Biology Nerve and Muscle Flashcards
(135 cards)
1
Q
Digestive system
A
Gastrointestinal tube from mouth to anus
2
Q
Coelom
A
Contains digestive system. Separated into thoracic and abdominal cavities.
3
Q
Thoracic Cavity
A
Heart + lungs
4
Q
Abdominal Cavity
A
Liver + stomach +intestines
5
Q
4 types of tissues and functions
A
Epithelial=lining, protection, secretion
Muscle=movement (voluntary or involuntary)
Connective=anchor and support
Nerve=innervation
6
Q
Tissue
A
Cells of a particular type coalesce
7
Q
Organ
A
Two or more tissue perform specific function
8
Q
Epithelium Tissue, Types & Shapes
A
Types: Simple (one layer) vs stratified (multiple layers)
Shapes: squamous (flat), cuboidal, columnar
9
Q
Lumen vs. Apical
A
Lumen=inside
Apical=outside
10
Q
Microvilli
A
Found on lumen side of epithelium. Increase surface area of absorption in GI tract
11
Q
Cilia
A
Found on apical side of epithelium. Move unidirectionally to remove foreign particles
12
Q
Tight Junctions (def and function)
A
Epithelium
Permeability layer b/w luminal and basolateral side. Hold neighboring cells together.
13
Q
Desmosomes
A
Epithelium
Join cells together to form basal lamina.
14
Q
Basal Lamina (def and function)
A
Epithelium
Contact w/ connective tissue that anchors cells
15
Q
Gap Junctions (def. and function)
A
Epithelium
Allow water soluble molecules to pass b/w cytoplasms of cells. Function to allow equilibration b/w cells and for cells to function as unit.
16
Q
Layering of epithelium
A
Epidermal Region=stratified tissue
Below that is Dermis
Below that is subcutaneous tissue=adipose deposits
17
Q
Erector muscles
A
Found in dermis. Straighten hair shafts
18
Q
Fibroblasts
A
Connective tissue.
Secrete proteins that make structural connective tissue.
19
Q
Collagen
A
Connective tissue.
Triple stranded, insoluble, fibrous, highly crosslinked, strong and flexible
20
Q
Reticulin
A
Connective Tissue.
Thin, not as cross-linked.
Found in spleen and lymph nodes.
21
Q
Elastin
A
Connective Tissue.
High cross-linkage, high elasticity.
Lungs, skin, bld vessels.
22
Q
Chondrocytes
A
Fibroblasts that secrete cartilage
23
Q
Cartilage
A
Connective Tissue.
Found in places of high stress.
Joins, spine, nose, ears.
24
Q
Osteoblasts
A
Fibroblasts that secrete bone
25
Bone
Connective Tissue.
| 1/3 collagen (organic) and 2/3 Ca3(PO4)2 & CaCO3 (inorganic)
26
Mast Cells
Connective Tissue.
Secrete histamine in response to allergy, injury, infection.
Increase bld flow to affected area.
27
Adipose Tissue
Connective Tissue.
| Stores Fat
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Melanocytes
Connective Tissue.
| Store Pigments.
29
Voluntary Muscle vs. Involuntary muscle
Can control action vs can't control action (i.e. cardiac and smooth)
30
Nervous system
Composed of nerves and support cells
31
Anatomy of Nerve Cell
Cell body=integrates info.
Dendrites=receive/transmit info to cell body
Axon=conduct info away from cell body
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Signalling pathway of neuron
(1) neuron excite by external stimulus
(2) cell body process info
(3) action potential=info goes down axon
(4) reaches end of axon (synaptic bulbs) and neurotransmitters released
(5) diffuse across synaptic cleft/synapse and induces adjoining neuron
33
Conc. of Ions in extracellular space
Na+=150mM
K+=5mM
Cl-=130mM
HCO3-=25mM
K+ & HCO3 higher inside at rest. Na+ and Cl- lower.
Diffusion is affected chemically (conc.) and electrically (voltage).
34
Electroneutrality
Conc. of anions and cations in extracellular space is equal (155mM)
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Na+/K+ ATPase
3Na+ for 2K+
| Responsible for asymmetrical conc. gradient across membrane.
36
Nernst Equation
Used to calculate potential difference across membrane.
Remember equation!!
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Resting State of Nerve
During resting state permeability of K is greater than Na.
More K+ channels. Na+ channels are mostly voltage gated. K has easier time moving out of cell than Na moving into cell
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Stimulated State of Nerve
Permeability of Na is greater than K.
Stimulus opens Na voltage gated channels.
39
Depolarization
Transient reduction of membrane potential by increasing permeability of Na+
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Threshold Potential
Minimum depolarization from stimulus needed to open voltage gated Na+ channels
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Action Potential
Think of it as a "range"
The threshold potential opens Na+ voltage gated channels and Na+ bursts into cell as it continues to depolarize.
Polarity of membrane switches (side that is (+) and side that is (-))
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Repolarization
Na+ voltage channels close and K+ voltage channels open so that K+ moves out of the cell
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Hyperpolarlization
When the potential difference goes below -80mV as K+ moves out of cell
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Refractory
Another action potential cannot be generated because Na+ channels remained closed.
Period so membrane potential will return to resting value.
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All-or-none phenomena of Action Potential
Generation of action potential depends on permeability of Na+ and K+
Action potential will occur if more Na+ moves into cell than K+ moving out of cell
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Cross-Sectional Area and Action Potential
Increased cross sectional area means a greater action potential
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Myelinated Nerves
Increase the rate of action potentials
Myelin=membrane w/ some proteins + lots of phospholipids.
48
Glial Cells
Deposit the myelin on axon.
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Node of Ranvier
Because of how myelin is deposited, ions can only pass through membrane at these nodes.
Nodes have high concentration of Na+ channels
50
Saltatory Conduction
Increased speed of conduction due to multiple sites of depolarization at nodes of ranvier.
51
Terminal Bouton
Area at the end of the axon where synapse occurs
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Synapse
When terminal bouton of one neuron interacts with dendrites or cell body of another
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Synaptic junction/ synaptic cleft
Area between terminal bouton and other neuron
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Pre-synaptic membrane
Membrane of terminal bouton
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Post-synaptic membrane
Membrane of other neuron (where synapse is being made to)
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Neuromuscular Junction
Synapse b/w terminal bouton and axon of muscle fiber
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Synaptic Vesicles
Vesicles in the terminal bouton that contain neurotransmitter
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Difference in action potential of muscle
(1) Action potential triggers influx of Ca2+ into terminal bouton.
(2) Ca2+ causes synaptic vesicles to bind with pre-synaptic membrane and release ACh by exocytosis
(3) ACh binds to receptors on post-synaptic membrane and conformation changes open ligand gated channels (i.e. Na+ channels)
(4) Post-synaptic cell depolarizes
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Ionophore
Na+ channels
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Acetylcholinesterase
Produced by post-synaptic cell and hydrolyzes ACh to acetate and choline so that it does not remain in synaptic cleft and cause stimulation.
Recycled back to pre-synaptic cell to make ACh again.
61
Excitatory post-synaptic potential
Increases the post-synaptic membrane to Na+
| Membrane will depolarize
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Inhibitory post-synaptic potential
Increases the post-synaptic membrane to K+ and Cl-
| Membrane will hyperpolarize
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Integrated action potentials
Excitatory and inhibitory potentials result in only 2 action potentials
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What happens when two action potentials meet?
They will both stop propagating. Region in front of action potential is being depolarized while behind is in resting.
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Tendons
Connects muscle and bone
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Belly of Muscle
Region b/w tendons
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Multinucleated muscle fibers
Muscles cells. Cells do not divide but get larger
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Myofibrils
Longitudinal striations of skeletal muscle. Contains contractile units of muscle.
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Sarcomere (describe structure)
Each unit bounded by Z line.
Know where A-band, I-band, H-zone.
What happens to size of these during muscle relaxation and contraction.
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Myosin Heads
Projections from myosin that interacts with actin filaments
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Actin
Thin muscle filament.
| Composed of G actin monomers.
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Myosin
Thick muscle filament.
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Muscle Contraction Cycle
(1)ATP bound to myosin prevents it from binding to actin
ATP reduces myosin's affinity for actin
(2)ATP hydrolyzed=P+ADP+myosin complex
(3)Myosin binds to actin
This step also depends on Ca2+ present (skeletal muscle)
(4)P and ADP release from from myosin and conformation change occurs.
74
Power Stroke
Actin moving relative to myosin
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Rigor complex
Myosin staying bound to actin after contraction (disappears when ATP rebinds)
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Tropomyosin
Protein that is in actin grove and prevents myosin head from attaching.
Actin based regulation.
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Troponin
Protein complex interacts w/ tropomyosin, actin and Ca2+.
| When Ca2+ binds to troponin it causes tropomyosin to shift its position so that myosin binding sites can be accessed.
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Sarcoplasmic Reticulum
Membranous structure like the endoplasmic reticulum that surrounds myofibrils.
Ca2+ sequestered here.
79
Transverse Tubules
Plasma membrane of myofibril.
| When action potential travels down T-tubule it causes release of Ca2+ from sarcoplasmic reticulum.
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What affects strength of contraction?
(1) Size of motor unit
(2) # of available motor units
(3) Amt of actin and myosin
81
Motor unit
Motor neuron and the muscles it innervates
82
Motor Neuron
Nerves whose cell bodies are located in CNS (Spinal+Brain Stem).
Innervate skeletal muscle.
Myelinated (makes sense because body mvmt is quick).
Size of motor unit depends on action muscle does (precise mvmt vs postural/large mvmt).
83
Fast contraction vs. Slow contraction
Aerobic vs anaerobic respiration.
| Lactic acid formation=pH drop=stops key enzyme in glycolysis=fatigue
84
Ganglion
Grouping of nerve cells.
| More elaborate grouping makes CNS and PNS
85
3 Vertebrate brain division
Forebrain, midbrain, hindbrain
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CNS
Brain and Spinal Cord
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PNS
Nerves that extend from CNS into limbs and extremities
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Afferent sensory neurons
Neuron carries information into CNS
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Efferent sensory neurons
Neuron carries info away from CNS
90
Forebrain
Cerebrum=right and left cerebral hemispheres joined by corpus callosum (hemispheres separated into 4 lobes)
Thalamus=relay station for visual and auditory info from environment
Hypothalamus=visceral activities
91
Frontal lobes
Associated w/ mvmt and personality
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Parietal lobes
Associated w/ touch and stretch
93
Temporal lobes
Associated w/ hearing
94
Occipital lobes
Associated w/ vision
95
Cerebral Cortex
Outermost layer of cerebrum.
| Made of gray matter and white matter
96
Gray matter
Nerve cell bodies and dendrites
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White matter
Myelinated axons of nerve cells
98
Central Sulcus
Groove that separates frontal and parietal lobes
99
Motor Cortex
Anterior to sulcus and controls mvmt of muscles.
| I.e. hands, speech, fingers
100
Sensory cortex
Posterior to sulcus and detects sensation
101
Premotor cortex
Anterior to motor cortex and controls grps of muscles
102
Pituitary Gland
Master endocrine gland (anterior and posterior pituitary).
| Receives info from hypothalamus and carries out action
103
Parts of Brainstem
Control motor and visceral activities.
Midbrain= sense pleasure and pain, direct head/eye mvmt
Cerebellum=coordinate muscular activity
Pons and Medulla=visceral activity
Reticular Formation=alerts brain; induces sleep
104
Monosynaptic reflex arc
Contraction occurs w/ only one synaptic connection.
| i.e. goes from spine to motor neuron
105
Polysynaptic reflex arc
Contraction occurs due to 2/more synaptic connections.
106
Interneuron
Neuron that connects other neurons
107
Extensor Muscle
Contraction results in increased angle b/w limbs
108
Flexor Muscle
Contraction results in reduced angle
109
Autonomic Nervous System
Efferent part of PNS.
Two divisions: sympathetic and parasympathetic
110
Parasympathetic
Nerve fibers leave sacral part of spinal, midbrain and medulla.
Generally tries to conserve energy and restore.
Increase digestion, lower hr and bp, pupils constrict
111
Preganglionic neurons (Parasymp.)
```
Cell bodies are found in sacral and brainstem.
Very long.
Releases ACh (cholinergic)
```
112
Postganglionic neurons (Parasymp.)
Found very close to organs being innervated.
Short.
Releases ACh (cholinergic)
113
Vagus Nerve (X cranial nerve)
3/4 of parasymp. neurons found here.
| Innervates heart, kidneys, stomach, heart, lungs, liver, small & large intestine, other.
114
Sympathetic Nervous System
Nerve fibers branch from thoracic and lumbar regions of spinal cord.
Flight or fight response=increase hr and bp, decrease digestive, pupils dilate.
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Sympathetic Trunk
Nerve fibers form chains of ganglia on either side of spinal. (symp.)
116
Preganglionic neurons (Symp.)
Tend to be short.
Release ACh.
Nerves pass through spinal trunk. 3 things can happen:
(1) synapse w/ other ganglia outside of trunk
(2) Ascend or descend to synapse w/ ganglia at other levels
(3) Directly synapse w/ ganglion
117
Postganglionic neurons (Symp.)
```
Tend to be longer.
Release Norepinephrine (adrenergic).
```
118
Adrenal Medulla
Endocrine gland that releases norepi and epi
| Special symp. nerve fibers=no postgang. (go directly to adrenal medulla)
119
Somatic nervous system (characteristics)
(1) Leave CNS and directly synapse on effector organ
(2) Releases ACh
(3) Innervates skeletal muscle
(4) Reponse is excitatory
120
Autonomic nervous system (characteristics)
(1) Synapse w/ other ganglion b/f effector organ
(2) Pregang. both release ACh; postgang of symp releases norepi and parasymp. releases ACh
(3) Innervates cardiac & smooth muscle and glands
(4) Excitatory or inhibitory
121
Mechanoreceptors
Pressure, hearing, balance, bp
122
Nociceptors
Sense pain
123
Thermoreceptors
Detect cold/warmth
124
Chemoreceptors
Sense taste, H+, CO2, smell, O2, bld glucose
125
Photoreceptors
Respond to photons of light (in eyes)
126
Receptor potential
Change in membrane potential generated by transduced stimulus.
Exceeding receptor potential generates action potential.
127
Action potential of nerves
Pressure or stimulus causes deformation of nerve and lets Na+ into nerve.
Flow of current propagated through nerve
128
Sensory adaption
Continued stimulus on nerve results in less action potentials.
Ex. Pressure receptors (touching things)
129
Receptive field
Branching from end of neuron that end at different receptors
130
Lateral Inhibition
Excited neuron reduces activity of neighbors.
Mediated by interneurons.
To prevent overactivity due to overlap.
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Somatic Sensory Pathways
Sensory input from one side will be represented by somatosensory cortex on opposite side of brain.
Right to left, Left to right
132
First Order Neurons (somatic sensory)
Neurons from receptive field enters spinal cord (afferent) and synapses w/ 2nd order neurons
133
Second Order Neurons (somatic sensory)
Ascend opposite side of spine and to thalamus and (afferent) synapse w/ 3rd order
134
Third Order Neurons (somatic sensory)
Ascend to specific region of somatosensory cortex
135
Essential Amino Acids
Valine, Methionine, Histidine, Leucine, Phenylalanine, Threonine, Isoleucine, Tryptophan, Lysine
