Sensory and Motor Mechanisms Flashcards
After the stimuli was processed by the brain in
the sensory pathway, The brain will release a
response in a form of _____ ______ which will
go to the _____ ______ that will instruct a
______ ________ a directed movement.
motor output, muscle neurons, muscle fiber
the product of filament movement powered by chemical energy; muscle extension occurs only passively.
Muscle contraction
Muscle cell contraction relies on the interaction between protein structures called _________________________.
thin and thick filaments
The major component of thin filaments is the _________________.
globular protein actin
In thin filaments, ___________________ called microfilaments function in cell motility.
actin structures
Muscle Contraction- A contracting muscle __________, but the filaments that bring about contraction _______________________.
shortens, stay the same length
To explain this apparent paradox, we’ll focus first on a single ___________. The filaments slide past each other, much like the segments of a ___________________.
sarcomere, telescoping support pole
According to the well-accepted __________________
model, the thin and thick filaments ratchet past each other, powered by myosin molecules.
sliding-filament
Types of Muscle Fibers (based on
myoglobin-OXIDATIVE FIBERS)
-Red Meat
-More Myoglobin
Types of Muscle Fibers (based on
myoglobin-GLYCOLYTIC FIBERS)
-White Meat
-Less Myoglobin
Types of Muscle Fibers (based on
speed of contraction) - FAST TWITCH FIBERS
◦enable brief, rapid, powerful contractions.
◦Could be oxidative or glycolytic
◦Type II Muscles
Types of Muscle Fibers (based on
speed of contraction)- SLOW TWITCH FIBERS
◦2-3x slower than fast twitch
◦Only oxidative
◦Type I Muscles
Types of Skeletal System
Hydrostatic Skeletons
Exoskeletons
Endoskeletons
he growth and development of plants in response to light. It allows plants to optimize their use of light and space.
Photomorphogenesis
is used to describe a sensory cell or organ, as well as the subcellular structure that detects stimuli.
Sensory Receptors
Sensory Pathways
- Sensory Reception and Transduction
- Transmission
- Perception
- Amplification and Adaptation
the ability to use light to track time. Plants can tell the time of day and time of year by sensing and using various wavelengths of sunlight.
Photoperiodism
A sensory pathway begins with ___________, the detection of a stimulus by sensory cells.
Sensory Receptions
a directional response that allows plants to grow towards, or even
away from, light.
Phototropism
made up of chromophore, light-absorbing pigment, and different photoreceptors, which mediates plant’s reaction to light.
Chromoprotein
Phytochromes have two photo-interconvertible forms:
Pr and Pfr
Some sensory cells are themselves ______________, whereas others are ______________ that regulate neurons.
Specialized neurons, Nonneuronal cells
The conversion of a physical or chemical stimulus to a change in the membrane potential of a sensory receptor
sensory transduction
the change in membrane potential itself
Receptor Potential
are graded potentials; their magnitude varies with the strength of the stimulus.
Receptor Potential
Sensory information travels through the nervous system as _________, or ____________.
transducing the energy in a ______ into a _______________ initiates action potentials that are transmitted to the ________.
Stimulus, Receptor potential, Central Nervous System (CNS)
When action potentials reach the brain via ____________ , circuits of neurons process this input, generating the _________ of the stimuli.
Sensory Neurons, Perceptions
are colors, smells, sounds, and tastes
Perceptions
are constructions formed in the brain and do not exist outside it.
Perceptions
The transduction of stimuli by sensory receptors is subject to two types of modification
amplification and adaptation.
refers to the strengthening of a sensory signal during transduction.
Amplification
Without ______________ , you would be constantly aware of feeling every beat of your heart and every bit of clothing on your body.
Sensory Adaptation
Types of Receptors
- Mechanoreceptors
- Chemoreceptors
- Electromagnetic Receptors
- Thermoreceptors
- Pain Receptors
sense physical deformation caused by forms of mechanical energy such as pressure, touch, stretch, motion, and sound.
Mechanoreceptors
sense physical deformation caused by forms of mechanical energy such as pressure, touch, stretch, motion, and sound.
Mechanoreceptors
the active form
Pfr
the inactive form
phytochrome (Pr)
The biologically inactive form of phytochrome (Pr) is converted to the biologically active form Pfr under ________________________________.
illumination with red light
________________ and __________ convert the molecule back to the inactive form.
Far-red light, darkness
those that transmit information about total solute concentration
general receptors
The phytochrome system acts as a _______________________. It monitors the ______, ______, ________, and __________________.
biological light switch-
level, intensity, duration, and color of environmental light.
phytochrome system is responsible for _______________________ and _______________ of plants.
Photomorphogenesis, Photoperiodism
those that respond to individual kinds of molecules.
specific receptors
include both general receptors and specific receptors
Chemoreceptors
__________________ in the mammalian brain, for example, detect changes in the total solute concentration of the blood and stimulate thirst when osmolarity increases.
Osmoreceptors
the directional bending of a plant toward or away
from a light source—is a response to blue wavelengths of light.
Phototropism
glucose, oxygen, carbon dioxide, and amino acids.
receptors for specific molecules
_____________ phototropism is growth towards a light source, while ___________ phototropism (also called ______________) is growth away from light.
Positive, negative (skototropism)
are protein-based receptors responsible for mediating the phototropic response.
Phototropins
In phototropins, the _________________ is a
covalently-bound molecule of flavin; hence, phototropins belong to a
class of proteins called flavoproteins.
chromophore
Two of the most sensitive and specific chemoreceptors known are found in ____________
the antennae of the male silkworm moth
another class of blue-light absorbing photoreceptors that also contain a flavin-based chromophore.
Cryptochromes
____________ set the plant’s circadian rhythm, using blue light cues. There is some evidence that _______________ work together with phototropins to mediate the phototropic response.
cryptochromes, cryptochromes
Blue Light Responses
-Phototropism
-Phototropins
-Cryptochromes
ensures that roots grow into the soil and that
shoots grow toward sunlight.
Gravitropism
Growth of the shoot apical tip
upward is called _______________________,
negative gravitropism
whereas growth of
the roots downward is called __________________.
positive gravitropism.
are specialized plastids that contain starch granules and settle downward in response to gravity.
Amyloplasts (also known as statoliths)
are found in shoots and in
specialized cells of the root cap.
Amyloplasts
_________________ a group of unrelated chemical substances that affect _____________________.
Plant hormones, plant morphogenesis
Five major plant hormones
◦ Auxins; responsible for apical dominance, root growth, directional growth toward light, and many other growth responses.
◦ Cytokinins; stimulate cell division and counter apical dominance in shoots.
◦ Gibberellins; inhibit dormancy of seeds and promote stem growth.
◦ Ethylene; speeds up fruit ripening and dropping of leaves, and
◦ abscisic acid; induces dormancy in seeds and buds, and protects plants from excessive
water loss by promoting stomatal closure.
◦ In addition, other nutrients and environmental conditions can be characterized as
growth factors.
responsible for apical dominance, root growth, directional growth toward light, and many other growth responses.
Auxins
stimulate cell division and counter apical dominance in shoots.
Cytokinins
For pheromones and other molecules detected by ___________, the stimulus molecule binds to the _____________ on the membrane of the ____________ and initiates changes in ion permeability.
Chemoreceptors, Specific receptors, sensory cells
detect forms of electromagnetic energy, such as light, electricity, and magnetism.
Electromagnetic Receptors
inhibit dormancy of seeds and promote stem growth.
Gibberellins
speeds up fruit ripening and dropping of leaves
Ethylene
induces dormancy in seeds and buds, and protects plants from excessive water loss by promoting stomatal closure.
abscisic acid
Thermoreceptors
detect heat and cold.
Jalapeno and cayenne peppers that we describe as “hot” contain a substance called a ______________.
capsaicin
Applying _________to a sensory neuron causes an influx of calcium ions.
Capsaicin
The receptor opens a___________ in response not only to capsaicin, but also to high temperatures (42°C or higher).
Calcium channel
spicy foods taste “hot” because they__________________ as hot soup and coffee.
activate the same receptors
By triggering defensive reactions, such as withdrawal from danger, the_____________ serves an important function.
Perception of pain
To detect stimuli that reflect such noxious (harmful) conditions, animals rely on ________(from the Latin nocere, to hurt), also called _________.
nociceptors, pain receptors
damaged tissues produce ____________, which act as local regulators of inflammation.
prostaglandins
worsen pain by increasing nociceptor sensitivity to noxious stimuli.
prostaglandins
reduce pain by inhibiting the synthesis of prostaglandins.
Aspirin and ibuprofen
Types of Sensory Processes in Humans
- Visual
- Auditory
- Olfactory
- Gustatory
- Tactile
- Proprioceptive
- Vestibular
- Interoceptive
