Material Covered: Cell Ultrastructure, Epithelium, Nervous Tissue
Connective Tissue, Skin, Cartilage, Bone and Muscle

Use the following letters to indicate your answer:

A: Only I is true
B: Only II is true
C: Both are true
D: Both are false

        II. The nucleolus is the region within the nucleus where ribosomal
            RNA is synthesized.
 

2.     I.  The function of the sER includes lipid synthesis, HCL formation
            and steroid hormone synthesis.

        II. rER and sER can be continuous.
 

3.     I.  Microtubules are about 10 nm in diameter and made of a protein
            dimers called alpha and beta tubulin.

        II. Calcium concentration, ATP and pH influence polymerization of
            tubulin.
 

4.     I. Intermediate filaments are a protein polymer and are relatively stable
            compared to microtubules and microfilaments.

        II. Microtubles are involved in ciliary movement and intracellular
            transport of secretory products.
 

5.     I.  Most of the proteins synthesized by ribosomes bound to ER will
            become intracellular protein.

        II. The forming face of the golgi is where secretory granules are formed.
 
 

6.     I.  Alpha actinin anchors actin to the tip of microvilli.

        II. Dynein, found in stereocilia, is a protein that is attached to microtubules
            and aids in the movement of stereocilia.
 

7.     I.  Macula adherens have a cytoplasmic plaque disk that attaches to tonofilaments.

        II. Hemidesmosomes connect epithelia to connective tissue and have
            intermediate filaments arising out of the cytoplasmic plaque.
 

8.     I.  The microfilaments of the centriole and in the basal body of the cilia have
            a 9x3 arrangement.

        II.  A cluster of alpha glycogen is called beta glycogen.
 

9.     I.  Gap junctions allow cell to cell communication.  The plasma membranes at the
           gap junction do not touch and are connected by a protein called connexon.

        II. A junctional complex is made of three types of junctions: a macula adherens,
            zonula adherens and macula occludens.
 

10.     I.  Perinuclear space can be continuos with the Golgi.

         II. Ribosomes, made of rRNA and protein, are the sight of transcription.
 

11.     I. Epithelia tissue are derived from all 3 embryonic germ layers.

          II. The apical surfaces of epithelial cells face air or fluid and have surface
            specializations such as cilia, microvilli, desmosomes, clathrin coated vesicles
            and glycocalyx.
 
 

12.     I.  Typical epithelial cells tend to have a higher concentration of rER at its base
            giving it a more acidophilic stain.

         II. Elastic fibers contain type IV collagen.
 

13.     I.  All epithelia rest on a basal lamina, which is consisted of a lamina lucida
            and a lamina densida.

         II. The basal lamina of epithelial lining is produced by connective tissue.
 

14.     I.  Two types of stratified squamous epithelium are keratinized (containing keratin)
            and non-keratinized (no keratin present).

          II. Transitional epithelium, which has a thin basement membrane and contains
            some bi-nucleated cells, is found in structures like the bladder and ureter.
 

15.     I.  Epithelia that serve as a lubricating membrane may or may not have glands.

         II. Mucous secretion is rich in proteins such as O-glycosylated with anionic
            oligosacharides. This protein increases the viscosity of the secretions.
 

16.     I.  Dendrites of neurons are often myelinated thereby increasing the conduction
            rate of the action potential.

         II. Microtubules are prevalent in the dendrites of neurons.
 

17.     I.  Axons tend to be smaller in diameter than dendrites.

         II. Axons do not contain ribosomes, although neurofilaments are prevalent.
 

18.     I.  Dendritic spines can contain smooth endoplasmic reticulum and free ribosomes.

         II. An example of pseudounipolar neurons would be sensory neurons found in the
            dorsal root ganglion.
 

19.      I.  There are only three types of glia in the CNS: astrocytes, microglia and
            oligodendrocytes.

          II. Protoplasmic astrocytes can be found in the gray matter of CNS.
 

20.     I.  Some functions of astrocytes include: glycogen storage, serving as a K+ sink,
            and synthesis of neurotransmitter enzymes.

         II. Schwann cells, the myelin producing cells of the CNS, have small dark round
            nuclei and can myelinate multiple axons.
 

21.     I.  Catecholamines such as epinephrine and dopamine undergo re-uptake after
            being released from the presynaptic terminal.

         II. All glia arise from the embryonic ectodermal layer.
 

22.      I.  Ependymal cells tend to be simple cuboidal/columnar and line the ventricles of the brain.

          II. Ependymal cells are ciliated and monitor CSF.
 

23.      I.  The spinal cord differs from the brain in that in the spinal cord, the gray matter
                is in the center, while in the brain, white matter is deep to the gray matter.

          II. There are two basic types of ganglia:  sensory and motor.  Sensory ganglia can
                be divide into additional categories:  sympathetic and parasympathetic.
 

24.     I.  Glial limitans are formed by the end feet of microglia cells at the surface of the brain.

          II. The most exterior CNS meninges is the dura mater.  The meninges closest to the
                brain is the arachnoid layer.
 

25.     I.  The perineurium covers individual axons/myelin sheaths in the PNS.

          II. One oligodendrocyte can myelinate several axons.
 

26.     I.  Tropocollagen units undergo polymerization in the Golgi.

         II. Proteoglycan is a glycosaminoglycan attached to a hyaluronic acid core.
 

27.     I.  Fibroblasts have an oval shaped nucleus with a distinct nucleolus, basophilic
            cytoplasm and synthesize components that make up collagen.

         II. Fibrocytes have few mitochondria.
 

28.     I.  Multilocular adipose is found in the adult kidney, adrenal and GI tract.

         II. Unilocular adipocytes have mitochondria that lack respiratory assemblies
            on the inner membrane.
 

29.     I.  Plasma cells, which are basophilic, secrete antibodies.

         II. Mast cells, which are widely distributed in the connective tissue, can release
            histamine and/or heparin.  The latter serves as an anticoagulant.
 

30.     I.  Langerhans cells, which can be found in the stratum spinosum, resemble
            melanocytes and play an important role in the immune response by presentation
            of antigens to T-Cells.

         II. Merkel cells, located in the stratum basale, function as mechanoreceptors.
 
 

31.     I.  The reticular layer of skin is deep to the papillary layer and contains dense
            connective tissue.

         II. Free nerve endings are the most numerous of the nerve endings in the skin.
            They are in the dermis as well as the epidermis, extending as far as the stratum
            granulosum.  They serve as pain and temperature receptors and are unmyelinated.
 

32.     I.  Meissner’s corpuscles are found in the dermis of the skin and are unmyelinated
            tactile receptors.

         II. The nerve fiber within the Pacinian corpuscle is unmyelinated.  These corpuscles
            serve as pressure receptors.
 

33.     I.  There are three layers of a hair: the cuticle, cortex and medulla, all of which are
            made of hard keratin.

         II. All hair follicles are joined to sebaceous glands.
 

34.      I. Apocrine sweat glands in humans are found only in the axilla, the areola and nipple
            of the mammary gland, the circumanal region and are associated with the external
            genitalia.

         II. Sebum, which is produce by apocrine secretion, is an oily substance that coats
            hair and skin.
 

35.     I.  Second-degree burns involve the dermis and epidermis.

          II. Basal cell carcinoma is a skin malignancy usually caused by excessive sun exposure
            and often metastasizes.
 

36.     I.  Chondrocytes are spindle shape cells that synthesize cartilage.

         II. The matrix in hyaline cartilage tends to be basophilic.
 

37.     I.  There are two types of cartilage growth, appositional, which means growth occurs
            at the surface of cartilage and interstitial growth, which means growth, occurs
            within the cartilage.

         II. Isogenous groups of cells are a result of interstitial cartilage growth.
 

38.     I.  Type IV collagen is the main collagenous fiber type found in cartilage.

         II. Chondroitan 6-sulfate and 4 sulfate are found in the ground substance in cartilage.
 

39.     I. Osteoblasts are responsible for the synthesis of osteoid, a non-mineralized
            extracellular material.

         II. The periosteum is attached to bone by Howship’s fibers.
 

40.     I.  Osteocytes, which do not make osteoid, communicate with each other by gap
            junctions in their cytoplasmic processes.

         II. The region between osteocytes and bone matrix is called the lacuna.
 

41.     I.  Osteoclasts are multinucleated cells that secrete lysosomes and are responsible
            for bone re-absorption and are stimulated by parathyroid hormone.

         II. Sharpey’s lacunae are areas of bone resorption by osteoclast.
 

42.     I.  Immature bone has more cells per unit area, grows more rapidly and is more
            acidophilic than mature bone.

         II. Endochondral ossification involves the enlargement of chondrocytes with increased
            accumulation of glycogen.
 

43.     I.  Cartilage that becomes calcified is by definition immature bone.

         II. Epiphysis region of the bone is the main shaft of the long bone.
 

44.     I.  The following is a complete list of the zones and the correct order in which they
            appear starting from the end of a growing long bone: proliferative, maturation, provisional
            calcification, degeneration, ossification, osseous and resorption.

         II. The major difference between immature bone and mature bone is the development
            of the Haversian system.
 

45.     I.  In the skeletal muscle, the heavy meromyosin contains the S-1 portion which binds
            to actin, and the light meromyosin binds to other myosin molecules.

         II. During skeletal muscle contraction calcium binds troponin, which causes the movement
            of tropomyosin to unmask a myosin/actin binding site.
 

46.     I. In cardiac muscle spot desmosomes are called fascia adherens.

         II. In the skeletal muscle, the triad is make of a terminal cisterna flanked by two T-tubules.
 

47.     I. In the skeletal muscle, during electrical excitation, calcium is released from the
            sarcoplasm into the sarcoplasmic reticulum causing muscle contraction.

         II.  In cardiac muscle, the T-tubules are located at the A-I junction.
 

48.     I.  There is about twice as much actin and troponin in smooth muscle as compared
            to skeletal muscle.

         II. Within smooth muscle, dense plaques called myosinin are attachment sites for actin.
 

49.      I.  Sarcoplasm of smooth muscle has a higher ratio of actin/myosin than does striated
            muscle.

           II. T-tubules conduct excitation to the interior smooth muscle fibers.
 

50.     I. Alpha motor neurons of the spinal cord innervate the intrafusal fibers of the skeletal
            muscle.

         II. Flower spray endings, located on the bag and chain of the intrafusal fiber, send
            sensory information to the CNS about the rate of contraction.