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99 Cards in this Set
- Front
- Back
which layer is only found in the thick skin regions (palmar/plantar) and is described as a glassy layer of flat cells packed with keratin?
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Stratum lucidum
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this is the most superficial layer which varies in the number of individual cell layers, it is composed of tightly packed, dead, keratinized cells called "squames" and is continuously shed and constantly replaced.
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Stratum corneum
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What are the three pigments that define skin color?
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1. Carotene
2. Hemoglobin 3. Melanin |
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what pigment is the least common and creates an orange-yellow pigment from diet?
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Carotene
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Which pigment is the pigment of blood which varies with oxygen content? (The color tinges from epidermis to dermis)
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Hemoglobin
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Which pigment is the most common and is produced by melanocytes in stratum basale? (This is the primary determinant of variability in the skin color.)
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Melanin
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What type of sweat gland secretes a sticky, cloudy, and odorous secretion onto the hair follicles. It provides a nutrient source for bacteria.
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Apocrine sweat gland
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Where can you find apocrine sweat glands?
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in the axilla, anal, groin regions, and around the nipples
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What type of secretion glands secrete water, electrolytes, and metabolites onto the surface?
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Merocrine/Eccrine sweat gland
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Where can the merocrine/eccrine sweat glands be found?
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widely scattered over the body surface
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What type of secretion method do the apocrine and eccrine sweat glands use?
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Merocrine secretion
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What type of gland is most active late in fetal development and puberty, it produces sebum into hair follicle to lubricate hair and skin?
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Sebaceous gland
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What type of secretion method does the sebaceous gland use?
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Holocrine secretion
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These type of glands evolved from sebaceous glands, their development and secretions are controlled by pituitary and sex hormones
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Mammary glands
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These type of glands are located in the external ear and secretes cerumen (ear wax)
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Ceruminous glands
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Which layer of skin transmits nerves and receptors for pain, touch, temperature, pressure, and vibration. It also transmits all small blood vessels supplying skin
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Dermis
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What is the papillary layer of the dermis composed of?
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Connective tissue organized to form dermal papillae. Also contains capillary beds and nerve endings.
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this layer of the dermis has the deepest layer of dense irregular connective tissue and bundles of collagen fibers extending through throughout.
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Reticular layer
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The elastin in the reticular layer are affected by what main factors?
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1. UV
2.Age 3. hormones |
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What is the hypodermis composed of?
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loose and adipose connective tissue with varying amounts of adipocytes that connects underlying muscle and bone to the dermis.
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What is different about the subcutaneous layer, compared to the rest of the layers?
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It contains larger blood vessels
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What structures are hard derivative of epidermis on the dorsal surface of digit tips, the cells that form this structure are heavily cornified and develop from specialized region of stratum corneum called nail matrix.
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Nails
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What is the purpose of the nails?
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To protect distal phalanges from damage.
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What is the purpose of hair?
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Offers protection, thermoregulation, chemical signal dispersal and secondary sexual characteristics.
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What does the hair follicle consist of ?
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Modified superficial stratum layers from epidermis, oblique tube that surrounds the hair, sebaceous glands secrete into follicle and it is surrounded by dermal root sheath.
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What are the three parts of the hair in which keratin is found?
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1. shaft
2. root 3. hair bulb |
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what is the shaft of the hair?
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the exposed end
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what is the root part of the hair?
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part set in the follicle in dermis
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What does the hair bulb consist of?
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1. Papilla
2.Matrix 3.Melanocytes |
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Small projection of dermis which provides blood supply found in the hair bulb
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Papilla
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the location of cell division found in the hair bulb
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Matrix
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pigment cells in papilla are known as?
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Melanocytes
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Define Errector (arrector) pili muscles
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smooth muscles from papillary region to hair follicle
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which epidermis layer do basal cell carcinoma arise from?
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Stratum basale
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which epidermis layer do squamous cell carcinoma arise from?
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stratum spinosum
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Cancer of melanocytes is known as?
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Malignant melanoma
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What type of tissue is responsible for the movement of the materials within and through out the body; temperature regulations and support?
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Muscle tissue
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four unique qualities of muscle tissue include
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1.excitability
2. contractibility 3.elasticity 4. extensibility |
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Where can you find smooth muscle?
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located in walls of blood vessels, gastrointestinal, lower respiratory tract, lower esophagus and glands
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What are the three types of skeletal muscle and what are the main characteristics of each?
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1. Fast glycolytic; very strong and fast but quick to fatigue. Lack myoglobin
2.Oxidative-glycolytic; Not quite as strong and doesn't last as long. INTERMEDIATE OF OTHER TWO. 3.Slow oxidative; physically weak and contract slower but fatigue resistant, last longer. Contains myoglobin |
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What are the three levels of organization of the skeletal muscle?
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1. Epimysium
2. perimysium 3. endomysium |
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What is the Epimysium layer made of and what is its purpose?
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Dense irregular connective tissue fascia that envelopes entire muscle belly
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What is the Perimysium layer made of and what is its purpose?
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Connective tissue septa that divides belly into compartments containing fiber bundles called fascicles.
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What is the Endomysium layer made of and what is its purpose?
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fine connective tissue extensions of perimysium that envelope fibers.
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what is the sarcolemma?
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cell membrane of muscle fibers
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What are t-tublues?
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transverse tubules continuous with sarcolemma passing around microfibrils
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what is sarcoplasmic reticulum?
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specialized ER, for Ca++ storage
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what are terminal cisternae?
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they are enlarged ends of SR
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What is a sarcomere and what are the 5 major components?
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A sacromere is the basic unit of muscle contraction and it is made of
1. Z- disc 2.I band 3. A band 4. H zone 5. M line |
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what is the z-disc of a sarcomere?
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dense structural protein discs
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what is the I-band of a sarcomere?
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area either side of the z-line composed of only think filaments.
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what is the A band of a sarcomere?
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this is the dark band with both thick and thin filaments
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what is the H zone of a sarcomere?
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contains only thick filaments
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what is the M-line of a sarcomere?
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Fine ling marking center of the sacromere
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What are thin filaments composed of?
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MULTIPLE LAYERS of actin
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What are thick filaments composed of?
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myosin
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What is the Huxley's sliding filament hypothesis?
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attach, pivot, detach, return.
slides filaments past each other and cause the sarcomere to shorten and the muscle to contract. When stimulation ends, calcium returns to the terminal cisternae, filaments slide back passively and the muscle relaxes. |
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What is Rigor Mortis?
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Without ATP cross bridges cannot detach, muscles contract and lock into a contracted position until autolytic processes start breaking down muscle fibers.
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What are the three systems in which nervous tissue is distributed?
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Central nervous system (CNS)
Peripheral nervous system (PNS) autonomic nervous systems (ANS) |
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What does the CNS consist of?
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brain and spinal cord
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what does the PNS consist of?
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peripheral nerves
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what does the ANS consist of?
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sympathetic and parasympathetic nervous system
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What are the two major types of cells that make up nervous tissue?
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Neurons or excitable cells and glial cells or non-excitable cells.
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What is the purpose of neuron cells?
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To initiate and transmit nerve impulses.
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What is the purpose of glial cells?
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To support and protect neurons
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What does a typical neuron consist of?
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cell body, dendrites and axons
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What does the cell body of a neuron do?
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it is the control center of the neuron, receives, integrates, and sends impulses.
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Clusters of cell body (Soma) in CNS are known as?
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nucleus
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Clusters of cell body (Soma) in PNS are known as?
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ganglion
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What are dendrites?
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Short processes from the body that may be single or multiple. They are the receptive region of the neuron that conducts impulses towards the body to be processed. The more dendrites the more nerve impulses that a neuron can receive from other cells.
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What are axons?
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Longer cell process, usually single. Transmits a nerve impulse away from the cell body towards another cell.
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What are telodendria?
What are synaptic knobs? |
1.processes at the end of an axon
2. axon terminals |
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what are Unipolar neurons?
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Single process from soma divides to form axon
(typical sensory neurons from receptor to CNS) |
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what are Bipolar neurons?
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Two processes from the soma.
(typical for sensory neurons of the retina, inner ear, olfactory epithelium) |
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What are multipolar neurons?
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dendrites and axons arise from soma. include all motor neurons, ascending and descending neurons of the CNS
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What do sensory/afferent neurons do?
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Carry impulses TO the CNS, ascending neurons within the CNS.
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what do motor/efferent neurons do?
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Carry impulses FROM the CNS, descending neurons within the CNS.
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What are internerons?
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Multipolar neurons, found only in the CNS, they receive impulses from many other neurons and carry out an integrative function of the nervous system.
Facilitate communication between sensory and motor neurons. |
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How common are Electrical synapses and where can you can find them?
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they are rare. They occur primarily between cells of smooth muscle and cardiac muscle (in gap junctions). Used where quick, uniform innervation is essential.
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What is chemical synapses?
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Facilitates most of the interactions between neurons, and neurons and effectors.
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what is the pre-synaptic membrane?
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cell membrane of axon terminals; stores vesicles with neurotransmitters
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what is the postsynaptic membrane?
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membrane has receptor for specific neurotransmitter
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what is the synaptic cleft?
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the gap between pre and post synaptic membranes. This is how most drugs are effective.
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What are Glial cells?
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supportive cells of the nervous system. They aid in conducting impulses, but do not carry any stimulus. They are smaller than neurons but out number them. They are also capable of mitosis and occur in both the PNS and CNS.
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What are the types of glial cells?
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Oligodendrocytes, Schwann cells, Astrocytes, Ependymal cells, microglia
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What are main characteristics of astrocytes?
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Have a star-like shape, most abundant of cells in CNS. Help for the Blood Brain Barrier that controls substances from entering the nervous tissue via the blood stream.
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What do Oligodendrocytes form?
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They form the myelin sheath around brain neurons. Found in CNS
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what do microglia do?
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Phagocytize microbes and damaged cells. (clean up crew)
CNS |
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What are main characteristics of ependymal cells?
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They posses microvilli and cilia, line ventricles and are involved in production and circulation of CSF.
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What are Schwann cells responsible for?
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responsible for myelinating PNS axons, multiple cells encircle an axon to for the myelin sheath.
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What are Satellite cells?
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Flat cells that surround PNS ganglia.
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What is a myelin sheath?
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A fatty coating that gives nerves glossy white appearance. It supports, protects and insulates the axon.
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Internodes are __?
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Segments of myelin
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gaps between internodes are called ___?
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Nodes of ranvier
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What is Saltatory conduction?
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when the nerve impulse jumps from node to node, produces a faster nerve impulse and requires less energy.
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What is an unmyelinated axon?
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the nerve impulse must travel the entire length of the axon in (Continuous conduction) produces slower nerve impulse.
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what is the difference between unmyelinated axon and a myelinated axon?
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myelinated axons produce faster, less expensive nerve impulses.
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What is Multiple Sclerosis?
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A nervous system disorder, an autoimmune disease where the body attacks the myelin and nerve impulses travel slower or not at all because of plaque.
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Are cell bodies of neurons replaced by daughter cells like in epithelial tissue?
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No, cell bodies of neurons can only be repaired through regeneration after an injury, they lose all mitotic features at birth.
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