IPAP, A&P I, Block 2

Create motion

muscles work with nerves, bones, and joints to produce body movements

Axon hillock

"Small hill" elevation in the cell body where the axon arises

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.

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

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

Slow axonal transport

1-5 mm per day, one way only, from the cell body to axon terminals

Abrasion

An area where skin has been scraped away

Cranial nerves

12 pairs of nerves that carry messages to and from the brain

Fast axonal transport

200-400 mm per day, two-way transport, both toward and away from cell body

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.

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

Stratum spinosum

8-10 layers of keratinocytes; few langerhans cells.

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

Tract

An association (bundle) of neuronal axons in the central nervous system

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

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.

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

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

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.

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)

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

Neural circuits

Billions of neurons in the CNS are organized into networks, a functional group of neurons that processes a specific kind of information

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.

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

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

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.

Graded potential

Can either hyperpolarize or depolarize a membrane

Extensible

Can extend or stretch

Elastic

Can return to their original shape

Spongy bone

Cancellous bone or trabecular bone

Autorhyhmicity

Cardiac muscle exhibits what?

Chondroblasts

Cartilage forming cells, form chondrocytes

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.

Integumentary system skin

Consists of two layers, epidermis and dermis

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.

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

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.

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

Varicosities

End of axon terminals, string of swollen bulbs

Synaptic end bulbs

Ends of axon terminals, bulb-shaped structure

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

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

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

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.

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

Intra-membranous and endocondral

Ossification processes

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

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

Nissl bodies

Prominent clusters of rough endoplasmic reticulum in neurons

Parathyroid hormone

Promotes resorption of bone matrix, increases blood calcium level

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.

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

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

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

Makeup of Integumentary system

Skin and accessory structures (hair, nails, various glands, muscles, nerves)

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

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.

Multipolar

Vast major of neurons in the body

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.

reuptake

a neurotransmitter's reabsorption by the sending neuron that released it

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

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.