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Physiology 1330 Q-Cards
U of Manitoba ZOOL 1330 Flashcards (Midterm)
110
Physiology
Undergraduate 1
02/23/2009

Additional Physiology Flashcards

 


 

Cards

Term

 

The Cell Membrane

Definition

 

The cell membrane:

  1. Phospholipid Bilayer
  2. Membrane Proteins
Term

Types of Membrane Proteins

Definition

 

  1. Transport Proteins
  2. Receptor Proteins
  3. Enzymes
  4. Joining Proteins
  5. Identifying Proteins
Term

Carrier

Definition

 

 

 A transmembrane protein that changes shape to envelop and transport a polar substance across the cell membrane

Term

Channel

Definition

A transmembrane protein that helps form aqueous channels that transport substances from one side of the membrane to the other

Term

Receptor Protein

Definition

 

 

A protein that binds specifically with other molecules, e.g., neurotransmitters, hormones, paracrines, antigens

Term

Enzyme

Definition
A protein that acts as a biological catalyst to speed up a chemical reaction
Term

Facilitated Diffusion

Definition
Passive transport process used by certain molecules, e.g., glucose and other simple sugars too large to pass through plasma membrane pores. Involves movement through channels or movement facilitated by a membrane carrier.
Term

Osmosis

Definition
Diffusion of a solvent through a membrane from a dilute solution into a more concentrated one.
Term

Simple Diffusion

Definition
The unassisted transport across a plasma membrane of a lipid-soluble or very small particle.
Term

Osmotic Pressure

Definition
 A measure of the tendency of water to move into a more concentrated solution.
Term

Tonicity

Definition
A measure of the ability of a solution to cause a change in cell shape or tone by promoting osmotic flows of water.
Term

Hypertonic Solution

Definition
A solution that has a higher concentration of nonpenetrating solutes than the reference cell; having greater osmotic pressure than the reference solution (blood plasma or interstitial fluid).
Term

Hypotonic Solution

Definition
A solution that is more dilute (containing fewer nonpenetrating solutes) than the reference cell. Cells placed in hypotonic solutions plump up rapidly as water rushes into them.
Term

Isotonic Solution

Definition
A solution with a concentration of nonpenetrating solutes equal to that found in the reference cell.
Term

Gated Ion Channels

Definition

Gated ion channels can open in response to:

  1. Membrane voltage changes
  2. Chemical changes
  3. Other stimuli
Term

Active Transport

Definition

Membrane transport processes for which ATP is provided, e.g., solute pumping and endocytosis.

Term

Vesicular Transport

Definition
The movement of large particles and macromolecules across a plasma membrane.
Term

Endocytosis

Definition
Means by which fairly large extracellular molecules or particles enter cells, e.g., phagocytosis, pinocytosis, receptor-mediated endocyotsis.
Term

Exocytosis

Definition
Mechanism by which substances are moved from the cell interior to the extracellular space as a secretory vesicle fuses with the plasma membrane.
Term

Pinocytosis

Definition
Engulfing of extracellular fluid by cells
Term

Phagocytosis

Definition
Engulfing of foreign solids by (phagocyctic cells)
Term

Resting Membrane Potential

Definition
The voltage that exists across the plasma membrane during the resting state of an excitable cell; ranges from -90mV to -20mV depending on the cell type.
Term

Concentration Gradient

Definition
The difference in the concentration of a particular substance between two different areas.
Term

Electrochemical Gradient

Definition
The combined difference in concentration and charge; influences the distribution and direction of diffusion of ions.
Term

Membrane Potential

Definition
Voltage across the plasma membrane.
Term

Primary Active Transport

Definition
A type of active transport in which the energy needed to drive the transport process is provided directly by hydrolysis of ATP
Term

Sodium-Potassium Pump

Definition
A primary active transport system that simultaneously drives Na+ out of the cell aganist a steep gradient and pumps K+ back in.
Term

Hyperpolarization

Definition
An increase in membrane potential in which the membrane becomes more negative than the resting membrane potential.
Term

Depolarization

Definition
Loss of a state of polarity; loss or reducation of negative membrane potential.
Term

Where do Graded Potentials usually occur?

Definition
On a dendrite or cell body
Term

Graded Potential

Definition
A local change in membrane potential that varies directly with the strength of the stimulus, declines with distance.
Term

Where are action potentials generated?

Definition
Typically, only in axons. Action potentials are also referred to as nerve impulses.
Term

Action Potentials

Definition

A large transient depolarization event, including polarity reversal, that is conducted along the membrane of a muscle cell or a nerve fiber.

 

A long-distance regenerative electrical signal transmitted along an axon. The action potential is an all-or-none event. Also called a nerve impulse, spike, or discharge.

Term

Where are Action Potentials generated?

Definition
Action potentials are generated at the axon hillock, where there is the greatest amount of Na+ channels.
Term

Threshold

Definition

A critical level of membrane potential at which the depolarization process becomes regenerative and the cell generates an action potential.

Term

Absolute Refractory Period

Definition

The period of time following an action potential when an excitable cell cannot generate another action potential no matter how large a stimulus it receives.

Term

Relative Refractory Period

Definition

The period of time following an action potential when an excitable cell can generate another action potential only if it receives a stimulus stronger than normal (i.e., more positive than its normal threshold).

Term

Propagation

Definition

In physiology, the process of reproducing and spreading the action potential along the sarcolemma and down the T tubules.

Term

Determinants of the Rate of Propagation

Definition
  1. Fiber Diameter
  2. Whether the fiber is myelinated or unmyelinated
Term

Saltatory Conduction

Definition

The process by which an action potential appears to jump from one node of Ranvier to the next along a myelinated axon.

Term

Excitatory PSPs

Definition

A local, graded, depolarization of an excitable cell. Function is to generate an action potential in the postsynaptic cell.

Term

Inhibitory PSPs

Definition

A local, graded, hyperpolarization of an excitable cell. Functions to prevent generation of an action potential in a postsynaptic cell.

Term

Somatic Reflex

Definition
Reflexes that activate the skeletal muscle.
Term

Visceral Reflex

Definition
Reflexes that activate smooth cardiac muscle or glands
Term

Ipsilateral

Definition
Situated on the same side.
Term

Monosynaptic

Definition
One sensory neuron and one motor neuron
Term

Polysynaptic

Definition
More than one synapse
Term

Contralateral

Definition
Relating to the opposite side
Term

Neuromuscular Junction

Definition
Region where a motor neuron comes into close contact with a skeletal muscle cell.
Term

Phasic Receptors

Definition

These show adaptation.

Term

Receptor Potential

Definition
A graded potential that occurs at a sensory receptor membrane.
Term

Functions of: Midbrain

Definition
  • Auditory and Visual Reflexes
  • Movement of eyes, head, or neck in response to visual or auditory stimuli
Term

Functions of: Pons

Definition
  • Functions with the medulla oblongata to regulate breathing
  • Sets the rhythm of breathing
Term

Functions of: Medulla Oblongata

Definition
  • Vital Reflex centers: respiratory area, vasomotor area, cardiac centers
  • Non-Vital Reflex centers: swallowing, vomiting, coughing, sneezing

 

Term

Overall Function of the Brainstem

Definition
  • It controls life-sustaining processes, for example, breathing and circulation
Term

Functions of the Hypothalamus

Definition
  • 1) Regulates the ANS (Smooth, cardiac muscle, and glands)
  • 2) Regulates Endocrine System
  • 3) Regulates Temperature
  • 4) Regulates Eating and Drinking
  • 5) Part of the Limbic System (emotional brain)
  • 6) Coordinates the reticular Activating System
  • 7) Recieves sensory input from cutaneous receptors of the nipples and external genitalia
Term

Sympathetic Nervous System

Definition
The division of the autonomic nervous system that prepares the body for activity or to cope with some stressor (danger, excitement, etc); the fight, fright, and flight subdivision.
Term

Autonomic Nervous System (ANS)

Definition

Efferent division of the peripheral nervous system that innervates cardiac and smooth muscles and glands; also called the involuntary or visceral motor system.

Term

Sympathetic Nervous System Neurons

Definition

Preganglionic Neurons: Cholinergic

Postganglionic Neurons: Anrenergic or Cholinergic

Term

Parasympathetic Nervous System Neurons

Definition
Pre and Postganglionic: Cholinergic
Term

Somatic Nervous System

Definition
Division of the peripheral nervous system that provides the motor innervation of skeletal muscles; also called the voluntary nervous system.
Term

Three Types of Movement in Somatic Nervous System

Definition

1) Reflexes: Spinal & Postural

2) Voluntary

3) Rhythmic

Term

Prefrontal Cortex

Definition
Necessary to understand written and spoken words (language)
Term

Wernicke's Area

Definition
Parietal/Temporal lobe junction, it is for sounding out unfamiliar words, and comprehension of language.
Term

Broca's Area

Definition
Expressive language area, frontal lobe, formulates the words as they are to be spoken (example, the expression of language). Puts the words together in a meaningful sentence.
Term

Second Messenger

Definition
Intracellular molecule generated by the binding of a chemical (a hormone or neurotransmitter) to a plasma membrane receptor; mediates intracellular responses to the chemical messenger.
Term

cAMP (Cyclic AMP)

Definition

Intracellular second messenger that mediates the effects of the first (extracellular) messenger (hormone or neurotransmitter), formed from ATP by a plasma membrane enzyme (adenylate cyclase)

Term

G Protein

Definition
Protein that relays signals between extracellular first messengers (hormones or neurotransmitters) and intracellular second messengers (such as cyclic AMP) via an effector enzyme.
Term

Luteinizing Hormone

Definition
Anterior pitutary hormone that aids in maturation of cells in the ovary and triggers ovulation in females. In males, causes the intersitital cells of the testis (Leydig cells) to produce testosterone.
Term

Follicle-Stimulating Hormone (FSH)

Definition

Hormone produced by the anterior pituitary that stimulates ovarian follicle production in females and sperm production in males.

Term

Progesterone

Definition
Hormone partly responsible for preparing the uterus for the fertilized ovum.
Term

Anabolism

Definition
Energy-requiring building phase of metabolism in which simpler substances are combined to form more complex substances.
Term

Catabolism

Definition
The process in which living cells break down substances into simpler substances.
Term

DNA Transcription

Definition

One of the two major steps in the transfer of genetic code information involving the transfer of information from a DNA gene's base sequence to the complementary base sequence of an mRNA molecule.

Term

Translation

Definition
One of two major steps in the transfer of genetic code information, in which the information carried by mRNA is decoded and used to assemble polypeptides.
Term

Lysosomes

Definition
Organelles that originate from the Golgi apparatus and contain strong digestive enzymes.
Term

ATP

Definition

Organic molecule that stores and releases chemical energy for use in body cells.

Term

Cellular Respiration

Definition
Metabolic processes in which ATP is produced.
Term

Glycogen

Definition
Main carbohydrate stored in animal cells; a polysaccharide.
Term

Skeletal System Functions

Definition
  1. Support
  2. Protection of vital organs
  3. Attaches muscles allowing movement
  4. Contains bone marrow (red & white blood cell production)
  5. Store calcium
Term

Fontanels

Definition
Unossified membranes in the skull that remain at birth.
Term

Endochondral Ossification

Definition
Embryonic formation of bone by the replacement of calcified cartilage; most skeletal bones are formed by this process.
Term

Factors Affecting Bone Growth and Remodelling

Definition
  1. Mechanical Stress
  2. Nutrition
Term

Callus

Definition
Repair tissue formed at a fracture site
Term

Muscular Characteristics

Definition
  • A) Excitable - respond to stimuli
  • B) Contractile - can shorten and tigthen
  • C) Extensible - stretch when they are pulled
  • D) Elastic - return to original shape after contraction or extension
Term

Motor Unit

Definition

A motor neuron and all of the muscle cells it stimulates.

Term

Neuromuscular junction

Definition

Synapse between a motor neuron and skeletal muscle fiber. The muscle cell and motor neuron do not actually touch, but are separated by the synaptic cleft.

Term

Motor end plate

Definition

The folded portion of the sarcolemma in close contact with the synaptic ending of the axon terminal.

Term

Sliding Filament Theory

Definition

The current theory of how a muscle cell contacts. This theory states that the contraction of a muscle cell occurs as the thin filaments slide past the thick filaments. The sarcomere shortens as the thin and thick filament overlap to a greater degree.

Term

Five molecules involved in sliding filament theory

Definition
  1. Myosin
  2. Tropomyosin
  3. Actin
  4. ATP
  5. Troponin
  6. Also calcium ions
Term

Crossbridge

Definition

A structure formed by the globular head of the myosin protein of the thick filament when it attaches to the thin filament during muscle contraction. Flexing the cross bridge moves the thin filament toward the center of the sarcomere.

Term

Power Stroke

Definition

The flexing movement of the myosin cross bridge that pulls the thin filament inward toward the center of the sarcomere.

Term

Role of ATP in Muscle Contraction

Definition
  1. Activation of Myosin
  2. Crossbridge Release
  3. Pumping Ca+2 into SR
  4. Maintaining the Na+/K+ - ATPase activity in muscle cell (Na+/K+ gradients)
Term

Tension

Definition

The force produced by a muscle in order to perform work.

Term

Negative Feedback Mechanisms

Definition
The most common homeostatic control mechanism. The net effect is that the output of the system shuts off the original stimulus or reduces its intensity.
Term

Factors Effecting Muscle Tension in Muscle Fibers

Definition
  1. Effect of Frequency of Stimulation on Muscle Fiber
  2. Fiber types in a muscle differ
  3. Effects of Fiber length on tension development
  4. The size of the fiber
  5. Fatigue
Term

Muscle Twitch

Definition

A single, rapid contraction of a muscle in response to a stimulus of adequate strength. In vivo, a muscle’s contraction is usually in response to multiple stimulations rather than a single impulse.

Term

Wave Summation

Definition

Phenomenon seen when another stimulus is applied to a muscle before the previous relaxation period is complete, resulting in a stronger contraction. In muscle physiology, also called wave summation. May be due to more calcium in stimulated muscle cells.

Term

Treppe

Definition

At first when a muscle is stimulated frequently, each muscle twitch shows a slight increase in strength of contraction and complete relaxation. The increase is not due to summation but may due to increased muscle warming and efficiency of enzymes.

Term

Incomplete Tetanus

Definition

A condition of rapid, shortened contraction/relaxation cycles resulting from increased frequency of stimulation. Some degree of cyclical relaxation is visible. Also called unfused tetanus.

Term

Complete Tetanus

Definition

The condition in which rapid multiple stimulations cause the contraction/relaxation cycles to fuse into a total contraction without evidence of any cyclical relaxation.

Term

Fast Fibers

Definition

White muscle fibers. Large in diameter; light in color due to reduced myoglobin; surrounded by few capillaries; relatively few mitochondria; mainly use glycolysis to synthesize ATP; quick and powerful but fatigue rapidly; fast cross bridge cycling.

Term

Slow Fibers

Definition

Red muscle fibers. Half the diameter of white muscle fibers; red due to myoglobin; many capillaries; numerous mitochondria; mainly uses Krebs cycle and oxidative phosphorylation to make ATP; fatigue resistant; high-endurance; slow cross bridge cycling.

Term

Isometric

Definition

A muscle contraction in which cross bridge cycling is activated and tension is developed, but the length of the muscle does not change.

Term

Physiology

Definition

is the study of how the body functions

Term

Homeostasis

Definition

A state of body equilibrium or stable internal environment of the body.

Term

Regulation of Homeostasis

Definition
  1. Change in internal environment must be detected (or anticipate)
  2. Nervous system and/or endocrine response alters a system(s) that are responsible for that condition.
Term

Proprioceptors

Definition

Sensory receptors located in muscles and joints that respond to changes in body position and movement.

Term

Positive Feedback Mechanism

Definition
Feedback that tends to cause the level of a variable to change in the same direction as an initial change.
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