Final Exam LOs units 1-3 Flashcards
Anatomy
think structures (internal vs. external), and what it’s made up of + location
Physiology
describes functions of the body
Explain the integrative relationship between structure and function
Specific functions are performed by specific structures, and the form of a structure relates to its function
Define homeostasis and explain why it is important to proper body function
all body systems work together to maintain a stable internal environment in response to external and internal changes (to function within a normal range)
it’s important because different parts of your body have an optimal range they work in, and homeostasis makes sure your body is in that range
Describe the three key components of homeostatic regulatory mechanism including receptor, control center, and effector
receptor- receives and recognizes the stimulus change
control center- processes the signal + sends instructions
effector- cell/organ that carries out instructions to oppose or enhance the stimulus
Autoregulation
think intrinsic, cell, tissue, or organ that adjusts in response to some type of change INDEPENDENTLY
Extrinsic Regulation
body’s response is controlled by nervous or endocrine system (system implies MULTIPLE things occurring at once)
Negative feedback mechanism + example
response of the effector negates the stimulus (can add or subtract) and the point is the body is brought BACK into homeostasis
ex: an increase in body temp —> sweat occurs to lower body temp
Positive feedback mechanism + example
response of the effector increases/amplifies the change of the stimulus, body is moved AWAY from homeostasis
ex: (not many) uterine contractions during childbirth
Dynamic Equilibrium
state in which physiological systems are continually adapting to changing conditions
Plasma membrane
it’s basically is the phospholipid bilayer thing that determines what substances move across the membrane
Describe which type of materials can easily pass through the plasma membrane and those that cannot
CAN pass: small nonpolar molecultes
CANNOT: large charged molecules
Diffusion
the idea that molecules like to spread themselves out evenly within a given area, net movement is molecules going from a high concentration to low concentration (which is the concentration gradient)
Simple diffusion
small, uncharged, and nonpolar molecules can move across the membrane WITHOUT help
Facilitated diffusion
diffusion of molecules WITH help of transport proteins
Osmosis
the diffusion of water across the membrane toward solution with more solutes
Hypertonic
there is more solute OUTside of the cell, and so water flows outside the cell and shrinks
Hypotonic
there is more solute INside of the cell, and so water goes into the cell and it bursts
Isotonic
solute concentrations are equal so this is healthy cell
Carrier mediated transport
1) Specificity: one transport protein, one set of substrates
2) Saturation limits: number of transport proteins may limit the amount of substrate transport
3) Regulation of Activity: cofactors, such as hormones
Facilitated Diffusion
carrier mediated transport, molecules too large and hydrophilic to fit through channel proteins
passive, goes down concentration gradient
Active Transport
carrier mediated transport, carrier proteins go AGAINST the concentration gradient, requires energy i.e. ATP
you’ve got primary and secondary
primary think sodium potassium pump
Secondary Active Transport
carrier proteins use Na+movement DOWN its concentration gradient to drive transport of a second molecule
ATP energy pumps back Na+ back out (via primary active transport)
Vesicular Transport
think bulk transport, materials moving in or out of vesicles
ENDOcytosis: INto the vesicle; receptor mediated
EXOcytosis: OUT of vesicles, the molecules are released from the vesicle
Tissue
cells working together w/discrete structural and functional properties
Types of tissue
epithelial, connective, muscle, and neural
Epithelial tissue
covers exposed surfaces, lines internal passageways, and forms glands
f(x)s: provide physical protection, control permeability, provides sensation, and provides specialized secretions
Cell Junctions
they form bonds w/adjacent cells or extracellular material, there are three types:
1) Gap Junctions: cells have to communicate, think your heart
2) Tight Junctions: prevents anything from getting in, think BBB
3) Desmosomes: keeps cells together enough that they don’t fall apart
Connective tissue
supporting tissue consisting of matrix containing cells
f(x)s: fills internal spaces and lies between other tissues, supports other tissues, transports materials, and stores energy
Areolar tissue
loosely organized array; mostly ground substance containing all cells and fibers
loose connective tissue
Adipose tissue
contains adipocytes and provides padding, insulation, and energy (think FAT)
loose connective tissue
Reticular tissue
3-D network supporting parenchyma of soft tissues
loose connective tissue found in pancreas, spleen, and liver
Three types of fibers in connective tissues
1) collagen fibers: most common in connective tissue, it’s long, straight, and unbranched, resists force in 1D
2) Elastic fibers: contain elastin, branched and wavy (returns to original length after stretching)
3) Reticular Fibers: network of interwoven fibers that stabilize functional cells and structures
Tissue Membrane
epithelial tissue + connective tissue
Mucous Membrane
lines passageways that have external connections, epithelial tissue must be moist (reduce friction and facilitate absorption/excretion)
Serous Membrane
line cavities not open to the outside, they line organs
Cutaneous Membrane
skin, surface of the body, it’s thick, waterproof, and dry
Synovial Membrane
located in articulating joint cavities, produces synovial fluid, protects the ends of bones
Integumentary System
largest system of the body that encompasses the skin and its accessory structures
Three components of cutaneous membrane
superficial to deep: epidermis, dermis, and hyperdermis
functions of integumentary system
protection of underlying tissues +organs, excretions of salt + water + organic wastes (glands), maintenance of body temp (insulation + evaporation), production of melanin + keratin, synthesis of vitamin D3, storage of lipids, detection of touch + pressure + pain
Skeletal system components
bones of the skeleton, cartilages, ligaments, and connective tissues that stabilize or interconnect them
Functions of the skeletal system
support, storage of minerals (calcium) and lipids (yellow marrow), blood cell production (red marrow), protection, leverage (force of motion)
Describe the characteristics of bones
it’s dense, supportive connective tissue; it has specialized cells, it’s a solid matrix of calcium salt deposits, and its collagen fibers act as rebar
Describe the components of the bone matrix and the f(x) of each
1) one-third of the bone matrix is made up collagen fibers (organic)
2) two-thirds of bone matrix is calcium phosphate (inorganic); calcium phosphate reacts w/calcium hydroxide to form crystals of hydroxyapatite
collagen fibers provide framework for hydroxyapatite to form
protein + crystal combo = flexibility (collagen) and compressive strength (hydroxyapatite)
Osteocytes
mature bone cells found in the matrix
Osteoblasts
think furnaces “blast” to create something new, these guys form new bones and they’re immature bone cells
Osteoclasts
they clash into bone cells, they destroy/dissolve them, and they secrete acids and enzymes to destroy them
Compact vs. spongy bone
Compact bone: have osteons (basic units of bone), they have a central canal w/blood vessels, and they run parallel to the axis of bone
Spongy bone: does NOT have blood vessels or osteons, houses the trabeculae and its filled with red marrow that creates blood cells and sometimes they have yellow marrow that creates fat
Describe the organization of osteons, lamellae, and canals in compact bone
your central canal is within your concentric lamellae, and that is in your compact bone
it is organized in those swirly things in your compact bone
List the bones, or parts of bones, that develop from each type of ossification
ossification is the process of bones being developed and formed, and there are two processes that occur 1) Endochondral ossification and 2) intramembranous ossification
endrochondral ossifies bones from hyaline cartilage, and it creates most of the bones in your body
intramembranous produces dermal bones such as the mandible, clavicle, and cranial bones of the skull
Outline the relationship between bone formation and bone resorption in bone remodeling
Process of remodeling:
-bone continually remodels, recycles, and replaces
-involves osteocytes, osteoblasts, and osteoclasts
-turnover rate varies
1) if deposition is greater than removal, bones get
stronger
2) if removal is faster than replacement, bones gets
weaker
Describe the major factors that affect bone growth including exercise, nutrition, hormones
increase in exercise heavily stresses your bones and so its constantly being replaced
decreased exercises makes your bones weaker because they degenerate quickly so abt 1/3 of bone mass can be destroyed if you aren’t active
Describe the major factors that affect bone growth including nutrition
you need calcium and phosphate salts, but vitamin c is used for collagen synthesis, and vitamin D as well for calcitriol which stimulates calcium and phosphorus absorption in digestive tract
Describe the major factors that affect bone growth including hormones
1) growth hormone w/thyroid hormone stimulates bone growth, 2) estrogen and androgens stimulate osteoblast activity, 3) calcitrol stimulates calcium + phosphorus absorption from digestive tract, 4) calcitonin and parathyroid hormone regulate calcium + phosphate levels in blood
Discuss how mechanical stress affects bone remodeling and bone strength
the more stress the more your bone cells are destroyed and remade so your bones become stronger
Explain general role of bone in calcitonin
when blood calcium levels are HIGH your thyroid (in its C cells) release calcitonin which decreases blood calcium levels
Explain the general role of the Parathyroid Hormone (PTH)
when calcium levels are low, the parathyroid glands secrete PTH which increases blood calcium levels by sometimes stimulating osteoclasts
Describe the type of movement at synovial joints
flexion, extension, hyperextension, abduction, adduction, and circumdunction
flexion
reduces angle between elements
extension
increases angle between elements
hyperextension
extension past anatomical position
abduction
frontal plane, moves away from longitudinal axis
adduction
frontal plane, moves toward longitudinal axis
circumduction
circular motion w/o rotation
List the six functions of skeletal muscle
produces skeletal movement, maintains posture/position, support soft tissue, guard entrances/exits, maintains body temp, stores nutrient reserves
Describe the basic structure of a myofibril including the arrangement of thick and thin myofilaments in a
sarcomere
ok so in your skeletal muscles you have fassicles which are just bundles of muscle fibers. Within the fassicle you have fibers which are just muscle cells. Each muscle fiber has myofibrils that contain sarcomeres with myofilaments. Myofilaments are the thick and thin filaments in your sarcomere.
Explain intracellular calcium levels during a resting and contracting skeletal muscle fiber
when skeletal muscles are CONTRACTING Ca2+ is being released from the SR via Ion channel (going down concentration gradient) to the sarcoplasm
when skeletal muscles are RELAXING Ca2+ is being pumped into SR from sarcoplasm via primary active transport because it’s going UP it’s concentration gradient, which means using ATP
Neuromuscular Junction
Neuromuscular Junction (NMJ): this is basically the first set of steps to control skeletal muscle activity. It’s when a special intercellular connection between the nervous system and skeletal muscle fiber is created, and it also controls calcium ion release into the sarcoplasm
Outline the series of steps in which a neuron controls skeletal muscle activity by stimulating a muscle fiber at the neuromuscular junction
1) action potential is generated, which is just a neuro signal, 2) Ca2+ entry via neuron (axon terminal), 3) release of ACh from the vesicles, 4) ACh binds to receptors, 5) generates AP on sarcolemma, 6) runs down T-tubules, 7) contraction occurs
Describe the events of excitation-contraction coupling
it’s a component of NMJ
excitation: action potential runs down t-tubules at the triad, and that stimulates calcium release into the muscle cell
contraction: contraction occurs as long as calcium ions stay in the sarcoplasm and are bound to troponin
List each step involved in cross-bridge formation and detachment during the contraction cycle
1) contraction cycle begins with the arrival of calcium ions, 2) active-site exposure where calcium ions bind to troponin, 3) cross-bridge formation created when myosin heads attach to active sites, 4) myosin head pivoting (stroke), 5) cross-bridge detachment occurs when ATP binds to myosin head so it leaves the active site, 6) myosin reactivation is when ATP is broken down to ADP so that the energy can be used to recock the myosin head
Describe the role of ATP in contraction and relaxation specifically at the level of the sarcomere
1) ATP provides energy for the pivot
2) ATP also causes myosin heads to detach
Requirements for muscle relaxation
contraction duration depends on: duration of neural stimulus, and number of free calcium ions in sarcoplasm
Ca2+ concentrations fall (calcium pumped back into SR), Ca2+ detaches from troponin so then active sites are recovered by tropomyosin
Tension
when muscles cells contract, they pull on the attached tendon fibers; tension is the pull, it needs energy because it’s an active force
Explain the two factors that determine the amount of tension produced by a whole skeletal muscle
1) fiber’s resting length (#of cross-bridges)
2) frequency of stimulation (how often it receives AP): determines the amount of calcium in sarcoplasm
Fiber’s resting length
optimum overlap of thick + thin filaments during cross-bridging is 75-130%
Motor unit
all muscle fibers have one single neuron attached to it, but one neuron can be attached to multiple muscles, which is a motor neuron part of a neuron unit
Describe the relationship between motor unit size and muscle control
the size of the motor unit dictates how fine the control movement can be
PRECISE control= 4-6 muscle fibers per neuron (i.e the eye)
GENERAL control= 1,000-2,000 fibers (i.e the leg)
Discuss energy production during resting, and moderate and peak levels of activity
Physical conditioning: alters muscle characteristics and fiber type
Anaerobic activities: improved by frequent, brief, intensive workouts, which reduces fatigue time in fast fibers
Aerobic activities: prolonged activity, improved by endurance training, training fast fibers to be more like intermediate fibers
Atrophy
lack of muscle activity, so it reduces muscle size, tone, and power
Explain calcium activation of myosin cross bridge in smooth muscle
the myofilaments don’t have sarcomeres, so the thin filaments are connected to dense bodies on the plasma membrane
calcium comes from pouch-like infolding called caveolae that contains extracellular fluid (no T-tubules and a less developed SR)
Hyperplasia
smooth muscles ability to increase in cell number, so cell division basically
Contraction steps for smooth muscle
1) calcium binds to calmodulin
2) calmodulin activates myosin light chain kinase, which phosphorylates myosin, activating it
3) contraction via the sliding filament mechanism
4) contraction ends when the calcium levels drop and the myosin is dephosphorylated (by an enzyme)
Smooth muscle length-tension relationship
smooth muscle stretches more and generates more tension than skeletal muscle at comparable lengths, and it allows for tremendous changes in volume without becoming flabby when empty (think stomach and bladder)
