Chapter 5-8 study guide(includes quiz)
Merkel cells.
) Which of the following are associated with the sense of touch?
Metaplasia
A change from one type of mature epithelium into another such as occurs in the human vagina at puberty when the vaginal lining of simple cuboidal epithelium changes to stratified squamous epithelium
E. complex of macromolecules; part of a cell; entire cell
A connective tissue fiber refers to a(n) __________________, a nerve fiber refers to a(n) ____________________, and a muscle fiber refers to a(n) _______.
complex of macromolecules, part of a cell, entire cell
A connective tissue fiber refers to a(n) __________________, a nerve fiber refers to a(n) ____________________, and a muscle fiber refers to a(n) _______.
superior articular processes
A pair of superior articular processes project upward from one vertebra and meet a similar pair of inferior articular processes projecting downward from the vertebra just above. (Fig. 8.23a) a. Each process has a flat articular surface (facet) facing that of the adjacent vertebra. b. These processes restrict twisting of the spine, which could damage the spinal cord.
epiphyseal plate
Achondroplastic dwarfism is a hereditary condition in which the long bones of the limbs fail to elongate normally because of reduced hyperplasia and hypertrophy of cartilage in the
pseudostratified columnar
All cells in this tissue reach the basement membrane and only cells that reach the free surface have cilia.
Simple Columnar
An epithelium with all cells tall and narrow and with every cell touching the basement membrane is called ________________
smooth muscle produces waves of contractions that propel material through the digestive tract
Astronauts in zero gravity are able to move food through their digestive tracts because
cartilage growth
Bone elongation is a result of
ridges, spines, bumps, depressions, canals, slits, cavities, and articular (joint) surfaces.
Bones exhibit a variety of anatomical features including
False
Bones grow in diameter by interstitial growth.
b) Keratinocytes.
Calluses or corns are the result of accelerated multiplication of
zone of cell proliferation
Chondrocytes multiply in this zone of the metaphysis.
. tendons, ligaments, and the deeper portion of the skin.
Collagenous fibers are very abundant in
-Bone (osseous tissue)—connective tissue with the matrix hardened by calcium phosphate and other minerals -Bone organ-consist of bone tissue, bone marrow, cartilage, adipose tissue, nervous tissue, and fibrous connective tissu& Permeated with nerves and blood vessels, which attests to its sensitivity and metabolic activity
Distinguish between bone as a tissue and bone as an organ
an elevated level of osteoclast activity
If a thyroid tumor secreted an excessive amount of calcitonin, we would expect
stratified epithelium
In a ___________________, some cells rest on top of other cells and do not contact the basement membrane. may have from 2 to 20 layers of cells with only the deepest layer resting on the basement membrane. 1. Three types of stratified epithelia are named for the shapes of the surface cells: stratified squamous, stratified cuboidal, and stratified columnar, which is rare. 2. A fourth type, transitional epithelium, was erroneously throught to represent a transitional stage between stratified squamous and stratified columnar, but the name has persisted.
In a simple epithelium
In a _______________________, every cell touches the basement membrane. Generally, a simple epithelium has only one layer of cells : simple squamous (thin, scaly), simple cuboidal (squarish, round), and simple columnar (tall, narrow). 2.pseudostratified columnar epithelium, shorter cells do not reach the free surface, but all cells reach the basement membrane. 3. Simple columnar and pseudostratified columnar epithelia often produce mucus, which is secreted by goblet cells.
In dark-skinned people, the melanin is also more spread out through the keratinocyte cell, while in light-skinned people, the melanin remains clumped near the nucleus.
In dark-skinned people, the melanin is also more spread out through the keratinocyte cell, while in light-skinned people, the melanin remains clumped near the nucleus.
hyaline cartilage
In endochondral ossification, the precursor connective tissue is _____________, which is replaced by bone.
tight junctions
In the intestine, __________________ ensure(s) that most digested nutrients pass through the epithelial cells and not between them.
False
Intramembranous ossification is common in children, whereas endochondral ossification is typical in young adults
flat bones of the skull.
Intramembranous ossification produces the
reticular; collagen
Leather is mostly made of the __________ layer of the dermis, which is very tough due to the high concentration of ____________ fibers
cells:Osteogenic cells; osteoblasts; osteocytes; osteoclasts fibers: fibers of the Periosteum ground substance:1/3organic and2/3 inorganic matter?
List and describe the cells, fibers, and ground substance of bone tissue
False (dead keratinocytes)
Living keratinocytes exfoliate from the epidermis as tiny specks called dander
phagocytize and digest tissue debris
Macrophages __________________ in the healing of a skin wound.
appositional growth
Mature bones are remodeled throughout life by employing
True
Melanin, hemoglobin, and carotene give color to the skin a) True b) False
totipotent
Most biologists see embryonic stem (ES) cells as a possible treatment for diseases that result from the loss of functional cells. This possibility is based on the fact that ES cells are _______________ stem cells.
True
Most blood cells are produced in the red marrow of bone.
simple cuboidal epithelium
Most kidney tubules are made of this tissue specialized for absorption and secretion.
1-2 mm
Most of the skin is ___________ mm thic
striated and voluntary.
Skeletal muscle is described as
Fingertips.
Skin covering the _____ has sweat glands but no hair follicles or sebaceous glands
Fingertips
Skin covering the __________ has sweat glands but no hair follicles or sebaceous (oil) glands
Smooth, cardiac, and skeletal muscle
Smooth muscle lacks striations and is involuntary. Cardiac muscle is limited to the heart. Skeletal muscle consists of long cells called muscle fibers.
spongy bone
Spicules and trabeculae are found in
206 bones in the typical adult body
State the approximate number of bones in the adult body
Stratified squamous epithelium
Stratified squamous epithelium is the most widespread epithelium in the body. a. The deepest layer of cells are cuboidal to columnar and undergo continual mitosis. b. Daughter cells push toward the surface and become flatter (more squamous). c. Eventually the cells migrate to the surface where they die and flake off, a process called exfoliation or desquamation. (Fig. 5.12) i. Exfoliated cells can be smeared on a slide, stained, and examined; this is the basis of the Pap test for uterine cancer. d. Keratinized epithelium, such as found on the skin surface, is covered with a layer of compact, dead squamous cells packed with keratin and coated with a glycolipid water repellent. e. Nonkeratinized epithelium lacks the surface layer of dead cells; it is found on the tongue, esophagus, vagina, and some other internal membranes.
metaphysis
The _____________ is a marginal zone of the epiphyseal plate where, in children and adolescents, bone can be seen replacing the hyaline cartilage.
exposure to UV radiation, which stimulates melanin synthesis
The amount of melanin in the skin also varies with
upper limb and pectoral girdle, and bones of the lower limb and pelvic girdle.
The appendicular skeleton includes bones of the
central supporting axis of the body and includes the skull, auditory ossicles, hyoid bone, vertebral column, and thoracic cage (ribs and sternum)
The axial skeleton forms the
epithelium and connective tissue.
The basement membrane is found between
a. The stratum basale is the innermost layer resting on the basement membrane. i. It consists of a single layer of cuboidal to low columnar stem cells and keratinocytes. The stratum spinosum consists of several layers of keratinocytes. i. As cells are pushed upward by cell division, they lose the ability to divide and produce more and more keratin fibers. c. The stratum granulosum consists of three to five layers of flat keratinocytes—more in thick skin than in thin skin; dark-staining keratohyalin granules give the layer its name. d. The stratum lucidum is a thin, translucent zone external to the stratum granulosum and is seen only in thick skin. Keratinocytes are densely packed with eleidin. e. The outermost stratum corneum consists of up to 30 layers of dead, scaly keratinized cells that form the surface layer.
The cells of the epidermis are arranged in four to five strata.
hairs to stand on end with no apparent function
The contraction of the piloerector muscles (pilomotor muscle or arrector pili) in humans causes
merocrine (sweat) glands
The cutaneous glands concerned with cooling the body are
False (hypodermis is not a layer of the skin)
The deeper of the two layers of the skin is the hypodermis
The dermis
The dermis is a connective tissue layer beneath the epidermis.It is composed mainly of collagen but contains elastic and reticular fibers, fibroblasts, and other cells of fibrous connective tissue. (pp. 185-186) 1. Hair follicles and nail roots are embedded in the dermis. 2. Piloerector muscles associated with hair follicles are responsible for "goosebumps" and other skin contraction in response to stimuli. 3. Skeletal muscles attached to dermal collagen fibers produce facial expressions. 4. The boundary between epidermis and dermis is usually wavy; upward waves are called dermal papillae and downward waves are epidermal ridges. (Fig. 6.5a) a. On the fingertips, the wavy boundary produces the friction ridges responsible for fingerprints.
False
The duct of an endocrine gland leads into the bloodstream rather than onto an epithelial surface. a) True b) False
a. Stem cells are undifferentiated cells that divide to give rise to keratinocytes; stem cells are found in the deepest layer (stratum basale). b. The majority of epidermal cells are keratinocytes, which synthesize keratin. c. Melanocytes also occur only in the stratum basale; they synthesize the pigment melanin. i. Melanocytes shed melanin-containing fragments from the tips of branching processes. ii. The keratinocytes phagocytize these fragments and accumulate melanin on the "sunny side" of the nucleus. d. Tactile (Merkel) cells are the receptors for the sense of touch; found in the stratum basale, they are associated with an underlying dermal nerve fiber. e. Dendritic (Langerhans) cells, which are microphages that migrate from bone marrow, are found in the stratum spinosum and stratum granulosum where they stand guard against foreign pathogens.
The epidermis is composed of five types of cells.
an epiphysis
The expanded head at each end of a long bone is called
Stratum basale.
The fastest rate of mitosis happens in the
Vertebral arch
The foramen is bordered by a vertebral arch composed of two parts on each side: a pillarlike pedicle and platelike lamina. a. Extending from the apex of the arch is a projection called the spinous process, which is directed posteriorly and downward. b. A transverse process extends laterally from the point where the pedicle and lamina meet. c. The spinous and transverse processes provide attachment points for ligaments, ribs and spinal muscles.
ossification or osteogenesis
The formation of bone is _______________;
fibrous.
The four primary tissue types found in adult organs include all of the following except A. connective. B. fibrous. C. nervous. D. epithelial. E. muscular.
True
The hemopoietic tissue in a bone is otherwise known as myeloid tissue
Adipose Tissue
The hypodermis usually has an abundance of this tissue.
The hypodermis
The hypodermis, or subcutaneous tissue, has an indistinct boundary but contains more areolar and adipose tissue; it binds the skin to the underlying tissues. (pp. 186-187) (Table 6.1) 1. The hypodermis is the target for subcutaneous injections because it is highly vascularized and absorbs drugs quickly. 2. Subcutaneous fat is hypodermis composed primarily of adipose tissue. a. Subcutaneous fat serves as an energy reservoir and provides thermal insulation. b. The subcutaneous fat averages about 8% thicker in women than in men and varies with age.
epithelium and lamina propraia
The membrane that lines digestive, respiratory, urinary, and reproductive tracts consists of
Fluid loss
The most immediate threat to the life of a patient with severe burns is
The body of the vertebra
The most obvious feature of a vertebra is the body (centrum), a mass of spongy bone and red bone marrow covered with a thin shell of compact bone; this is the weight bearing portion of the vertebra
Hemoglobin.
The reddish color of the skin of the lips is primarily due to this pigment.
Fibrosis
The replacement of damaged tissue with scar tissue is called
elastic cartilage.
The shape of a person's external ear is given by
True
The skin carries out the third step in the synthesis of vitamin D a) True b) False
Hematoma.
The skin discoloration most likely to suggest physical abuse is
True
The skin is the largest organ of the body and consists of the outer epidermis and the deeper dermis. The hypodermis underlies this latter layer but is not a true part of the skin
skeletal, cardiac, and smooth
The three types of muscle are
brownish-black eumelanin and reddish-yellow pheomelanin, which contains sulfur.
The two forms of melanin are
7 cervical vertebrae in the neck, 12 thoracic vertebrae in the chest, 5 lumbar vertebrae in the lower back, 5 sacral vertebrae at the base of the spine, and 4 tiny coccygeal vertebrae at the very end.
The vertebrae are divided into five groups:
The vertebral column
The vertebral column (spine) physically supports the skull and trunk, allows for their movement, protects the spinal cord, absorbs stresses of walking, running, and lifting. It provides attachment for the limbs, thoracic cage, and postural muscles. (pp. 250-251)
of a chain of 33 vertebrae with intervertebral discs of fibrocartilage between most of them. 2. The vertebral column averages about 71 cm (28 in.) long, with the discs accounting for about 1/4 of the length.
The vertebral column consists
hyaline cartilage.
These are all types of fibrous connective tissues except A. reticular tissue. B. hyaline cartilage. C. dense regular connective tissue. D. dense irregular connective tissue. E. areolar tissue.
a calcified matrix.
These are features that fibrous connective tissues have in common except A. very conspicuous fibers. B. the presence of fibroblasts. C. the presence of collagen. D. ground substance with a gelatinous to rubbery consistency. E. a calcified matrix.
Langerhans cells.
These cells in the skin that protect against toxins, microbes and other pathogens.
B. interstitial fluid is so scarce that it is not visible with a light microscope.
These features are common to all connective tissues except A. most cells are not in direct contact with each other. B. interstitial fluid is so scarce that it is not visible with a light microscope. C. cells usually occupy less space than extracellular material. D. protein fibers are usually present in the ground substance. E. most of them are highly vascular.
interstitial fluid is so scarce that it is not visible with a light microscope.
These features are common to all connective tissues except A. most cells are not in direct contact with each other. B. interstitial fluid is so scarce that it is not visible with a light microscope. C. cells usually occupy less space than extracellular material. D. protein fibers are usually present in the ground substance. E. most of them are highly vascular.
Totipotent
They can develop into any type of human cell. Stem cells are are an example.
Stratum corneum
This layer of the epidermis consists of up to 30 layers of dead cells.
mucous membrane
This membrane lines passageways that open to the exterior environment.
mesoderm; mesenchyme
This primary germ layer is the middle layer, called ______, and gives rise to a gelatinous material called ________________, which gives rise to different types of connective tissue such as bone, muscle, and blood.
pallor.
This skin color is most likely to result from anemia.
regeneration or fibrosis
Tissues are repaired through regeneration or fibrosis
The epidermis is a keratinized stratified squamous epithelium, and like other epithelia, lacks blood vessels and depends on diffusion for nutrients and waste removal.
What type of cell is the epidermes made of
osteoblasts; osteocytes
When ____________ become enclosed in lacunae, they become cells called ___________
osteoblasts; osteocytes
When ____________ become enclosed in lacunae, they become cells called _____________.
intervertebral foramen
When two vertebrae are joined, they exhibit an opening between their pedicles called the intervertebral foramen. a. This foramen allows passage of spinal nerves that connect with the spinal cord at regular intervals. b. Each foramen is formed by an inferior vertebral notch in the superior vertebra, and a superior vertebral notch in the inferior vertebra. (Fig. 8.23b)
The first few crystals to form attract more calcium and phosphate
Which of the following exemplifies a positive feedback process happening in bone mineral deposition? a) Collagen is digested by enzymes and hydroxyapatite by hydrochloric acid b) Osteoclasts secrete acid phosphatase that digests collagen c) Osteoblasts neutralize inhibitors that prevent bone resorption d) The first few crystals to form attract more calcium and phosphate e) Solubility product is reached in the tissue fluids
hydroxyapatite
Which of these is an inorganic component of the bone matrix?
osteoclasts
Which one of the following bone cells would have the greatest number of lysosomes?
osteoclasts
Which one of the following bone cells would have the greatest number of lysosomes? a) osteoblasts b) osteoclasts c) osteocytes d) osteogenic cells e) stem cells
spinosum and basale
Which two strata of the epidermis are most susceptible to cancer?
mechanical stress on bone remodeling
Wolff's law of bone explains the effect of
medial surface of the fibula
You cannot palpate the ________________ on a living person a) lateral malleolus b) tibial tuberosity c) medial surface of the fibula d) anterior crest of the tibia e) calcaneus
Fibrous
_______ connective tissue is the most diverse type
Blood
_______ is a fluid connective tissue that travels through tubular vessels. They consists of plasma as the ground substance, and cells and cell fragments called formed elements.
Albinism
________ is a genetic lack of melanin that results in white hair, pale skin, and blue-gray eyes. It is caused by nonfunctional enzyme tyrosinase which converts tyrosine to melanin.
Osteoblasts
__________ are bone-forming cells.
Merocrine; holocrine
____________ glands (such as tear glands) have vesicles that release their secretion by exocytosis, whereas __________________ glands (such as oil-producing glands) secrete a mixture of disintegrated cells and their products.
Mucous; serous
____________ glands secrete mucin, which combines with water to form a thick and sticky product, whereas __________________ glands produce a relatively watery fluid.
Apoptosis
____________(programmed cell death) is the normal death of cells that have completed their function. (pp. 173-175) 1. Cells undergoing apoptosis are quickly phagocytized and their cell contents never escape. 2. Every cell has a built-in "suicide program" that enables the body to dispose of it when necessary. a. Some cells respond to an extracellular suicide signal that binds to the Fas protein in the plasma membrane. b. Other cells undergo apoptosis if they stop receiving growth factors from other cells. 3. Apoptosis dissolves the webbing between fingers and toes during embryonic development and causes the shrinkage of the uterus after pregnancy, among other things.
Goblet
_____________ cells in simple columnar and pseudostratified columnar epithelia produce protective mucous coatings over the mucous membranes.
Simple squamous
_____________ epithelium allows for rapid diffusion of oxygen and carbon dioxide through the air sacs (alveoli) of the lungs.
Carotene
_____________, a yellow pigment, can become concentrated in the stratum corneum and subcutaneous fat.
Hemoglobin
_____________, the red pigment of blood, imparts reddish to pinkish hues to the skin.
Central canals
______________ are common in compact bone but rarely seen in spongy bone.
Freckles are flat melanized patches that vary with heredity and exposure to the sun.
______________ are flat melanized patches that vary with heredity and exposure to the sun.
Birthmarks (hemangiomas)
______________ are patches of discolored skin caused by benign tumors of the blood capillaries.
Nonkeratinized; vagina
______________ epithelium provides a moist and slippery surface and is well suited to resist stress, as in the ________________.
Compound acinar
______________ glands have branched ducts and secretory cells that form sacs at one end of the ducts.
Epithelial tissue
______________ lines body cavities, covers the body surface, and forms the lining of many organs.
Stratified squamous; stratified columnar
_______________ epithelium is the most widespread epithelium in the body, whereas _______________ epithelium is rare.
Stratified squamous; stratified columnar
_______________ epithelium is the most widespread epithelium in the body, whereas _______________ epithelium is rare. A. Simple columnar; stratified columnar B. Stratified squamous; stratified columnar C. Pseudostratified; stratified squamous D. Simple cuboidal; stratified squamous E. Stratified squamous; simple squamous
Jaundice
_______________ is yellowing of the skin and whites of the eyes resulting from high levels of bilirubin in the blood. If liver function is compromised, bilirubin can accumulate.
Endocrine glands; hormones; the blood
_______________ secrete __________________ into __________________.
Areolar tissue
_________________ exhibits a lot of apparently empty space, and is found in many serous membranes.
Muscular and nervous; excitable
_________________ tissues respond quickly to outside stimuli by means of changes in membrane potential, thus they are called __________________ tissues.
Transitional; stratified squamous
__________________ epithelium found in the bladder resembles ______________ epithelium, but the apical cells are rounded, not flattened.
Simple squamous; stratified squamous
__________________ epithelium is associated with rapid transport of substances through a membrane, whereas __________________ epithelium is associated with resistance to abrasion.
Blood; transport nutrients to the tissues
__________________ is found in the heart, and one of its functions is to __________________.
Chondroblasts; fibroblasts
__________________ secrete the rubbery matrix of cartilage, whereas ________________ produce the fibers and ground substance that form the matrix of fibrous connective tissue.
Areolar; cartilage
__________________ tissue is highly vascular, whereas _______________ is not.
A hematoma, or bruise
___________________, is a mass of clotted blood showing through the skin. Bruising is usually due to accidental trauma but may also occur in hemophilia, physical abuse, or metabolic or nutritional disorders.
Cyanosis
________________is a blue color to the skin resulting from deficiency of oxygen, which turns hemoglobin to a more violet color; it may result from blockage of airways, respiratory arrest, and cold weather that slows blood flow.
Erythema
____________is abnormal redness of the skin caused by increased blood flow, such as during exercise, emotions such as anger and embarrassment, and sunburn.
Removal of the parathyroid glands
___________does not put women at risk of hypocalcemia.
A mole (nevus)
_________is an elevated patch of melanized skin, often with hair. Moles are harmless but should be watched for changes that might mean malignancy.
Pallor
________is a pale or ashen color that occurs when blood flow through the skin is diminished. It may be caused by low blood pressure, shock, severe anemia, or emotional stress.
Stem cells
are undifferentiated cells that have the potential to change into one or more types of mature functional cells. (p. 172) 1. Embryonic stem cells compose the early human embryo; these are totipotent cells, meaning they can develop into any type of human cell. 2. About 4 days after fertilization, at the embryonic blastocyst stage, the cells of the inner mass of cells are called pluripotent: they can become any cell type in the embryo, but not cells of the placenta or amniotic sac. (Fig. 29.4) 3. Adult stem cells occur in small numbers in mature organs and tissues. a. Some adult stem cells are multipotent and can develop into two or more different cell lines (but not just any type of cell). b. Unipotent adult stem cells can produce only one mature cell typ
Jaundice
ilirubin causes a skin discoloration called
Metaplasia
is a change from one type of mature epithelium into another, such as occurs in the human vagina at puberty when the vaginal lining of simple cuboidal epithelium changes to stratified squamous epithelium.
Epithelial tissue
is a flat sheet of closely adhering cells, one or more cells thick, with the upper surface usually exposed to the environment or to an internal space. (p. 147) 1. Epithelium covers the body surface, lines body cavities, forms the external and internal linings of many organs, and constitutes most gland tissue. 2. Epithelium almost always lies on a layer of loose connective tissue and is dependent on this tissue's blood supply for nutrients and waste removal. 3. The basement membrane anchors an epithelium to the underlying connective tissue.
The epidermis
is a keratinized stratified squamous epithelium, and like other epithelia, lacks blood vessels and depends on diffusion for nutrients and waste removal.
The endoderm
is an inner layer that gives rise to the mucous membranes of the digestive and respiratory tracts and to digestive glands.
The ectoderm
is an outer layer that gives rise to the epidermis and nervous system.
The mesoderm
is between the other two layers and eventually turns into a tissue called mesenchyme; this gives rise to muscle, bone, blood, and some other tissues
Hyperplasia
is growth through cell multiplication, and it occurs during embryonic development and childhood.
Neoplasia
is the development of a tumor composed of abnormal, nonfunctional tissue.
Hypertrophy
is the enlargement of preexisting cells, such as muscle fibers upon exercise and enlargement of adipocytes upon storage of triglycerides.
Necrosis
is the premature, pathological death of tissue due to trauma, toxins, or infection.
Fibrosis
is the replacement of damaged tissue with scar tissue, composed mainly of collagen produced by fibroblasts; fibrosis does not restore normal function.
Regeneration
is the replacement of dead or damaged cells with the same type of cells as before; an organ's function is restored in this way.
Atrophy
is the shrinkage of a tissue through a loss in cell size or number. (pp. 173-175) 1. Senile atrophy is a result of normal aging. 2. Disuse atrophy results from lack of use, as in muscles that are not exercised.
Infarction
is the sudden death of tissue that may occur in cardiac muscle or brain tissue when the blood supply is cut off.
Gangrene
is tissue necrosis resulting from an insufficient blood supply, usually involving infection.
epithelium and lamina propraia
the membrane that lines disgestive, respiratory, urinary and reproductive tracts consists of
metaplasis
the pseudostratified columnar epithelium of the bronchi in smokers may transform into stratified squamous epithelium. this exemplifies
intramembranous ossification and endochondral ossification.
the two methods of bone development in the human fetus are
True
vertebra is considered to be an irregular bone.
ectoderm, mesoderm, and endoderm.
• Name the three embryonic germ layers and some adult tissues derived from each.
dense regular and dense irregular connective tissues.
Fibroblasts and protein fibers are associated with both
Collagenous fibers; Reticular fibers; Elastic fibers
Fibrous components include three types of protein fibers. i. Collagenous fibers are made of collagen and are tough, flexible, and resist stretching; they are often called white fibers due to their appearance in fresh preparations. ii. Reticular fibers are thin collagen fibers coated with glucoprotein, forming a spongelike framework in some organs. iii. Elastic fibers are made of elastin, which can recoil from stretching like a rubber band; these are often called yellow fibers due to their appearance in fresh preparations. . Ground substance occupies the space between cells and fibers and usually has a gelatinous consistency because of three classes of molecules.
periosteum; endosteum
A bone is covered externally with a sheath called ______________, whereas the internal surface is lined with _____________.
simple columnar; small intestine
A brush border of microvilli belongs to _______________ epithelium found in the ______________.
Healing of an injury such as a cut in the skin occurs in four stages
. Healing of an injury such as a cut in the skin occurs in four stages. (Fig. 5.34) a. Bleeding occurs, and mast cells and damaged cells release histamine increasing blood flow and capillary permeability. b. A blood clot forms in the tissue, knitting the edges of the cut together and helping to prevent entry of pathogens. The surface of the clot forms a scab while macrophages underneath begin to clean up tissue debris. c. New blood capillaries grow into the wound, and the mass of capillaries and fibroblasts is called granulation tissue. Macrophages remove the blood clot and fibroblasts deposit new collagen in its place. d. Surface epithelial cells around the wound multiply and migrate into the wounded area, beneath the scab. The scab loosens and falls off, and the epithelium grown thicker. Epithelium undergoes regeneration while underlying connective tissue undergoes fibrosis (scarring). Remodeling of the injured area may take up to two years.
Intramembranous ossification
. Intramembranous ossification produces the flat bones of the skull and the clavicle; they develop within a fibrous sheet, and their development includes four stages. (p. 214) (Fig. 7.7) 1. Embryonic connective tissue (mesenchyme) condenses into a layer of soft tissue with a dense supply of blood capillaries. a. The mesenchymal cells enlarge and differentiate into osteogenic cells. b. Regions of the mesenchyme become a network of soft sheets called trabeculae. 2. Osteogeneic cells gather on the trabeculae and differentiate into osteoblasts. a. These osteoblasts deposit osteoid tissue, which is soft collagenous tissue similar to bone except for a lack of minerals. (Fig. 7.8) b. As trabeculae become thicker, calcium phosphate is deposited in the matrix; osteoblasts become trapped in the matrix and are now osteocytes. 3. Osteoblasts go on to deposit minerals, producing a honeycomb of bony trabeculae; some trabeculae persist as permanent spongy bone while osteoclasts resorb and remodel others to form a marrow cavity. 4. Trabeculae at the surface continue to calcify until the spaces are filled in, converting spongy bone to compact bone; this process leads to the sandwich-like arrangement of mature flat bones.
Endochondral ossification
Endochondral ossification is a process by which bone develops from a preexisting model composed of hyaline cartilage. Most bones of the body develop in this way, and the development includes six stages. (pp. 214-217) (Fig. 7.9) 1. Mesenchyme develops into a body of hyaline cartilage covered with a fibrous perichondrium. The perichondrium produces chondrocytes and the cartilage model grows in thickness. 2. Eventually, the perichondrium starts producing osteblasts instead of chondrocytes and is now considered to be periosteum. a. The osteoblasts deposit a thin collar of bone around the middle of the cartilage model. b. Chondrocytes in the middle of the model enlarge to become the primary ossification center. c. The walls of matrix between the lacunae calcify, blocking nutrients from reaching the chondrocytes, which die; their lacunae merge into a single cavity in the middle of the model. . Blood vessels penetrate the bony collar and invade the primary ossification center; the hollowed-out center of the model becomes the primary marrow cavity. a. Stem cells introduced with the blood give rise to osteoblasts and osteoclasts. b. Osteoblasts begin depositing osteoid tissue, and the bony collar thickens and elongates toward the ends of the bone, along with a wave of cartilage death. c. Osteoclasts follow, dissolving calcified cartilage remnants and enlarging the marrow cavity of the diaphysis. d. The region of transition at each end of the primary marrow cavity is called a metaphysis. e. At the epiphyses, secondary ossification centers form as chondrocytes enlarge and die. 4. The secondary ossification center becomes hollowed out, generating a secondary marrow cavity in the epiphysis. a. In bones with two secondary ossification centers, one center lags behind the other in development. b. The joints of the limbs are still cartilaginous at birth. (Fig. 7.10) 5. During infancy and childhood, the epiphyses fill with spongy bone, and cartilage becomes limited to the articular cartilage of each joint surface and to an epiphyseal plate that separates the primary and secondary marrow cavities. 6. Growth occurs from the epiphyseal plate. a. By the late teens to early twenties, all remaining cartilage has been consumed and the gap between epiphysis and diaphysis closes.
Quantity of melanin produced
Ethnic differences in skin color are primarily caused by differences in
Nervous and Muscular Tissue
Excitable Tissues The basis for nerve and muscle excitation is an electrical charge difference called the membrane potential. (p. 163) B. Nervous tissue consists of neurons and neuroglia (glial cells), which protect and assist the neurons.
206 in an adult, but at birth there are 270 and even more form during childhood. (p. 234) 1. The number of bones decreases as separate bones fuse during aging. 2. This fusion is completed by late adolescence to the mid-20s to bring the average number to 206 Sesamoid bones are bones that form within some tendons in response to stress, such as the patella (kneecap). b. Some people have extra bones in the skull called sutural or wormian bones
Explain why the number of bones in the skeletal system varies with age and from one person to another.
Fibrous connective tissue
Fibrous connective tissue consists of cellular and fibrous components in a ground substance. Cellular components include six types, depending on the tissue. i. Fibroblasts are large flat cells that produce the fibers and ground substance of the tissue. ii. Macrophages are large phagocytic cells that engulf and destroy bacteria, foreign particles, and dead or dying cells; they also respond to antigens. iii. Leukocytes, or white blood cells (WBCs), enter connective tissues from the blood stream and wander in search of bacteria. iv. Plasma cells synthesize antibodies. v. Mast cells near blood vessels secrete heparin and histamine. vi. Adipocytes, or fat cells, may group together into adipose tissues; they are very large cells that contain a globule of triglycerides.
loose connective tissue and dense connective tissue.
Fibrous connective tissue is divided into two broad categories: loose connective tissue and dense connective tissue. (Tables 5.4 and 5.5) a. In loose connective tissue, much of the space is occupied by ground substance. Examples include areolar and reticular tissues. (Table 5.4) (Figs. 5.14, 5.15) b. In dense connective tissue, fiber occupies more space than cells and ground substance. Examples include dense regular connective tissue and dense irregular connective tissue. (Table 5.5) (Figs. 5.16, 5.17) c. Areolar tissue exhibits loosely organized fibers, abundant blood vessels, and a lot of empty space. (Fig. 5.14) i. Fibers are randomly organized and mostly collagenous, although elastic and reticular fibers are present. ii. It is found underlying nearly all epithelia, including the skin and membranes of the body and surrounding blood vessels and nerves. d. Reticular tissue is a mesh of reticular fibers and fibroblasts forming the structural framework (stroma) of many organs. (Fig. 5.15) Dense regular connective tissue is named for two properties: Closely packed collagen fibers with little open space; and the parallel arrangement of fibers. (Fig. 5.16) i. The parallel arrangement is an adaptation to directional pull, such as on tendons and ligaments. ii. In general the only cells are fibroblasts. iii. Yellow elastic tissue is a dense regular connective tissue found in the vocal cords, suspensory ligament of the penis, and some ligaments of the vertebral column. iv. Elastic tissue also takes the form of wavy sheets in the walls of the large and medium arteries, allowing expansion and recoil of these arteries.
Dermal papillae.
Fingerprints left on things we touch are associated with
True
Freckles are elevated patches with an abnormal coloration of the skin a) True b) False
Glands
Glands are broadly classified as endocrine or exocrine; both types originate as invaginations of surface epithelium. (Fig. 5.29) a. Exocrine glands usually maintain contact with the surface by way of a duct. Examples are sweat, mammary, and tear glands, and also salivary glands, the liver, and the pancreas. b. Endocrine glands have no ducts; they secrete their products into the blood via the capillaries. i. The secretions, called hormones, function as chemical messengers that act on cells elsewhere in the body. ii. Examples of endocrine glands include the pituitary, thyroid, and adrenal glands. 3. Some glands have both exocrine and endocrine functions, such as the liver, pancreas, testis, ovary, and kidney.
Glands
Glands may also be classified by the nature of their secretions. a. Serous glands produce thin, watery fluids, such as tears. b. Mucous glands secrete a glycoprotein called mucin, which absorb water once it is secreted to form the sticky product mucus; examples are the goblet cells. c. Mixed glands contain both serous and mucous cells, such as the salivary glands in the chin. d. Cytogenic glands release whole cells; only the testes and ovaries are cytogenic glands.
Glands
Glands may be classified as merocrine or holocrine depending on how secretions are produced. (Fig. 5.32) a. Merocrine glands (eccrine glands) have vesicles that release secretions by exocytosis, such as tear glands. b. Holocrine glands accumulate the product in their cells, and then these cells disintegrate to release the product. An example is oil-producing glands of the scalp. c. Sweat glands and mammary glands are named apocrine glands from an earlier belief that the secretion consisted of apical cytoplasm. These glands have been found to be primarily merocrine in their mode of secretion.
Long Bone
Much of a long bone is composed of an outer shell of dense, white osseous tissue called compact (dense or lamellar) bone. The cylinder of compact bone encloses a space called the medullary cavity or marrow cavity, which contains bone marrow. 3. At the ends of the bone, the central space is occupied by osseous tissue called spongy (cancellous) bone; spongy bone is always enclosed by compact bone. The principle features of a long bone are its shaft (diaphysis) and an expanded head at each end (epiphysis). a. The diaphysis provides leverage. b. The epiphysis is enlarged to strengthen the joint and provide added surface area for attachment of tendons and ligaments. 6. The joint surface where bones meet is covered with a layer of hyaline cartilage called the articular cartilage, which enables a joint to move easily. 7. Blood vessels penetrate into the bone through minute holes called nutrient foramina. 8. Externally, a bone is covered with a sheath called the periosteum, which has a tough d. There is no periosteum over the articular cartilage. 9. A thin layer of reticular connective tissue called the endosteum lines the internal marrow cavity, covers all surfaces of the spongy bone, and the canal system. 10. In children and adolescents, an epiphyseal plate of hyaline cartilage separates the marrow spaces of the epiphysis and diaphysis. The cranium is a typical flat bone, with a sandwich-like arrangement in which two layers of compact bone enclose a middle layer of spongy bone.
. Nervous tissue consists of neurons and neuroglia (glial cells), which protect and assist the neurons. (p. 163) (Table 5.10) (Fig. 5.24) 1. Neurons detect stimuli, respond, and transmit information rapidly. a. Each neuron has a neurosoma, or cell body, that contains the nucleus and most other organelles and is the center of genetic control and protein synthesis. b. Dendrites are multiple short, branched processes extending from the neurosoma that receive signals from other cells. c. An axon, or nerve fiber, conducts outgoing signals from the neurosoma to other cells, some are more than a meter long. 2. Glial cells outnumber neurons and make up most of the volume of nervous tissue; they provide support, protection, and housekeeping functions.
Name the cell types that compose nervous tissue
epithelial, connective, nervous, and muscular tissue.
Name the four primary classes into which all adult tissues are classified.
. neuroglia.
Nervous tissue consists predominantly of two cell types, neurons and
adipose tissue.
New triglycerides are constantly synthesized and stored and others are hydrolyzed and released into circulation mostly from cells in
False
Nonkeratinized cells exfoliate from the surface of the skin a) True b) False
connective
Osseous tissue is a(an) ____________ tissue
False
Osteogenic cells are bone stem cells that differentiate into osteoblasts and osteoclasts.
True
Osteoid tissue is similar to bone except for a lack of minerals.
a. Lanugo is fine, downy, unpigmented hair that appears on the fetus in the last 3 months of development. b. Vellus is fine, pale hair that replaces lanugo by the time of birth. It is the body hair of children and comprises two-thirds of the body hair of women and one-tenth of the body hair of men. c. Terminal hair is longer, coarser, and pigmented, and forms the eyebrows and eyelashes, covers the scalp, and after puberty forms the axillary and pubic hair, the male facial hair, and some hair on the trunk and limbs.
Over the course of a lifetime, a person grows three different kinds of hair:
True
Parathyroid hormone (PTH) binds to receptors on osteoblasts
the same number of melanocytes, but in dark-skinned people, these cells produce greater quanitities of melanin, and the melanin breaks down more slowly.
People with different skin colors have
vertebral foramen
Posterior to the body is a triangular canal, the vertebral foramen. a. The vertebral foramina collectively form the vertebral canal through which the spinal cord passes.