ALHT 2025

Schwann cells

Oligodendrocytes cells

Resting potential, slow depolarization, fast depolarization, repolarization and hyperpolarization

Dendrites bring information to the neuron

The axon carries nerve impulses away from the soma

The axon hillock connects the cell body to the axon

Axon terminals are button-like endings of axons that contain synaptic vesicles and release neurotransmitters when activated by an action potential

Nodes of Ranvier are periodic spaces between the myelin sheath where the Na+/K+ pump is located. They are necessary for depolarization, allowing action potentials to travel down the axon

The presynaptic terminal is the endpoint of a neuron that allows communication with a succeeding neuron

The postsynaptic terminal receives an action potential from the preceding neuron

The synaptic cleft (or synapse) is the space between the presynaptic and postsynaptic terminals.

The synaptic cleft (or synaptic gap) is the small gap between two communicating neurons

- Association fibers connect different regions of the cerebrum within the same hemisphere. An example is the arcuate fasciculus, which links Broca’s and Wernicke’s areas, facilitating language processing
- Commissural fibers connect regions between the two hemispheres, enabling interhemispheric communication. The corpus callosum is the largest example, linking the left and right cerebral hemispheres.
- Projection fibers carry information between the cerebral cortex and lower structures. The internal capsule is an example, transmitting both motor and sensory signals between the cortex and the rest of the nervous system.

It is the site for the transmission of action potential from nerve to the muscle.

Dura Mater, Arachnoid Mater, Pia Mater

The dura mater is the outermost meningeal layer.

The falx cerebri is responsible for separating the two cerebral hemispheres.

The subarachnoid space provides buoyancy and protection to the cerebrum

Arachnoid granulations are involved in CSF reabsorption.

Meningitis primarily affects the meninges

The third ventricle is located between the thalami

The choroid plexus is responsible for forming cerebrospinal fluid (CSF)

A large anterior fontanel is commonly observed in infants with hydrocephalus

The anterior cerebral artery primarily supplies the medial portions of the frontal and parietal lobes

The midbrain is the uppermost part of the brainstem. It controls vision, hearing, and motor control

The pons connects different brain regions and helps with breathing, facial movements, and communication between the cerebrum and cerebellum

The medulla oblongata regulates involuntary functions such as heart rate, breathing, and blood pressure

The pyramids contain motor fibers that cross over (decussation), allowing movement control on the opposite side of the body.

If you have a skill and stop practicing it, you will lose it over time

The more you practice something, the better you will get at it

You need to train exactly what you want to improve

A new skill must be practiced again and again to become permanent

Training must have a good intensity level to drive improvement

The first three months after an injury are crucial for therapy and recovery

Training is most effective when it is meaningful to the person

Younger people tend to learn and improve skills faster than older people

Getting better at one skill can help improve similar skills, like learning a third and fourth language after mastering two

Training multiple skills at the same time can improve learning overall

The lateral corticospinal tract originates from the medial and lateral aspects of the motor cortex, primarily controlling limb movements rather than the face. The face area of the homunculus is controlled by the corticobulbar tract instead.

Damage to the corticospinal tract in the midbrain results in loss of fine motor control on the contralateral side of the body below the point of the lesion

Large motor units are found in the thigh, where they control powerful, gross movements

The corticobrainstem pathway facilitates cranial nerves V, VII, IX, X, XI, and XII.

The corticobrainstem pathway originates from the lateral aspect of the motor homunculus, corresponding to the face and head area.

It descends to the cranial nerve nuclei with motor output to facilitate action.

Most cranial nerves receive bilateral information, but CN XII (hypoglossal nerve) receives contralateral innervation

The corticobrainstem pathway decussates in the brainstem at the level of the cranial nerve it innervates

UMN damage causes increased muscle tone (spasticity)

LMN damage causes decreased muscle tone (flaccidity)

Hyperreflexia is NOT a characteristic of a lower motor neuron lesion. Lower motor neuron lesions typically present with hyporeflexia and hypotonia

Upper motor neurons (UMNs) include the corticospinal and corticobrainstem tracts, which are responsible for controlling voluntary movements

The corticospinal tract primarily controls voluntary movements of the limb

LMNs are located in the anterior horn of the spinal cord

A positive Babinski sign is indicative of an upper motor neuron lesion

Acetylcholine is released at the neuromuscular junction by alpha motor neurons

The pre-motor cortex is responsible for planning and guiding movement based on sensory input

The supplementary motor cortex is crucial for sequencing movements and mental rehearsal

Somatotopic organization refers to the orderly mapping of different body parts onto specific areas of the motor cortex, forming the "motor homunculus." This ensures precise motor control, with larger cortical representation for body parts requiring fine motor skills (e.g., hands, face)

UMNs originate in the cerebral cortex or brainstem and send motor commands down to LMNs. LMNs are located in the spinal cord and brainstem and directly innervate muscles to produce movement

Damage to the myelin sheath reduces the speed at which neuronal impulses are transmitted from one neuron to another, leading to slower communication

1. Multiple sclerosis (MS): An autoimmune condition where the immune system attacks the myelin sheath in the central nervous system (CNS).
2. Guillain-Barré Syndrome (GBS): An autoimmune condition where the immune system attacks the myelin sheathin the peripheral nervous system (PNS).

Damage to the myelin sheath disrupts efficient nerve impulse transmission, leading to motor symptoms such as muscle weakness. Sensory disturbances like numbness, tingling, and pain may occur due to impaired signal conduction along affected nerves.

The thalamus is a paired deep grey matter structure that acts as a relay station, filtering information between the brain and body

The hypothalamus maintains homeostasis by influencing the autonomic nervous system (e.g., heart rate, blood pressure) and works closely with the endocrine system via the pituitary gland

The epithalamus connects the limbic system to other parts of the brain and influences circadian rhythms by secreting melatonin

The subthalamus regulates movement along with the rest of the basal ganglia

The primary motor cortex is located anterior to the central sulcus. It generates neuronal impulses to bring about voluntary motor movement

The premotor cortex is located in the frontal lobe, in front of the primary motor cortex. It is involved in the planning of voluntary motor movement

The supplementary motor area is located in the frontal lobe, in front of the primary motor cortex. It is involved in generating the sequences required for voluntary motor movement

The primary somatosensory cortex is located posterior to the central sulcus. It is a key area for processing sensory/afferent input

The secondary somatosensory cortex is located adjacent to the primary somatosensory cortex, in the upper part of the lateral sulcus. It is associated with spatial and tactile sensory experiences and stores, processes, and retains sensory information

Broca’s area is located on the inferior frontal gyrus. It is the motor speech area of the brain, required for formulating words and written language

Wernicke’s area is located in the posterior part of the left temporal lobe, near the junction between the parietal and temporal lobes. It is the receptive language center, required for comprehending language

The primary visual cortex is located in the occipital lobe. Its primary function is to receive, segment, and integrate visual information. Processed information is then sent to other regions of the brain for analysis and utilization

The secondary visual cortex surrounds the primary visual cortex in the occipital lobe. It integrates visual information from the primary visual cortex and is associated with object recognition, spatial tasks, and visual-motor skills

The primary auditory cortex is located on the superior temporal gyrus in the temporal lobe. It has a tonotopic map that mirrors the distribution of receptors in the cochlea, with a gradient of neurons responding to high and low frequencies

The cell body, or soma, contains the nucleus and controls all functions of the neuron. It houses important organelles, including the nucleus, which is essential for cell function

Dendrites bring information to the neuron by receiving signals from other neurons

The axon carries nerve impulses away from the soma to other neurons or muscles

The axon arises from the axon hillock, a specialized area of the cell body, and serves as the site where action potentials are initiated

The axon terminal contains synaptic vesicles that release neurotransmitters to communicate with other neurons. It allows the neuron to make synaptic contact with other neurons

The myelin sheath is an insulating layer around axons that increases the speed of nerve impulses

- Oligodendrocytes produce myelin in the central nervous system (CNS)
- Schwann cells produce myelin in the peripheral nervous system (PNS)

The Nodes of Ranvier are periodic gaps between sections of the myelin sheath where Na+/K+ pumps are located. These gaps allow for rapid depolarization, which speeds up the transmission of action potentials

The pre-synaptic terminal is the end point of a neuron where neurotransmitters are released to communicate with a succeeding neuron

The post-synaptic terminal receives an action potential from the pre-synaptic neuron and processes the signal

The synaptic cleft (or gap) is the small space between two communicating neurons where neurotransmitters are released and received. It allows for signal transmission between neurons

Ion channels in the plasma membrane can open to allow ion movement across the membrane or close to prevent movement, regulating the flow of ions into and out of the cell

When the myelin sheath is damaged, signals cannot travel as quickly or may not reach their destination at all. This occurs in the CNS, where oligodendrocytes produce myelin, and is associated with diseases like multiple sclerosis

Grey matter is a type of tissue in the brain and spinal cord that plays a crucial role in enabling the functions of the CNS by processing and integrating information

White matter is a network of nerve fibers that facilitates communication and information exchange between different areas of grey matter

Grey matter consists of neuronal cell bodies and dendrites, which communicate with nearby neurons. White matter consists of long axons that transmit impulses over longer distances within the brain and spinal cord

Bumps are called gyri, and depressions are called sulci

It controls voluntary motor movements. If damaged, a person may experience a loss of motor function

It processes sensory input from the body. If compromised, a person may lose the ability to feel different sensations

The person will have difficulty processing auditory information and may struggle to interpret sounds

It processes visual information. Damage to this area can lead to visual impairments, including blindness

It is responsible for language comprehension. If damaged, a person may struggle to understand spoken or written language

It controls motor functions related to speech production, such as moving the tongue and lips. If damaged, a person may struggle to form words properly

Aphasia is a language disorder caused by damage to Wernicke’s or Broca’s area, leading to difficulties in either understanding (Wernicke’s aphasia) or speaking (Broca’s aphasia).

1. Projection fibres – Carry sensory or motor signals between the brain, brainstem, and spinal cord.
2. Commissural fibres – Allow communication between the left and right hemispheres of the brain.
3. Association fibres – Connect different regions within the same hemisphere of the brain.

The diencephalon is found on top of the brainstem

The third ventricle is a fluid-filled space located between the two halves of the diencephalon

The diencephalon is divided into:
1. Thalamus – The main component, acting as the relay center.
2. Hypothalamus – Involved in hormone regulation via the pituitary gland.
3. Subthalamus – Associated with the basal ganglia for motor control.
4. Epithalamus – Involved in circadian rhythm and sexual reproduction.

Closer to the midline

Further from the midline

Cranial nerve 1 (Olfactory) and Cranial nerve 2 (Optic)

The Olfactory nerve and its function is Smell

The Optic nerve and its function is Purely sensory; transmits visual information from the eye to the brain

The Oculomotor nerve and its a Motor nerve that innervates muscles to move the eyeball

The Trochlear nerve and its function is Abduction (outward movement) of the eyeball

The Trigeminal nerve and its a Mixed nerve with 3 branches:
- Ophthalmic (TOP) branch – Blinking
- Maxillary (MIDDLE) branch – Sensory
- Mandibular (BOTTOM) branch – Chewing and swallowing

The Abducens nerve and its function is to Innervates muscles that help with eyeball movement

The Facial nerve and its a Motor and sensory nerve responsible for facial expressions and eating (Maccas!).
It has 5 branches:
- Temporal
- Zygomatic
- Buccal
- Marginal Mandibular
- Cervical

The Vestibulocochlear nerve and it is a Sensory nerve responsible for balance and hearing.
It has two branches:
- Vestibular Branch: Sense of balance and gravity response
- Cochlear Branch: Sense of hearing

The Glossopharyngeal nerve and its a Mixed nerve that:
- Contributes to muscles around the pharynx
- Takes in taste information from the posterior 1/3 of the tongue
- Controls the release of saliva

The Vagus nerve and its function is to Assists with swallowing, gag reflex, and taste

The Accessory nerve and it Has two types:
- Cranial Accessory Nerve – Works with CN 10
- Spinal Accessory Nerve – Moves and shrugs the shoulders

The Hypoglossal nerve and its a Motor nerve that innervates muscles that move the tongue

They are cranial nerves 3 and 4

They are cranial nerves 5, 6, 7 and 8

They are 9, 10, 11 and 12

Cell bodies

Processes sensory (ascending) information

Processes autonomic information:
- Sympathetic: T1–L2
- Parasympathetic: S2–S4

Processes motor (descending) information

It contains sensory axons that bring information into the spinal cord

It contains motor axons that take information from the spinal cord to the body/limb segments

It contains sensory axons and cell bodies

It is a mixed nerve, containing both motor and sensory axons

It supplies sensory and motor axons to deep back muscles, zygapophyseal (Z) joints, and overlying back skin

It supplies sensory and motor axons to all plexi, the trunk, and overlying skin

The ACA supplies the medial cortical surfaces of the frontal and parietal lobes, including the lower limb and prefrontal cortex

- Paralysis of the contralateral lower limb
- Sensory loss in the contralateral lower limb
- Mental impairments (e.g., distraction, indecisiveness)
- Urinary incontinence

The MCA supplies the entire lateral cortical surfaces of the frontal, parietal, and temporal lobes, including:
- Head, upper limb, and thorax
- Hearing & language areas (Wernicke’s, Broca’s, and angular gyrus)
- Frontal cortex
- Basal ganglia
- Internal capsule (posterior part)

• Contralateral motor and sensory loss (especially in the upper limb and face)
• Aphasia (if in the dominant hemisphere)
• Hemineglect (if in the non-dominant hemisphere)
• Contralateral homonymous hemianopia

The PCA supplies the occipital lobe and inferior cortical surfaces of the temporal & parietal lobes.
- Mainly visual areas and subthalamic nuclei

Contralateral homonymous hemianopia – injury to one side of the brain affects the contralateral visual field in both eyes

(Knee, hip, neck, head), (arm, elbow, forearm, hand, finger, thumb), (eye, nose, face, lips, teeth, gums and tongue)

Ischemic stroke and haemorrhagic stroke

A stroke caused by a blockage in a blood vessel, preventing blood flow to the brain

Blood clots (thrombus or embolism)

A stroke caused by a ruptured blood vessel, leading to bleeding in the brain

High blood pressure (hypertension)

Haemorrhagic strokes, due to rapid brain damage from bleeding

The process of becoming less sensitive to a stimulus after repeated exposure

A long-lasting increase in synaptic efficacy following high-frequency stimulation of afferent fibers

The phenomenon by which synapses become less efficient in transmitting neuronal signals

LTP is the conversion of a silent synapse to an active synapse, leading to strengthened neural pathways and potential for new learning, especially after a stroke

LTD is the conversion of an active synapse into a silent synapse, resulting in weakened pathways. This process helps refine movement by decreasing unnecessary motor activity

Recovery occurs when local edema reduces, allowing normal action potential conduction to resume

When presynaptic neurons are destroyed, postsynaptic neurons develop more receptors to compensate for the lost neurotransmitter supply

When some branches of a presynaptic axon are destroyed, the remaining branches receive excess neurotransmitters, leading to an increased release and stronger signaling

Normally unused synapses in the nervous system can become active when injury to other pathways triggers their activation