Week 4 - Nervous System (CNS/PNS) Flashcards
What is the function of the brain stem?
- Connects the cerebrum and cerebellum to the spinal cord
* Controls basic body functions such as breathing, heart rate and swallowing
What is the function of the thalamus?
Relays incoming sensory information to the appropriate brain area
What is the function of the hypothalamus?
Is the master control centre of the autonomic nervous, helping to regulate a variety of body functions through the release of hormones by the pituitary gland (homeostasis)
What are some of the bodily functions that the hypothalamus regulates?
- Body temperature
- Blood pressure
- Heart rate
- Oxytocin release
What structure acts as an intermediate between the nervous and endocrine system?
Hypothalamus
What are the 3 functions of the limbic system?
The limbic system is associated with:
• Memory
• Emotions
• Arousal
What is the function of the cerebellum?
Helps coordinate muscle movements and is associated with balance
Distinguish between sulcus, gyrus and fissure
- Gyrus - ridge
- Sulcus - groove
- Fissure - deeper groove
What are the 12 cranial nerves and indicate whether they have sensory functions, motor functions or both.
- I - Olfactory (s)
- II - Optic (s)
- III - Oculomotor (m)
- IV - Trochlear (m)
- V - Trigeminal (b)
- VI - Abducens (m)
- VII - Facial (b)
- VIII - Vestibulocochlear (s)
- IX - Glossopharyngeal (b)
- X - Vagus (b)
- XI - Accessory (m)
- XII - Hypoglossal (m)
What is the spinal cord?
Is a long thin tubular bundle of nerve fibers that extends from the medulla to L1-L2.
What structure protect the spinal cord?
- Cerebrospinal fluid (CSF)
- Meninges
- Vertebrae
What is white matter?
Bundles of myelinated axons
What is grey matter?
Consists of the cell bodies of neurons
Distinguish between the dorsal, ventral and lateral horns in terms of function
- Dorsal horn -contains neurons that transmit sensory information to the CNS
- Lateral horn - contains the cell bodies of neurons that innervate smooth and cardiac muscles
- Ventral horn - contain the cell bodies of neurons that innervate skeletal muscles
Distinguish between ascending and descending pathways in terms of function
Ascending neural pathways transmit sensory information to the brain, whereas descending pathways transmit motor information to muscles and glands.
Name and describe the types of senses transmitted by the 3 ascending tracts in the spinal cord
- Dorsal column - medial lemniscus (DCML): discriminative touch, pressure and proprioception
- Spinothalamic: Pain and temperature
- Spinocerebellar: Proprioception to the cerebellum
Name and describe the functions of the 2 descending spinal tracts
- Corticospinal: Motor information to skeletal muscles
- Reticulospinal: Arise from the reticular formation of the brain stem and makes postural adjustments and aids in balance.
Define reflex
Is a rapid predictable motor response to a stimulus that acts as a survival mechanism.
Describe the 5 components of a reflex arc.
1) Receptor - Detects stimulus
2) Sensory neuron - sends information to the CNS
3) Integration centre - redirects signal to motor neuron
4) Motor neuron - transmits motor information to effector
5) Effector- produces the desired response (contraction or secretion)
Describe the stretch reflex (patella tendon reflex) in basic terms
The stretch reflex is initiated when the stretch receptors in the quadriceps detects excessive stretch. This stretching initiates a spinal reflex which causes the quadriceps to contract to cause extension of the knee, and hamstring to receive inhibitory signals to allow the movement to occur.
How is the stretch reflex used in everyday life?
It is used to help maintain balance by straightening the knee if excessive stretching of the quadriceps is detected.
Why do doctors asses reflexes in a clinical scenario?
It can be used to asses spinal cord damage or peripheral nerve damage.
What is the role of brain in reflexes?
The brain is not directly involved in the spinal reflex, but interprets sensory information after the reflex has occurred and can also control the extent of the reflex.
What structures make up the diencephalon?
- Thalamus
* Hypothalamus
What structures make up the brain stem?
- Mid brain
- Pons
- Medulla oblongata
