IPAP, A&P I, Block 2
Synaptic end bulbs
Ends of axon terminals, bulb-shaped structure
Nissl bodies
Prominent clusters of rough endoplasmic reticulum in neurons
Parathyroid hormone
Promotes resorption of bone matrix, increases blood calcium level
Actin
1
Axon
1
Cell body
1
Axon terminal
15
Epidermis
15
I band
15
Central nervous system
1
Dendrites
1
Dermal papilla
1
Inner compact bone
1
Interosseous membrane
1
Interstitial lamellae
1
Keratin
1
Leakage channel
1
Schwann cell myelin sheath
15
Extensible
Can extend or stretch
Elastic
Can return to their original shape
Spongy bone
Cancellous bone or trabecular bone
Autorhyhmicity
Cardiac muscle exhibits what?
reuptake
a neurotransmitter's reabsorption by the sending neuron that released it
Myosin heads hydrolyze ATP and become oriented and energized
1
Gomphosis between tooth and socket of alveolar process
4
Myosin binding site (covered by tropomyosin)
4
Sarcolemma
4
Sensory neuron
4
Stratum spinosum
4
Thin Filament
4
Voltage gated K+ channels are open; Na+ channels are inactivating
4
Voltage gated channel
4
Chondroblasts
Cartilage forming cells, form chondrocytes
Two types of sweat glands
Eccrine and apocrine
Outer circumferential lamellae
Encircles bone tissue beneath the perisoteum
Inner circumferential lamellae
Encircles the medullary cavity in bone tissue
Blood vessels
4
Coronal suture
4
Corpuscle of touch
4
Resting membrane potential; voltage gated Na+ channels are in the resting state and voltage gated K+ channels are closed
1
Root of tooth
1
Sarcoplasmic reticulum
1
Stratum corneum
1
Thick filament
1
Z disc
1
Zone of Overlap
13
Cell body
14
Free nerve ending
14
H Zone
14
Epilepsy
"Electrical storm of the brain", discharges stimulate neurons to send spontaneous impulses, resulting in the perception of lights, noises, and smells that do not exist and for which the corresponding sense organ has not been stimulated.
Axon hillock
"Small hill" elevation in the cell body where the axon arises
Transverse tubules
(T-tubule) a cul-de-sac opening from outside the fiber toward the interior of the fiber. Invaginate from the sarcolemma, and extend toward the interior of the cell.
Calcitrol
(Vitamin D) promotes intestinal absorption of calcium
9%
1
Slow axonal transport
1-5 mm per day, one way only, from the cell body to axon terminals
Schwann cell cytoplasm
14
9%
10
Axon terminal
10
Enteric Motor Neurons
10
Lamellated (Pacinian) corpuscle
10
Mitochondrian
10
Neurofibril
10
Tactile disc
10
Titin filament
10
1%
11
Dendrites
11
Enteric Sensory neurons in GI tract
11
Nucleus
11
Sarcomere
11
Sensory nerve
11
Sensory neuron
11
Z disc
11
14%
12
Adipose tissue
12
Melanocyte
12
Nucleus of Schwann cell
12
Sarcomere
12
Trigger zone
12
Z disc
12
Cranial nerves
12 pairs of nerves that carry messages to and from the brain
Axon
13
Hair shaft
13
Neurolemma of Schwann cell
13
A band
16
Papillary region
16
Schwann cell neurolemma
16
Dermis
17
Node of ranvier
17
Neurofibril
18
Reticular region
18
Axoplasm
19
Subcutaneous layer
19
18%
2
Cell body
2
Dendrites
2
Fibula
2
Ligand gated channel
2
M line
2
Melanin granule
2
Myofibril
2
Myosin Tail
2
Myosin heads bind to actin, forming cross-bridges
2
Outer Circumferential lamellae
2
Peripheral nervous system
2
Schwann cell
2
Socket of alveolar process
2
Spongy bone
2
Stimulus causes depolarization to threshold
2
Stratum lucidum
2
Sweat pore
2
Troponin
2
Axolemma
20
Fast axonal transport
200-400 mm per day, two-way transport, both toward and away from cell body
Axon terminal
21
Synaptic end bulb
22
Dendrites
23
Cell body
24
Neuroglia
25
Bone matrix
25% water, 25% collagen (for flexibility and tensile strength), 50% hydroxyapatite (calcium phosphate and calcium carbonate) - for hardness
Stratum corneum
25-30 layers of flattened, dead cells. Interior of cells contains mostly keratin. Lipids form lamellar granules between cells, providing waterproofing.
Axon
26
18%
3
Axon
3
Concentric lamellae
3
Endoneurium
3
Mechanically gated channel
3
Myosin Heads (crossbridges)
3
Myosin cross-bridges rotate toward center of sarcomere (power-stroke)
3
Outer compact bone
3
Periodontal ligament
3
Sarcoplasm
3
Sebacious gland
3
Somatic Nervous System
3
Stratum granulosum
3
Tactile (Merkel) disc
3
Thick filament
3
Tibia
3
Trigger zone
3
Tropomyosin
3
Voltage-gated Na+ channel activation gates are open
3
Stratum granulosum
3-5 layers of flattened keratinocytes, transition between deeper living cells and the more superficial dead cells.
Spinal nerves
31 pairs of nerves arising from the spinal cord
9%
4
Anterior tibiofibular ligament
4
As mysoin heads bind ATP, the cross-bridges detach from actin
4
Autonomic Nervous System
4
Axon
4
Axon collateral
4
Axon terminal
4
18%
5
Arrector pili muscle
5
Axon terminal
5
Enteric Nervous System
5
Inhibitory Neurotransmitter
5
Initial segment
5
Lymphatic vessels
5
Nucleus
5
Stratum basale
5
Z disc
5
voltage-gated K+ channels are still open; Na+ channels are in resting state
5
1%
6
Absolute refractory period
6
Axon hillock
6
Dead keratinocytes
6
Dendrite
6
Excitatory neurotransmitter
6
Hair follicle
6
Osteon
6
Sarcomere
6
Somatic and Special Sensory nerves
6
Thick filament
6
18%
7
Cell body
7
Hair root
7
Lamellar granules
7
Lymphatic vessel
7
Mitochondrion
7
Relative refractory period
7
Somatic motor neurons (voluntary)
7
Thin filament
7
Trigger Zone
7
thin filament
7
18%
8
Autonomic sensory neurons
8
Compact bone
8
Cytoplasm
8
Eccrine sweat gland
8
Keratinocyte
8
Postsynaptic Neuron
8
Thick filament
8
Threshold
8
Transverse tubule
8
Trigger zone
8
Stratum spinosum
8-10 layers of keratinocytes; few langerhans cells.
18%
9
Apocrine sweat gland
9
Autonomic Motor Neurons (involuntary)
9
Axon
9
M line
9
Merkel cell
9
Nissl bodies
9
Resting membrane potential
9
Terminal Cisterns
9
Keratinocyte
A
Multipolar neuron
A
Myofibril
A
Open Fracture
A
Sarcomere
A basic functional unit of skeletal muscle.
Twitch
A brief contraction of all the muscle fibers in a motor unit
Aponeurosis
A broad, flat tendon
Fascicle
A bundle of muscle fibers
Calsequestrin
A calcium-binding protein inside the sarcoplasmic reticulum, thereby enabling the calcium concentration in a relaxed muscle to be 10,000 times higher than in the cytosol
Varicosities
End of axon terminals, string of swollen bulbs
Blister
A collection of serous fluid within the epidermis or between the epidermis and dermis, due to short-term but severe fricton
Myograph
A device used to measure the force generated by contracting muscle. It is an example of a transducer, which is something that converts one form of energy into another.
Myopathy
A disease or disorder of skeletal muscle tissue
Rabies
A fatal disease caused by a virus that reaches the CNS via fast axonal transport, usually transmitted by the bite of a dog or other meat-eating animal.
Ganglion
A group of neuronal cell bodies in the peripheral nervous system
Synapse
A junction between two neurons, or between a neuron and an effector (muscle or gland). Contribute to homeostasis by providing for evaluation, and integration of stimuli. Physically changed with repeated use.
Ligand-gated channel
A ligand is a chemical that binds to a receptor molecule and opens this type of channel
Motor unit recruitment
A mechanism for increasing tension (contractile length) in a muscle by activating more motor units. Much of initial strength gain after initial weight training is a result of this.
Diverging circuit
A nerve impulse from a single presynaptic neuron causes the stimulation of increasing number of cells along a circuit, amplifies the original signal.
Peripheral nerves
A network of nerves that branch out from the spinal cord and connect to the rest of the body and transmit signals to and from the brain through the spinal cord.
Cramp
A painful spasmodic contraction. May be caused by inadequate blood flow to muscles, overuse of muscle, dehydration, holding a position for an extended period of time, or low levels of electrolytes.
Converging circuit
A post synaptic neuron receives nerve impulses from several different sources, more effective stimulation or inhibition of the postsynaptic neuron that synapse with skeletal muscle fibers may receive input from several pathways
Tropomyosin
A protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscular contraction
Myogram
A record of muscle contraction initiated by direct electrical stimulation of either a motor neuron or its muscle fibers.
White matter
A region predominantly filled with myelinated tract fibers. Appearance is due to whitish color myelin.
Gray matter
A region predominately filled with neuronal cell bodies. There is little or no myelin in these areas, and the Nissl bodies impart a gray color
Myofiber
A single muscle cell
Motor unit
A somatic motor neuron plus the muscle fibers that it stimulates
Saltatory conduction
A special mode of impulse propagation that occurs along myelinated axons
Fibrillation
A spontaneous contraction of a single muscle fiber that is not visible under the skin, but can be recorded by electromyography. Fibrillation may signal destruction of motor neurons.
Spasm
A sudden involuntary muscle contraction
Carotene
A yellow-orange pigment that is a precursor to vitamin A, used to synthesize pigments needed for vision.
Suture between skull bones
A.
glycolysis
ATP from this method lasts 30-40 seconds
Aerobic cellular respiration
ATP production from this method lasts indefinitely (assuming sufficient oxygen and nutrients such as pyruvic acid, fatty acids, and amino acids which can enter the aerobic respiration pathway are present)
Neuromuscular disease
Abnormalities of skeletal muscle function may be due to disease or damage of any of the components of a motor unit (somatic motor neruon, neuromuscular junction, muscle fibers - encompasses problems at all three sites)
Depolarization
Accompanies opening of voltage-gated Na+ channels, triggering an action potential.
Repolarization
Accompanies voltage gated K+ channels opening and Na+ channels closing.
Motor end plate
Acetylcholine binds to special receptor-channels at this locations. Has deep grooves called junctional folds.
Small molecule neurotransmitters
Acetylcholine, amino acids, biogenic amines, ATP and other purines, nitric oxide
Thin filaments of myofibril
Actin, troponin, tropomyosin
Two types of neuronal electrical signals
Action potentials and graded potentials
Electrical synapse
Action potentials are conducted between adjacent gap junctions- hundreds of connexons per gap junction connect the cytosol of the adjacent cells, ions flow from one cell to the other, conveying the action potential.
Impulses
Action potentials generally arise in the trigger zone, the junction of the hillock and initial segment
Muscle action potential arrives in T-tubules, calcium channels open in the terminal cisterns
Active transporter continuously pumps calcium ions into the sarcoplasmic reticulum, concentration of calcium in the cytosol is very low when the muscle is relaxed.
Bone deposition
Addition of minerals and collagen fibers to bone by osteoblasts
2 grams
Adults need _______ grams per day of creatine, to make up for urinary loss and breakdown
Neural circuits
Billions of neurons in the CNS are organized into networks, a functional group of neurons that processes a specific kind of information
Neurolemmocytes
Also known as Schwann cells
Subcutaneous layer
Also known as hypodermis; composed of areolar and adipose tissues (fat, fibers that attach dermis to deeper tissues, large blood vessels, sensory receptors)
Eccrine sweat glands
Also known as merocrine, the more common sweat gland, functions in thermoregulation
Unipolar neurons
Also known as pseduounipolar neurons
Perforating canals
Also known as volkmann's canal, allow transit of blood and lymphatic vessels to the outer cortex of bone.
Callus
An area of hardened and thickened skin that is usually seen in palms and soles and is due to persistent pressure and friction
Abrasion
An area where skin has been scraped away
Tract
An association (bundle) of neuronal axons in the central nervous system
Nucleus
An association (bundle) of unmyelinated nerve cell bodies in the central nervous system
Nerve
An assoiciation (bundle) of neuronal axons in the peripheral nervous system
Membrane potential
An electrical voltage difference across the membrane, exhibited by virtually all cells in the body.
Muscle
An entire organ (named)
Plexus
An extensive network of nerves found within the peripheral nervous system (PNS)
Fasciculation
An involuntary, brief twitch of an entire motor unit that is visible under the skin. Occurs irregularly and is not associated with movement of the affected muscle.
Myofibril
An organelle in a muscle fiber composed of filaments
Glycolysis
Anaerobic respiration process used in smooth muscle
9%
Anterior and poster head and neck
18%
Anterior and posterior shoulders, arms, forearms, and hands
36%
Anterior and posterior thighs, legs, and feet
36%
Anterior and posterior trunk
Sarcomere
Arrangement of thick and thin filaments sandwiched between two Z discs
Cartilage
Articulate surfaces smooth and low friction. Template for bone formation. The younger the person, the more they have.
Calcium ion
Bind to the exterior surfaces of the sodium channel protein molecule. The positive charges alter the electrical state of the channel protein, increasing the voltage level required to open the gate.
Amino acids
Associated with the CSN, most common excitatory examples are glutamate and aspartate. Most common inhibitory examples are GABA and glycine.
Neuroglia of the CSN
Astrocytes, oligodendrocytes, microglia, ependymal cells
Dense bodies
Attach to intermediate filaments in smooth muscle, similar to z disks of striated muscle. Found in both the sarcoplasm and the sarcolemma.
Myasthenia gravis
Autoimmune disease that causes chronic, progressive damage of the neruomuscular junction by producing antibodies that bind to and block acetylcholine receptors. Decreases number of function ACh receptors at the motor end plates of skeletal muscles, causing weakness and fatigue, may result in loss of function.
Multiple Sclerosis
Autoimmune disorder that causes progressive destruction of myelin sheaths in the CNS, mutiple regions of myelin sheaths deteriorate to sclerosis, destruction of myelin sheaths first slows, then short circuits nerve impulse propagation.
Telodendria
Axon terminals are also called
Synaptic end bulbs or varicosities
Axon terminals end in what?
Axon terminals
Axons and axon collaterals end by dividing into ____________ ______________, (telodendria)
Bipolar neuron
B
Comminuted Fracture
B
Melanocyte
B
Syndemoses between tibia and fibula
B.
Closridium botulinum
Bacterial toxin that blocks exocytosis of synaptic vesicles at the NMJ, causing flaccid muscle paralysis since ACh is not released, and muscle contraction does not occur. Used in Botox.
Epidermal wound healing
Basal cells at the margins of the wound move to close the wound, and stop when they are touching each other (contact inhibition). Stimulates mitosis of basal cells. keratinocytes move up to form the more superficial layers.
Osteogenesis
Begins around the 6th week of development, bone formation
Muscle refractory period
Begins upon stimulation and commonly lasts into the early part of the contraction period, but duration varies.
Acetylcholine
Best studied neurotransmitter, released by many PNS neurons, and some CNS neurons. Excitatory or inhibitor depending on where it is released
Histamine
Biogenic amine that mediates arousal and attention, also pro-inflammatory signal released from mast cells in response to allergic reactions
Catecholamine neurotransmitters
Biogenic amines - dopamine, norepinephrine, epinephrine
Exogenous amines
Biogenic amines absorbed directly in the intestine.
Endogenous amines
Biogenic amines formed by decarboxylation of amino acids or by animation of aldehydes and ketones
Serotonin
Biogenic amines thought to be involved in sensory perception, temperature regulation, control of mood and appetite, and induction of sleep.
Local anestethics
Block pain and other somatic sensations, and are commonly used to produce anesthesia in the skin during suturing, or in the mouth during dental work. Ex. Novocain and lidocaine. Act by blocking the opening of voltage-gated Na+ channels, preventing trasmission of pain signals.
Parathyroid hormone
Blood calcium levels decrease, activity this hormone in the control center, which increases kidney retention of calcium and release of calcium from bone matrix.
Hematopoiesis
Blood cell production, occurs in spongy bone
Graded potential
Can either hyperpolarize or depolarize a membrane
Calcium reservoir
Bone stores 99%, used to regulate the level in blood
Fibrous joints
Bones attached by fibrous connective tissue, provides little movement. Examples - suture, syndemoses, and gomphoses.
Gliomas
Brain tumors derived for glia - can be highly malignant and grow rapidly and include astrocytes, oligodendrogliomas, and schwannomas.
Neurology
Branch of medical science that deals with the normal functioning and disorders of the nervous system
Axon collaterals
Branches off the main axon
Greenstick Fracture
C
Langerhans cell
C
Unipolar neuron
C
Summation
CNS neurons typically receive input from thousands of synapses
Contraction period
Calcium binds to troponin resulting in exposure of myosin binding sites on actin, crossbridges form; peak tension develops in the muscle fiber
calcium flows out of terminal cistern into cytosol
Calcium binds with troponin, changing it's shape.
Dopamine
Catecholamine neurotransmitter for brain neurons that are active during emotional responses, addictive behaviors, and pleasurable experiences, plus regulating skeletal muscle tone and skeletal muscle contractions.
Epinephrine
Catecholamine neurotransmitter used by some neurons of the brain and is also an adrenal medulla hormone.
Norepinephrine
Catecholamine neurotransmitter used by some neurons of the brain, has role in awakening from deep sleep, dreaming, and regulating mood. Also a hormone produced in the adrenal medulla.
Basic parts of a neuron
Cell body, nerve fibers (axon and dendrites)
Stratum spinosum
Cells are still alive, some are dividing, older cells start to flatten
ATP
Cells do not store this, it must be made at the same rate it is used, via creative phosphate, glycolysis, and aerobic respiration.
Melanocytes
Cells in the epidermis that produce melanin. Projections between keratinocytes transfer melanin granules to keratinocytes, which shield the sun exposed side from sunlight.
Neuroglia
Cells of the nervous system that support, nourish, and protect the neurons, more numerous than neurons
Neurons
Cells that have the property of electrical excitability, and are specially adapted to produce and transmit action potentials
H zone
Center of an A band; only thick filaments
Neuropeptides
Certain brain neurons have plasma membrane receptors for opiate drugs such as morphine and heroin, called opioid peptides, including enkephalins, endorphins, and dynorphins.
Crossbridges
Change shape (move toward or away from an M line) and bind reversible to actin
Axoaxonic
Chemical synapse from axon to axon
Axosomatic
Chemical synapse from axon to cell body
Axodendritic
Chemical synapse from axon to dendrite
14%
Child's leg (each) in rule of nines
18%
Childs head
Reticular region
Combination of collagen and elastic fibers in the reticular region provides the skin with strength, extensibility, and elasticity.
Epidermal ridges
Commonly called fingerprints, develop during third and fourth fetal months as epidermis conforms to the contours of the underlying dermal papillae of the papillary region.
Osteons
Compact bone units also known as Haversian systems, formed from concentric lamellae.
Hair
Composed of dead, keratinized cells bonded by proteins
Epidermis
Composed of keratinized stratified squamous epithelium which contains four major types of cells - keratinocytes, melanocytes, langerhans cells, Merkel cells
Thick filament
Composed of myosin molecules, half point in each direction toward the z discs and connects at the middle
Cartilage
Comprises parts of the Skelton where flexibility is required
Nervous sytem
Comprises the brain, spinal cord, spinal nerves, ganglia, enteric plexuses, and sensory receptors
Hirsutism
Condition of excessive body hair
Cartilage
Consists of a dense network of collagen fibers and elastic fibers embedded in a jellylike ground substance of chondroitin sulfate. Capable of enduring more stress than either loose or dense connective tissue due to collagen fibers and resilience (plasticity) of chondroitin sulfate.
Peripheral nervous system
Consists of all nervous tissue outside of the central nervous system
Nails
Consists of body, free edge, and root.
Unipolar neurons
Contain one process which extends from the body into a central branch that functions as an axon and as a dendritic root
Dermis
Contains blood vessels, nerves, glands (sebaceous and sudoriferous), hair follicles, arrectores pilorum muscles
Axon
Contains mitochondria, microtubules, and neurofibrils, does not contain rough endoplasmic reticulum so protein synthesis does not occur in the axon.
Neurolemma
Contains the nucleus and all of the cytoplasm of the myelin sheath, found only around axons in the PNS
Smooth muscle contraction
Contraction of thick and thin filaments generates tension on intermediate filaments, which pulls the dense bodies causing shortening of muscle fiber.
Compacts bone
Cortical bone
Terminal hairs
Course, heavily pigmented hair; includes hair of the head, eyebrows, eyelashes, and hair the develops as a secondary characteristic
Articulate cartilage
Covers epiphyses of bone; not covered by synovial membrane.
Peripheral nervous sytem
Cranial nerves, spinal nerves, peripheral nerves
Striations
Created by the overlap of thick and thin filaments that are seen both in single myofibrils and whole muscle fibers
Sarcoplasm
Cytoplasm of a muscle cell, chocked full of contractile proteins arranged in myofibrils.
Impacted fracture
D
Merkel cell
D
A band
Darker zone, which comprises the length of the thick filaments and a varying overlap of thin filaments
Atrophy
Decrease in the size of a cell, tissue, organ, or entire body; it is accompanied by diminished function.
Reticular region
Deep to the papillary region, consists of dense, irregular connective tissue containing bundles of collagen and some elastic fibers. Spaces between fibers are occupied by adipose cells, hair follicles, nerves, sebaceous glands (oil) and sudoriferous glands (sweat)
Papillary region
Deep to the stratum basale, dermal papillae greatly increase it's surface area
Dermis
Deeper, ,thicker layer composed of dense irregular connective tissue
Stratum Basale
Deepest layer of epidermis
Osteoarthritis
Degeneration of articular cartilage such that bony ends touch, resulting in bone against bone which results in friction that worsens the condition. Usually associated with the elderly.
Guillain-Barre Syndrome
Demyelinating disorder in which macrophages strip myelin from axons in the PNS, may result from immune system's response to a bacterial infection
Periosteum
Dense irregular connective tissue that covered the bone (except for the articulate cartilage)
Dermis
Dense irregular connective tissue; collagen and elastic connective tissue
Depolarizing neurotransmitters
Depolarize the postsynaptic membrane causing an excitatory graded potential
Third degree burns
Destory a portion of the epidermis as well as underlying dermis and associated structures. Function is lost, appear either marble white or mahogany or charred, dry wounds. Marked edema, and numbness due to destruction of sensory nerve endings. Regeneration is slow, grafting may be required. (full thickness burn)
Second degree burn
Destroys a portion of the epidermis and possibly parts of the dermis. Pain, redness, blister formation and edema. Some skin functions are lost, associated structures are normally not injured, heals in 3-4 weeks, scarring may result
Terminal cistern
Dilated regions that flank the t-tubules
Rickets
Disease of children in which growing bones become soft and are easily deformed. New bone formed at the epiphyseal plates fails to ossify, resulting in bowed legs and deformities of the skull, rib cage, and pelvis.
Epiphyses
Distal or proximal end of a long bone
Hair growth
Division of cells at the base of the follicle, whereby new cells produced by mitosis push up through a pilary channel.
Neurons
Do not typically undergo mitosis, if one dies, there are no reservoir cells to replace it
Hypertrophy
Dramatic muscle growth after birth is due to ______________, because muscle cells are unable to undergo mitosis. During childhood, the growth is stimulated by hormones, primarily HGH and testosterone.
Resting membrane distribution
Due to a small buildup of anions in the cytosol just inside the membrane, and an equal buildup of cations in the extracellular fluid outside
Pott's Fracture
E
Titin
Each molecule spans half a sarcomere, from a Z disc to an M line, and attaches thick filaments to Z discs and M lines; very elastic and probably helps sarcomere return to its resting length.
Erythema
Engorgement of capillaries in the dermis due to skin injury, heat exposure, infection, inflammation, allergic reaction
Two kinds of wound healing
Epidermal or deep wound
Nail matrix
Epithelium deep to the nail root, divide mitotically to produce growth. Superficial cells are transformed into nail cells, and older, harder cells are pushed along the stratum basale toward the fingertip.
Thermoregulation
Evaporation of sweat cools skin, increased blood flow to skin promotes heat loss by radiation, hairs trap heat, thereby reducing heat loss in cold temperatures
Reticular region
Everything in the dermis that is deep to the papillary region
Colles Fracture
F
Electrical synapse
Faster than chemical synapse, can synchronize groups of neurons or muscle fibers, locations include muscle fibers of the heart, and visceral smooth muscle.
gomphoses
Fibrous joint in the teeth of the upper and lower jaw
Syndesmoses
Fibrous joint with more space than a suture; more fibrous connective tissue
Filaments
Fibrous protein molecules within myofibrils
Stratum granulosum
Filled with granules of keratin, lemellar granules release a waterproofing lipid solution
Maturation phase
Final stage of deep wound healing, scab is lost, collagen fibers become organized, fibroblast numbers decrease, blood vessels are restored to normal
Remodeling
Final step of fracture repair, spongy bone is replaced by compact bone, fracture line disappears, but evidence of break still remains.
Laguno
Fine, nonpigmented, downy hairs that cover the body of the fetus
Initial segment
First part of the axon
Excretion
Function of skin; sweat eliminates some water, salts, CO2, ammonia, and urea
Create motion, stabilize body position, store substances, move substance, generate heat
Functions of muscular tissue include
Nitric oxide
Gas formed on demand, rather than being synthesized and stored in synaptic vesicles produced by endothelial cells in blood vessel walls, is lipid soluble and diffuses into neighboring smooth muscle cells causing them to relax, producing vasodilation.
Hair matrix
Germinal layer of cells stemming from stratum basale where cell division occurs in hair.
Membrane current
Flow of charged atoms or molecules, flow of electrons; in the body is the flow of ions; sodium, potassium, calcium, etc. when it flows through a membrane, charges are redistributed across the membrane and the potential charges
Graded Potential
For short distance only (localized). Physiological role is to affect (and effect) the generation of action potentials. Not all-or-none.
Muscle strain
Forceful stretching or tearing of muscle fibers, this often occurs in contact sports where it frequently affects the quadriceps femoris
Regeneration tube
Formed by the neurolemma when an axon is injured in the PNS, guides and stimulates regrowth of the axon.
Fibrocartilaginous callus
Formed within a few weeks to as many as 6 months after fracture, phagocytes remove cellular debris and fibroblasts, deposit collagen to form this.
Fracture hematoma
Formed within the first 6-8 hours after injury as a result of broken blood vessels. First step in repair
Biogenic amines
Found in a wide range of foods, neurotransmitters generally associated with the brain, can be excitatory or inhibitory.
Apocrine sweat glands
Found in association with hair the develops at puberty
Merkel cells
Found in the deepest layer of the epidermis where they contact the flattened processes of tactile discs (Merkel discs - sensory neuron). Together they function in the sensation of touch.
Bipolar neurons
Found in the retina of the eye, inner ear, and olfactory area of the brain
Protection from external environment
Function of integumentary system (skin), protects internal environment from abrasion, microbes, heat, chemicals, UV light, and evaporation
Synthesis of Vitamin D
Function of skin; first step in activation of vitamin D begins in the skin by action of UV light
Cutaneous sensation
Function of skin; pain, touch, pressure and temperature
Duchenne muscular dystrophy
Group of inherited muscle-destroying diseases causing progressive skeletal muscle fiber degeneration, the most common form being this. Gene that codes for the protein dystrophin is mutated, resulting in little or no dystrophin in the sarcolemma. Absent from reinforcing effect of dystrophin, the sarcolemma tears easily during muscle contraction, causing muscle fibers to rupture and die.
Hair root plexus
Groups of dendrites and nerve fiber endings that form a network around a hair follicle, act as receptors to generate nerve impulses when hair shaft are moved, acting like a fulcrum. Sensitive to touch, and movement of the hair shaft.
Changes in length during contraction
H zone and I band decrease, A band remains the same. Sarcomere length decreases, the thick and thin filaments do not change length.
Skin accessory structures
Hair, nails, skin glands
Caritlage
Has poor blood supply, so heals and grows slowly
Oligodendrocytes
Have multiple processes, each process can form a myelinated segment (can myelinate several segments of one axon, or participate in myelination of several axons)
Bipolar neurons
Have one main dendrite and one axon, used to convey the special sense of sight, smell, hearing and balance
Multipolar neurons
Have several dendrites and only one axon, located through the brain and spinal cord.
Crossbridges
Heads of myosin molecules, bind and hydrolysis ATP, also bind the products of ATP hydrolysis (ADP and phosphate).
Biogenic amines
Histamine, serotonin, catecholamine neurotransmitters
Articulate cartilage
Hyaline cartilage covering the epiphyses
Inhibitory neurotransmitters
Hyperpolarize the postsynaptic membrane
Central canal
In bone tissue, location of blood and lymphatic vessels
Cardiac muscle
In response to a single action potential, this muscle contracts 10-15 times longer than skeletal muscle and must continue to do so without rest. Generates ATP through a rich supply of O2 through aerobic respiration.
Dendrites
In sensory neurons, produces generator or receptor potential. In motor neurons and interneurons produces excitatory and inhibitory postsynaptic potentials
Sebaceous glands
In the dermis, secrete sebum (oil) into the hair follicle
Muscle fatigue
Inability for muscle to maintain strength of contraction after prolonged activity, due to inadequate release of calcium, depletion of creatine phopshate, insufficient oxygen, depletion of glycogen and other nutrients, buildup of lactic acid and ADP, and failure of action potential in the motor neuron to release enough acetylcholine
Reverberating circuit
Incoming impulse stimulates the first neuron, which stimulates the second, etc. branches from later neurons loop back to synapse with earlier neurons, sending impulses back through the circuit many times. Thought to be used in breathing, waking up and short term memory.
Muscular hypertrophy
Increase in the diameter of muscle fibers, organelles increase in number achieved by forceful, repetitive muscular activity. Muscles are capable of more forceful contractions because they contain more myofibrils.
Hyperplasia
Increase in the size of tissues and organs due to an increase in the number of cells.
Dermal papillae
Increase surface area of papillary region, creating better adhesion to epidermis and more surface area for diffusion
Exposure to UV light
Increases the enzymatic activity of melanosomes, leading to increased melanin product, which gives the skin a tanned appearance and further protects the body against UV radiation.
Plasticity
Individual neurons can sprout new dendrites, synthesize new proteins, and change the nature and number of synapses.
Myositis
Inflammation of muscle fibers
Contact dermatitis
Inflammation of the skin characterized by redness, itching, and swelling, and caused by exposure of skin to chemicals that bring about an allergic response.
Eczema
Inflammation of the skin, characterized by patches of red, blistering, dry, extremely itchy skin
Stages of deep wound healing
Inflammatory, migratory, proliferative, maturation
Axon terminals and synaptic end bulbs
Inflow of Ca2+ caused by depolarizing phase of nerve impulse triggers exocytosis of neurotransmitters from synaptic vesicles
Positive feedback of propagation
Inflow of sodium ions causes depolarization that opens voltage-gated Na+ channels in adjacent segments of the membrane, which in turn allows the segment to depolarize, and so on down the axon.
Synthesis of creatine, can cause dehydration and kidney dysfunction
Ingestion of creatine supplements has what effect on the body's mechanisms?
Albinism
Inherited inability of an individual to produce melanin, missing from hair, eyes and skin
Inflammatory phase
Initial phase of wound healing, a blood clot forms and binds the wound edges. Blood flow increases, and blood vessels become more permeable. WBCs and mesenchymal cells migrate to the area.
Medulla
Inner layer of hair root
Synchronous contraction
Interconnectedness of cardiac fibers results in what?
Spongy bone
Interior of long bones is made up primarily of ______________ _________, which lessens the overall weight of the bone.
Neurofibrils
Intermediate filaments, provide cell shape and support
Layers of hair follicle
Internal root sheath and external root sheath
First degree burn
Involves only the epidermis, characterized by mild pain and erythema but no blisters, skin functions remain intact, will heal in 3-6 days, may peel or flake. (Sunburn)
Cartilaginous joints
Joint components connected by cartilage. Composed of fibrocartilage or hyaline cartilage, no synovial cavity, and little to no movement. Examples- synchondroses and symphyses.
Membrane negativity
K+ diffuses down its concentration gradient out of the cell, intracellular negatively charge ions are left behind, because they can't get through. Na+ is diffusing into the cell, but at a slower rate than the efflux of K+, and a small amount of Cl- moving into the cell
Psoriasis
Keratinocytes divide and move more quickly than normal from the stratum basale to the stratum corneum, and are shed prematurely. immature keratinocytes make abnormal keratin which forms flaky, silvery scales at the skin surface, commonly on knees, elbows, and scalp.
Dendrites
Known as little trees, the receiving portion of neuron, typically short, tapering, highly branched
Pacinian corpuscles
Lamellated corpuscles in the subcutaneous layer that sense pressure
A fibers
Large diameter nerve fibers, myelinated, conducted at about 100 meters/sec
Integumentary system
Largest organ in the body in terms of weight and external surface area
Trabeculae
Lattice of thin columns of spongy bone tissue, protect bone marrow and oriented along lines of stress (helps bones resist stresses without breaking)
Malignant melanoma
Least common but most deadly type of skin cancer
Number of sensory neurons activated
Light touch stimulates only a few pressure sensitive neurons, a firm pressure stimulates more pressure sensitive neurons
Synovial membrane
Lines the synovial capsule, secretes synovial fluid
Delayed onset muscle soreness
Linked to strenuous exercise, occurs 12 to 48 hours after, and has microscopic muscle damage as a major factor, allows torn sarcolemmas, damaged myofibrils, and disrupted Z discs, allowing increase in blood levels of myoglobin and creatine kinase, both of which should be confined in the muscle tissue.
Dystrophin
Links the thin filaments of the sarcomeres to the integral membrane proteins in the sarcolemma, transmitting the tensive forces of the sarcomeres
Interstital lamellae
Located between osteons, are left over fragments of older osteons.
Visceral (smooth) muscle tissue
Located in the GI tract, uterus, eye, blood vessels, functions in peristalsis, blood pressure, and pupil size. Involuntary.
Langerhans cells
Located in the epidermis, participate in the immune response to microbes that invade the skin. They are a type of dendritic cell.
Cardiac muscle tissue
Located in the heart, pumps blood constinuously, involuntary
Epiphyseal plate
Located the metaphysic of a growing bone
Lacunae
Located within each trabecula, contains osteocytes that nourish the mature bone tissue from the blood circulating through the trabeculae.
Osteoporosis
Loss of calcium from bone, results in weakening
Neuroglia
Make up about half of the volume of the CNS, if an injury occurs, these multiply to fill in the spaces formerly occupied by neurons
Kertatinocytes
Make-up most of the cells in the skin, formed when new cells produce by mitosis become filled with keratin.
Interneurons
Many integrative neurons are ________________, relatively short neurons in the brain, spinal cord, and ganglia that connect nearby neurons. .
Wart
Mass produced by uncontrolled growth of epithelial skin cells, caused by a papillomavirus
Osteocytes
Mature bone cells, regulate the composition of bone matrix
Chondrocyte
Mature cartilage cell
Fibrocartilage
Mature cartilage tissue, thick bundles of collagen fibers, very strong and tough. Typically occurs as a disc-shaped segment of cartilage between bones.
Elastic cartilage
Mature connective tissue, consists of chondrocytes located in a threadlike network of elastic fibers, makes up the external part of ear and the epiglottis.
Unmyelinated axons
May be associated with schwann cells, but the axons simply lay in the grooves on the surface of the Schwann cell, in which case there is no myelin sheath and no neurolemma.
Articulate discs
May be contained within synovial joints (also called menisci)
Topical
Medication applied to the skin surface, rather than ingested or injected
B fibers
Medium diameter nerve fibers, myelinated, conduct at about 15 meters/sec
Three layers of hair root and shaft
Medulla, cortex, cuticle
Genetically determined
Melanin and carotene expression are ___________ _____________ and are associated with classic races of humans.
Depolarization
Membrane becomes less polarized (less negative or more positive)
Hyperpolarization
Membrane becomes more polarized (less negative)
Endosteum
Membrane lining the marrow cavity
Endochondrial ossification
Method used in formation of most bones, especially long bone. Involves replacement of cartilage by bone, there are primary and two secondary centers of growth.
Cortex
Middle layer of hair root
M line
Midline of a sarcomere
Papillary region
More superficial are of the dermis, just deep to the epidermis
Hyaline cartilage
Most abundant type of cartilage; covers the ends of long bones and parts of the ribs, nose, trachea, bronchi, and larynx. Provides a smooth surface for joint movement
Basal cell carcinoma
Most common and least severe type of skin cancer; often characterized by light or pearly nodules.
Synovial joints
Most movable joints, articulations capsule: dense irregular and regular connective tissue
Metabolism
Most of the brains energy consumption goes into sustaining the electric charge of neurons. Majority of vertebrate species devote 2 - 8% to the brain, while humans it rises to 20-25%.
Compact
Most of the skeleton is composed of ___________ bone, although both types may be present in the same bone.
Stratum corneum
Most superficial layer of the epidermis
Stratum basale
Mostly kertinocytes, a few melanocytes, and Merkel cells. Keratinocytes have intermediate filaments called tonofilaments, composed of a protein that will later form keratin.
Efferent neurons
Motor neurons are known as
Propagation
Movement of a nerve impulse from where it is triggered (typically the axon hillock) down to the axon terminals. Depends on positive feedback.
Saltatory conduction
Much faster and more energy efficient than continuous conduction, requiring less ATP to repolarize
Cyanosis
Mucous membranes, nail beds, and skin appear bluish, due to hemoglobin that is depleted of oxygen.
Myelin
Multi-layered complex of lipids and proteins (layers of plasma membranes insulate axons) prevents loss of electrical signal; speeds up conduction of nerve impulses
Demyelination diseases
Multiple sclerosis (CNS), Guillain-Barre Syndrome (PNS)
Multinucleated
Muscle cells are ________________, largely due to embryonic development, where a number of myoblasts fuse to form one fiber.
contractile, extensible, elastic
Muscle cells, unlike nerves, are also
Thermogenesis
Muscle tissue contractions produce heat
Store substances
Muscular tissue does this by using sphincters
Excitable or irritable
Muscular tissue, like nervous tissue, is
Peristaltic contractions
Muscular tissues move substances through
Balance
Must exist between osteoclasts and osteoblasts. If not, results in excessive tissue formation, or loss of calcium, weakening the bone.
Contractile proteins
Myosin and actin
Relaxation period
Myosin binding sites are covered by tropomyosin, myosin heads detach from actin; muscle tension decreases
Power stroke
Myosin crossbridges rotate toward center of sarcomere, third step of contraction
Detachment
Myosin heads bind ATP, the crossbridges detach from actin, fourth step of contraction
Attachment
Myosin heads bind to actin, forming crossbridges, second step of contraction
ATP hydrolysis
Myosin heads hydrolysis ATP and become reoriented and energized, first step of contraction.
Membrane potential
Na+ and Cl- are in higher concentrations in the extracellular fluid, K+, organic phosphates (-), amino acids (-), and proteins (-), are in higher concentrations in the intracellular fluid
Vitamin D
Necessary for normal bone metabolism, essential for healthy bones, promotes absorption of calcium from food in the GI tract into the blood
Vitamin C
Necessary for normal bone metabolism, needed for synthesis of collagen
Vitamin A
Necessary for normal bone metabolism, stimulates activity of osteoblasts
Vitamins K and B12
Needed for synthesis of bone proteins
Chemical synapse
Nerve impulses arrive at a synaptic bulb or presynaptic neuron, depolarization of nerve impulse opens voltage-gated Ca2+ channels, and Ca2+ flows inward through opened channels due to concentration differences. Increased concentration triggers exocytosis of synaptic vesicles releasing neurotransmitter into the synaptic cleft, binding to neurotransmitter receptors on the post-synaptic neuron's plasma membrane. Ligand gated channels open, allowing ions to cross membrane and creating a postsynaptic potential, triggering nerve impulses.
Action potential
Nerve impulses for both short and long distance communication within the body. All-or-none.
Somatic motor neuron
Nerves that supply a group of muscle fibers
Oligodendrocytes
Neuroglia of CNS; myelinated axons in the CNS
Microglia
Neuroglia of CNS; perform phagocytic functions
Ependymal cells
Neuroglia of the CNS; line the ventricles of the brain; produce, monitor, and aid in the circulation of cerebrospinal-fluid; help form the blood-CSF barrier
Astrocytes
Neuroglia of the CSN, regulate the composition of extracellular fluid in the CNS, help form the blood brain barrier; take up excess neurotransmitters; may influence formation of neural synapses
Schwann cells
Neuroglia of the PNS; myelinate the axons of the PNS
Satellite cells
Neuroglia of the PNS; provide structural support and regulate teh exchange of materials between neuronal cell bodies and interstitial fluid
Schwann cell
Neurolemmocyte is also known as
Postsynaptic neuron
Neuron is receiving the message
Presynaptic neuron
Neuron is sending the signal
Regeneration
Neurons are generally not able to regenerate, that is to undergo mitosis and replicate. PNS dendrites and myelinated axons may be repaired if the cell body remains intact
Uptake
Neurotransmitter is absorbed by the cell that did not release it
Neuropeptides
Neurotransmitters that comprise 3 to 4 amino acids (short chain amino acids) linked by peptide bonds. Widespread in both CNS and PNS. Have both excitatory and inhibitory actions, formed in the neuron cell body, packaged into vesicles and transported to axon terminals. Many o them also serve as hormones, regulating physiological response elsewhere in the body.
Stimulus strength and generation of action potential
No action potential is generated by sub threshold stimulus. Several action potentials result from a suprathreshold stimulus, yet each has the same amplitude. Perceived as a stronger stimulus.
Visceral (smooth) muscle tissue
No striations, one central nucleus
75 times per minute
Normal heart contraction rate
Neuroglia
Not excitable cells, smaller and more numerous than neurons, play a supporting role
Leakage channels
Not gated; randomly open and close; may be specific for certain ions
Frequency of stimulation
Number of impulses per second on a muscle fiber
Central fatigue
Occurs before muscle fatigue; causes feelings of tiredness and desire to cease activity, which may be a protective mechanism to stop the exercise before muscles become damaged
Epidermal wound healing
Occurs following superficial wounds that only affect epidermis, return to function is normal rule
Saltatory conduction
Occurs only in myelinated axons, voltage gated channels are concentrated at nodes of Ranvier, with few in regions where the myelin sheath covers the axolemma. Electric current is carried by extracellular and intracellular ions from one node to the next, and the nodes depolarize and repolarize as previously discussed.
Deep wound healing
Occurs when an injury extends to the dermis and subcutaneous layer, loss of function and development of scar tissue is the rule.
Unipolar neurons
Often employed for sensory neurons that convey touch and stretching information from the extremities
Sebaceous glands
Oil glands that keep hair from drying, prevents excessive evaporation of water from skin, and inhibits the growth of some bacteria.
Creating phosphate
Once ATP is used, this plus stored ATP can provide maximum contraction for approximately 15-20 seconds
Action potentials
Once activated, travels the length of the neuron and can activate a subsequent neuron, muscles or glands (all or none)
thick and thin filaments slide on one another and the sarcomere is shortened (contracted)
Once the myosin binding sites are exposed in the presence of ATP and Ca2+, what occurs?
Myelination in the CNS
One oligodendrocyte myelinates portions of many axons, there is no neurolemma, there are nodes of ranvier.
Parallel after-discharge circuit
One presynaptic input neuron has one output neuron with variable number of intermediate neurons between input and output. Imposes varying synaptic delays, so the last neuron exhibits multiple EPSPs and IPSPs.
Simple series circuit
One presynaptic neuron stimulates only a single postsynaptic neuron
Bone remodeling
Ongoing replacement of old bone tissue by new bone tissue. Involves bone resorption and bone deposition.
Stratum lucidum
Only found on fingertips, palms of hands, and soles of feet. 3 layers of flattened dead keratinocytes filled with keratin
Nodes of Ranvier
Only on nerve fibers supplied by potentially myelin-producing cells; found in gaps between myelinating cells in both the PNS and CNS
Stratum lucidum
Only present where exposure to friction is greatest, fingertips, palms and soles
I band
Only thin filaments; consist of parts of 2 adjacent sarcomeres
Voltage gated channels
Open and close in response to changes in the membrane potential
Mechanically gated channels
Open in response to mechanical stimuli (tension in the plasma membrane due to pressure)
Ducts of sweat glands
Open on top of the epidermal ridges as sweat pores, forming a pattern of smooth objects that are touched
Transverse tubules
Open to the outside of the fiber, so they are filled with interstitial fluid. Important in propagation of muscle action potentials.
Melanosome
Organism inside melanocyte that produces melanin from the synthesis of amino acid tyrosine in the presence of tyrosinase
Intra-membranous and endocondral
Ossification processes
Ossification
Osteogenesis, is the process of forming new bone under four situations 1. Formation of bone in embryo, formation of bones until adulthood, remodeling of bone, repair of fractures.
Cuticle
Outer layer of hair root
Hemoglobin
Oxygen carrying pigment in red blood cells, when melanin or carotene concentrations are low, the epidermis appears translucent, allowing the capillaries of the dermis to be expressed, generally causing a pink appearance to skin
Myalgia
Pain in or associated with the muscles
Channel gates
Part of the channel protein that opens or closes to allow or prevent the passage of ions, not all membrane channels have them
Alopecia
Partial or complete lack of hair, may result from aging, endocrine disorders, chemotherapy for cancer, or skin disease.
Vitiligo
Partial or complete loss of melanocytes from patches of the skin, produces white spots. May be an autoimmune disorder in which melanocytes are killed. There is an apparent genetic link.
Myomalacia
Pathological softening of muscle tissue
Amount of melanin
People all have about the same number of melanocytes. The differences in skin color come from differences in the _______ __ ______ that the melanocytes produce.
Refractory period
Period of time after the first stimulus when response to a second stimulus isn't possible (both muscles and nerves)
Neurologist
Physician specializing in the diagnosis and treatment of disorders of the nervous system
Sarcolemma
Plasma membrane for a muscle fiber, located beneath the tissue endomysium.
Axolemma
Plasmalemma of an axon
Joints
Point of contact between two bones, between bone and cartilage, or between bone and a tooth
Osteoporosis
Porous bones caused by bone resorption outpacing bone deposition due in large part to depletion of calcium from the body. Bone mass becomes so depleted that bones fracture. Primary affects the middle-aged and elderly; 80% of those affected are women.
Nail body
Portion of the nail that is visible. Appears pink due to blood flowing through the underlying capillaries
Potential
Potential energy that can cause a flow of electrical current, positive charges attract negative charges, like charges repel each other, if opposite charges are separated in space, their attractive force is this, measured in volts
Intermediate filaments
Present in smooth muscle fibers and attach to dense bodies
Synchondrose
Primary cartilaginous joint; hyaline cartilage connecting bones, may ossify with age. (Ex - epiphyseal plates)
Enzymatic degradation
Process of removing neurotransmitter from synaptic cleft (acetylcholesterase breaks acetylcholine into acetyl and choline)
Endochondrial ossification
Process whereby cartilage is replaced by bone, forms both compact and spongy bone
Calcitonin
Produced by parafollicular cells of the thyroid gland, lowers blood calcium levels by inhibiting bone resorption.
Myelination
Produced by schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous sytem
Intra-membranous ossification
Produces spongy bone, may be subsequently modeled to form compact bone
Parathyroid hormone
Promotes resorption of bone matrix, prevents loss of calcium in urine, promotes vitamin D (calcitriol formation)
Axon
Propagates impulses to another neuron, muscle, or nerve. Can approximate three feet long in humans
Rule of nines
Provides a quick means for estimating the surface area affected by a burn in an adult, only for second or third degree burns, and for adults
ATP
Provides active transport fuel for Na+-K+ pumps, calcium ion pump via active transport inside the sarcoplasm, and energizes the myosin head in preparation for the power stroke.
Dendrites
Receive stimuli through activation of ligand-gated or mechanically gated ion channels.
Cell body
Receives stimuli and produces EPSPs and IPSPs through activation of ligand-gated mechanically gated ion channels
Sensory function
Receptors detect changes in the internal or external environment, sensory nerve cells carry the information to the brain and spinal cord
Myoglobin
Red colored protein, found in the muscle. Similar to hemoglobin in both structure and chemical composition, and function. Binds oxygen in muscle cells and releases it when needed by the mitochondria during high levels of aerobic respiration.
Osteoclasts
Release enzymes that digest bone matrix for remodeling of bone (bone WBC)
Bone resorption
Removal of minerals and collagen fibers from bone by osteoclasts
Bone remodeling
Removes injured bone and replaces it with new bone tissue, providing for strengthening of bone tissue to meet demands. Alters shape for better support based on stress patterns. Makes new bone more resistant to fracture, and supports calcium homeostasis.
Somatic nervous system
Sensation from body and wall, limbs, head, special senses, and motor control of skeletal muscle (voluntary)
Enteric nervous system
Sensation from gastrointestinal tract, motor control of smooth muscle and glands of the GI tract (involuntary) (through the autonomic nervous system)
autonomic nervous system
Sensation from internal organs like heart, lungs, bladder, motor control of smooth and cardiac muscle (involuntary muscle), and glands (involuntary control)
Afferent neurons
Sensory neurons are known as
Functions of the nervous system
Sensory, integrative, motor functions
Calcium
Required for many important activities (synaptic transmission, muscle contraction, and blood clotting)
Membrane permeability
Resting membrane is 50 to 100 times more permeable to K+ than to Na+, Cl- permeability is in between that of Na+ and K+. Membrane is impermeable to nearly all negatively charged intracellular molecules
Temporal summation
Results from buildup of neurotransmitter released by a single presynaptic end bulb many times in rapid succession
Spatial summation
Results from buildup of neurotransmitter released simultaneously by several presynaptic end bulbs
Tremor
Rhythmic, involuntary, purposeless contraction that produces a quivering or shaking movement.
Rigor mortis
Rigidity of death, 3-4 hours after death, cell membranes no longer maintained at death, and leak Ca2+, which binds to troponin-tropomyosin complex, allowing myosin crossbridges to attach and complete one power stroke. Because no ATP is produced, the crossbridges cannot detach. Symptom disappears after about 24 hours as proteolytic enzymes from lysosomes digest the crossbridges.
Concentric lamellae
Rings of calcified matrix in compact bone.
Neuroglia of the PNS
Schwanna cells, satellite cells
Associated with hair
Sebaceous glands, arrector pili, hair root plexuses
migratory phase
Second phase of deep wound healing, epitheleal cells migrate beneath the scab and bridge the wound. Fibroblasts migrate into the wound and begin to produce collagen fibers.
Symphyses
Secondary cartilaginous joints; fibrocartilage connecting bones; (ex. Pubic symphysis)
Osteoblasts
Secrete bone matrix, mature into osteocytes
Diaphysis
Shaft or body of long bone
Vellum hairs
Short, fine, pale hairs that develop most of the body during childhood
special senses
Sight, hearing, taste, balance, and smell
Intra-membranous ossification
Simpler of two bone formation methods
Neuromuscular junction
Site where the neuron contacts the muscle fiber
Myotonia
Slow relaxation, or decreased ability to relax muscles after voluntary contraction, may be accompanied by increased muscular excitability and contractility
Muscle tone
Small amount of tension or contraction that a muscle exhibits even at rest, caused by weak, involuntary contractions of motor units. Established my neurons in the brain and spinal cord. Keeps muscles firm but does not fully contract.
Canaliculi
Small channels filled with extracellular fluid connecting the lacunae.
C fibers
Small diameter nerve fibers, unmyelinated, conduct at about 1 meter/sec
Lacunae
Small spaces between the lamellae which house osteocytes
Lacunae (little lakes)
Small spaces where chondrocytes reside
Neurotransmitter classes
Small-molecule and neuropeptide
Sarcoplasmic reticulum
Smooth endoplasmic reticulum of a muscle fiber
autorhythmic
Smooth muscle and cardiac muscle
Glycolysis
Smooth muscle has a low capacity for generating ATP unlike cardiac muscle, and does so only through this process
Multiunit smooth muscle
Smooth muscle lacking gap junctions, contract independently
Calcium ion deficit
Sodium channels become activated by very little change of the membrane potential from its normal resting level, causing the nerve fibers to become highly excitable, sometimes discharging repitively without provocation, rather than remaining in the resting state. Associated with muscle contraction, cramps, even tetany,which can be lethal because of titanic contraction of respiratory muscles.
Organization of the Nervous System
Somatic, autonomic, and enteric
Multipolar
Vast major of neurons in the body
Osteomalacia
Sometimes called adult rickets, occurs when new bone formed during remodeling fails to calcify.
Liver, kidneys, pancreas, derived from milk, red meat, some fish
Sources of creatine in the body
Marrow cavity
Space inside the diaphysis
Tic
Spasmodic twitching made involuntary by muscles that are ordinarily under voluntary control
Osteogenic cells
Stem cells that arise from mesenchyme and differentiate into osteoblasts
Continuous conduction
Step-by-step depolarization and repolarization of adjacent segments
Sarcoplasmic reticulum
Stores calcium ions, and releases them when the muscle fiber is stimulated
Layers of epidermis superficial to deep
Stratum cornermen, stratum lucidum, stratum granulosum, stratum spinous, stratum basale
Striae
Streaks, scarring of skin caused by tearing of the dermis. First appear as purple or reddish lines, but later fade to a lighter color. Due to rapid stretching of skin from weight gain, puberty, or pregnancy.
Skeletal muscle tissue
Striated, multinucleated (eccentric), fibers are parallel
Cardiac muscle tissue
Striated, one central nucleus, muscular tissue
Athlete's foot
Superficial fungal infection of the skin of the foot
Shaft
Superficial portion of the hair
Stratum spinosum
Superficial to stratum basale
Stratum granulosum
Superficial to stratum spinosum, deep to stratum lucidum
Bone functions
Support, protections, movement, mineral homeostasis, blood cell production, triglyceride storage
Perimysium
Surrounds a muscle fascicle
Endomysium
Surrounds a muscle fiber
Epimysium
Surrounds the entire muscle, all blend together to tie into a tendon.
Endoneurium
Surrounds the nerve fiber, outermost layer. (Covers myelin sheath when present)
Neuromuscular junction
Synapse betwen a somatic motor neuron and a skeletal muscle fiber. Synaptic end bulbs at the tips of the axon terminals contain synaptic vesicles filled with acetylcholine (ACh), which carries the impulse across the synaptic cleft.
Trigger zone
Synaptic input is integrated by summation, which occurs where?
Electrical synapse
The cells on each side are in physical contact, action potential moves from one cell tot he other as a flow of ions through gap junctions
Chemical synapses
The cells on each side are not in physical contact, action potential moves from one cell to the other by means of a neurotransmitter that bridges the gap between the two cells
Neurofibrils and microtubules
The cytoskeleton of a neuron is made up of
Bulb
The enlarged base of the hair follicle. Contains the matrix.
Rate at which it's stimulated
The force of a single muscle fiber is primarily dependent on what?
Diameter
The greater the _______ of the axon, the faster the axon conducts
sympathetic and parasympathetic
The motor portion of the autonomic nervous system consists of two parts
Latent period
The muscle action potential sweeps over the sarcolemma, and the Ca2+ are released from the sarcoplasmic reticulum
Integrative function
The nervous system analyzes and stores information and makes decisions.
Motor function
The nervous systems function to respond to decisions, neurons carry information from the brain and spinal cord to the effectors (muscles and glands)
Neurolemma
The outer nucleated cytoplasmic layer of the Schwann cells, which encloses the myelin sheath
Stimulus perception
The process a nerve fiber uses to distinguish different magnitudes of stimuli - frequency of impulses and number of sensory neurons activated
Myelination
The process of the Schwann (PNS) cell wrapping around a 1-mm long segment of an axon many times.
Graded potentials
The size of the change in the membrane potential varies in proportion to the strength of the stimulus (not all or none). Produce only local effects; channels open, flow through membrane, and travels only a short distance before diminishing to zero.
Epidermis
The superficial, thinner layer composed of epithelial tissue
Calcium binds with troponin
The troponin, tropomyosin complex moves aside, uncovering myosin-binding sites on the actin molecules, triggered by what?
Functions of Skin
Thermoregulation, protection, cutaneous sensation, excretion, synthesis of vitamin D, reservoir for blood, absorbs substances
Actin
Thin contractile protein in a myofibril
Troponin
Thin regulatory protein in a myofibril
Proliferative phase
Third phase of deep wound healing, growth of epidermal cells beneath the scab, increase the amount of collagen, and regeneration of blood vessels.
Spongy bone callus
Third step in fracture repair, osteoblasts form this after the fibrocartilaginous callus.
Opioid peptides
Thought to be the body's natural painkillers
Nails
Tightly packed, hard keratinized epidermal cells
Burns
Tissue damage caused by excessive heat, electricity, radioactivity or corrosive chemicals that destroy proteins in the skin cells.
Structure proteins
Titian, myomesin, dystrophin, sarcolemmal proteins
Regeneration requirements
To regenerate any neurons, the neurons must be located in the PNS, have an intact cell body, and be myelinated.
Papillary region receptors
Touch corpuscles (Meissner) for light touch, free nerve endings with no apparent structural specialization that give rise to the sensations of warmth, coolness, pain, tickle and itch.
Keratin
Tough, fibrous protein that waterproofs the skin and helps protect the skin and underlying tissues from heat, microbes, and chemicals
Slow axonal transport
Transports axoplasm to growing or regenerating axons
Muscle action potential
Travels along the entire sarcolemma and down the t tubules to the inferior of the fiber
Axon hillock and initial segment junction
Trigger zone in many neurons, integrates EPSPs and IPSPs - if sum is depolarization that reaches threshold, initiates action potential.
Movement of troponin-tropomyosin
Triggered by calcium binding to troponin, allows contraction to begin
Regulatory proteins
Troponin and tropomyosin
Microtubules
Tubulin, participate in moving material between the cell body and axon (in neuron)
Myoma
Tumor consisting of muscle tissue
Rickets and osteomalacia
Two forms of the same disease that result from inadequate calcification of the extracellular bone matrix, usually caused by vitamin D deficiency. Prevention and treatment for both consists of administration of adequate vitamin D.
Inhibitory Postsynaptic Potential (IPSP)
Typically result from opening a ligand gated anion channels for Cl- or ligand-gated channels for K+, which then diffuse according to concentration gradients resulting in the inside becoming more negative (hyperpolarize)
Excitatory postsynaptic potential (EPSP)
Typically result from opening of ligand-gated cation channels, the three most common cations being Na+, K+, and Ca++. A single one does not normally initiate a nerve impulse, but the neuron does become more excitable, being partially depolarized is more likely to reach threshold in the future.
Arrector pili
Under physiologic or emotional stress, autonomic nerve endings stimulate these to contract, causing goose bumps. Helps regulate temperature and make one look larger (if being attacked)
Neuroglia cells
Undergo mitosis, replace neuronal cells if there is damage
Skeletal muscles tissue
Used for movement, heat, and posture. Voluntary muscle
Intra-membranous ossification
Used in forming the flat bones of the skull, mandible, and clavicle. Bone forms from mesenchymal cells that develop within a membrane without going through a cartilage stage. Has many ossification centers.
Fast axonal transport
Uses microtubules as "tracks" and "motors", transports organelles and materials that are used to form axolemma membranes, synaptic end bulbs, and synaptic vesicles
Ion channels
Various types located in the plasma membrane of neurons and muscle fibers; give the cells the property of electrical excitability. When open, specific ions are allowed to move across the plasmalemma, down their electrochemical gradient from places of higher concentration to lower. Flow of ions comprises a flow of electrical current that can change the membrane potential.
Axon
Virtually always a single one per neuron, typically arises from an elevation in the cell body call the axon hillock
Sun
Virutally all skin cancers are attributed to excessive exposure to what?
Synovial fluid
Viscous, clear fluid; lubricates, allows diffusion of nutrients and waste (secreted by synoviocytes)
Rickets
Vitamin D deficiency
Resting membrane potential
Voltage difference measured across the plasma membrane when the neuron isn't signaling. Membrane is polarized. (Measured as the potential of the inside vs. outside) ranges from -40 to -90 mV, average -70mV
The binding of two acetylcholine molecules
What opens the ACh receptors on the motor end plate, which allows the inflow of Na+ inside of the muscle fiber, triggering an action potential?
ATP
When this is present inside muscle fibers, it can power contractions for only a few seconds during hydrolysis
Z discs
Where adjacent sarcomeres abut; center of an I band
Metaphyses
Where the diaphysis and epiphyses meet
Lunula
Whitish, crescent-shaped area of the proximal end of the nail
Jaundice
Yellowish appearance to the whites of eyes and skin, caused by buildup of bilirubin in the blood. Usually indicates liver disease.
Mesenchyme
all connective tissues arise from
Hypodermis
also known as subcutaneous layer, consists of areolar and adipose tissue and is not part of the skin
Single unit smooth muscle
also known as visceral smooth muscle; units connect to one another by gap junctions and contract as a single unit
Greenstick fracture
bending and incomplete break of a bone; most often seen in children
Central nervous system
brain and spinal cord
Impacted fracture
broken bone ends are forced into each other
Frequency of impulses
codes for intensity of the stimulus; a light touch generates a low frequency of widely spaced nerve impulses, a firm pressure causes nerve impulses to go down the axon closer (higher frequency).
open fracture
compound fracture; broken bone with an open wound
Axoplasm
cytoplasm of axon
Neurotransmitter removal
diffusion, enzymatic degradation, uptake into cells
Sutures
fibrous joints between the bones of the skull
Comminuted fracture
fracture in which the bone is splintered or crushed
Distal fragment
if an axon is cut, what portion dies?
Mitochondria
larger and more numerous in cardiac muscle tissue due to the greater dependence on aerobic respiration to generate ATP
Squamous cell carcinoma
malignant tumor of the squamous epithelial cells in the epidermis
Three pigments that affect skin color
melanin, hemoglobin, carotene
Create motion
muscles work with nerves, bones, and joints to produce body movements
Neurolemma
not present in the CSN because oligodendrocyte cell body and nucleus do not envelop the axon
1%
perineum
Demyelination
process of losing the myelin sheath of a nerve fiber. In axons that are normally myelinated, voltage-gated channels are concentrated (or exclusively present) only at the nodes of Ranvier. Myelin insulates the neuron and allow the current to spread further before it attenuates. Destruction of myelin means the current does not spread as far.
Axon
propagates nerve impulses to axon terminals in a self-reinforcing manner. Impulse amplitude does not change as it propagates along the axon.
Osteomalacia
softening of the bone
Peripheral nervous system
somatic, autonomic, and enteric make up
Motor end plate
the region of the sarcolemma opposite the synaptic end bulbs. Comprises the muscle fiber part of the neuromuscular junction.
Contractible
they can shorten in length
Triad
two terminal cisternae and a T tubule
Wave summation
when a second stimulus occurs before the muscle fiber has relaxed, the second contraction is stronger than the first (more Ca2+ is released into the sarcoplasmic reticulum.