Exam 2 Flashcards
How many muscle cells are in motor unit 1?
How many neurons in motor unit 1?
What is the functional classification of the neuron in motor unit 1?
Differentiate b/w gray matter and white matter in structure and function.
3
They conduct action potentials
Grey matter: neural cell bodies
White matter: Milinated neuron fibers axons and dendrites
FUNCTION:
What are the special characteristics of skeletal muscle tissue (e.g. what features enable them to contract under voluntary control)?
- Skeletal muscle cells develop from the fusion of many smaller cells during fetal development, resulting in long, straight muscle fibers that contain many nuclei. Multi-Nucleiated
- When viewed under the microscope, skeletal muscle cells appear to have a striped, or striated, pattern of light and dark regions. These stripes are caused by the regular arrangement of actin and myosin proteins within the cells into structures known as myofibrils.
- Myofibrils are responsible for the skeletal muscles’ great strength and ability to pull with incredible force and propel the body.
- NMJ allows for voluntary control.
What is this component of the nerve?
Neurclemma of shwann cell?
Define Obligodendrocytes
Provide myelination in CNS (white matter)
Wraps arpund portions up to 40 fibers
Consequence: damage increases loose portion of myelination up to 40 fibers
What is the significance of the refractory period?
Nerve is unresponsive to stimulus. No action potentials can take place during the 1-2ms period
Which areas are part of our conscious mind?
Which are unconscious areas of the brain?
Describe examples of how activity in the limbic system may affect autonomic functions.
- Conscious
- Forebrain
- Unconscious
- Midbrain
- Hindbrain
Are the functions of both hemispheres identical?
No
Basic Tasks of the Nervous System….
How is this similar to the normal function of the endocrine system? How is it different? Describe the receptor, control center, and effector in several neural reflexes.
Are the calcium channels in cisternae voltage-gated or chemically-gated?
Voltage
In this flow chart, what do the components in blue have in common?
Explain why the Enteric Nervous System is referred to as the “little brain”.
Where are the Autonomic sensory receptors located?
The blue components all have sensory receptors and neurons
Referred to as little brain because it’s just to digest and make functions work effiently
Plasma membrane of the postsynaptic neuron or effector cell?
Where is CSF made?
Describe the chemical composition of CSF.
How is CSF “recycled”?
- CSF is produced mainly by a structure called the choroid plexus in the lateral, third and fourth ventricles.
- CSF is an ultrafiltrate of plasma, but the exact composition of CSF is altered by active transport. Spinal fluid thus has a much lower concentration of protein, glucose, potassium, calcium and magnesium than does serum.
- CSF is recycled (or absorbed) by special structures in the superior sagittal sinus called arachnoid villi.
- Recycled CSF likely drains back into the ventricles.
Name the two main functions of the spinal cord.
- Connects peripheral nervous system to the brain
- Coordinates simple reflexes such as sending a signal to pull your hand away from a hot object
Describe how a muscle attaches to a bone, as shown in this figure.
- Extracellular connective tissue between muscle fibers find to tendons at distal and proximal ends
- Periosteum binds with tendon at muscles orgin and insertion
How does the Na-K pump contribute to the “potential”?
Why is the cell membrane described as “polarized”?
Because it’s more positive inside and negative outside
What tissue passes through the middle of the third ventricle?
- Running through the third ventricle is the interthalamic adhesion, which contains thalamic neurons and fibers that may connect the two thalami.
- Are oligodendrocytes capable of reproduction?
- Why is this significant?
- No, they do not. The oligodendrocyte precursor cells divide instead and differentiate into oligodendrocytes.
- Significannce
- Thier function is to wrap around axons and provide insultion to increase speed of action potentials down an axon.
- They “stay in place” to offer constant support.
- idk
Name the enzyme that controls these reactions.
Where would you find this enzyme, and why?
What is the blood-brain barrier?
Very tight barriers (tight junctions) destruction of capilaries of brain and spinal cord
Cells are overlaping
Simple squamous epithelium
What are the functions of skeletal muscles?
Is a muscle (e.g. Deltoid) considered a tissue or an organ? Justify your answer.
- Movement
- Structure
- Attached to the bones of the skeletal system are about 700 named skeletal muscles that make up roughly half of a person’s body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves.
Why is there such a large connective tissue component to skeletal muscles?
Elasticity
Extensibility
connect muscle to skeleton
help indiviudal skeletal muscles contract
What is a neuroma?
Tumor found on a shwann cell seath
From which embryonic germ layer do these neuroglia originate?
All neurgolia derive from ectoderm besides microglia
Write the summary equation for aerobic cellular respiration.
C6+H12+6O2——-6CO2+ 6H2O+ATP
Reactants ——————–Products
The appropriate stimulus for skeletal muscle cells is _____________________.
Compare the mode of communication in the nervous and endocrine systems
Nervous: information transmistted as electical impulses (action potentials) by specific neuron cells
Fast acting
Effects are short
Endocrine:Information transmitted by hormone molecules transported by circulitory hormone
Hormone only effect target cell containing hormone receptor
Slow acting
Effect act long-term
Why are there cervical and lumbar enlargements?
- The cervical and lumbar enlargements of the spinal cord result from enlargement of the gray matter that contains the neural machinery necessary to operate the limbs.
Name the two locations where ATP synthesis takes place in a cell.
Mitchondria and cytosal
Why do you think white matter surrounds gray matter in the spinal cord?
If the brain and spinal cord contain no pain receptors, what are the possible explanations for head pain?
- What you feel when you have a headache is not your brain hurting – there are plenty of other areas in your head and neck that do have nociceptors which can perceive pain, and they literally cause the headaches.
What are cisternae and what chemical is stored within the cisternae of muscle cells?
Flattened membrane makes up endoplasmic recticulmum and golgi apparatus
Calcium
The reticular formation extends from the spinal cord to the diencephalon (thalamus).
Name the brain structures in which this neuron “network” is found.
- The reticular formation has projections to the thalamus and cerebral cortex that allow it to exert some control over which sensory signals reach the cerebrum and come to our conscious attention.
- It plays a central role in states of consciousness like alertness and sleep. Injury to the reticular formation can result in irreversible coma.
- Structures
- Traditionally the nuclei are divided into three columns In the median column
- – the raphe nuclei In the medial column
- – gigantocellular nuclei (because of larger size of the cells) In the lateral column
- – parvocellular nuclei (because of smaller size of the cells)
- Thalamus
- Traditionally the nuclei are divided into three columns In the median column
What do the following prefixes mean:
peri-, endo-, epi-, myo-, and sarco-?
peri- around
endo- within ish
epi- on top of ish
myo and mys - muscle,
sarco - flesh
Are dendrites always shorter than axons?
Can the neuron processes that conduct information toward the cell body also be myelinated?
At time 0, does the membrane begin to depolarize or repolarize?
Will a stronger stimulus produce a larger action potential? Explain.
Give an example of where a graded potential would take place.
Depolarize
No because the actin potetial is always the same size
Graded potentials occur in the dendrites and cell body of a neuron
They do not travel down axon
There are 31 segments to the spinal cord; each segment giving rise to a pair of ____________.