Central, peirpheral and autonomic nervous systems

What are the 4 major regions of the adult brain

Cerebrum

Diencephalon

Brain stem

Cerebellum

What is the cerebrum

Responsible for conscious thought, memory, sensation, language and voluntary movement

Contains the lobes

What is the diencephalon

Includes thalamus, hypothalamus and epithalamus

Involved in sensory relay and homeostasis

What is the brain stem

Consists of the midbrain, pons and medulla oblongata

Control vital functions and connects the brain to the spinal cord

What is the cerebellum

Coordinates movement, balance, posture and motor learning

What are the ventricles of the brain

Ventricles are the empty spaces within the brain and contain CSF

There are lateral ventricles (1st and 2nd) and then third and fourth

What is the lateral ventricles

Located within the left and right cerebral hemisphere

One ventricle in each hemisphere, largest ventricle

What is the 3rd ventricle

Located in diencephalon, between 2 halves of thalamus

Connected to the lateral ventricles by inter ventricular foramina

What is the 4th ventricle

Located between brainstem and cerebellum

Connected the 3rd ventricle by cerebral

Continues into central canal of the spinal cords

What are the functional areas of the cerebral cortex

Gyri

Sulcus

What is the gyri

Raised elevations

What is the sulcus

Shallow grooves

What are the major lobes of the cerebral cortex

Frontal

Parietal

Temporal

Occipital

Insula

What is the frontal lobe

Voluntary movement, planning, personality, speech production

What is the parietal lobe

Sensory perception (touch, pressure, pain, temperature and skin sensation)

What is the temporal lobe

Hearing, memory, smell and language comprehension

What is the occipital lobe

Responsible for vision

What is the Insula lobe

Responsible for taste, visceral sensation, emotions and balance

What are the fissures of the cerebral cortex

Longitudinal fissure

Central sulcus

Lateral cercus

Parieto occipital sulcus

What is the longitudinal fissure

Separates left and right cerebral hemisphere

What is the central sulcus

Separates frontal and parietal lobes

What is the lateral sulcus

Separates temporal lobe from frontal and parietal lobe

What is the Parieto occipital sulcus

Separates parietal and occipital lobes

What is the lateralisation of cortical function

The tendency for certain functions to be specialised in one cerebral hemisphere more than the other

They communicate through the corpus callosum

What is the left hemisphere responsible for

Language, speech, reading, writing, mathematics, logical thinking

What is the right hemisphere responsible for

Spatial awareness, creativity, imagination, facial recognition, music and emotional interpretation

What is the location of the diencephalon

Found deep within the brain, between cerebrum and brain stem, surrounding the 3rd ventricle

What are the subdivisions of the diencephalon

Thalamus

Hypothalamus

Epithalamus

What is the thalamus

Primary relay station for sensory inputs to the cerebral cortex

What is the hypothalamus

Maintains homeostasis by regulating temperature, hunger, thirst and emotions

What is the epithalamus

Contains pineal gland, secretes melatonin and help regulate sleep and wake rhythms

What is the brain stem

Connects the cerebrum to the spinal cord

What are the 3 major regions of the brain stem

Midbrain

Pons

Medulla oblongata

What is the midbrain

Contains visual and auditory reflex centres

Controls eye movements and motor control pathways

What is the pons

Relays information between the cerebrum and cerebellum and helps regulate breathing

What is the medulla oblongata

Controls vital autonomic centres that control HR, BP, breathing, swallowing, coughing and vomiting

What is the structure of the cerebellum

Located at the back of the brain, inferior to occipital lobes and posterior to the brain

Consists of two hemispheres connected by vermis and has highly folded outer cortex

What is the function of the cerebellum

Maintains balance and equilibrium

Coordinated voluntary movements

Regulates posture and muscle tone

Ensures movement are smooth, precise and coordinated

Involved in motor learning and memory

what are the meninges

3 connective tissue membranes that surround the brain and spinal cord

What are the 3 connective tissue membranes (meninges)

Dura matter: outer layer

Arachnoid matter: middle layer

Pia material: inner layer

What is the CSF

Cerebral spinal fluid

Clear fluid found in ventricles, central canal and subarachnoid space

What is the function of of the CSF

Cushions the brain and spinal cord from injury

Acts as a shock absorber

Provided buoyancy, reducing weight of the brain

Transports nutrient and removes waste products

What is the blood brain barrier

Formed by astrocytes and capillary tight junctions

What are the functions of the blood brain barrier

Prevents toxins and pathogens from entering the brain

Maintains stable chemical environment for neurons

Allows essential substance (oxygen and glucose) to enter

How is CSF formed

Produced by choroid plexus in the ventricles

The choroid plexus filters blood plasma to form CSF

What is the circulatory pathway of CSF

What is the gross structure of the spinal cord

2 cm wide

Grey matter on inside and white matter on outside

Contains the conus medullaris and the cauda equina

What is the conus medullaris

Where the spinal cord terminates before the end of the veterbral column

What is the cauda equina

Drooping of the lumbar and sacral nerve roots below conus medullaris

What is the filum terminale

An extension of the Pia mater

Anchors spinal cord to the coccyx

What is the microscopic structure of the spinal cord

Central canal

Posterior median sulcus

Anterior median fissures

Posterior (dorsal) horns

Anterior (ventral) horns

What is the central canal

Lined by ependymal cells and contains CSF

What is the peripheral nervous system

Consists of all nervous tissues outside hte brain and spinal cord

Contents CNS to the rest of the body, carries sensory information to and away from the CNS

What are the components of the peripheral nervous systems

Cranial nerves

Spinal nerve

Ganglia

Sensory receptors

What are the sensory receptors

Mechanoreceptors

Thermoreceptors

Photoreceptors

Chemoreceptors

Nocirecptors

What are Mechanoreceptors

Detect touch, pressure, vibration, stretch and hearing

Found in skin, muscles, tendons, joins and inner ear

What are Thermoreceptors

Respond to temperature change

Found in the skin and hypothalamus

What are photoreceptors

Respond to changes in light

Found in the retina of the eye

What are chemoreceptors

Respond to chemical in solution

Found in tastebuds, blood vessels and brain

What are nocireceptors

Respond to damaging stimuli and pain

Found everywhere

What is sensory perception

Conscious awareness and interpretation of sensory information by the cerebral cortex

Allows us to recognise and understand stimuli such as touch, temperature, pain, sound and light

What is sensory adaptation

A decrease in receptor sensibility and awareness of a constant, unchanging stimulus over time

As a result, the frequency of nerve impulses decrease

What is the structure of a nerve

Endoneurium (in) - surrounds individual axons

Perineurium (mid) - surrounds a bundle of axons

Epineurium (out) - surrounds entire nerve and binds fascicles together

What are the 12 cranial nerves

Olfactory - smell

Optic - vision

Oculomotor - 4 out of 6 eye muscles

Trochlear - pulley muscle of eye

Trigeminal - sensory fibres to face and jaw

Abducens - turns eyeball laterally

Facial - facial expression muscle

Vestibulocochlear - hearing and balance

Glossopharyngeal - swallowing

Vagus - parasympathetic control

Accessory - moves head and neck

Hypoglossol - tongue muscles and movement

What are the major plexuses

Central (C1-C4)

Brachial (C5-T1)

Lumbar (T12-L4)

Sacral (L4-S4)

Central plexus

Head, neck, shoulders and diaphragm

Phrenic nerve: controls diaphragm for breathing

Brachial plexus

Chest shoulders and arms

Axillary nerve (shoulder)

Radial nerve (posterior arm and forearm muscle)

Median (forearm and hand)

Ulnar (hand and medial forearm)

Lumbar plexus

Back, abdomen, growing and legs

Femoral nerve thigh flexion and knee extension

Sacral plexus

Pelvis, buttocks, genitals and legs

Sciatic nerve

What are the components of a reflex arc

Receptor - detects stimulus

Sensory neuron - carries signal

Integration centre - processes information in the CNS

Motor neuron - efferent pathway away from CNS

Effector - muscle or gland response, produces response

Difference between somatic and autonomic response

Autonomic - effector is the smooth or cardiac muscles internal organ function e.g. pupillary reflex

Somatic - effector is skeletal muscles controls body movement e.g. knee jerk reflex

What is the difference between stretch and withdrawal reflexes

Stretch - triggered when a muscle is stretched requires no interneuron. No brain input

Withdrawal reflex - triggered by a painful stimulus, protective reflex limb withdrawn. Requires interneuron. Involves brain input

what is a cholinergic receptors

responds and binds to acetylcholine

What are adrenergic receptors

Binds adrenaline and noradrenaline

Includes alpha and beta receptors