test 2 Flashcards
what type of system do the heart and blood vessels form
closed-loop
how are blood vessels usually named
by the body region they transverse or the bone next to them
what does systemic circulation consist of
the blood vessels that extend to and from the body tissues
what does pulmonary circulation consist of
the vessels that take the blood to the lungs for gas exchange and then return oxygenated blood to the heart
what are the 3 main classes of blood vessels
arteries, capillaries and veins
where does gas and nutrient exchange occur
capillaries
define anastomosis
site where 2+ vessels merge to supply the same body region
what are the 3 layers of an artery
tunica intima: intimate/innermost layer
tunica media: middle layer
tunica externa: outside layers
what is the tunica intima composed of
layer of simply squamous epithelium called endothelium
what is the tunica media composed of
circularly arranged layers of smooth muscle cells under autonomic control
what is the tunica externe composed of
areolar connective tissue that contains elastic and collagen fibers and nerve helps. it helps anchor the vessel to other tissues, protects, and supports vessel
define vasa vasorum
small blood vessels that supply the cells of the wall
what are the 3 basic types of arteries
elastic arteries, muscular arteries and arterioles
what do pulmonary arteries do
carry deoxygenated blood to the lungs
what do arteries in systemic circulation do
carry oxygenated blood to the body tissues
what are some properties of elastic arteries
- dampen BP changes associated with heart contraction
* passive accommodation results in smooth flow of blood
define arteriosclerosis and atherosclerosis
arterio: hardening of arteries
athero: fatty deposits and occlusion
what are risk factors for atherosclerosis
genetics, hypercholesterolemia, sex (male), age, smoking, hypertension
what layer does the capillaries have
tunica intima (consists of basement membrane and endothelium only)
what do capillaries do
allow gas and nutrient exchange between the blood and the body tissues to occur rapidly
what is the sequence of blood movement through capillary bed:
terminal arteriole–> metateriole–> true capillaries branch off–> pre-capillary sphincter controls blood flow into capillaries–> thoroughfare channel–> capillaries rejoin–> post-capillary venule
what are the 3 basic kinds of capillaries
continuous capillaries, fenestrated capillaries, sinusoids
what is the difference between systemic veins and pulmonary veins
systemic carry deox. blood too R atrium
pulmonary car oxygenated blood to L atrium
what is the thickest layer of a vein
tunica externa
what is the difference between systolic and diastolic BPq
systolic: during ventricular contraction (120)
diastolic: during ventricular relaxation (70).
what are the branches of the aortic arch in sequence relative to L ventricle
- coronary artery
- brachiocephalic
- L common carotid
- subclavian
c. thoracic aorta
what is the route of venous return to the heart
external iliac and lower limb/internal iliac & pelvis–> common iliac v–> inferior vena cava
what are the branches of the external carotid that arise in carotid triangle
superior thyroid artery, ascending pharyngeal artery, lingual artery, facial artery, occipital artery
what supplies arterial supply to the brain (internal)
vertebral arteries and internal carotid artery
what arterial supply goes to the head (external)
external carotid arteries
what arterial supply goes to the neck (external)
external carotid arteries, thyrocervical trunks (from subclavian arteries)
what is the venous drainage of the head and neck
brain: dural sinuses to internal jugular veins
head: internal and external jugular veins, vertebral veins
neck: internal and external jugular veins
what is the circle of willis/cerebral arterial circle formed from
posterior cerebral arteries and posterior communicating arteries, internal carotid arteries, anterior cerebral arteries, and anterior communicating arteries
what does the circle of willis/cerebral arterial circle do
equalizes blood pressure in the brain and can provide collateral channels should one vessel become blocked
what are the branches of the abdominal aorta and where do they go
to diaphragm (inferior phrenic)
to GI tract (celiac, superior & inferior mesenteric)
to other organs not part of the gut (suprarenal, renal, gonadal)
to the body wall (lumbar arteries, analogous to intercostal arteries)
define the hepatic portal system
venous network that drains the GI tract and shunts the blood to the liver for processing and absorption of transported materials
what does blood exit the liver through
hepatic veins that merge with the inferior vena cava
what are the 3 sources of blood supply to the thoracic wall
axillary (supreme thoracic and lateral thoracic)
subclavian *(internal thoracic artery)
aorta (intercostal arteries)
what occurs to systolic blood pressure with age
it typically increases
what epithelium makes up the early neural tube
pseudo stratified columnar epithelium
what are the 2 cell lineages of bipotential progenitor cells
neuronal lineage–> neurons
glial lineage–> neuroglia
what is contained in the mantle layer
gray matter in the spinal cord (neural glia)
what is contained in the marginal layer
neuronal processes (axons)
what are the steps of molecular regulation of nerve differentiation in the spinal cord
- BMP4 and & serceted ni the ectoderm establish a signaling center in the roof plate
- BMP4 in the roof plate up regulates a cascade of TGF-beta proteins
- SHH from notochord establishes additional SHH signaling in the floor plate
- overlapping gradient involving the dorsal and ventral factors is established in the neural tube
define paraxial mesoderm
longitudinal blocks of tissue on either side of the notochord. it gives rise to the axial skeleton and skeletal muscle
what does the intermediate mesoderm give rise to
urogenital system
what does the lateral plate mesoderm give rise to
connective tissue and skeleton of the limbs and smooth muscle and connective tissue of viscera and blood vessels
what s the segmentation of the axial mesoderm controlled by
pulses of gene expression
what is the notch signaling network
evolutionarily conserved intercellular signalling pathway that regulates interactions between physically adjacent cells
where does notch protein accumulate
in presomitic mesoderm destined to form the next somite and then decreases as that somite is established
what regulates the boundaries of each somite
retinoid acid and combination of FGF8 and WNT3a
what are the 3 divisions of a sometime and what do they become
sclerotome: ventromedial portion of closest to the notochord
dermatome: will become the dermis
myotome: gives rise to muscles
where does resegmentation take place
sclerotome
how is the kind of vertebrae a somite will become controlled
the interaction of Hox genes
what does MyoD do
transcription factor that regulates hypaxial muscle development
what does MYF5 do
transcription factor that regulates epaxial muscle development
what does the intermediate mesoderm form
gonads (except primitive germ cells)
ducts, accessory glands of urinary and reproductive tracts
define congenital scoliosis
abnormal lateral curvature of the spine, resulting from disruption of normal vertebral development
what do ribs arise from
zones of condensed mesenchyme lateral to the body of the vertebra
what does the sternum develop from
cartilaginous sternal bars in ventral body wall (fuse with one another in cranial-caudal direction)
explain pectus carinatum
overgrowth of cartilage causing the sternum to protrude
explain pectus excavatum
assumed to be caused by overgrowth of the costal cartilage. costal cartilage overgrowth restricts the expansions of the ribs and pushes the sternum inward
how is the position of limbs along the craniocaudal axis regulated
Hox genes
what is limb outgrowth initiated by
TBX5 and FGF10 in the forelimb and TBX4 and FGF10 in the hindlimb secreted by the lateral plate mesoderm cells
what is the partial or complete absence of a limb called
part: mesomelia
all: amelia
define phocomelia
feet and hands arise very close to the trunk
what induces the formation of the AER
once limb outgrowth is initiated, BMP, expressed in ventral ectoderm induce its formation
what 2 regions control limb tissue development
AER
ZPA
what occurs in the progress zone
mitosis and limb lengthening
what does AER do
it is a thickened ectoderm on apex of limb bud
it directs limb bud organization along proximo-distal axis and matins dorsal/ventral axes
what does AER express after it is established and what do they do
FGF4 and 8: maintain the progress zone
what is the ZPA
mesodermal cells located at the base of the limb bud
what does the ZPA produce and do
produces retionic acid (which initiated expression of SHH)
it directs the organization of limb bud and patterning of digits
what is polydactyly due to
misimpression of RA and/or SHH
duplication of AER
define zone of differentiation
region of cell specialization
what happens to cells that are no longer within range of AER
they remain proximal in nature
explain syndactyly
most common limb abnormality
webbed fingers or toes
failure of programmed apoptosis in digital ray
what does the neural crest give rise to
schwann cells
how do the upper limbs rotate
90 degrees laterally
how do the lower limbs rotate
90 degrees medially
explain achondroplasia
most prevalent form of dwarfism
mutate of FGF-R3
pathological changes at epiphyseal plate: zones of proliferation and hypertrophy are narrow and disorganized
what is the difference between tendons and ligaments
tendons: attach muscle to bone, skin or another muscle
ligaments: attach bone to bone
define aponeurosis
thin, flattened sheet of tendons
define origin
less movable attachment of a muscle
define insertion
more movable attachment of the muscle
describe circular organization of fascicles
muscle is also called a sphincter because contraction of the muscle closes off the opening
describe convergent organization of fascicles
muscle has widespread muscle fibers that converge on a common attachment site and are often triangular in shape
describe parallel organization of fascicles
fascicles run parallel to its long axis (have a central body called belly/gaster)
describe pennate organization of fascicles
have one or more tendons extending through their body, and the fascicles are arranged at an oblique angle to the tendon
define effort, load and fulcrum
effort: work required
load: what is being resisted or being moved
fulcrum: point of movement (joint)
define resistance arm
distance between axis and point of resistance application
define force arm
distance between axis and point of force
describe the 3 classes of levers
1: has fulcrum in middle (between force and resistance)
2: resistance is between the fulcrum and applied force
3: force is applied between the resistance and the fulcrum (most common levers in the body)
define agonists
primer mover contracts to produce a particular movement
define antagonist
actions oppose those of the agonist
define synergist
assist the prime mover in performing its action
contraction contributes to tension exerted close to the insertion of the muscle or stabilizes the point of origin
may also assist an agonist by preventing movement at a joint and thereby stabilizing the origin of the agonist
called fixators
