Mini 2: Histology

Front 1

functions of blood?

Back 1

-transport
-stabilization of pH and electrolyte conc. in interstitial fluids
-body temp. regulation
-pathway for migration of WBCs btwn. various connective tissue compartments

Front 2

materials transported via blood?

Back 2

O2, CO2, hormones, waste, nutrients, enzymes

Front 3

amount of blood in adult?

Back 3

5-6 liters
(~7% total body weight)

Front 4

3 components of blood?

Back 4

-RBCs (erythrocytes)
-WBCs (leukocytes)
-platelets (thrombocytes)

Front 5

functions of...
RBCs?
WBCs?
platelets?

Back 5

-RBCs=oxygen transport
-WBCs=defense against microorganisms
-platelets=blood clotting

Front 6

the 3 components of blood are suspended in a yellowish clear liquid composed of water, proteins, and other solutes called...

Back 6

plasma

Front 7

plasma is composed of...

Back 7

water (90%)
proteins (7%)
electrolytes
nutrients (2%)
gases
hormones, enzymes, vitamins, wastes

Front 8

plasma is _?_% of total blood volume.

Back 8

55%

Front 9

cellular components make up _?_% of total blood volume

Back 9

45%

-buffy coat = WBCs and platelets
-RBCs

Front 10

the clear fluid that remains after blood coagulation is ___.

anticoagulants and centrifugation yield___.

Back 10

serum

plasma

Front 11

blood smear is stained with ___.

Back 11

Wright's stain

Front 12

hemoglobin results in RBCs characteristic ___ staining property.

Back 12

acidophilic

Front 13

what type of dye is methylene blue and what color does it stain structures?

Back 13

-basic/positively charged dye
-it stains acidic (neg. charged)
-blue

Front 14

what cell strucures are neg. charged and thus stain w/ methylene blue?

Back 14

DNA (in nucleus), RNA (in cyto), specific granules of basophils.

these structures are said to be basophilic.

Front 15

what type of dye is eosin and what color does it stain structures?

Back 15

-acidic/neg charged dye
-it stains basic (pos. charged)
-pink

Front 16

what structures stain pink w/ eosin?

Back 16

hemoglobin, specific granules of eosinophils.

these structures are said to be acidophilic or eosinophilic.

Front 17

substances formed as a result of oxidation of methylene blue are called ___.

Back 17

azures

compounds are colored a reddish blue by binding to azures.

Front 18

primary function of RBCs

Back 18

transport of O2 and CO2.

Front 19

RBCs make up __% of all blood cells.

RBCs form __%-__% of the volume of whole blood.

Back 19

99%

35-45%

Front 20

hematocrit is...

Back 20

percentage by volume of packed RBCs in a given sample of blood after centrifugation.

Front 21

erythropoietin is...

Back 21

-a hormone that adjusts RBC production to match O2 demand.
-secreted mainly by kidneys in adults and by the liver in the fetus.

Front 22

how does the shape of RBCs help its function?

Back 22

the biconcave shape of RBCs maximizes their SA/volume ratio, thus, maximizing O2 exchange.

Front 23

how do RBCs get energy once they are formed?

Back 23

-get energy through glucose in plasma (via cytoplasmic glycolysis, since they don't have mitochondria)
-during formation, RBCs lose nucleus and organelles, only keeping the cytoskeleton.

Front 24

life span of RBCs?

Back 24

-120 days
-cell mb. ruptures or aged cell is phagocytosed in spleen, liver, and bone marrow.
-1% RBCs replaced daily (new ones = reticulocytes)

Front 25

hemoglobin makes up __% of RBCs protein content.

Back 25

95% (30% weight of RBC)

Front 26

RBC membranes are organized with what 2 integral membrane proteins?

Back 26

-glycophorins
-band 3 proteins (ion transporter that transports bicarbonate out of the RBC)

Front 27

hereditary spherocytosis (HS)

Back 27

-somatic dominant trait
-defective spectrin or ankyrin, leads to abnormal spectrin lattice binding to band 4.1 protein or the absence of ankyrin and spectrin binding.
-RBCs in HS do not form their normal biconcave shape (they are round and convex)
-RBCs are abnormally fragie, rapidly break down, and transport less O2.

Front 28

anemia (hemoglobin disorder)

Back 28

-most common blood disorder
-inadequate Hb supply
-causes weakness, pallor, and breathlessness.
-increased destruction
-decreased production, iron, Vit. B12

Front 29

sickle cell disease (Hb disease)

Back 29

-single pt. mutation (GAA->GUA, valine substitutes glutamic acid)
-occurs in gene that encodes the beta chain of Hb A.
-sickled blood cells are more rigid and more readily adhere to endothelium, creating obstruction of blood vessels -> severe O2 shortage in tissues.

Front 30

WBCs/leukocytes are made in...

Back 30

bone marrow

Front 31

WBCs are active in...

Back 31

tissues

Front 32

diapedesis

Back 32

WBCs leave the bloodstream by migrating btwn. endothelial cells of the blood vessels

Front 33

classification of WBCs is based on presence or absence of specific granules

Back 33

-granulocytes(myeloid cells): have specific granules (includes neutrophils, eosinophils, and basophils)
-agranulocytes: have no specific granules but do have nonspecific azurophilic granules (lymphocytes and monocytes)

Front 34

granulocytes

Back 34

-have specific functions
-are nondividing terminal cells w/ a life span of a few days
-die by apoptosis in connective tissue
-include neutrophils, eosinophils, and basophils

Front 35

non-specific (azurophilic) granules found in both granulocytes and agranulocytes are known as ____.

Back 35

lysosomes

Front 36

neutrophils

Back 36

-most numerous of WBCs (60-70%)
-short-lived (half-life=6-7 hrs, lifespan=1-4 days)
-lobes of their multilobed nucleus are connected to each other by slender chromatin threads
-in females, nucleus has a small appendage (Barr body) but this is not evident in every neutrophil.
-first cells to appear in acute bacterial infections
-inactive and spherical while circulating
-they are active phagocytes of bacteria
-select bacteria/particles to be phagocytosed by opsonization or chemoattractant
-able to survive in anaerobic env't. -> can kill bacteria and help clean up debris in poorly oxygenated regions (inflamed or necrotic tissue)

Front 37

azurophilic granules

Back 37

-aka primary granules
-in all WBCs
-are lysosomes (contain myeloperoxidase)

Front 38

specific granules

Back 38

-aka secondary granules
-smallest granules w/ various enzymes and antimicrobic agents (lysozyme, lactoferrin)

Front 39

chronic granulomatous disease (CGD)

Back 39

-inherited disorder of phagocytic cells
-results from inability of phagocytes to produce bactericidal superoxide anions (O2-)
-leads to recurrent life-threatening bacterial and fungal infections
-caused by a defect in the NADPH oxidase of phagocytes
-refers to characteristic granulomas that develop in response to chronic inflammation.
-diagnostic test uses the dye nitroblue tratazolium (NBT)

Front 40

eosinophils

Back 40

-4% of WBCs
-sausage-shaped bilobed nucleus in which 2 lobes are connected by a thin chromatin strand and nuclear envelope
-function in parasitic infections and phagocytosing antigen-antibody complexes
-round cells containing large pink specific granules
-also contain non-specific granules (lysosomes)

Front 41

major basic protein (MBP)

Back 41

-50% of total granule protein
-highly basic nature contributes to its toxicity

Front 42

eosinophilia

Back 42

-increase in the number of eosinophils in blood
-assoc. w/ parasitic infection and allergic reactions

Front 43

basophils

Back 43

-less than 1% of WBCs
-round cells w/ S-shaped nucleus
-# of basophils increases during infection
-have several surface receptors on their plasmalemma (including IgE receptors)
-supplement the functions of mast cells in immediate hypersensitivity reactions (anaphylaxis)
-specific granules of basophils contain heparin and histamine.

Front 44

lymphocytes

Back 44

-20-25% of circulating WBCs
-round cells w/ slightly indented, dense, round nucleus that occupies most of the cell
-contains a few azurophilic granules but no specific granules
-subdivided into 1. B cells 2. T cells 3. null cells(circulating stem cells and natural killer cells)
-function in immune response
-only types of leukocytes that return from tissues back to blood after diapedesis

Front 45

monocytes

Back 45

-constitute 3-8% of WBCs
-largest circulating blood cells
-large, acentric, kidney-shaped nucleus
-precursor cells of macrophages (differentiate into macrophages after leaving blood vessels and entering CT)
-has numerous azurophilic granules (lysosomes)
-no specific granules
-has occasional vacuole-like spaces
-slightly basophilic cytoplasm

Front 46

platelets

Back 46

-aka thrombocytes
-nonnucleated, disklike cell fragments
-critical for blood clotting
-lifespan = 14 days
-originate from fragmentation of giant polyploid megakaryocytes that reside in bone marrow
-promote blood clotting and help repair gaps in blood vessel walls, preventing blood loss.

Front 47

Skeletal muscle is innervated by this type of motor neurons.

Back 47

Somatic motor neurons

Front 48

Unlike cardiac and smooth muscle, skeletal muscle cell contain __________ of nuclei.

Back 48

Hundreds

Front 49

Hundred of nuclei within the skeletal muscle cell are an example of a _______________.

Back 49

Syncytium

Front 50

The relative strength of a skeletal muscle fiber depends on its _____________.

The strength of an ENTIRE MUSCLE is a function of the _____________ and ___________ of its component fibers.

Back 50

Number, thickness

Front 51

Damage to skeletal tissue can be overcome if two properties of the muscle fiber are intact.

Name them.

Back 51

External lamina and satellite cells

Front 52

What is the function of satellite cells?

Back 52

They are the resident precursor cells and as a result can divide to form new muscle cells after tissue damage

Front 53

Name the three types of skeletal muscle fibers and their properties.

Back 53

Type I (red):

* Smallest diameter
* Slow, repetitive, not easily fatigued
* Rich in myoglobin, mitochondria

Type IIa:

* Intermediate

Type IIb (white):

* Largest diameter
* Fast, not repetitive, easily fatigued
* Poor in myoglobin, mitochondria

Front 54

Name the three coverings of muscle fibers.

Which of the coverings has connective tissue and capillaries associated with it?

Back 54

Endomysium, Perimysium, Epimysium

Only the perimysium is associated with connective tissue and capillaries

Front 55

A myofibril is composed of _________ and _______ filaments.

Back 55

Thick (myosin)
Thin (actin)

Front 56

Together with accessory proteins, actin and myosin form this functional unit.

Back 56

Sarcomere

Front 57

The striations within skeletal muscle fibers can be easily summed up into dark and light bands.

Given A, H, and I bands, which directly associates with dark and which with light?

Back 57

Light bands: I band
Dark bands: A band

Front 58

This intermediate filament holds skeletal muscle fibers together.

Back 58

Desmin

Front 59

The heads of the myosin II molecules are pointing [away | towards] the center of the sarcomere

Back 59

Away

Front 60

These two protein mask the myosin binding site on actin filaments.

Back 60

Troponin and tropomyosin

Front 61

In order to open the myosin binding site on the actin filament, Ca++ is released and bind to this protein.

Back 61

Troponin C

Front 62

The myosin molecule can have its head and mid-section hinged ready for the "stroke" motion.

What two proteases help in this regard? Their action creates these regions.

Back 62

Papain:

* Creates a hinge between the head (S1) and mid-section of the myosin (S2)
* The head contain two heavy chains and two pairs of light chains


Trypsin:

* Creates a hinge in the mid-section (heavy meromyosin and light meromyosin)

Front 63

These two proteins are associated with the actin and myosin filaments.

HINT: They help to regulate stretching and lengthening.

Back 63

Nebulin - actin
Titin - myosin

Front 64

This protein binds to the end of the actin filament and prevents it from growing.

Back 64

Tropomodulin

Front 65

This enzyme provides a ready supply of ATP at the M line.

Back 65

Creatine kinase

Front 66

This protein binds to actin and aids in the transmission of contraction to the epimysium.

Back 66

Dystrophin

Front 67

Skeletal muscles fibers are depolarized through this triad of components.

Back 67

2 terminal cisternae
1 T-tubule

Front 68

What is the function of the sarcoplasmic reticulum?

Back 68

Store intracellular calcium and release it when the voltage-gated Ca++ channels are depolarized

Front 69

Impulses from the nerve fiber are transmitted to the muscle cell through _______________.

Back 69

Neuromuscular junction (NMJ)

Front 70

At what angle is the myosin head bound to the action filament?

Back 70

60 degrees

Front 71

Explain Huxley's sliding filament theory.

Back 71

During contraction, the lengths of the individual myofilaments do not change.

The two Z lines are brought closer together as the thick and thin filaments slide past each other.

A band remains the same
I and H bands diminish in width

Front 72

CLINICAL CORRELATION:

What does Botulism Toxin do?

Back 72

It interferes with the release of acetylcholine leading to muscle paralysis

Front 73

CLINICAL CORRELATION:

What is Myasthenia Gravis?

Back 73

It is an autoimmune disorder where self antibodies bind to the acetylcholine receptors on the post-synaptic membrane

Front 74

What is the function of muscle spindles and golgi tendon organs?

Back 74

They both detect change in the length of the tendon/muscle, degree of tension.

Their main function is to keep the muscle fibers and tendons from tearing

Front 75

Where are muscle spindles and golgi tendons located?

Back 75

Within the muscle fibers

Front 76

What are the two types of intrafusal fibers?

Back 76

* Nuclear bag fiber
* Nuclear chain fiber

Front 77

This disc is unique to cardiac muscle fibers.

Back 77

Intercalated discs

Front 78

What do intercalated discs represent?

Back 78

Specialized cell junctions between cardiac muscle cells.

Front 79

What kinds of junctions are in the transverse and the longitudinal portions of the intercalated disc?

Back 79

Transverse: Desmosome, Adhering junction, gap junction

Longitudinal: Gap junction

Front 80

Intercalated discs are analogous to _____________.

Back 80

Z lines

Front 81

What is the function of the transverse portion of the intercalated disc?

Back 81

To anchor actin filaments and bind cells together

Front 82

What is the function of the longitudinal portion of the intercalated disc?

Back 82

To spread depolarization

Front 83

What are lipofuscin granules?

Back 83

It is considered one of the aging or "wear and tear" pigments.

Front 84

What are TWO major differences between skeletal and cardiac muscle?

Back 84

1. Cardiac muscle only have diads instead of triads (2 terminal cistarna and 1 T-tubule) -- diads are located within the vicinity of Z lines

2. Ca++ supply is transported into cardiac muscle cell from the extracellular fluid

This is called the "trigger calcium"

Front 85

Heart beat is initiated, regulated, and coordinated by these types of cells

Back 85

Cardiac conducting cells

Front 86

Sympathetic and parasympathetic fibers do this ______________.

Back 86

Modify the rate of intrinsic cardiac muscle contraction

Front 87

Smooth muscle fiber can be found in these types of organs.

List a few.

Back 87

Hollow organs: GI tract, blood vessels, secretory ducts, uterus

Front 88

Where are cardiac endocrine cells normally found?

Back 88

Intraventricular septum and the walls of the atria

Front 89

What is produced by cardiac endocrine cells?

What is its function?

Back 89

Antrial natriuretic polypeptide

* It decreases the renal tubes ability to re-absorb Na+ and H2O

* Increase Na+ and H2O loss (natriuresis and diuresis)

Front 90

Smooth muscles cells lack these elements of skeletal and cardiac muscles.

Back 90

Sarcomeres, myofibrils, troponin

Front 91

Do smooth muscles have thin and thick filaments?

What are they attached to?

Back 91

Yes

Dense bodies

Front 92

Dense bodies are composed of ___________ and resemeble the ___________ of striated muscles.

Back 92

alpha-actinin, Z lines

Front 93

What is the function of the Caveolae in smooth muscles?

Back 93

Function in the sequestering and release of Ca++

Front 94

In smooth muscle, the myosin molecule is in the inactive state. What enzyme helps to activate it?

Back 94

MLCK

Front 95

Explain how the contraction of smooth muscle.

Back 95

1. Nerve signal activates release of Ca++ from caveolae.

2. Ca++ binds to calmodulin

3. Calmodulin-Ca++ complex activates MLCK

4. Conformational change occurs in myosin unmasking the myosin actin-binding site

5. Actin binds on the S1 of myosin

6. Contraction

Front 96

Name the two nonneural factors involved in modulating the activity of MLCK.

Back 96

Estrogen increases the concentration of cAMP -> activating MLCK

Progresterone decreases the concentration of cAMP -> deactivating MLCK

Front 97

Name two types of smooth muscle and describe them.

Back 97

1. Multiunit

* Richly innervated - every muscle cell receives individual innervation

* Specialized for precise, graded contraction

* Found in iris, vas deferens


2. Unitary

* Minimal innervation
* Impulse transmitted via nexus (gap junction)
* Regulated by oxytocin, stretching
* Found in the wall of hollow organs

Front 98

Name the two types of contractile nonmuscle cells in smooth muscles.

Back 98

1. Myoepithelial


2. Myofibroblasts

Front 99

What is the function of myoepithelial cells?

Back 99

To push secretions out of the cells and into ducts.

- Seen in mammary glands, lacrimal glands

Front 100

What is the function of myofibroblasts?

Back 100

To contract/close wounds by decreasing the size of the opening

Front 101

The lateral plate mesoderm splits into two layers.

Name them and their function.

Back 101

1. Somatic Mesoderm [BODY WALL]
- Forms the inner lining of the body wall, bones, and connective tissue
- Associated with ectoderm

2. Splanchnic Mesoderm [GUT WALL]
- Form the mesothelial covering of the viscera.

Front 102

The musculoskeletal system develops from three sources.

Name them.

Back 102

1. Lateral plate mesoderm

2. Paraxial mesoderm

3. Neural crest cells

Front 103

What are the two types of bone formation?

List the differences.

Back 103

1. Intramembranous ossification

- Mesenchyme precursor ossifies directly into bone


2. Endochondral ossification

- Preformed hyaline cartilage directly ossifies into bone

Front 104

The skull can be divided into two parts and those parts can be further subdivided into separate portions.

Name them.

Back 104

1. Neurocranium

a. Membraneous neurocranium
b. Chondrocranium
- Prechordal neurocranium
- Chordal neurocranium

2. Viscerocranium

Front 105

The membranous neurocranium is equally derived from ____________ and _____________.

Back 105

Neural crest cells, paraxial mesoderm

Front 106

The membranous neurocranium undergoes this type of ossification.

Back 106

Membranous ossification

Front 107

Define the following terms:

1. Cranioschisis
2. Cranial meningocele
3. Meningoencephalocele

Back 107

1. Cranioschisis: Failure of the cranial neuropore to close; brain tissue exposed to amnion = anencephaly

2. Cranial meningocele: The meninges herniate through the defect

3. Meningoencephalocele: The meninges and brain tissue herniate through the defect

Front 108

At birth, the skull bones are separated by __________.

Back 108

Sutures

Front 109

Name the three major sutures of the head.

Back 109

Sagittal
Coronal
Lamboid

Front 110

The sagittal suture is derived from this cell type.

The coronal suture is derived from this cell type.

Back 110

Neural crest cells

Paraxial mesoderm

Front 111

What is the term for an area where two or more bones meet and the sutures are wide?

Back 111

Fontanelle

Front 112

What is the most prominent fontanelle?

Back 112

Anterior fontanelle

Front 113

Define the following terms:

* Craniosynostosis
* Scaphocephaly
* Acrocephaly
* Brachycephaly

Back 113

Craniosynostosis: The premature closure of sutures

Scaphocephaly: Closure of the sagittal suture

Acrocephaly: Closure of the coronal suture

Brachycephaly: Close of the coronal and lamboid suture

Front 114

The chondocranium is made of the following two separate cartilages.

Name them.

Back 114

Prechordal and chordal chondrocranium

Front 115

What is the cellular origin of the prechordal and chordal chrondocranium?

Back 115

Prechordal: neural crest cells

Chordal: paraxial mesoderm

Front 116

What is the type of ossification that the chondocranium undergoes?

Back 116

Endochondral ossification

Front 117

What is the cellular origin of the viscerocranium?

Back 117

Neural crest cells

Front 118

What forms from the first and second pharyngeal arches?

Back 118

First arch:

Dorsal portion: maxilla, zygomatic bone, temporal bone

Ventral portion: mandibular process, mandible


Second arch:

Ossicles - incus, stapes, malleus

Front 119

Which portion of the mesoderm aids in the development of bone and connective tissue?

Back 119

Lateral plate mesoderm - somatic layer

Front 120

What is the function of the apical ectodermal ridge (AER)?

Back 120

It is essential for limb growth

Front 121

On the limb, where is the AER located?

Back 121

At the most distal apex

Front 122

The AER maintains this zone of highly proliferative cells.

Back 122

Progress zone

Front 123

What occurs as the AER moves distally?

Back 123

The proximal edge of the limb begins to forms muscles and cartilage

Front 124

When are handplates and footplates formed during the embryogenesis?

Back 124

6th week - first constriction

Front 125

What occurs at the 8th week of embryogenesis with respect to hand and footplates?

Back 125

Second constriction - limb extremities recognized

Formation of separate digits on hands and feet

Front 126

What occurs at the 7th week of embryogenesis with respect to the hands and feet?

Back 126

ULL - Upper Limb Lateral rotation of 90 degrees

LLM - Lower Limb Medial rotation of 90 degrees

Front 127

Define the following terms:

* Dactylys
* Brachydactyly
* Syndactyly
* Polydactyly
* Cleft hand foot

Back 127

Dactylys: Limb defects affecting the digits

Brachydactyly: Shortening of the digits

Syndactyly: Fusion of two or more digits

Polydactyly: Extra digits on the upper or lower limb

Cleft hand foot: Lobster claw deformity

Front 128

In the 1960s, this drug was given for resolving the symptoms of morning sickness.

Back 128

Thalidomide

Front 129

Thalidomide was found to cause limb defects in fetuses.

Define the terms associated with limb defects:

* Meromelia
* Amelia
* Phocomelia
* Sirenomelia

Back 129

Meromelia: Partial absence of the limbs

Amelia: Complete absence of the limbs

Phocomelia: Rudimentary hands/feet on trunk

Sirenomelia: Mermaid syndrome

Front 130

Cartilage differentiates from ___________ to form bones.

The process of bone formation is called ____________.

Back 130

Mesenchyme, lateral plate mesoderm - somatic mesoderm

Front 131

All long bones of the fetus are completed by the _______ week.

Back 131

12th

Front 132

Ossification of the fetal bones begins at the _____________ and progress to the ______________.

Back 132

Diaphyses, Cartilage anlage

Front 133

At birth, the ___________ is ossified and the _____________ is still cartilaginous.

Back 133

Diaphyses, Epiphyses

Front 134

Limb development is regulated along 3 axes.

Name them.

Back 134

Anterior-posterior
Dorsal-ventral
Proximal-distal

Front 135

Describe the patterning of the proximal-distal axis.

Back 135

* Limb growth initiated by FGF10
* BMP in the ventral ectoderm induces the AER
* Radical fringe restrict the AER to the distal tip
* Engrained-1 in the ventral ectoderm represses the Radical fringe
* AER express FGF4 and FGF8 -- maintain progress zone

Front 136

Describe the patterning of the anterior-posterior axis.

Back 136

Regulated by the ZPA (zone of polarizing cells)

* ZPA produces retinoic acid (vit. a) and induces SHH
- Positioning of thumb on anterior side (radial)

Front 137

What occurs if their is misexpression of the retinoic acid?

Back 137

Mirror image duplication of limb structures

Front 138

Describe the patterning of the dorsal ventral axis.

Back 138

* Engrained-1 on the ventral side represses WNT7a -- restricting to the dorsal ectoderm

* WNT7a induces LMX1 in dorsal ectoderm

Front 139

Vertebrae are formed from the ______________ of the ______________.

Back 139

Sclerotome, paraxial mesoderm

Front 140

Each vertebrae develops from the combination of ___ somites.

Give a number.

Back 140

2

Front 141

Sclerotome cells migrate around the spinal cord and notochord at the ____ week.

Back 141

4th

Front 142

The patterning and shape of vertebrae and the vertebral column is shaped by the ____ genes.

Back 142

HOX

Front 143

This portion of the paraxial mesoderm somites permits spinal movement.

Back 143

Myotome

Front 144

What is resegmentation?

Back 144

The combination of the caudal and cranial half of the somite to form the vertebrae.

Front 145

The intervertebral disc is composed of the ____________ and _____________.

Back 145

Nucleus pulposus, nucleus fibrosis

Front 146

What is the origin of the nucleus pulposus?

Back 146

The notochord

Front 147

What is the origin of the nucleus fibrosis?

Back 147

The sclerotome

Front 148

What is the Klippel-Feil sequence?

Back 148

It is a vertebral defect where the person has fewer cervical vertebrae

Front 149

What is spina bifida?

Define spina bifida occulta, spina bifida cystica

Back 149

Spina bifida: imperfect fusion or alignment of vertebrae

Spina bifida occulta: The incomplete fusion of the vertebral spine -- bony defect [MINOR]

Spina bifida cystica: The incomplete fusion of the vertebrae where spine is open to the outside environment. [SEVERE]

Front 150

Name the derivations of the different muscle type.

Skeletal
Smooth
Cardiac
Integumentary Glands

Back 150

Skeletal: Paraxial mesoderm - myotome of somites

Smooth and Cardiac: Splanchnic mesoderm of the lateral plate

Integumentary Glands: Ectoderm

Front 151

The somites of the paraxial mesoderm can differentiate into:

Back 151

* Sclerotome
* Dermomoyotome
- dermotome
- myotome

Front 152

The myotome itself can be split into the following regions:

Back 152

VLL (ventrolateral lip)
DML (dorsomedial lip)

Front 153

The ventral hypomere contains muscles for the ___________ and ____________

Back 153

* Body wall of the thorax and abdomen
* Limbs

Front 154

Muscles of the lateral and ventral body wall are called _____________

Back 154

Hypaxial muscles

Front 155

How many somites are there in the body wall?

Break down the somites per region.

Back 155

42-44

4 occipital
8 cervical
12 thoracic
5 lumbar
5 sacral
8 coccygeal

Front 156

Muscle patterns are regulated by _________________

Back 156

Connective tissue

Front 157

Muscles of the dorsomedial lip (dorsal epimere) are collectively called ___________

Back 157

Epaxial muscles

Front 158

The epaxial muscles are composed of the ____________ and _________

Back 158

Erector spinae
Transversospinalis

Front 159

The myogenic regulatory factors inducing development of the ventrolateral lip and dorsomedial lip are _________ and ___________ respectively

Back 159

VLL: MYF4 and MYO-D
DML: MYF5 and MYO-D

Front 160

What is the role of MYO-D?

Back 160

It is an important regulator / inducer of muscle differentiation.