Histology 2

Front 1

skeletal muscle

Back 1

bundles of long multinucleated cells with cross-striations; contraction is quick, forceful, voluntary control

Front 2

cardiac muscle

Back 2

cross-striations, elongated and branched cells bound at intercalated discs; contraction involuntary, vigorous, rhythmic

Front 3

intercalated discs

Back 3

dark-staining transverse lines that cross the chains of cardiac cells at irregular intervals where the cells join, contain many junctional complexes

Front 4

smooth muscle

Back 4

collections of fusiform cells with no striations; contractions slow and involuntary

Front 5

sarcoplasm

Back 5

cytoplasm of muscle cells

Front 6

sarcoplasmic reticulum

Back 6

smooth endoplasmic reticulum of muscle cells, specialized for Ca ion sequestration

Front 7

sarcolemma

Back 7

muscle cell membrane and external lamina

Front 8

muscle fibers

Back 8

long, cylindrical multinucleated cells with diameters of 10 to 100 um

Front 9

satellite cells

Back 9

reserve muscle progenitor cells that sit adjacent to most differentiated skeletal muscle fibers

Front 10

epimysium

Back 10

external sheath of dense CT that surrounds the entire muscle- brings large nerves, blood vessels, and lymphatics

Front 11

perimysium

Back 11

thin CT layer that surrounds each fascicle

Front 12

fascicle

Back 12

bundle of muscle fibers- functional unit in which fibers work together

Front 13

endomysium

Back 13

thin layer of reticular fibers and scattered fibroblasts that surrounds external lamina of individual muscle fibers- brings nerve fibers and capillaries

Front 14

myotendinous junction

Back 14

where epimysium is continuous with the dense regular CT of a tendon

Front 15

A bands

Back 15

anisotropic/birefringent/dark in EM, consist of thick filaments and overlapping thin filaments,

Front 16

I bands

Back 16

isotropic/light in EM, consist of the portions of the thin filaments that do not overlap the thick filaments, have titin and nebulin

Front 17

Z disc

Back 17

dark band that bisects I band

Front 18

sarcomere

Back 18

repetitive functional subunit of the contractile apparatus- Z disc to Z disc

Front 19

myofribrils

Back 19

cylindrical filament bundles in the sarcoplasm, consisting of an end-to-end arrangement of sarcomeres

Front 20

myofilaments

Back 20

thick and thin filaments in the sarcoplasm composed of myosin and F-actin

Front 21

myosin

Back 21

large complex with two identical heavy chains and two pairs of light chains

Front 22

actomyosin ATPase activity

Back 22

the function of myosin when it binds ATP and catalyzes energy release

Front 23

alpha-actinin

Back 23

actin binding protein that anchors actin filaments on the Z disc

Front 24

tropomyosin

Back 24

long coil of two polypeptide chains located in the groove between the two twisted actin strands

Front 25

troponin

Back 25

complex of three subunits: TnT- attaches to tropomyosin, TnC- binds Calcium ions, TnI- regulates actin-myosin interactions

Front 26

titin

Back 26

largest protein in the body, has scaffolding and elastic properties, supports the thick myofilaments and connects them to the Z disc

Front 27

nebulin

Back 27

large accessory protein that binds each thin myofilament laterally, helps anchor them to alpha-actinin, and specifies length of the actin polymers during myogenesis

Front 28

H zone

Back 28

lighter staining zone in A band where only rodlike portions of myosin lie and there are no thin filaments, bisected by M line

Front 29

M line

Back 29

line that bisects the H zone and contains a myomesin and creatine kinase

Front 30

myomesin

Back 30

myosin-binding protein found in M line, holds thick filaments in place

Front 31

creatine kinase

Back 31

enzyme that catalyzes transfer of phosphate groups from phosphocreatine to ADP to supply ATP for muscle contraction, found in M line

Front 32

transverse/T tubules

Back 32

long invaginations of cell membrane that encircle every myofibril near the aligned A and I band boundaries and cause uniform contraction of all myofibrils

Front 33

terminal cisterns

Back 33

expanded cisterns on either side of the t tubule that store concentrated calcium ions

Front 34

triad

Back 34

t tubule and two terminal cisterns

Front 35

rigor mortis

Back 35

rigidity of skeletal muscles after death when mitochondrial activity stops, removing ATP and making actin-myosin crossbridges stable

Front 36

motor end plate

Back 36

synaptic structure where the axonal branch forms a dilated termination in a trough on the muscle cell surface

Front 37

acetylcholine

Back 37

neurotransmitter located in synaptic vesicles

Front 38

synaptic cleft

Back 38

space between the axon and the muscle

Front 39

junctional folds

Back 39

folds in the sarcolemma that add postsynaptic surface area and transmembrane acetylcholine receptors

Front 40

acetylcholine receptor

Back 40

receptor on the sarcolemma that binds acetylcholine and has a nonselective cation channel that allows the influx of sodium ions, depolarizes the sarcolemma, and produces the muscle action potential

Front 41

acetylcholinesterase

Back 41

extracellular enzyme that removes free acetylcholine after the muscle contraction

Front 42

motor unit

Back 42

an axon and all the muscle fibers in contact with its branches

Front 43

muscle spindles

Back 43

stretch detectors in muscle fascicles, encapsulated by modified perimysium, has concentric layers of flattened cells, interstitial fluid, and intrafusal fibers

Front 44

intrafusal fibers

Back 44

thin muscle fibers in muscle spindles with nuclei

Front 45

Golgi tendon organs

Back 45

smaller encapsulated structures that enclose sensory axons that penetrate myotendinous junctions, detecting changes in tendon tensions

Front 46

myoglobin

Back 46

cytoplasmic protein abundant in slow, oxidative muscle fibers that contains iron and stores oxygen molecules

Front 47

caveolae

Back 47

short membrane invaginations of smooth muscle cells

Front 48

calmodulin

Back 48

alternative to troponin in smooth muscle cells

Front 49

myosin light-chain kinase

Back 49

Calcium ion-sensitive kinase involved in contractile mechanism

Front 50

dense bodies

Back 50

bodies associated with the sarcolemma and cytoplasm of smooth muscle cells that have alpha-actinin and are functionally similar to Z discs in skeletal muscle

Front 51

neurons

Back 51

nerve cells, which have numerous long processes

Front 52

glial cells

Back 52

cells that support and protect neurons, have short processes, and participate in neural activities, neural nutrition, and the defense of CNS cells

Front 53

central nervous system

Back 53

division of the nervous system consisting of the brain and spinal cord

Front 54

peripheral nervous system

Back 54

division of the nervous system consisting of the cranial, spinal, and peripheral nerves that conduct impulses to and from the CNS and ganglia outside the CNS

Front 55

stimuli

Back 55

environmental changes that neurons respond to

Front 56

excitable

Back 56

cells that rapidly change their electrical potential in response to stimuli

Front 57

membrane depolarization

Back 57

reversal of the ionic gradient of the plasma membrane

Front 58

action potential/nerve impulse

Back 58

propagation of the depolarization across the entire plasma membrane

Front 59

neural plate

Back 59

thickened ectoderm on the mid-dorsal side of the embryo, epithelial

Front 60

neural tube

Back 60

when neural plate bends and grows together medially

Front 61

neural crest

Back 61

large population of cells that will differentiate into cells of the PNS and other things

Front 62

perikaryon/cell body

Back 62

cell body of the neuron, which contains the nucleus and most organelles

Front 63

dendrites

Back 63

numerous elongated processes extending from the perikaryon and specialized to receive stimuli from other neurons at synapses, branch a lot

Front 64

axon

Back 64

single long process that ends at a synapse, specialized to generate and conduct nerve impulses

Front 65

multipolar

Back 65

one axon and two or more dendrites

Front 66

bipolar

Back 66

one dendrite and one axon

Front 67

unipolar/pseudounipolar

Back 67

one process that bifurcates near perikaryon, longer branch going to the PNS and other to the CNS

Front 68

anaxonic

Back 68

many dendrites but no true axon- regulate electrical changes of adjacent neurons

Front 69

sensory/afferent neurons

Back 69

receive stimuli from receptors throughout the body

Front 70

motor/efferent neurons

Back 70

send impulses to effector organs

Front 71

somatic

Back 71

nerves under voluntary control, innervate skeletal muscle

Front 72

autonomic

Back 72

nerves under involuntary control, control activities of glands, cardiac muscle, and smooth muscle

Front 73

interneurons

Back 73

99% of neurons, establish relationships among other neurons and form functional networks called circuits

Front 74

gray matter

Back 74

part of CNS in spinal cord where neuronal perikarya concentrated

Front 75

white matter

Back 75

part of CNS in spinal cord where axons concentrated

Front 76

nerves

Back 76

bundles of axons in the PNS

Front 77

neurofilaments

Back 77

intermediate filaments abundant in nerve cells

Front 78

Nissl substance

Back 78

clumps of basophilic material that consist of concentrated RER and polysomes

Front 79

dendritic spines

Back 79

short blunt structures projecting at points along dendrites that initially process synapses

Front 80

axon hillock

Back 80

pyramid-shaped region of the perikaryon where axon originates

Front 81

axolemma

Back 81

plasma membrane of an axon

Front 82

axoplasm

Back 82

cytoplasm of the axon that contains mitochondria, microtubules, neurofilaments, and SER but no RER or polyribosomes

Front 83

terminal arborization

Back 83

distal end of the axon that branches

Front 84

collaterals

Back 84

branches of interneuron and some motor neuron axons

Front 85

terminal bouton

Back 85

dilation of each branch of an axon that contacts another axon or non-nerve cell at a synapse

Front 86

anterograde transport (neuron)

Back 86

from perikaryon to synaptic terminal through axon, mediated by kinesin

Front 87

retrograde transport (neuron)

Back 87

from synaptic terminal to perikaryon, not as common, mediated by dyenin

Front 88

voltage-gated Na+ and K+ channels

Back 88

produce waves of membrane depolarization by opening and closing to allow the ion content of the cell to change

Front 89

resting potential

Back 89

little Na+ in cell compared to ECF and lots of K+ in cell

Front 90

presynaptic cell

Back 90

cell that gives off an electric signal (nerve impulse)

Front 91

postsynaptic cell

Back 91

cell affected by impulse/synapse- receives chemical signal

Front 92

neurotransmitters

Back 92

small molecules that bind specific receptor proteins to open or close ion channels

Front 93

synaptic vesicles

Back 93

vesicles that carry neurotransmitter released by exocytosis

Front 94

postsynaptic cell membrane

Back 94

has receptors for transmitter and ion channels

Front 95

excitatory synapses

Back 95

cause Na+ channels to open, resulting in depolarization

Front 96

axosomatic

Back 96

synapse between axon and cell body

Front 97

axodendritic

Back 97

synapse between axon and dendrite

Front 98

axoaxonic

Back 98

synapse between axon and axon

Front 99

glial cells

Back 99

cells that support neuronal survival and activities, develop from progenitor cells in the embryonic neural plate

Front 100

neuropil

Back 100

cellular processes of neurons and glial cells that make up a fibrous intercellular network

Front 101

oligodendrocytes

Back 101

glial cells that produce the myelin sheaths around axons, in white matter

Front 102

astrocytes

Back 102

glial cells that have a large umber of radiating processes, are in the CNS

Front 103

fibrous astrocytes

Back 103

astrocytes with few, long processes- in white matter

Front 104

protoplasmic astrocytes

Back 104

many shorter, branched processes, in the gray matter

Front 105

glial fibrillary acid protein

Back 105

protein that makes up intermediate fibers of astrocyte processes, common source of brain tumors

Front 106

inhibitory synapse

Back 106

opens Cl- or other anion channels to hyperpolarize cell membrane

Front 107

perivascular feet

Back 107

expanded ends of astrocyte processes that cover capillary endothelial cells

Front 108

glial limiting membrane

Back 108

barrier layer that lines the meninges, formed from expanded processes of astrocytes

Front 109

ependymal cells

Back 109

columnar or cuboidal glial cells that line the ventricles of the brain and the central canal of the spinal cord-move and absorb CSF

Front 110

microglia

Back 110

small glial cells with short irregular processes that secrete immunoregulatory cytokines and act as the immune defense in the CNS

Front 111

Schwann cells

Back 111

glial cells in PNS that myelinate axons and act as support

Front 112

satellite cells of ganglia

Back 112

glial cells in the PNS that form an intimate covering layer over the large neuronal cell bodies in the ganglia of PNS

Front 113

tract

Back 113

groups of myelinated axons in white matter

Front 114

white matter

Back 114

myelinated axons and oligodendrocytes, very few neuronal bodies, some astrocytes and microglia

Front 115

gray matter

Back 115

neuronal cell bodies, dendrites, unmyelinated parts of axons, where synapses occur

Front 116

cerebellar cortex

Back 116

part of brain that coordinates muscular activity throughout the body, and has three layers: outer molecular, Purkinje, inner granular

Front 117

cerebral cortex

Back 117

composed of six layers, integrates sensory info and initiates voluntary motor responses

Front 118

pyramidal neurons

Back 118

efferent neurons that comprise a layer in the cerebral cortex

Front 119

molecular layer

Back 119

outer layer of cerebellar cortex

Front 120

Purkinje cells

Back 120

large neurons that compose the central layer of the cerebellar cortex

Front 121

granule layer

Back 121

inner layer of the cerebellar cortex

Front 122

central canal

Back 122

opening in the spinal cord that develops from the lumen of the embryonic neural tube, continuous with ventricles, contains CSF, lined with ependymal cells

Front 123

anterior horns

Back 123

formed from gray matter, motor neurons

Front 124

posterior horns

Back 124

gray matter, sensory fibers

Front 125

meninges

Back 125

membranes of connective tissue between bones and nervous tissue: dura mater, arachnoid mater, pia mater

Front 126

dura mater

Back 126

thick external mater, dense, fibroelastic CT continuous with the periosteum of the skull

Front 127

subdural space

Back 127

space that separates the arachnoid mater from the dura mater

Front 128

arachnoid mater

Back 128

middle mater with 2 layers: sheet of CT and a system of loosely arranged trabeculae composed of collagen and fibroblasts

Front 129

subarachnoid space

Back 129

cavity surrounding trabeculae filled with CSF that communicates with ventricles of the brain

Front 130

arachnoid villi

Back 130

CSF filled protrusions of the arachnoid into the venous sinuses that are covered by vascular endothelial cells

Front 131

pia mater

Back 131

innermost mater that consists of flattened, mesenchymally derived cells

Front 132

perivascular spaces

Back 132

spaces covered by pia mater that blood vessels penetrate

Front 133

blood-brain barrier

Back 133

functional barrier that allows tight control over what passes from blood to CNS tissue, consists of capillary endothelium sealed with occluding junctions

Front 134

limiting layer of perivascular astrocytic feet

Back 134

completely envelopes the basal lamina of the capillaries in CNS regions- regulates passage of ions and molecules from blood to brain

Front 135

choroid plexus

Back 135

highly specialized tissue with elaborate folds and many villi in the ventricles that removes water from blood and makes CSF

Front 136

CSF

Back 136

clear fluid, contains Na+, K+ and Cl-, and a few lymphocytes- fills the ventricles and subarachnoid space to provide ions for neuronal activity and avoid physical shocks

Front 137

chromatolysis

Back 137

onset of regeneration: perikaryon swells slightly, Nissl substance diminishes, nucleus peripheral, etc.

Front 138

neurotrophins

Back 138

growth factors produced by neurons and glial cells

Front 139

autonomic ganglia

Back 139

control activity of smooth muscle, small bulbous dilations in autonomic nerves, layer of satellite cells

Front 140

intramural ganglia

Back 140

ganglia in the wall of the digestive tract

Front 141

sensory ganglia

Back 141

ganglia that receive afferent impulses, have large neuronal bodies with satellite cells and a CT capsule

Front 142

epineurium

Back 142

dense, irregular fibrous coat of entire nerves

Front 143

perineurium

Back 143

CT layer around nerve fascicles that contain flat fibrocytes joined by tight junctions

Front 144

fascicles

Back 144

bundles of axons with Schwann cells and endoneurium

Front 145

endoneurium

Back 145

reticular fibers, scattered fibroblasts, and capillaries that surround one Schwann cell

Front 146

nerve

Back 146

bundle of nerve fibers

Front 147

unmyelinated fibers

Back 147

axons enveloped in a simple fold of Schwann cell

Front 148

internodal segment

Back 148

length of an axon ensheathed by one Schwann cell

Front 149

nerve fibers

Back 149

analagous to tracts in CNS, axons enclosed in sheaths of Schwann cells

Front 150

myelin sheath

Back 150

layers of Schwann cell membrane fused together around an axon

Front 151

major dense lines

Back 151

fused, protein-rich cytoplasmic surfaces of the Schwann cell membrane

Front 152

myelin cleft

Back 152

separations in cytoplasmic surfaces to allow cytoplasm to move

Front 153

nodes of Ranvier/nodal gaps

Back 153

gaps between adjacent Schwann cells on a single axon

Front 154

cardiovascular system

Back 154

consists of heart, arteries, veins, arterioles, venules, and capillaries- circulates blood through body

Front 155

arteries

Back 155

vessels that carry blood to the tissues from the heart

Front 156

capillaries

Back 156

the smallest vessels that are the sites of O2, CO2, nutrient, and waste exchange between blood and tissues

Front 157

microvasculature

Back 157

network of capillaries, arterioles, and venules that anastomose

Front 158

veins

Back 158

vessels that carry blood from tissue to heart

Front 159

pulmonary circulation

Back 159

division of the circulatory system where blood is oxygenated in the lungs

Front 160

systemic circulation

Back 160

division of the circulatory system where blood brings nutrients and removes waste in tissues throughout the body

Front 161

lymphatic vascular system

Back 161

system that returns fluid from tissue spaces back to the heart

Front 162

lymphatic capillaries

Back 162

thin-walled, closed-ended tubules carrying lymph

Front 163

endothelium

Back 163

single layer of squamous epithelium that lines all components of the blood and lymphatic systems- selectively permeable

Front 164

ventricles

Back 164

chambers of heart that pump blood to systemic and pulmonary circulation

Front 165

atria

Back 165

chambers of the heart that receive blood from the body and pulmonary veins

Front 166

endocardium

Back 166

inner layer of heart wall- consists of thin endothelial layer with CT, a middle myoelastic layer of smooth muscle and connective tissue, and a deep layer of connective tissue

Front 167

subendocardial layer

Back 167

deep CT layer of endocardium that merges with the myocardium

Front 168

myocardium

Back 168

thickest layer of heart wall that consists of cardiac muscle surrounding heart, thicker around ventricles

Front 169

epicardium

Back 169

simple squamous mesothelium with loose CT, same as visceral layer of the pericardium

Front 170

visceral layer of pericardium

Back 170

membrane surrounding heart, known as epicardium

Front 171

parietal layer of pericardium

Back 171

outer layer of membrane surrounding heart

Front 172

cardiac skeleton

Back 172

dense irregular fibrous connective tissue that anchors and supports heart valves, provides points for insertion of cardiac muscle, and helps coordinates heartbeats

Front 173

conducting system of the heart/subendocardial conducting network

Back 173

generates and propagates waves of depolarization that go to myocardium- heartbeat

Front 174

sinoatrial node

Back 174

node in right atria of specialized cardiac muscle cells that creates initial impulse

Front 175

atrioventricular node

Back 175

in floor of right atrium, spreads depolarization

Front 176

Atrioventricular bundle

Back 176

takes impulse from AV node to subendocardial conducting network

Front 177

Purkinje fibers

Back 177

myofibers of subendocardial conducting network, pale staining, mingle with contractile muscle fibers, and cause contraction

Front 178

vasa vasorum

Back 178

blood vessels within the tunica adventitia in larger vessels

Front 179

tunica adventitia

Back 179

outer layer of vessels made up of collagen I and elastic fibers

Front 180

tunica media

Back 180

middle layer of vessel walls made up of smooth muscles, controls blood pressure, has elastic, reticular fibers, and proteoglycans

Front 181

internal elastic lamina

Back 181

limiting layer of tunica intima made of elastic

Front 182

tunica intima

Back 182

endothelium and loose CT subendothelial layer- inner layer of vascular wall

Front 183

angiopoietins

Back 183

growth factors that stimulate endothelial cells to attract smooth muscle fibers

Front 184

angiogenesis

Back 184

process of sprouting capillaries and vessels from existing ones

Front 185

vasculogenesis

Back 185

creation of vasculature from embryonic mesenchyme

Front 186

endothelium

Back 186

specialized epithelium that acts as a semipermeable barrier between blood plasma and interstitial tissue fluid

Front 187

nonthrombogenic surface

Back 187

endothelium- surface where blood will not clot

Front 188

P-selectin

Back 188

secreted to activate white blood cells in time of injury

Front 189

interleukins

Back 189

secreted by endothelial cells, affect the activity of local white blood cells during inflammation

Front 190

elastic/conducting arteries

Back 190

aorta, pulmonary artery, and large branches

Front 191

systole

Back 191

ventricular contraction, causes blood to move forcefully through arteries

Front 192

diastole

Back 192

ventricular relaxation, elastin passively rebounds in elastic arteries

Front 193

carotid sinuses

Back 193

slight dilations of the internal carotid arteries- act as baroreceptors

Front 194

baroreceptors

Back 194

monitor arterial blood pressure

Front 195

chemoreceptors

Back 195

monitor blood levels of CO2 and O2 and hydrogen ion concentrations

Front 196

carotid bodies and aortic bodies

Back 196

sites for chemoreceptors in the internal carotid arteries and the aortic arch

Front 197

paraganglia

Back 197

carotid bodies and aortic bodies that are parts of the autonomic nervous system and have rich capillary networks

Front 198

glomus (type I) cells

Back 198

large, neural crest-derived cells surrounding capillaries around carotid and aortic bodies- filled with dense-core vesicles containing neurotransmitters that regulate blood chemical levels

Front 199

thoracic duct

Back 199

lymphatic trunk that enters the cardiovascular system between the left subclavian vein and the left internal jugular vein

Front 200

right lymphatic duct

Back 200

lymphatic trunk that enters the cardiovascular system between the right subclavian vein and right internal jugular vein

Front 201

lymphatic vessels

Back 201

similar structure to veins except with thinner walls and no distinct separation of tunics and more internal valves, often dilated with lymph, bring lymph back from lymphatic capillaries to lymphatic ducts

Front 202

lymphatic capillaries

Back 202

closed-ended vessels with a single layer of endothelial cells on an incomplete basal lamina that collect lymph in tissues

Front 203

lymph

Back 203

excess interstitial fluid in tissue spaces that is usually rich in light staining proteins

Front 204

large veins

Back 204

big venous trunks with a well-developed intima, thin media with alternating muscle and CT layers, and thick adventitia with longitudinal muscle cell bundles; run with elastic arteries

Front 205

small and medium veins

Back 205

veins that correspond to muscular arteries, have diameters of 10mm or less, have a thin subendothelial layer, well-developed adventitia, and a media with muscle cell bundles and reticular and elastic fibers

Front 206

veins

Back 206

vessels that carry blood back to heart, have valves to prevent backflow

Front 207

muscular venules

Back 207

venules with a tunica media consisting of 2-3 smooth muscle layers, large lumen and thin walls

Front 208

collecting venules

Back 208

convergence of postcapillary venules, have more contractile cells than the former

Front 209

postcapillary venules

Back 209

structurally similar to capillaries, have pericytes, slightly larger, primary site where white blood cells adhere to endothelium and leave circulation to treat infection/injury

Front 210

pericytes

Back 210

mesenchymal cells with long cytoplasmic processes that partly surround the endothelial layer of capillaries and postcapillary venules; make their own basal lamina and have a contractile function

Front 211

discontinuous capillaries/sinusoids

Back 211

permit maximal exchange of macromolecules, have endothelial cells with perforations, gaps between cells and a discontinuous basal lamina, have a larger diameter, found in liver, spleen, bone marrow, and some endocrine organs

Front 212

fenestrated capillaries

Back 212

sieve-like structure that allows more molecular exchange- endothelial cells have perforations sometimes covered by proteoglycan diaphragms, have a continuous basal lamina, found in kidneys, intestine, choroid plexus, and endocrine glands

Front 213

continuous capillaries

Back 213

many tight occluding junctions, slightly overlapping endothelial cells; most common type of capillary; found in muscle, CT, lungs, exocrine glands, and nervous tissue

Front 214

precapillary sphincters

Back 214

muscle fibers that contract or relax rhythmically to control entry of blood into capillaries

Front 215

thoroughfare channels

Back 215

channels that connect metarterioles to postcapillary venules and bypass capillaries

Front 216

metarterioles

Back 216

terminal arteriole branches that supply capillary beds

Front 217

capillary beds

Back 217

groups of capillaries around organs, size and structure depends on metabolic activity of organ

Front 218

capillaries

Back 218

small vessels that regulate metabolic exchange between blood and surrounding tissues

Front 219

portal system

Back 219

system in which a portal vein connects two capillary beds- transport of hormones and nutrients

Front 220

arteriovenous shunts

Back 220

a way to bypass capillary networks, media and adventitia thicker

Front 221

microvasculature

Back 221

where exchanges between blood and tissue fluid occur

Front 222

arterioles

Back 222

smallest artery branches- 1-2 smooth muscle layers, beginning of microvasculature