BI 331 Quizes 9-22

Consider the data examined in class for developing burn therapies. Which of these data most strongly support the idea that fish skin are a superior product to the Kaltostat? (* indicates p<0.05, T-test relative to control, # indicates direct comparison between bracketed items, p<0.05, T-test)

After 7 days, the wound covered with collagen was significantly smaller than the wound covered with Kaltostat

Whole skeletal muscles are organs. Therefore they contain (select all that apply):

Connective tissue, Muscle tissue, Epithelial tissue, Neural tissue

Vitamin D is required for absorption of dietary calcium. Using the graphs, which graph best depicts the effect of increasing calcium intake (assume vitamin D present) on bone mass?

Graph D

Using the prior figure, where do you find the cells capable of producing osteoid?

H & O, but not N

Using this figure, where would you find canaliculi?

I & F but not M

For connective tissues compared to muscle tissues, are the proteins intracellular or extracellular?

In connective tissues, the proteins are extracellular

Where do you find the cells that act to remodel or maintain bone?

In osteon lacunae, In the periosteum found covering bones, In the endosteum found lining the medullary cavity, Lining the central canal of the osteon

Below represents data from four different clinical trials in which different medications were administered and lumbar spine bone mineral density was observed. For each clinical trial, medications and a placebo were given to postmenopausal women (treatment group, control group), except for the growth hormone trial in which growth hormone (or placebo) was administered to growth hormone deficient adult males age 24-63. All data shown are in relative reference to baseline bone mineral density recorded before trial onset. Using this image, what do these hormones/medications show?

Increased bone density with treatments of growth hormone, calcitonin, bisphosphonates & estrogen

Tendons are a connective tissue. They have many collagen fibers. Which of the following best describes where these fibers are located?

Outside the tendon cells, in the extracellular matrix

According to this figure, what gland is the primary controller for regulating blood calcium?

Parathyroid gland

What type of epithelium is shown here?

Stratified squamous epithelium

You are a histologist and are looking at a sample in the microscope. There are many layers of well defined cells that contact each other. The cells at the bottom (near the next underlying tissue) are cuboidal in shape and the cells at the surface (not in contact with another tissue) are flat and thin. What is the most likely classification of this tissue?

Stratified squamous epithelium

Suppose you step on a nail. What layer of the epidermis do you penetrate first?

Stratum corneum

You are a histologist and are looking at a sample in the microscope. There are many layers of well defined cells that contact each other. The cells at the bottom (near the next underlying tissue) are cuboidal in shape and the cells at the surface (not in contact with another tissue) are flat and thin. What is the most likely source of this tissue?

The oral cavity (mouth)

The periosteum is a double layered structure on the outside of all bones. The outermost layer is a fibrous connective tissue, the innermost layer (adjacent to the cortical bone) is a layer of osteoblasts, osteoclasts and osteogenic/osteoprogenitor cells. What are the two roles of the periosteum?

The outer fibrous layer attaches muscle; the inner cellular layer deposits or removes bone

Which of the following happens during formation of the ulna?

The outer periosteal bone forms before the inner spongy bone

Using figure 1, what is happening during C & D?

The sodium voltage gated channels are either open or are incapable of opening.

What is the relationship between the muscles crossing a joint and that joint's properties (ie: joint stability, mobility or range and type of motion)? When answering this question, assume muscles are balanced on all sides of the joint.

The stronger the muscles crossing a joint, the more stable the joint

In vitamin C deficiency you cannot synthesize collagen. Which of the following would most likely occur?

Your skeleton would become malformed.

Using the big graph above, which of the following is TRUE about the trace above?

all these traces were recorded on the axon membrane

The compressible fibrocartilaginous joint between spinal vertebrae is functionally classified as _________and structurally classified as __________

amphiarthrosis; cartilaginous

What is a myofibril?

an organelle

This image is of a skeletal muscle cell (myofiber). What is the sarcolemma?

cell membrane

What level of organization is this image?

muscle cell

After a bone fracture, bone repair occurs. Depending on the severity of the break and the distance between the bone fragments, bone healing can occur in two ways: direct and indirect bone healing. With direct bone healing, the broken elements must be very close together and osteoblasts present at the site of injury deposit concentric lamellae around blood vessels. Indirect bone healing occurs when bone fragments are further apart. Initially, a large vascular response occurs, bringing cells and nutrients to the site of injury. Then, a temporary bridge (patch) forms. The temporary patch consists of cells and collagen fibers in a gelatinous, avascular matrix. The patch is then replaced by woven, trabecular bone but is later remodeled into mature bone. This type of bone repair can occur in spongy or compact bone and involves many cell types.Using the passage, what structures are formed during direct fracture healing?

osteons

The growth plate between the epiphysis and diaphysis of a long bone is functionally classified as ________ and structurally classified as____________

synarthrosis; cartilaginous

The Joint between the teeth and the jaw bone is functionally classified as ______ and structurally classified as __________

synarthrosis; fibrous

The calcified suture lines between flat skull bones is functionally classified as _____ and structurally classified as _________-

synarthrosis; fibrous

In the body we identify four primary tissue types: epithelial tissue, muscle tissue, connective tissue and neural tissue. Epithelial tissues usually share an embryological origin and are located over external body surfaces (epidermis from the ectoderm), lining body cavities and hollow organs (stomach, lungs, bladder, etc from the endoderm), and make up glandular tissue throughout the body (exocrine sweat, mammary glands derived from the ectoderm, as well as endocrine glands like thyroid, pancreas, etc derived from the endoderm). In this first model, you will investigate the structure of epithelial tissues. Shown here are 6 types of epithelia - the name of each type of epithelium is written below the tissue shown.

the number of layers of cells

After a bone fracture, bone repair occurs. Depending on the severity of the break and the distance between the bone fragments, bone healing can occur in two ways: direct and indirect bone healing. With direct bone healing, the broken elements must be very close together and osteoblasts present at the site of injury deposit concentric lamellae around blood vessels. Indirect bone healing occurs when bone fragments are further apart. Initially, a large vascular response occurs, bringing cells and nutrients to the site of injury. Then, a temporary bridge (patch) forms. The temporary patch consists of cells and collagen fibers in a gelatinous, avascular matrix. The patch is then replaced by woven, trabecular bone but is later remodeled into mature bone. This type of bone repair can occur in spongy or compact bone and involves many cell types.Using the passage, during indirect bone healing, what likely happens before the woven, trabecular bone is deposited?

the temporary patch is destroyed

Which of the following make up spongy bone?

trabeculae

_____ are useful in the skeleton because they remodel most readily in response to stress and efficiently transmit forces while remaining lightweight.

trabeculae

Finish the sentence: I think if a joint is more stable, it will....

will be less likely to dislocate than a similar type, but less stable joint.

Using the big graph above, which trace(s) directly reflect/s movement of chloride ions through open chemically gated channels (adult cell)?

5

Using figure 1, what type of stimulus would generate another action potential during E & F?

A large suprathreshold depolarizing graded potential.

In certain neurological disorders, the neurons controlling muscles continuously activate skeletal muscles causing rigidity. Which of the following medications would be most effective at treating these disorders?

A medication that extends the absolute refractory period in these neurons

For the adrenal gland, which of the following would explain why some cells of the body do not respond to hormones from the outer adrenal cortex?

Because some cells lack receptors for cortex hormones in their cytoplasm

After a fracture, what is the correct sequence of repair for indirect bone healing?

Blood clot, cartilage patch, bony patch, bone remodel

Which statement correctly describes both the epidermis AND dermis?

Both are superficial to the hypodermis.

Which of the following would be a symptom of severe lack of vitamin D in children aged 4-6?

Bowed lower limbs

Looking at these graphs, what is different about the calcitonin graph compared to the others (calcitonin is the lower left graph)?

Calcitonin has a smaller bone mineral density change compared to the others.

Which of the following is the most likely mechanism by which blood calcium levels are detected in the thyroid and parathyroid?

Calcium binds to a cell membrane receptor which activates a second messenger system

In the picture of the epidermis in this quiz, what are those lines between the keratinocytes?

Desmosomes

How does the epidermis receive its nutrients?

Diffusion from capillaries in the dermis

For connective tissue compared to muscle tissue, do cells or extracellular matrix (ECM) make up more of the total tissue volume?

ECM

According to this image, what connective tissue layer surrounds whole muscle?

Epimysium

Bone mass (or bone density) is homeostatically regulated.

False

During formation of the mandible, the first osteoblasts to appear were delivered by blood vessels.

False

True or False? Accessory structures are called "epidermal structures" because even though they reside in the dermis, they are made of, and by, epidermal cells.

False

True or False? All epithelial cells are dead because all epithelial tissues are avascular.

False

True or False? People with darker skin have more melanocytes than people with lighter skin.

False

True or False. This movement is rotation.

False (This shown movement in the question is circumduction.)

Muscle tissue is specialized for creating movement. Connective tissues are all derived from a common embryological tissue (mesenchyme which can derive from either ectoderm or mesoderm) and perform various functions including support, binding, storage, and transportation. In this image, the top panel shows the three types of muscle tissue, the bottom panel shows some of the many connective tissues. For Connective Tissue, are the cells relatively close to each other or relatively far from each other (when compared to muscle)?

Farther away than muscle cells

Which of the following explains why females at end of life have lower bone mass than males?

Females have lower peak bone mass than males

Which organ is best described as one in which most of the tissues have some cells, but there is more extracellular matrix than cells and that ECM is solid at maturity?

Femur

Using the graphs, which graph best depicts the effect of age at time of regular exercise introduced (min=5 years, max = 80 years) on end of life bone mass? Assume otherwise equal factors (sex, hormone level, diet, etc). (Age at time of regular exercise introduced means that at age 5, this person started exercising regularly and continued to do so until they died.)

Graph A

Thinking about adrenal gland hormones, answer the following questions using an appropriate graph from these graphs. Consider the adrenal cortex hormones. Which graph depicts cortex hormone diffusion rate across the cell membrane as blood concentration of the hormone increases to maximal levels? (Assume no net increase in intracellular hormone concentration, assume maximal levels far exceed normal physiological levels)

Graph C

Consider the adrenal cortex hormones. Which graph depicts target cell's response as blood concentration of the hormone increases to maximal levels? (Assume no adaptation of target cell to hormone over time, assume maximal levels far exceed normal physiological levels)

Graph D

Using the graphs above, consider an excitatory synapse between a presynaptic and postsynaptic neuron. Which trace depicts increasing Ca2+ influx into the presynaptic neuron on AP frequency of the post synaptic neuron? (Assume no neural fatigue)

Graph D

Using the graphs, which graph best depicts the effect of increasing protein intake (assume calcium & vitamin D present) on bone mass?

Graph D

What type of tissue growth is occurring inside the circled area shown?

Interstitial growth

What is the effect of increased blood flow to the dermis?

It increases heat loss to a colder external environment., It causes a change in light skin color in the area of increased blood flow, It increases nutrient delivery to the cells of the epidermis.

The liver is a glandular organ that functions to secrete many substances to the blood or digestive tract, detoxify chemicals and synthesize molecules utilized by all the cells of the body. What do you think is its likely histologic composition?

It is mostly epithelial tissue

The most abundant type of cell in your epidermis is:

Keratinocytes

This figure shows the levels of sex hormones (estrogen and testosterone) from birth to old age. Estrogen in women is the solid purple line; Testosterone in men is the dotted green line. Using this figure, why are men less likely to suffer osteoporosis than women?

Men's adult sustained levels of sex hormone continue to stimulate osteoblasts preventing osteoporosis

Mature osseous connective tissue (bone) is composed of collagen fibers and mineralized matrix. When osseous CT is first made, the osteoblasts secrete osteoid onto which calcium salt then precipitates. What is osteoid?

Mostly collagen or collagen pre-cursors

Neurons are specialized for communication. They are capable of sending electrical signals due to the presence of many ion channels and pumps on the cell membrane that they constantly maintain or replace as needed. Which of the following would be NOT consistent with this information?

Neurons are anucleate (they do not have nuclei)

Using figure 1, what type of stimulus would generate another action potential during C & D?

None

Which trace(s) of the transmembrane potential shows additional action potentials occurring during the absolute refractory period?

None

The skeletons of newborn children lack the bony processes where muscles attach, though they form in the first years of life. Which of the following best explains how and where these processes develop?

Periosteal osteoblasts are stimulated by physical stresses generated by tendons

Consider the data examined in class for Causes of Death from Burns. Which of the following best explains why sepsis rates in recovering burn victims has changed over the two time periods examined (note that the line divides the data in two different ways, by year above the line and by sex below the line)?

Sepsis rates increased because bacteria became resistant to antibiotics which prevented effective treatment

During development, if a problem arises with the ectoderm, which of the following would most likely be affected?

Signal conduction in the brain

What is the difference between spongy bone and compact bone?

Spongy bone and compact bone are microscopically arranged differently

In the normal 30 year old skeleton, osteoclast activity is matched by osteoblast activity. What would happen if osteoclast activity was greater than osteoblast activity?

The bones would become weaker.

Which of the following would be most likely found in a cell that is subjected to significant mechanical strain (such as a cell in the outer skin)?

The cell would have many cytoskeletal elements

In which of the following would you expect to find osteons?

The diaphyseal cortex of the humerus

What determines the maximum frequency of AP generations in a neuron?

The duration of the absolute refractory period

In bones, a layer of osteoblasts and osteoclasts line the interior of the bone (this cellular layer covers all trabeculae, is adjacent to the medullary cavity and lines the inside of osteons). This layer is called the endosteum. What is its role in bone?

The endosteum can add or remove bone from the inside of bones, remodeling them.

The below graphs show schematic illustrations of the effect of physical activity on bone mass throughout life for both male and female humans. For each graph, the red curve represents a continuous exercise effect (meaning, from the appearance of the red line, this is when exercise was introduced into their life and regular exercise remained). The yellow curve represents a sedentary person engaging in normal activities (such as walking, but not regular continuous exercise). Note for each group that exercise is introduced at different points in life (ages). Using this model, What can be said about bone mass?

The greater peak bone mass, the greater end of life bone mass.

Which are cartilaginous joints?

The joint between the pubes and the joint between the bodies of adjacent vertebrae

What characteristic unites all connective tissue?

They all come from a common embryonic tissue (mesenchyme)

What changes occur in the epidermal keratinocytes as they migrate from the stratum basale (germinativum) to the stratum corneum?

They dehydrate, die and become full of keratin

How does calcium act during synapses?

To play a role in chemical reactions at the terminal end

Keratin is an intracellular protein.

True

True or False? The epidermis protects the body from excessive water los

True

True or False? The sooner a person enters puberty, the sooner they will reach peak bone mass.

True

The joint between mandibular condyle and mandibular fossa is functionally classified as _______and structurally classified as __________

diarthrosis; synovial

How do nutrients reach osteocytes trapped between lamellae of osteons?

diffusing from the central canal to the cells via canaliculi

The liver is a glandular organ of the digestive tract. What is its most likely embryological origin?

endoderm

Shown below are cross-sections through a long bone at the level of the mid-diaphysis. The light gray represents new bone that is being formed at three different life stages. Secondary osteons represent where a previous osteon has been removed and then a new one deposited.

endosteal cells of osteons

Third degree burns injure: (select all that apply)

epidermis, dermis, hypodermis

According to this image, what is wrapped by the perimysium?

fascicles

The __________ are joined to one another by __________ joints.

flat hand bones (carpals); synovial

In the growing 10 year old, the humerus becomes longer through ____ and wider through ____.

interstitial growth and endochondral bone formation; appositional growth at the periosteum

After a bone fracture, bone repair occurs. Depending on the severity of the break and the distance between the bone fragments, bone healing can occur in two ways: direct and indirect bone healing. With direct bone healing, the broken elements must be very close together and osteoblasts present at the site of injury deposit concentric lamellae around blood vessels. Indirect bone healing occurs when bone fragments are further apart. Initially, a large vascular response occurs, bringing cells and nutrients to the site of injury. Then, a temporary bridge (patch) forms. The temporary patch consists of cells and collagen fibers in a gelatinous, avascular matrix. The patch is then replaced by woven, trabecular bone but is later remodeled into mature bone. This type of bone repair can occur in spongy or compact bone and involves many cell types.Using the passage, during indirect and direct bone healing in the normal, healthy adult aged 40, which of the following would be recommended to help repair a fractured bone?

moderate weight bearing activity

Using figure 1, what type of stimulus would trigger an additional action potential during time period 9?

persistent binding of neurotransmitter at a chemically gated Na+ channel

In skeletal muscle, the sarcoplasmic reticulum stores calcium. What organelle is the sarcoplasmic reticulum?

smooth ER

Sitting superior to the kidneys are two small, endocrine glands called the adrenal glands. Anatomically, these glands have an outer cortex and inner medulla, with each part responsible for producing different hormones (see picture).For the adrenal gland, the cells of the outer cortex produce hormones that require a blood transport protein for circulation through the blood. Which of the following organelles would you expect to find in great abundance in the adrenal cortex cells to produce these hormones?

smooth ER