digestive tract that hold fecal mass; continuous proximally with sigmoid colon and distally with anal canal; follows curve of sacrum and coccyx and ends at the tip of coccyx; sharp anorectal flexure maintained by puborectalis part of levator ani
Where do renal calculi usually occur?
kidney-ureter junction, pelvic brim and passage through bladder wall
muscular tube from kidney to bladder; crossed superiorly by ductus deferens in males and uterine artery in females; pass obliquely through posterior bladder wall, which prevents reflux of urine during emptying of bladder
muscular sac posterior to pubic bones; relatively free except for inferior tapered part that is attached to prostate gland (male) or pelvic diaphragm (female);
What is the name of smooth muscle of the bladder?
prostatic, intermediate (encircled by voluntary sphincter) and spongy parts
Where can a catheter rupture the urethral wall of a male?
transition between mobile and fixed parts; passage through deep perineal space
corresponds to prostatic and intermediate parts of male urethra
infundibulum of uterine tubes
funnel-shaped distal end with fringed edges called fimbrae
ampulla of uterine tubes
widest and longest part of tube where fertilization of ovum occurs
isthmus of uterine tubes
short, narrow part that joins uterus
thick-walled muscular tube from epididymis that passes through abdominal wall and approaches bladder from posterior aspect; crosses ureter and joins duct of seminal gland to form ejaculatory duct within prostate gland
lobulated glands having size and shape of small finger; attached to posterior aspect of bladder; release thick, alkaline secretion forming most of seminal fluid;