Terminology: 23-27 Flashcards
(106 cards)
1
Q
Frick’s Law of Diffusion
A
Describes the rate of diffusion of a gas between two areas separated by a barrier.
Rate of diffusion increases when
* Area of gas exchange is larger
* Thickness of barrier is smaller
* Larger difference in gas pressure
2
Q
Which epithelium type are Alveoli covered with?
A
Squamous epithelium
3
Q
Ventilation
A
Movement of medium (air/water) over the respiratory surface to ensure the pressure difference between gasses on either side of the barrier is as high as possible
4
Q
Gas exchange
A
Exchange of gas (oxygen/Carbon dioxide) at a respiratory surface between medium (air/water) and blood.
5
Q
Countercurrent Flow
A
The gas exchange system used in fish gills.
The flow of water runs the opposite direction of the flow of blood.
6
Q
Tracheal System
A
A system of tubes through which air travels to provide gas exchange for insects.
Insects have spiracles which are valves that open to the exoskeleton.
Some flying insects use their wing muscles to push air in and out of their tracheal system as they flap.
7
Q
Ventilation method of Mammals
A
Ribs & Diaphragm
Inhalation by negative pressure
8
Q
Ventilation method of Birds & Reptiles
A
Ribs & NO Diaphragm
Inhalation by negative pressure
9
Q
Ventilation method of Frogs
A
Inhalation by positive pressure
Cutaneous respiration (skin)
10
Q
Diaphragm contracts
negative or positive pressure?
A
Negative pressure
11
Q
Diaphragm relaxes
negative or positive pressure?
A
Positive pressure
12
Q
Albumin
A
A major constituent of plasma that helps keeping blood fluids from leaking into the tissues.
- Maintenance of osmotic pressure
- Binding and transport of substances
- Neutralization of free radicals
13
Q
Hemoglobin
A
- A protein in red blood cells that carries oxygen.
- Each hemoglobin protein has four heme groups each with their own iron ion (Fe²+).
- Each iron ion can carry one O₂ molecule, thus a single hemoglobin protein can carry four O₂ molecules.
14
Q
Cooperative Binding (Hemoglobin)
A
Muscles that are depleted of oxygen will saturate faster than muscles that are full of oxygen.
The oxygen unloading rate of hemoglobin is most efficient where oxygen levels are low.
15
Q
Bohr Shift (Hemoglobin)
A
During exercise:
PCO₂ (Pressure CO₂) is high
pH is low.
Temperature increases
These conditions induce increased rate of oxygen unloading.
16
Q
Carbonic Anhydrase
A
An enzyme in red blood cells that converts CO₂ and water into bicarbonate and vice versa.
PCO₂ in tissues favor CO₂ -> Bicarbonate
PCO₂ in lungs favor Bicarbonate -> CO₂
Bicarbonate is transported in plasma
17
Q
Ventilation rate & Homeostasis
A
Chemoreceptors in the brain & carotid arteries detect pH changes.
Low pH triggers increased ventilation rate through medulla respiratory control.
18
Q
Closed Circulation
A
Blood travels within heart & blood vessels. Allows for greater control of material distribution.
19
Q
Open Circulation
A
Hemolymph (blood equivalent) is not confined within vessels, it is held in large cavities called hemocoels where the hemolymph is in direct contact with tissues and organs.
Blood or hemolymph fluid may serve as hydrostatic skeleton.
20
Q
Hemocoels
A
Cavities in which hemolymph is held
21
Q
Hemolymph
A
Blood equivalent fluid in open circulatory systems
22
Q
Arteries
A
- Impermeable walls
- Oxygenated blood transport (except for pulmonary arteries)
- Heart -> Body
- Smooth muscle
23
Q
Veins
A
- Impermeable walls
- Deoxygenated blood transport (except for pulmonary veins)
- Body -> Heart
- Smooth muscle
24
Q
Capillaries
A
Permeable walls that allow material diffusion.
Interior wall composed of simple squamous epithelium
25
Interstitial Fluid
Fluid found in the space between cells. It comes from substances that leak from the capillaries. Helps bring oxygen and nutrients to cells and take away waste products from them.
New interstitial fluid replaces old, which drains towards lymph vessels.
26
Fish have how many heart chambers?
Two chambers of the heart
One circuit
27
Difference between one and two blood circuits
Dual circuit systems have separate blood vessels from the heart going to the lungs and the body. Pulmonary Circuit, Systemic Circuit.
Single circuit systems go between the lungs and the body before returning to the heart.
28
Sinoatrial Node (SA Node)
Pacemaker
Generates nerve impulses (depolarizations) that spread over atria.
Located in the **right atrium**
29
Atrioventricular Node (AV Node)
Picks up the nerve impulses from the Sinoatrial node (SA) and passes it to the ventricles.
Located in the **right atrium**
30
Blood Pressure
Systole/Diastole
31
Diastole
Semilunar valves: Closed
Atrioventricular valves: Open
All chambers relaxed
Blood flows passively into the chambers
32
Atrial Systole
Semilunar valves: Closed
Atrioventricular valves: Open
Atrium Contracts
Blood is pushed into the ventricles to fill them up fully
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Ventricular Systole
Semilunar valves: Open
Atrioventricular valves: Closed
Ventricle Contracts
Blood is squirted out of the ventricles to the pulmonary artery and the aorta artery.
34
Hypertension
Abnormally elevated blood pressure
Can lead to damage to blood vessels, especially in conjunction with high blood cholesterol levels.
35
Blood
Blood is a fluid connective tissue
Composed of 55% Plasma & 45% cellular elements
36
Cellular elements of blood
* Red blood cells (Erythrocytes)
* White blood cells (Leukocytes)
* Platelets
37
What are the components of Plasma?
* Water (92%)
* Ions
* Nutrients
* Proteins (Especially albumin)
38
Erythrocytes
Red blood cells
5-6 million per mm³ of blood
39
Leukocytes
White blood cells
5,000-10,000 per mm³ of blood
40
Monocytes
White blood cell (Leukocyte)
Help break down bacteria
41
Lymphocytes
White blood cell (Leukocyte)
Create antibodies to fight against bacteria and viruses
42
Neutrophils
White blood cell (Leukocyte)
Kill and digest bacteria and fungi. First line of defense and the most numerous type of white blood cell.
43
Basophils
White blood cell (Leukocyte)
The alarm system that signal the body when infectious agents invade. Secretes chemicals such as histamine to help regulate the body's immune response.
44
Eosinophils
White blood cell (Leukocyte)
Kill parasites and cancer cells, also helps with allergic responses.
45
Platelets
Functions in blood clotting and sealing of damaged blood vessels.
46
Chemical Signals
A signal molecule that is released from one cell to bind to a receptor on another cell, which triggers a response.
Example: Hormones or Ligand (which can trigger Action Potential events in neurons)
47
Electrical Signals
Signals transmitted through changes in electrical potentials across cellular membranes due to differential distribution of ions.
48
Neurons
Nerve cells.
Specialized for nerve impulse conduction.
Electrical signals
49
Sensory Receptors
Detects stimuli and generates electrical signals
50
Sensory Neurons
Carries signals from receptors to the central nervous system for integration of sensory signals and initiating motor responses.
51
Motor Neurons
Carries commands for responses from the CNS to **effectors** (e.g. muscles)
52
Effector Cells
Cells that respond to commands from **Motor Neurons**
e.g. Muscles
53
Components of a Neuron Cell
* Dendrites
* Cell Body
* Axon
54
Neuron: Dendrites
Branching protoplasmic protrusions from the neuron body that receives electrochemical impulses from other neurons.
55
Neuron: Cell Body
Contains the nucleus.
Integrates incoming signals from dendrites and generates outgoing signals for the Axon.
56
Neuron: Axon
Tail-like protrusion of the neuron that transmits impulses away from the cell body. Some have a myelin sheath for insulation.
57
Synapse
The gap between two neurons
58
Neurotransmitter
Chemical signal secreted by a neuron to affect another cell across a synapse. The receiving cell could be another neuron or a muscle cell or a gland cell.
Neurotransmitters are **Ligands**, which can act on **Ligand-gated ion channels** of a post-synaptic neuron to trigger **Action Potential events**.
59
Reflex Arc
A neural pathway that controls a reflex (involuntary response).
1. Sensory receptor is triggered
2. Sensory neurons relay information to interneurons at the CNS.
3. CNS sends command to motor neurons
4. Motor neurons relay command to effector cell (muscle)
5. Effector cell responds to command
60
Schwann Cells
A type of glial cell that forms each section of the myelin sheath of a neuron's axon.
61
Glial Cells
Accessory cells that hold nerve cells in place and help them work the way they should.
62
Myelin Sheath
* An insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord.
* It is made up of protein and fatty substances.
* This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells.
63
Nodes of Ranvier
A gap in the myelin sheath of a nerve, between adjacent Schwann cells.
These nodes allow action potential to jump from one node to the next quickly.
64
NA⁺/K⁺ ATPase Pump
(Sodium Potassium Pump)
A membrane enzyme using ATP to transport import potassium and export sodium. For every ATP molecule that the pump uses, three sodium ions are exported and two potassium ions are imported. Thus, there is a net export of a single positive charge per pump cycle.
1 ATP = 3Na⁺ EXPORT & 2K⁺ IMPORT
Net loss of one positive charge
65
Equilibrium Potential of K⁺
K⁺ is in electrochemical equilibrium when the cell is 90 mV lower than the extracellular environment.
Equilibrium potential is the voltage in which there is equilibrium of the concentration gradient that moves K⁺ in and out.
66
Chemical Gradient
The difference in solute concentration between the inside and outside of a cell's membrane.
67
Electrical Gradient
The difference in electrical charge (voltage) between the inside and outside of a cell's membrane.
68
Electrochemical Gradient
The gradient of an ion's electrochemical potential across a cell's membrane.
Consists of both the chemical gradient and the electrical gradient
69
Nernst Equation
A mathematical equation that permits the calculation of the reduction potential of a reaction.
70
Membrane Potential
The difference in electrical charge between the inside and the outside of the neuron.
The main positive ion inside the neuron is K⁺
The main positive ion outside the neuron is Na⁺
71
Resting Membrane Potential
The static membrane voltage of inactive cells. More K⁺ ions **inside** the cell, more Na⁺ ions **outside** the cell.
-70mV
72
Hyperpolarization
Negatively charging a cell's membrane potential below the resting potential of -70mV to -75mV. This induces a refractory period in which potassium ions are filtered back into the cell until membrane potential is reset to resting potential. A neuron cannot be triggered again until it resets to resting potential.
-75mV
73
Depolarization
The positive change of a cell's membrane potential. Na+ ions flow into the cell.
When an action potential is triggered past the -55mV threshold, it peaks at +40mV.
74
Repolarization
Negatively charging a cell's membrane potential. K⁺ ions flow back into the cell, Na⁺ ions flow outside the cell.
After an Action Potential's peak of +40mV, the membrane potential drops back to a negative charge.
75
Ligand-gated Ion Channels
Membrane channels that open in response to **ligand** binding to the channel receptor.
76
Ligand
A chemical messenger that signal **Ligand-Gated Ion Channels** to open and allow ions to flow across the membrane.
77
Voltage-gated Ion Channels
Membrane channels that open in response to changes in electrical charge.
When a sufficient stimulus causes the electrical charge of a membrane to increase to -55mV, it triggers voltage-gated Na⁺ channels to open and rapidly depolarize the cell.
78
Action Potential
The electrical mechanism through which nerve cells conduct information. When a neuron is depolarized, it triggers a wave of depolarization across adjacent cells.
1. Resting potential is -70mV, stimulus disturbs the resting voltage and increases the voltage (depolarization)
2. Sufficient stimulus to depolarize past the trigger threshold (-55mV) will trigger an action potential event.
3. When triggered, rapid depolarization causes the membrane potential to increase and peak at +40mV. This causes other neurons to also depolarize, rippling across all adjacent neurons.
4. The membrane potential then rapidly repolarizes after the peak, dipping down to -75mV. It will steadily return to its resting potential of -70mV during which it is hyperpolarized.
79
Myelinated Axons
Axons of a neuron that are myelinated (sheathed). They only have voltage-gated sodium channels in the gaps between their sheath. These gaps are called Nodes of Ranvier.
Unmyelinated Axons do not have a sheath and have voltage-gated sodium channels across the entire length of the membrane.
80
Saltatory Conduction
The mechanism of which an electrical impulse skips along the gaps of myelinated axons.
81
Graded Potential
Incremental changes in membrane potential that vary in voltage and duration.
As opposed to Action potentials that are all-or-none and require crossing of a threshold.
82
Pre-synaptic Neuron
A neuron that fires the neurotransmitter as a response to an Action Potential event.
83
Post-synaptic Neuron
A neuron that receives a neurotransmitter from a pre-synaptic neuron, which causes depolarization. If the Action Potential threshold is reached, it will create an action potential event and ripple.
84
Synaptic Vesicles
Synaptic vesicles of a pre-synaptic neuron store neurotransmitters and release them when Ca²⁺ ions enter a pre-synaptic cell.
The synaptic vesicle inside a pre-synaptic neuron fuses with the cellular membrane to release neurotransmitters.
85
Excitatory Post-Synaptic Potentials (EPSP)
A temporary depolarization of a post-synaptic neuron's membrane potential caused by the opening of ligand-gated ion channels.
This increases the likelihood of an Action Potential event within a post-synaptic neuron.
Can be added together with EPSPs from other neurons to increase the depolarization past the Action Potential trigger threshold.
86
Inhibitory Post-Synaptic Potentials (IPSP)
A temporary hyperpolarization of a post-synaptic neuron's membrane potential.
This decreases the likelihood of an Action potential event within a post-synaptic neuron.
Can cancel out EPSPs to inhibit depolarization past the threshold.
87
Central Nervous System (CNS)
Brain & Spinal Cord
88
Peripheral Nervous System (PNS)
Nerve structures outside of the brain & spinal cord, for example the nerves of your hand.
Within the PNS are:
Somatic Nervous System
Autonomic Nervous System
* Sympathetic Division
* Parasympathetic DIvision
89
Afferent Division
Sensory signals from receptors travel to the CNS through afferent neurons.
S.A.M.E.
**S**ensory **A**ffluent
**M**otor **E**fferent
90
Efferent Division
Motor commands from the CNS travel to effectors through efferent neurons.
S.A.M.E.
**S**ensory **A**ffluent
**M**otor **E**fferent
91
Somatic Nervous System
A subdivision of the peripheral nervous system that transmits voluntary response signals in skeletal muscle
SNS innervation involves a **single motor neuron** to the effector
92
Autonomic Nervous System
A subdivision of the peripheral nervous system that transmits involuntary signals to smooth muscle (e.g. cardiac muscle and glands).
Within the ANS are:
Sympathetic Division
Parasympathetic Division
ANS innervation involves **TWO motor neurons**
93
Sympathetic Division
Relays commands from the CNS/ANS regarding stress responses (e.g. Fight or Flight).
94
Parasympathetic Division
Relays commands from the CNS/ANS regarding rest and digest body processes.
95
Spinal Reflexes
Motor responses that don't require brain processing.
96
Reflex Arcs
A neural pathway that controls a reflex. These sensory neurons do not pass directly into the brain but rather synapses in the spinal cord. This allows for faster reflex actions to occur as the signal is not delayed by routing through the brain.
97
Synaptic Plasticity
The ability of synapses to strengthen or weaken over time in response to increases or decreases in their activity.
98
Brain Structures
* Left/Right Hemisphere
* Cerebrum
* Cerebellum
* Diencephalon
* Brain Stem
* Corpus Callosum
99
**Left Cerebral Hemisphere**
Functions
* Controls motor functions of the right side
* Language
* Math computation
100
**Right Cerebral Hemisphere**
Functions
* Controls motor functions of the left side
* Spatial visualization and analysis
101
**Brain Stem**
Functions & Substructures
Functions:
* Connects brain to spinal cord
* Regulates the heart, lungs, and digestive system
Substructures:
* Midbrain
* Pons
* Medulla
102
Corpus Callosum
The band of axons that connect the left and right hemispheres of the brain
103
**Diencephalon**
Functions & Substructures
Functions:
* Relays sensory information to the cerebellum
* Controls homeostasis
Substructures:
* Thalamus
* Hypothalamus
104
Cerebellum
Coordinates complex motor patterns
105
**Cerebrum**
Functions & Substructures
* Makes up most of the brain
* Divided Into Left & Right
* Conscious thought
* Memory
* Sight
* Hearing
* Language
Four Lobes:
* Frontal
* Parietal
* Occipital
* Temporal
106
Interneuron
Relay interneurons:
The intermediate neurons between sensory or motor neurons and the CNS. Long axons
Local interneurons:
Forms circuits with nearby neurons to analyze small pieces of information. Short axons
