Central Nervous System, Brain And Cranial Nerves Flashcards
What are the principals of cells in the nerve system
The nervous system consists of two types of principals
Neuro glial cells - support the nervous system
Nerve cells/neurons - conduct signals
What is the sensory function?
Receptors detect a stimulus (changes in the environment)
Cell body of a neuron
Contains nucleus and cytoplasmic organelles
Dendrites of an neurone
- Conduct impulses to the cell body
- They are all over the place
- they are connected to other nerves
- The stronger the cell signal, the more likelihood of a nerve signal impulse.
Axon of a neuron
Conducts impulses away from the body to transmits impulses towards another neuron
Synapse
junction between nerves where a nerve impulse is transmitted
Describe the process of generation and propagation of a nerve impulse
A neuron receives a stimulus.
The nerve travels to the axon membrane - axon terminal
The axon terminal releases neurotransmitters that carry nerve impulses to the next cell
Outline the cells function of nervous system
- Neurons send and receive neurotransmitters
- Maintaining homeostasis
- Interpreting sensory information
- Creating motor responses
Identify the 4 neuro glial cells in the CNS
Astrocytes - star shaped, can become cancerous regulate blood brain barrier, connect capillaries and neurones together, provide nutrients and support for neurones
Microglial cells - convert into macrophages (white blood cells) and engulf pathogens, first line of defence, acts as a way of changing chemical environment
Oligodendrocytes - forms myelinated sheath ( a fatty sheath of myelinated fibres) to transmit signals faster, conserves energy
Ependymal cells - can become cancerous, made up of squamous and columnar cells, sometimes ciliated cells forms csf, filters blood, provides nutrients and support to csf, the ciliated cells help with the circulation of csf in the brain
Identify the two neuro glial cells in the PNS
Schwann cells - like oligodendrocyte cells, form myelinated sheath to speed up transmission of signals, conserves energy, in pns
Satellite cells - muscle stem cells, located in the periphery of muscle fibre,
Describe structure and function of the spinal cord and relationship with the vertabrae
The vertebra encloses and protects the spinal cord within the spinal canal.
Describe integration of the brain and spinal cord
The brain is what controls all the body’s functions.
The spinal cord runs from the brain down through the back.
It contains threadlike nerves that branch out to all organs and body parts
These nerves relays messages back and forth from the brain to different parts of the body.
Describe the processes involved with a spinal reflex
Receptors - stimulus - something triggers a sensory receptor
sensory neuron - carries the signal from the receptor to the spinal cord
spinal cord - interneurons process the signal
motor neuron - processed signal sent to motor neuron
muscles - motor neuron causes muscles to contract
The path taken by nerve impulse in a reflex action is called a reflex arc.
Describe the structure and functional aspects of the autonomic nervous system
It regulates functions such as cardiac regulation, vasomotor activity, respiration, reflex activities such as sneezing, swallowing, coughing and vomiting. It works in conjunction with the peripheral nervous system.
The sympathetic nervous system is associated with fight-or-flight response. On the other hand, the parasympathetic nervous system is associated with rest and digest.
What is CSF
Cerebrospinal fluid (CSF) is a watery liquid that continually circulates through the brain’s ventricles (hollow cavities) and around the surface of the brain and spinal cord.
CSF washes out impurities from the brain, transfers nutrients and provides protective cushioning to the brain and spinal cord.
Describe saltatory conduction
On myelinated nerves, the signal speeds up bc instead of travelling through each nerve, it can jump between synapses and gaps between nodes of ranvier/Schwann cells
*Name the two sets of bones that make up the skull.**
Cranial - 8
Facial - 14
How are cranial bones different from facial bones?
The cranium (skull) is the skeletal structure of the head that supports the face and protects the brain. It is subdivided into the facial bones and the brain case.
The facial bones underlie the facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws.
Which suture articulates the parietal bone with the frontal bone?
Coronal suture
Name the paired bones that form a large part of the roof of the cranium.**
Left and right parietal bones
How many bones form the cranium
22
How many parts is the temporal bone divided into?**
The temporal bone consists of four parts— the squamous, petrous, mastoid and tympanic parts.
What are the features of the squamous portion of the temporal bone?*
Largest and most superior positioned
Name the parts of the petromastoid division of the temporal bone.**
Petrous part. The petrous part is a wedge shaped mass of bone located between the sphenoid and occipital bones within the cranial cavity. It is the most medial part of the temporal bone
What features are found on the external surface of the frontal bone?**
Suprciliary arch, - curved arch
Glabella - prominence
Where does the frontal bone articulate with the parietal bones
Coronal suture
How is the occipital bone internally divided?
Name the external features of the occipital bone.**
What are the main features of the ethmoid bone?**
The ethmoid bone is a small bone with a cuboidal structure that forms the lateral boundaries of the orbit, the anterior cranial fossa superiorly, and the nasal cavities inferiorly.
It is relatively light and has a spongy texture
What does the crista galli project superiorly from?*
Falx cerebri
What does the crista galli project superiorly from?**
Falx cerebri
- What shape is the sphenoid bone?
Butterfly/bat
- Name the parts of the sphenoid bone.
Optic canal
- What is the key function of the sphenoid bone in the cranium?
Sphenoid bone has many essential functions. It helps form the base and lateral sides of the skull in combination with the orbital floor.
- What are the functions of facial bones?
the facial bones serve as protection for the brain and the organs responsible for smell, sight, and taste.
My - mandible - 1
Mouths - maxillary - 2
Palette - parietal bones - 2
Never - nasal bones - 2
Liked - lacrimal - 2
Zucchini - zygomatic - 2
In - inferior nasal conchea - 2
Vinegar - vomer - 1
- Name the bones that form the bridge of the nose.
Nasal bones
- bridge
- What bones contribute to the formation of the orbit?
Maxilla
Zygomatic
Lacrimal
Palatine
Frontal
Ethmoid
Sphenoid
- Name the passages in the orbit for the optic nerve.
enters the bony skull through the optic foramen
- What type of joint is the TMJ?
synovial joint
consists of articulations between three surfaces; the mandibular fossa and articular tubercle (from the squamous part of the temporal bone), and the head of mandible.
- **Name the ligaments associated with the TMJ.*
Lateral ligament
Sphenoidmandibular ligament
Stylomandibular ligament
- List the movements possible at the TMJ.
Protrusion and retraction
- upper part of the joint allows this
- the lateral pterygoid muscle is responsible
Elevator and depression
- lower part of the joint allows this
Depression is caused by gravity