Boot Camp Day 2.1 Flashcards
(114 cards)
1
Q
What is the movement in skeletal, cardiac, smooth muscle ?
A
- Skeletal muscle->moves the skeleton
- Cardiac muscle->moves blood
- Smooth muscle->moves “stuff” through hollow organs
2
Q
What are the functions of muscle?
A
- Movement
- Posture (skeletal muscles)
- Joint Stabilization (skeletal muscles)
- Thermogenesis- heat generation
- Venous Return
- Energy source
- Glycemic control
- Control of openings and passageways
3
Q
Thermogenesis:
* How does this happen?
A
Contracting skeletal muscles produce as much as 85% of our body heat
* Working out
* Shivering
4
Q
What is the Venous Return for muscle
A
- Muscle pump action during dynamic exercise helps to pump/squeeze blood back to left ventricle
- This rhythmic pumping via contraction/relaxation increases venous blood return to the heart
5
Q
Energy source of muscle?
A
Protein becomes an alternative source of energy during states of malnutrition or starvation
6
Q
Glycemic control in muscle?
A
Muscles absorb and store glucose which helps regulate blood sugar concentration within normal range
7
Q
Control of openings and passageways of muscle?
A
Sphincters: internal smooth muscle rings that control the movement of food, blood, and other materials within body
8
Q
How are muscles classified?
A
Action: effect produced by a muscle to produce or prevent movement
9
Q
What are the four functional groups of muscles?
A
10
Q
What is the origin and insertion of muscles?
A
- Origin: Point of muscle attachment on the immovable or less movable bone (in limbs, the origin is usually proximal to the insertion)
- Insertion: Point of muscle attachment that moves toward the origin
11
Q
What is the innervation of a muscle?
Why it is important to know the inn?
A
refers to the identity of the nerve that stimulates it
* Knowing innervation enables diagnosis of nerve, spinal cord, and brainstem injuries
from muscle tests
12
Q
- Spinal nerves arise from where?
- Where do they emerge through?
- Immediated branch where?
- What do they innervate ?
- What is a plexus?
A
Spinal nerves arise from the spinal cord
– Emerge through intervertebral foramina
– Immediately branch into posterior and anterior rami
– Innervate muscles below the neck
– Plexus: web-like network of spinal nerves adjacent to the vertebral column
13
Q
- Cranial nerves arise from where?
- Where do they emerge through?
- Inn what muscles?
- Numbered how?
A
Cranial nerves arise from the base of the brain
– Emerge through skull foramina
– Innervate the muscles of the head and neck
– Numbered CN I to CN XII
14
Q
What is a motor unit?
A
a motor neuron and all the muscle fibers it innervates
The nerve muscle functional unit
15
Q
What is the size principle?
A
16
Q
Components of the NMJ:
* Axon terminal?
* Synaptic cleft?
* Motor End Plate?
A
17
Q
- Tendon cont. into what?
- Why is CT imp?
A
- Tendon to fascia
- Imp to force transmission (relay muscles)
18
Q
Sheaths of CT hold muscle fibers together in parallel alignment so they can work together. List them for the muscles
A
Epimysium
– encircles the entire muscle
– dense regular connective tissue
– lots of collagen (unidirectional)
Perimysium
– surrounds groups of 10-100+ muscle fibers into bundles called fascicles
– carries nerves, blood vessels, and stretch receptors
Endomysium-> cont with myocyte
– surrounds individual myocytes
– fine areolar connective tissue
19
Q
A
20
Q
What is the skeletal fiber structures?
A
21
Q
What is the structure of a skeletal muscle fiber
A
22
Q
What is the smallest contractile unit? Where is it located and composed of?
A
- Sarcomere
- Region of a myofibril between two Z discs
- Composed of thick (myosin) and thin (actin) myofilaments
23
Q
how many actin encircle each myosin thick filament?
A
6
24
Q
What are the myofilament proteins (proteins of the sarcomere)
A
- Actin (contractile function)
- Myosin (contractile function)
- Tropnin (regulatory function)
- Tropomyosin (regulatory function)
- Titan (structural function)
- Dystrophin (structural function)
25
* What are the thin and thick myofilaments
* What is a crossbrigde?
26
Give the 7 steps in the exitiation-contraction couping process
27
What is the cross bridge cycle?
What is the sliding filament theory?
1. The cross-bridge cycle: Cycle of events that explains how a **single myosin** protein undergoes movement
2. The sliding filament theory :Theory which explains how, by virtue of all mysoins undergoing the “cross-bridge cycle” the whole sarcomere can **shorten in length**
28
What happens when ca is present with muscles?
29
What are the subdivisions of the Nervous System?
30
What are the multipolar neuron and bipolar neuron?
* Multipolar neuron
– One axon and multiple dendrites
– **Most common** – most neurons in CNS
* Bipolar neuron
– One axon and one dendrite
– Olfactory cells, retina, inner ear
31
What is a unipolar neuron and anaxonic neuron?
* Unipolar neuron
– Single process leading away from neurosoma
– Sensory cells from skin and organs to spinal cord
* Anaxonic neuron
– Many dendrites but no axon
– Retina, brain, and adrenal gland
32
What are the four types of glia cells in the CNS and functions
33
What two neuroglia cells occur in the PNS and their functions
Schwann cells
* Envelope nerve fibers in PNS
* Wind repeatedly around a nerve fiber
* Produce a **myelin sheath** similar to the ones produced by oligodendrocytes in CNS
* Assist in regeneration of damaged fibers
Satellite cells
* Surround the neurosomas in ganglia of the PNS
* Provide electrical insulation around the neurosoma
* Regulate the chemical environment of the neurons
34
Speed of nerve impulse depends on two factors, what are they?
**Diameter** of fiber
* Larger fibers have more surface area and conduct signals more rapidly
Presence or absence of **myelin**
* Myelin further speeds signal conduction
35
What is the slowest to fastest nerve fibers?
i. Small, unmyelinated fibers: 0.5 to 2.0 m/s
ii. Small, myelinated fibers: 3 to 15.0 m/s
iii. Large, myelinated fibers: up to 120 m/s
36
Where are slow and fast signals sent to?
* Slow signals sent to the gastrointestinal tract where speed is less of an issue
* Fast signals sent to skeletal muscles where speed improves balance and coordinated body movement
37
What is a electrical potential?
A **difference in concentration** of charged particles between one point and another
38
* What are living vells and what do they have?
* Are cells more negative or positive on the inside?
* What is the resting membrane potential of neruons?
– Living cells are polarized and have a resting membrane potential
– Cells have more negative particles on inside of membrane than outside
– Neurons have about −70 mV resting membrane potential
39
What is a electrical current?
A flow of charged particles from one point to another
40
* In the body, currents are what?
* How are gated channels opened or closed?
* What does it enable?
* in the body, currents are **mvt of ions**, such as Na or K, through channels in the plasma membrane
* Gated channels are opened or closed by various stimuli
* Enables cell to turn electrical currents on and off
41
Why is the resting membrane potential present?
The resting membrane potential is due to a small buildup of negatively charged ions, mainly organic phosphates (PO43−) and proteins, in the cytosol just inside the membrane and an equal buildup of positively charged ions, mainly sodium ions (Na+), in the interstitial fluid just outside the membrane
42
What is the ionic basis of the resting membrane potential?
43
What are the change phases in the membrane potential?
44
The plasma membrane is _ at rest... what does that mean?
POLARIZED, there is a difference in potential across the membrane
45
How does excitation of a neuron happens by a chemical stimulis?
**Ligands** (chemicals that bind to a receptor) can bind and **cause opening** of certain ion channels in the plasma membrane. This allows ions to travel into (or out) of the cell, changing the membrane potential. This change is termed a local (or graded) potential.
46
What is an action potential?
A dramatic change in membrane polarity produced by voltage-gated ion channels
47
Where is there an abundance of voltage-gated ion channels? When do these channels up or close?
The axon, and especially the axon hillock, have an abundance of voltage-gated ion channels. The channels open at a specific membrane voltage. They also close at a specific voltage.
48
If the stimulus makes the conditions at the axon hillock reach the threshold stimulus of _ then an _ _ will travel down the whole length of the axon
-55mV and ACTION POTENTIAL
49
How does an action potential look?
50
What happens with the sodium and potassium channels during an action potential?
51
What is the all or none principle?
52
During an action potential and for a few milliseconds after, it is what?
**difficult or impossible** to stimulate that region of a neuron again
53
What is the absolute and relative refractory period
53
How does the conduction in an unmyelinated fiber?
* Chain reaction continues until the nerve signal reaches the end of the axon
* The nerve signal is like a wave of falling dominoes
* Called **continuous conduction**
54
How does conduction in a myelinated fiber work?
* Myelinated fibers conduct signals with **saltatory conduction** (signal appear to jump from node to node)
* Nodes of Ranvier contain many voltage-gated ion channels, while myelin-covered internodes contain few
55
What does refractory periods ensure?
Refractory periods ensure the action potential continues in the correct direct, away from the axon hillock towards the axon terminals
56
Explain how synaptic transmission works?
57
* What are neurotransmitters?
* What are the four major chemical categories?
* Neurotransmitters are molecules that are released when a signal reaches a synaptic knob that binds to a receptor on another cell and alter that cell’s physiology
* More than 100 neurotransmitters have been identified but most fall into **four major chemical categories:** (see pic)
58
What can the spinal cord be divided into ?
1. Cervical region
2. Thoracic region
3. Lumbar region
4. Sacral region
59
Two areas of the cord are thicker than elsewhere:
- **Cervical enlargement**: nerves to upper limb
- **Lumbar enlargemen**t: nerves to pelvic region and lower limbs
60
What is the medullary cone (conus medullaris)?
* cord tapers to a point inferior to lumbar enlargement
* Where spinal cord ends
61
What is the cauda equina?
* bundle of nerve roots that occupy vertebral canal from L2 to S5
62
* What are the different meninges of the spinal cord?
* How is the white and gray matter organized in the SC and brain?
63
What does the gray and white matter spilt into in the spinal cord?
64
What is the composition of CSF?
– Watery solution
– Less protein & different ion concentrations than plasma
– **Constant volume**-> do not want volume to go or down
65
What are the functions of CSF?
– Gives **buoyancy** to the CNS organs
– **Protects** the CNS from blows and other trauma
– Nourishes the brain and carries **chemical signals**
66
What is the gray and white matter of the spinal cord?
* Gray matter: neuron cell bodies with little myelin
– shaped like a butterfly
– site of information processing, synaptic **integration**
* White matter: abundantly myelinated axons (tracts)
– three columns
– **carries signals** from one part of the CNS to another
67
Explain the Ascending tracts carry sensory signals up the spinal cord
Involves three neurons from receptors to destinations in the sensory areas of the brain:
1. **First-order neurons**: detect stimulus and transmit signal to spinal cord or brainstem
2. **Second-order neurons**: continues to the thalamus at the upper end of the brainstem
3. **Third-order neurons**: carries the signal the rest of the way to the sensory region of the cerebral cortex
68
Explain the Descending tracts carry motor signals down brainstem and spinal cord
Involve two motor neurons:
* **Upper motor neuron** originates in cerebral cortex or brainstem and terminates on a lower motor neuron
* **Lower motor neuron** neurosoma is in brainstem or spinal cord
– Axon of lower motor neuron leads to muscle or other target organ
69
The spinal cord communites with what? What is a nerve?
* Spinal cord communicates with the rest of the body by way of spinal nerves
* **Nerve**: a cord-like organ composed of **numerous nerve fibers** (axons) bound together by connective tissue
70
Explain the horns and roots
71
What are the five branched nerve plexuses?
* Cervical plexus in the neck, C1 to C5
* Brachial plexus near the shoulder, C5 to T1
* Lumbar plexus in the lower back, L1 to L4
* Sacral plexus in the pelvis, L4, L5, and S1 to S4
* Coccygeal plexus, S4, S5, and Co1
72
What are the somatosenory function and the motor function?
* **Somatosensory function:** carry sensory signals from bones, joints, muscles, and skin
* **Motor function**: primarily to stimulate muscle contraction
73
* What does the cervical plexus supply? What is an imp nerve?
* Supply/receive from the muscles of the neck and diaphragm
* Phrenic nerve: C3,4,5 keep you alive
74
What does the branchial plecus supply? What is an imp nerve?
* Supply/receive from the muscles and skin of the arm
* Ulnar nerve: funny bone
75
* What does the lumbar plexus supply? What an imp nerve?
* Supply/receive from the muscles of the abdomen and thigh
* Femoral nerve: supply thigh
76
What does the sacral and coccygeal plexuses supply? What an imp nerve?
* Supply/receive from the buttock, lower limb, pelvic structures
* Sciatic nerve: combo of common fibular nerve and tibal nerve
77
What is complete transection?
complete severance of cord
78
* What happens below level of injury of spinal cord?
* Above C4 poses threat to what?
* Spinal shock causes what?
* Immediate loss of motor control below level of injury
* Above C4 poses the threat of respiratory failure
* Spinal shock (hypotension
79
* What is paralysis?
* What are the different types? (4)
Paralysis(loss of motor and sometimes also sensory function):
– **Paraplegia**: paralysis of both lower limbs
– **Quadriplegia**: paralysis of all four limbs
– **Hemiplegia**: paralysis on one side of the body
– **Paresis**: partial paralysis or weakness of the limbs
80
What is a dermatome and dermatome map?
* Dermatome: a specific area of skin that conveys **sensory input** to a spinal nerve
* Dermatome map: a diagram of the cutaneous regions innervated by each spinal nerve
81
* Dermatomes overlap their edges as much as _
* What is necessary?
* Dermatomes overlap their edges as much as **50**%
* Necessary to **anesthetize** three successive spinal nerves to produce a total loss of sensation in one dermatome
82
What is A Representative Reflex Arc
83
* What is embeded in skeletal muscles?
* What are proprioceptors?
* Muscle spindles inform what?
* What does it enable?
* **Stretch receptors** embedded in skeletal muscles
* Proprioceptor - specialized sense organs to monitor position and movement of body parts
* Muscle spindles inform the brain of **muscle length** and body movement
* Enables brain to send motor commands back to the muscles that control coordinated movement, corrective reflexes, muscle tone, and posture
84
What is the patellar tendon reflex?
85
What are the flexor and crossed extension reflexes?
86
* What are tendon organs?
* What are golgi tendon organ?
* Tendon organs: **proprioceptors** in a tendon near its junction with a muscle
* Golgi tendon organ:1mmlong, nerve fibers entwined in collagen fibers of the tendon
87
What is the tendon reflex?
* What does it inhibit? what does it moderates?
Tendon reflex: in response to **excessive tension** on the tendon
– Inhibits muscle from contracting strongly
– Moderates muscle contraction before it tears a tendon or pulls it loose from the muscle or bone
88
What are the four regions of the brain?
89
What are the surface markings of the two cerebral hemispheres?
Ridges (gyrus), shallow grooves (sulcus), and deep grooves (fissures), ventricles (spaces)
90
What are the five lobes of the cerebral hemispheres?
1. Frontal 2. Parietal 3. Temporal 4. Occipital **5. Insula**
91
* What is the fissues that separates the two hemis?
* What connects the two hemi?
* Longitudinal fissue
* Corpus colusm (white matter)
92
What is the precentral gyrus and postcentral gyrus?
* Precentral: impulse for motor commands to relay to UMN to LMN
* Postcentral gyrus: somatosensory-> touch, pain, pressure, 3/4 orders of neurons
93
What is the fissure between cerebellum and cerebrum?
transverse cerebral fissue
94
How is the gray and white matter organized in the brain?
95
What is off of the hypothalamus?
pituitary gland
96
What is the epithalmus made up of?
habenula and pineal gland
97
What is the midbrain, pons, medulla oblongata?
98
Cerebral Cortex:
* superficial layer is what?
* _ of the mass of the brain
* Superficial layer of gray matter
* **40%** of the mass of the brain
99
What is the site of conscious mind?
awareness, sensory perception, voluntary motor initiation, communication, memory storage, understanding
100
Each hemisphere connects to what/
to **contralateral** side of the body
101
What are the meninges?
Meninges: three connective tissue membranes that envelop the brain
101
What are the ventricles?
102
What is the Flow of Cerebrospinal Fluid
103
* What is imp of the cerebellum and what is the white matter called?
* What are the different lobes?
* Where do the two hemis come together?
104
What are the three parts of the diencephalon?
1. Thalamus
2. Hypothalamus
3. Epithalamus
105
what are the Five Lobes of the Cerebrum and Some of Their Key Functions
106
What are higher brain functiosn?
SECS LMM
107
* Functions of brain do not have easily defined anatomical boundaries:
* involve **interactions** between cerebral cortex, basal nuclei, brainstem and cerebellum
* integrative functions focus mainly on cerebrum, but involve combined action of **multiple brain levels**
108
What is the Primary Somatosensory Cortex (Postcentral Gyrus)
109
What is the primary motor cortex (precentral gyrus)
110
What are the two language centers of the left hemI?
Brocas and wernicke area
111
What is the lateralization of cerebral functions?
112
* How many cranial nerves are there?
* Most are what?
* What do they connect? what is the exception?
* Most cranial nerves carry what?
