WEEK 3 Flashcards
(37 cards)
What is the role of the Peripheral Nervous System (PNS)?
The PNS connects the CNS to limbs and organs, relaying information between the body and brain. It is essential for sensory input and motor output.
What are the types of peripheral nerves?
- Sensory nerves: Carry information from the body to the brain and spinal cord.
- Motor nerves: Carry messages from the brain and spinal cord to the body.
- Mixed nerves: Contain both sensory and motor fibers, performing both functions.
What is the function of spinal nerves?
Spinal nerves are responsible for motor, sensory, and autonomic signals. Each nerve innervates a specific body region called a dermatome.
What is a dermatome?
A dermatome is an area of skin where sensations are felt, controlled by a single spinal nerve.
What are the sensory cranial nerves?
- Olfactory (CN I): Smell
- Optic (CN II): Vision
- Vestibulocochlear (CN VIII): Hearing and balance
What are the motor cranial nerves?
- Oculomotor (CN III): Eyelid and eyeball movement
- Trochlear (CN IV): Moves eye downward and laterally
- Abducens (CN VI): Turns eye laterally
- Accessory (CN XI): Controls trapezius, sternocleidomastoid, and swallowing movement
- Hypoglossal (CN XII): Controls tongue muscles
What are mixed cranial nerves?
- Trigeminal (CN V): Facial sensation, chewing
- Facial (CN VII): Facial expression, taste, salivation, tear secretion
- Glossopharyngeal (CN IX): Taste, senses carotid blood pressure
- Vagus (CN X): Senses aortic blood pressure, slows heart rate, stimulates digestion, taste
What are the functions of the Trigeminal (CN V) and Facial (CN VII) cranial nerves in speech?
- Trigeminal: Activates muscles for mastication, impacting articulation.
- Facial: Controls facial expressions (e.g., lip movement) essential for articulation.
How does the Glossopharyngeal (CN IX) nerve contribute to speech?
The Glossopharyngeal (CN IX) nerve aids in the movement of the pharynx, vital for speech (e.g., narrowing the pharynx).
What is the role of the Vagus (CN X) nerve in speech?
The Vagus (CN X) nerve controls movements in the larynx, pharynx, and velum (important for nasals and voicing).
How does the Hypoglossal (CN XII) nerve contribute to speech production?
The Hypoglossal (CN XII) nerve controls tongue movements, which are crucial for articulating consonants and vowels.
Which cranial nerve is primarily involved in speech perception?
The Vestibulocochlear (CN VIII) nerve is primarily involved in speech perception, transmitting auditory information from the cochlea to the brain.
How do disorders in the Vestibulocochlear (CN VIII) nerve affect speech?
Disorders in the Vestibulocochlear (CN VIII) nerve can lead to hearing loss and impact speech comprehension.
Which cranial nerve is responsible for feeling a mosquito bite on the cheek?
CN V (Trigeminal) is responsible for facial sensation.
Which cranial nerve is essential for hearing and balance?
CN VIII (Vestibulocochlear) is responsible for hearing and balance.
If someone has a drooping mouth, which cranial nerve is likely involved?
CN VII (Facial) is likely involved in a drooping mouth, as it controls facial expression.
What are the spinal nerves and their function?
Spinal nerves connect the spinal cord to various parts of the body, transmitting sensory and motor information.
How many pairs of spinal nerves are there, and what is their function?
There are 31 pairs of spinal nerves. They innervate various regions of the body:
8 cervical: Neck, shoulders, arms, hands
12 thoracic: Chest, certain abdominal muscles, mid-back
5 lumbar: Lower abdomen, legs, bowel, bladder
5 sacral: Same as lumbar
1 coccygeal
What are the categories of the vertebrae in the spine?
7 cervical vertebrae (Neck)
12 thoracic vertebrae (Chest cavity, ribs)
5 lumbar vertebrae (Lower back)
5 sacral vertebrae (Fused)
3-5 coccygeal vertebrae (Tailbone)
What is the function of the Phrenic Nerve?
The Phrenic Nerve provides motor innervation to the diaphragm, essential for breathing. Damage can cause diaphragm dysfunction and affect respiratory function.
What are afferent and efferent nerves?
- Afferent (sensory) nerves: Carry sensory information into the spinal cord via the dorsal root.
- Efferent (motor) nerves: Carry motor information from the spinal cord to muscles via the ventral root.
What does the phrenic nerve do?
It provides motor innervation to the diaphragm, stimulating contraction for inspiration. Damage can lead to diaphragm paralysis.
What is the structure of skeletal muscles?
Skeletal muscles are composed of muscle fibers, connective tissue, blood vessels, and nerves. Muscle fibers contain myofibrils, which are made up of repeating units called sarcomeres.
What is the sliding filament theory of muscle contraction?
The sliding filament theory states that upon stimulation, myosin filaments within the sarcomere pull on actin filaments, causing the sarcomere to shorten and muscle contraction to occur.
