Exam 2 Flashcards
Active transport
Primary vs. secondary active transport
Active transport requires expending cellular energy-the movement of a solute AGAINST its concentration gradient (low to high)
A) Primary active transport: uses energy from ATP breakdown using phosphorylized ion pumps to move ions across the membrane
B) Secondary active transport: the kinetic energy of one substance moving down concentration gradient provides power to pump another substance against concentration gradient
Moving two substances at once (cotransport)
Calcium pump
Ca2+ concentration is low inside, high outside cell
ATPase pump splits ATP->ADP+Pi, uses energy to move Ca2+ outside cell
Define symport and antiport as it relates to secondary transport
Symport: two substances are moved in the SAME direction by a symporter/cotransporter, ex. glucose and Na+
Antiport: two substances are moved in the OPPOSITE direction by an antiporter/countertransporter, ex. Na+ and H+ (Na+ into cell, H+ out of cell)
Define vesicular transport and describe the difference between exocytosis and endocytosis
Vesicular transport: allows for movement of large substances/large amounts of a substance to move across the membrane using vesicles
A) exocytosis: vesicle binds to membrane->contents released outside the cell ex. neurotransmitter release
B) Endocytosis: uptake of large amounts/substances INTO cell eg. uptake of nutrients
ATP is required for Primary Active Transport because solutes
are …
A. being moved down/with their concentration gradient
B. too big to move across the membrane otherwise
C. being moved up/against their concentration gradient
D. None of the above
Question
C. being moved up/against their concentration gradient
Sodium/Potassium Pump
AKA Na+/K+/ATPase exchange pump
Electrical gradient, chemical gradient
Sodium and ATP bind, ATPase splits ATP, pushes sodium out of cell, grabs K+ ions and brings inside cell
Electrical gradient: more positive outside cell, more negative inside
Chemical gradient: Sodium concentration higher outside cell, potassium high inside cell
1. 3 Na+ ions and ATP bind to cytoplasmic/inner surface of pump
2. Pump splits ATP into ADP+Pi, Pi binds to pump, energy released causes pump to change shape and release Na+ into interstitial fluid
3. 2 K+ ions from interstitial fluid bind to pump, Pi released into cytosol
4. Transport protein reverts to original shape, releasing K+ into cytosol
1:3:2 ratio
3 types of endocytosis
- Phagocytosis: “cellular eating” cell engulfs particle using pseudopodia membrane extensions and fuses to form a vesicle, ingested material is broken down
- Pinocytosis: “cellular drinking”, multiple, smaller regions of plasma membrane form multiple smaller vesicles to internalize interstitial fluid- occurs in most cells
- Receptor-mediated- binding triggers vesicle creation eg. cholesterol
How does O2 diffuse into a cell and CO2 diffuse out
of a cell?
a. down their concentration gradients, b. simple diffusion, c. primary active transport d.
fascilitated diffusion
A. a
B. a, b
C. a, b, c
D. a, d
E. b, c, d
B. a, b
What type of transport is used to bring cholesterol into
the cell?
a. Exocytosis, b. endocytosis, c. active processes, d. pinocytosis, e. receptor-mediated
A. a
B. a, b
C. b, c, d
D. a, c, d
E. b, c, e
Question
E. b, c, e
Endocytosis-bringing substance INTO cell
Active process- requires energy
Receptor mediated
Identify and briefly describe the four types of tissues in the body
- Epithelial- covers the surface of the body, hollow organs, 3 shapes and sizes (cuboid, columnar, squanous)
- Connective- found all over the body
- Muscle- skeletal, cardiac, smooth
All form can contract, all contain actin and myosin - Nervous-neurons and support cells
Name the different structures associated with the integumentary
What percentage of body weight?
Skin and accessory tissues
Nails, hair, sweat glands, sebaceous glands, nerve endings, blood vessels
Largest organ
6-8% of body weight
5 functions of the integument
- Protection- physical barrier, protects from toxins, injury, solar radiation
- Prevention of water loss/gain- sweat, transpiration
- Secretion and absorption-waste products including urea, heavy metals, Na+ secreted in sweat, selectively permeable (lipid soluble)
- Temperature regulation-vasoconstriction and dilation
- Metabolic, immune, and sensory function
True or False, to effectively administer drugs
through a transdermal patch the drugs must
be highly water soluble?
A. True
B. False
False
They must be lipid soluble
To increase blood flow to the skin blood
vessels would need to ______________.
A. vasoconstrict
B. vasodilate
Vasodilate
Three layers of integument
Epidermis: stratified (multiple layers) squamous epithelium
Dermis: dense irregular connective tissue-bundles and clumps of collagen fibers with blood supply
Hypodermis: not part of integument proper, contains connective tissue and blood vessels
Describe the different cells in the epidermis (4 types)
- Keratinocytes- most abundant, synthesize keratin protein
- Melanocytes- produce and store pigment melanin
- Tactile cells
- Epidermal dendritic cells-immune function
Describe how keratinocytes change as they mature
What shape are they?
How many days does the process take?
Cuboidal shape
Cells divide and produce new cells, pushing older cells up
More mature cells synthesize more keratin (keratinization)
Keratin accumulation->cell death through death of nucleus and organelles
Takes about 20-40 days
Which layer of the integument proper is the
deepest?
A. Hypodermis
B. Dermis
C. Peridermis
D. Epidermis
B. Dermis
Hypodermis is not part of the integument proper
Which layer of the integument proper contain
capillaries?
A. Hypodermis
B. Dermis
C. Peridermis
D. Epidermis
B. Dermis- contains most structures including blood vessels, sweat glands, sebaceous glands, nail roots
Melanocytes
How is melanin transferred?
Types of melanin
Melanin produced in response to UV radiation
Melanosomes (pigment granules) are transported to keratinocytes through exocytosis
A) Eumelanin-black and brown shades
B) Pheomelanin-tan, red, yellow shades
Proteins, structures, muscles, and cells found in the dermis
Proteins: collagen, elastic, reticular
Blood vessels and capillaries
Sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve endings
Muscles: arrector pilli (hair follicle muscles)
Mobile dendritic cells-immune function
Features of hypodermis
More fat, adipose tissue
Extensive vascular network-cite of drug injection
Thicker in women than men
Moles (nevus) vs. freckles
Moles/nevus: overgrowth of melanocytes
Freckles: increased melanocyte activity, sun exposure and heredity determine degree of pigmentation
Explain what causes differences in skin color
Why do blood vessels appear red?
Hemoglobin, melanin, carotene
Hemoglobin is oxygen binding protein in red blood cells
Blood vessels in the dermis have a reddish tint because of the bright red color of hemoglobin when it binds with oxygen
The pigmentation of freckles is influenced by:
a. biological sex, b. heredity, c. sun exposure, d. aging
A. a
B. a, b
C. a, c
D. b, c
E. b, c, d
E. b, c, d
Sun exposure, heredity, and aging influence pigmentation
Two epidermal derivates
When are they formed?
What are they made of?
Hair and nails
Formed during embryonic development, epidermis projecting into dermis
Mainly composed of dead keratin cells
Describe the general function of hair (4)
Protection- keeping sweat out of eyes, trapping particles, protect scalp from sunburn
Facial expression
Heat retention- prevents loss of heat via scalp
Sensory reception
3 types of hair
- Lanugo- fine, unpigmented downy hair-last trimester->
- Vellus- fine, primary human hair, found on limbs->
- Terminal hair- coarser, pigmented hair-found on scalp, eyebrows, eyelashes, replaces vellus hair on genitals and axillary region
Explain the six general functions of skeletal muscle
- Movement
- Maintaining posture, stabilizing
- Protection and support-layers of skeletal muscle in abdominal and pelvic cavity protect organs
- Regulation of elimination-sphincters at openings of gastrointestinal and urinary tracts
- Producing heat
- Storage and utilization of fuel
Regeneration vs. fibrosis
Regeneration: replacement cells are the same type- funtion is maintained
Fibrosis: replacement cells are different (collagen, connective tissue)- function is lost
4 stages of wound healing
- Wound- blood vessels bleed into wound to transport cells
- Blood clot- macrophages (cleanup), fibroblasts (replacement), neutrophils
- Granulation tissue forms, blood vessels reform
- Epithelium regenerates, connective tissue reforms
Composition of skeletal muscle from smallest->largest
Myofilaments->myrofibrils->muscle fibers->fascicles->skeletal muscle
Gross anatomy of skeletal muscle
3 components
Amazon box metaphor
Connective tissue:
1. Epimysium: outermost layer, covers entire muscle (box)
2. Perimysium: surrounds fascicles (bundles of muscle fibers) (packing peanuts)
3. Endomysium: surrounds muscle fibers, areolar connective tissue light layer of insulation (like tissue paper)
Blood vessels: arteries, veins, 60% capillaries
Nerves: somatic/alpha motor neurons (conscious control), beta and gamma motor neurons, sensory nerves
Microscopic anatomy of skeletal muscle
What are they composed of?
Striation
Myoblasts fuse together->form muscle fibers with many nuclei, satellite cells
Striation=stripes in muscle fibers, only in skeletal and cardiac muscle
Organelles and structures found in cardiac muscle
- Mitochondria
- Glycogen
- Triglycerides
- Hemoglobin and myoglobin (O2 transport)- proteins
Excitable cells
What is resting membrane potential?
What maintains RMP?
Cells whose activity is changed when a change in membrane potential occurs
Resting membrane potential=-70mV
RMP maintained by Na+ and K+ leak channels
Which of the following are functions of
skeletal muscle?
A. Maintain posture
B. Heat production
C. Fuel storage/utilization
D. All of the above
D. all of the above
Process of innervating a skeletal muscles
Synaptic knob, sarcolemma, motor endplate,
Electrical signal travels to synaptic knob, which houses ACh vesicles
Signal triggers Ca2+ release into synaptic knob
Ca2+ triggers release of ACh vessicles, ACh binds to ligand-gated receptor ion channels on the motor endplate of the sarcolemma (plasma membrane)
Receptors are preferential for Na+, binding allows Na+ in and K+ out
If an RMP of -55mV is reached, the Na+/K+/ATPase pump opens
Pathway of force production
Upper and lower motor neurons
Motor unit-large and small
Upper motor neuron originates in primary motor cortex, innervates right side of body
Lower motor neuron originates in anterior horn of spinal cord, innervates the left side
Motor unit: alpha motor neuron and the muscle fibers it innervates
Small MU: less than 5 muscle fibers, precise movements eg. eyes and hands
Large MU: thousands of muscle fibers, lots of force, little precision eg. thighs
T-tubules
Sarcoplasmic reticulum
T-tubules: transverse tubules
Sarcoplasmic reticulum: stores calcium
Excitation-contraction coupling
Sarcolemma, t-tubules, sarcoplasmic reticulum
Ligand-gated ACh receptors on endplate open at ACh binding, preferential for Na+
If enough Na+ enters to depolarize cell to -55mV, voltage-gated Na+ and K+ channels open
Action potential continues along sarcolemma to T-tubule, opens voltage-gated Ca2+ channels on T-tubule, triggers release of Ca2+ from sarcoplasmic reticulum->crossbridge cycling
Describe the proteins that make up a sarcomere
Sarcomere: link in the chain that makes up muscle fiber
Made up of thin and thick filament
1. Thin filament: made up of actin, tropomyosin (blocks myosin binding site), and troponin (calcium, tropomyosin, inhibit)-binds calcium
2. Thick filament: made up of myosin filament with two heads w/ binding site for actin and two twisted tails
3. Titin: largest protein in body, anchors myosin filament
How is a motor unit defined?
A. Alpha-motor neuron and all the muscle fibers it innervates
B. Beta-motor neuron and all the muscle fibers it innervates
C. All the muscle fibers in a muscle
D. None of the above
A. Alpha motor neuron and all the muscle fibers it innervates
Where on skeletal muscle fibers are chemically/ligand
gated channels concentrated?
A. Sarcoplasmic reticulum
B. Sarcolemma
C. Motor end plate
D. T-tubules
C. Motor end plate
Which protein inside skeletal muscle cells binds
oxygen?
A. mitochondria
B. hemoglobin
C. myoglobin
D. youroglobin
C. Myoglobin
Hemoglobin binds oxygen in BLOOD
Which protein in skeletal muscle binds
calcium?
A. Actin
B. Tropomyosin
C. Troponin
D. Myosin
C. Troponin
Which protein in skeletal muscle cells make up
the thick filaments?
A. Actin
B. Tropomyosin
C. Troponin
D. Myosin
D. Myosin
Where in skeletal muscle cells is calcium
stored?
A. At the neuromuscular junction.
B. In the sarcoplasmic reticulum.
C. In satellite cells
D. Calcium is not stored in skeletal muscle cells
B. Sarcoplasmic reticulum
Crossbridge cycling
4 steps
When Ca2+ binds to troponin on thin filaments, tropomyosin moves and uncovers the myosin binding cite on actin
1. Attach- Ca2+ binds, myosin head attaches to actin binding site
2. Pull- power stroke: myosin head pulls thin filament towards center of sarcomere, ADP and Pi released
3. Release: ATP binds to myosin head-> release from actin protein
4. Reset: ATP breaks down into ADP and Pi by myosin ATPase, energy used to reset myosin head
Describe the different periods of a muscle twitch
Which is the longest?
How does Ca2+ reuptake work?
- Stimulus
- Latent period: electric signal is traveling along the sarcolemma and t-tubules, Ca2+ releasing from sarcoplasmic reticulum
- Contraction period: faster than relaxation, Ca2+ release from SR (power stroke)
- Relaxation- longest period, Ca2+ reuptake using SR Ca2+ ATPase calcium pump (reset)
Which of the following is the correct order of events
for crossbridge cycling?
A. attach, pull, reset, release
B. attach, reset, pull, release
C. attach, pull, release, reset
D. pull, pull, pull, pull!
C. Attach, pull, release, reset
Which period of a muscle twitch is longest?
A. Latent period
B. Contraction period
C. Relaxation period
D. They are all the same duration
C. Relaxation period
Two methods of producing more force/tension in skeletal muscle
A) recruit more motor units
Size principle: start with smaller, slower units
B) Increase stimulation frequency: allows for less time to relaxation, allows buildup of Ca2+->sustained contraction
Increasing which of the following is likely to result in an
increase in the force of a muscle contraction?
A. Stimulation frequency
B. Motor unit recruitment
C. Intracellular Ca2+
D. All the above could increase the force of a
muscle contraction
D. All of the above
All the following are found inside of a skeletal
muscle fiber/cell EXCEPT
A. Actin and Myosin
B. Myoglobin
C. Glycogen
D. Hemoglobin
D. hemoglobin
Describe the relationship between muscle length and muscle tension and be able to describe how the overlap
between myosin and actin play into this relationship
Muscles at resting length generate the most crossbridges-allow most myosin/actin overlap=more force
Describe different types of muscle contractions
Concentric vs. eccentric
A) Isometric: Tension generated is less than resistance, no muscle movement (concentric/eccentric)
B) Isotonic: tension results in concentric (shortening) or eccentric (lengthening) movement
3 types of muscle fiber
SOFAST acronym
Contraction length and speed, diameter, oxygen vs. glycogen
- Slow oxidative (SO, Type I)
Slow contraction speed, long duration-fatigue resistant, high capacity for oxygen, endurance, small diameter - Fast glycolytic (FG, Type IIx)
Fast, powerful contraction, short duration-short intense movement, high glycogen, low oxygen - Fast oxidative (FO, Type IIa)
Fast, powerful contraction, moderate duration
medium duration and moderate movement
Define homeostasis and the components of a homeostatic system
Ability of an organism to maintain a consistent internal environment “ready-state” in response to changing internal or external factors
1: receptor-detects a stimulus (change in variable)->2. control center: integrates input from receptors, initiates change through effectors->3. effector: brings about change
Describe passive transport and distinguish between simple and facilitated diffusion
2 forms of facilitated diffusion
Passive transport requires no external energy-substances move DOWN their concentration gradient from high to low
Simple diffusion: small, nonpolar (noncharged) molecules like oxygen, CO2 move down their concentration gradient
Facilitated diffusion: channel mediated- polar (charged) molecules move down gradient through water-filled channels eg. sodium, potassium
Facilitated diffusion: carrier mediated- carrier proteins change shape to transport small, polar molecules eg. glucose
Describe the factors the influence diffusion
- Temperature-higher temp.=faster diffusion
- Gradient-steeper gradient=faster diffusion
- Surface area- larger=slower
- Size of particles-larger=slower
- Distance-larger=slower
Describe how ATP is synthesized within skeletal muscle though creatine kinase, glycolysis and aerobic respiration
- Immediate supply: enzyme creatine kinase transfers Pi from phosphocreatine to ADP->ATP
- Short term, high intensity: glycolysis
anaerobic, glucose/glycogen converted to lactate/pyruvate - Long term, low intensity: aerobic cellular respiration
Oxygen and glucose->water, CO2, 30 ATP
Describe why we continue to breath heavily after you stop exercising
No oxygen debt/excess oxygen consumption
Restoring the body to homeostasis
1. Resynthesize phosphocreatine (ADP+PCr<->ATP+Cr)
2. Eliminate CO2
3. Dissipate heat
Describe delayed-onset muscle soreness
Due to micro-tears and an inflammation cascade that peaks 24-48 hours after exercise
Explain why muscles fatigue
5 reasons
Fatigue is task specific
Failure can happen at any point in the force production pathway
1. Cortical excitability reduced
2. Neuron/muscle cell excitability reduced
3. Reduced calcium release/slow uptake
4. Cell swelling
5. Glycogen depletion
How is ATP synthesized in skeletal muscle?
a. aerobic respiration, b. phosphate transfer, c. glycolysis, d. photosynthesis
A. a
B. a, b
C. a, c
D. a, b, c
E. A, b, c, d
D. a, b, c
Aerobic respiration=long term
Phosphate transfer=immediate
Glycolysis=high intensity, short term
In exercise lasting more than a 1-2 minutes the
higher the intensity of exercise the more you rely
on ________ as a fuel source.
A. PCr
B. Glycogen
C. Blood Glucose
D. Lipids
B. glycogen
Describe the three general functions of the nervous system
- Collect information (receptor)
- Process information (control center)
- Initiate change in cardiac muscle, skeletal muscle, and smooth muscle (effector)
Describe the structural organization of the nervous system
Central (brain and spinal cord)
Peripheral (nerves, ganglia)
Cells include neurons, glial cells
Describe the tissues associated with a nerve
Nervous, epithelial, and connective (3 types)
Neurolemmacytes
Nervous: nerves and support cells
Epithelial: blood vessels
Connective: epineurium surrounds entire nerve, perineurium surrounds fascicles/bundles of axons
endoneurium surrounds individual axon
Neuralemmacytes create the myelin sheath surrounding axons
Describe the three basic anatomical features common to most neurons
A) dendrites-input
B) soma/cell body-integration
C) axon-output, initiates response by sending signals to cells, muscles, or glands
Which portion of a neuron is often myelinated?
A. Dendrites
B. Cell Body
C. Axon
D. All the above
C. axon
Which portion of a neuron contains the nucleus?
A. Dendrites
B. Cell Body/Soma
C. Axon
D. All the above
B. cell body/soma
The plasma membrane of a neuron is called the
_____________ .
A. Soma
B. Sarcolemma
C. Neurolemma
D. Nervolemma
C. neurolemma
Identify the three functional categories of neurons and where each is primarily located
SAME DAVE acronym
- Sensory: conduct sensory input to CNS (afferent)
- Interneurons: entirely within the CNS, facilitate communication between sensory and motor
- Motor: conduct motor output away from CNA
Sensory Afferent, Motor Efferent, Dorsal (back) Afferent, Ventral (front) Efferent
Briefly describe the physiological events that occur along the segments of the neuron
Receptive, initial, conductive, and transmissive
Receptive: neurotransmitter binding, production of graded potential
Initial: summation of graded potential, initiation of action potentials
Conductive: propagation of action potential
Transmissive: action potential triggers neurotransmitter release to a cell, muscle, or gland
Describe how neurons can either be inhibited or excited and the general process involved
Inhibitory inputs open Chloride (Cl-) channels, make membrane potential more negative and further from threshold
Excitatory inputs open Na+ preferential channels, make membrane potential more positive, closer to threshold
EPSPs vs IPSPs
EPSP: sodium flows into cell, inside of neuron becomes more positive
IPSP: K+ channel or Cl- channel opens, K+ flows out or Cl- flows in, neurons becomes more negative
Binding of a neurotransmitter and opening of a
ligand-gated ion channels happens in which
segment of the neuron?
A. Transmissive
B. Initial Segment
C. Receptive
D. All segments
C. Receptive
Another name for a ligand gated ion channel is chemically gated ion channel.
A. True
B. False
A. true
