Kap 3. Structure of the Nervous system Flashcards
Cerebrospinal fluid (CFS)
an ultrafiltrate of plasma contained within the ventricles of the brain and the subarachnoid spaces of the cranium and spine.
It performs vital functions, including providing nourishment, waste removal, and protection to the brain.
CFS is made by special tissue with a rich blood supply called choroid plexus, which extends into all four of the ventricles
What is the Cortex?
the outer layer of the brain
“bark fra et tree”
The neuraxis is ….
the axis of the central nervous system. It denotes the direction in which the central nervous system lies.
- from bottom of SC to front of brain
Anterior
front of face
- nese/snute
Posterior
back
- tail
- feet
Rostral
front of the brain
Dorsal
the top and the back of the brain
(Dorsum = back)
Caudal
back
- tail
- feet
Ventral
faces to the ground
(ventrum = belly)
Superior
in the brain …. means above
Inferior
in the brain… means below
Lateral
toward the side
Medial
toward the middle
Ipsilateral
refers to stuctures on the same side of the body
Contralateral
refers to structures on opposite sides of the body
Coronal plane
cutting to create a cross section. (Often called frontal section when referring to the brain)
- like slicing a loaf of bread
Horizontal plane
a parallel cut to the ground.
- If you do a parallel cut to the middle of the brain, it would result in cutting off the upper half of the brain
“transverse plane” (cross section
Vannrett
Vinkelrett
Perpendicular
Sagittal plane / section
Cutting perpendicular (vinkelrett) to the ground and parallel to the neuroaxis
Midsagittal plane
divides the brain into two summetrical right and left halves
Meniges
the protective sheaths aroun the brain and spinal cord (Greek word for “membrane”)
Dura Mater
the outer layer of the “meniges”
It is durable, thick, tough, and flexible but unstreachable
Arachnoid membrane
the middle layer of the “meniges”
It is soft, spongy and lies beneath the dura mater
(Greek word for “spider” “track”)
Pia mater
the inner layer of the “meniges”
It is closely attached to the brain and spinal cord, and following every surface convolution.
In this layer, the smaller surface blood vessels of the brain and spinal cord are contained here.
Subarachnoid space
a gap between the pia mater and arachnoid membrane. This space is filled with cerebrospinal fluid (CSF)
Ventricles
The ventricles system of the brain consists of a series of hollow, interconnected chambers called …., which are filled with CSF
“little bellies”
Massa intermedia
a bridge of neural tissue, crosses through the middle of the third ventricle and makes a convenient landmark
Cerebral aqeduct
a long tube that connects the third ventricle to the fourth ventricle
Lateral ventricles
the two largest chambers
Arachnoid granulations
reabsore the CFS into the blood supply after flowing around the CNS in the subarachnoid space.
Det er avgjørende for å forhindre opphopning av cerebrospinalvæske i hjernen, som kan føre til tilstander som hydrocephalus, en alvorlig tilstand hvor væskeopphopning kan forårsake økt intrakranielt trykk.
Obstructiven hydrocephalus
a condition that oxures if the walls of the ventricles then expand and produce
“Vannhode”
The Forebrain is split into two subdivisions. Hva heter de?
Telencephalon (Cerebral cortex, basal ganglia, Limbic system) - Utsiden and Diencephlon (Thalamus, hypothalamus) - innsiden
The cerebral hemispheres
is two symmetrical hemispheres, that are made up of the cerebral cortex, the limbic system (subcortical regions), and the basal ganglia (subcortical regions)
Cerebral cortex
surrounds the cerebral hempishere (bark of a tree)
In humans it is convoluted –> Sulci (small groves), fissures (large grooves), and gyri (bulges between adjacent sulci or fissures)
The surface is 2360 cm^2, med tykkelse på 3 mm.
It consists of gray matter (cell bodies) and white matter (myelin)
Lobes of the Cerebral cortex
Frontal lobe (everything in front of central sulcus)
- planing etc.
Pariental lobe (“the wall”)
-
Temporal lobe (“the temple”)
- Audiotory
Occipital lobe (“in back of head”)
- Visual information
Three areas of the cerebral cortex receive information from the sensory organs. What are they called?
The primary visual cortex
- receives visual information
- Occipital lobe/Calcarine fissure)
The primary auditory cortex
- auditory information
- temporal lobe / lateral fissure
The primary somatosensory cortex
- receives information from the body senses
- vertical strip, just caudal to the central sulcus
- Pariental lobe
- taste together with insular cortex
Sensory associsation cortex
Each primary sensory area of the cerbral cortex send information to the adjacent region-Sensory associasation cortex
Primary motor cortex
the region of the cerebral cortex that is most directly involved in the control of movement
“keyboard”
Motor association cortex
” premotor cortex”
- located just rostral to the primary motor cortex (frontal lobe)
- controlls behavior
“piano player”
Hvilke elementer er spesielle for venstre hemisphere?
- good at recognzing several events
- controlling sequences of behavior
- Verbal activites (talking, writing, understanding speech of others, reading)
“Språk”
Hvilke elementer er spesielle for den høyre hemisphere?
- synthesis (analysere)
- draw sketches
- read maps
- contruxt objects
“romlig oppfattelse og kreativitet”
“Spatial maps?”
Corpus Callosum
- a large band of axons that connects corresponding parts of the cerebral cortex of the left and right hemisphere
“bro mellom høyre og venstre hemisphere”
Limbic system
- located around the medial edge of the cerebral hemipshere.
- another form of cerebral cortex
- cingulate gyrus is an important region of the limbic cortex
- it includes hippocampus (learning and memory), amydala (emotions), fornix (axons that connects to the hippocampus with other brain regions like “mammillary bodies”
Basal Ganglia
- collection og nuclei below the cortex in the forebrain
- major parts
1. “caudate nucleus” (tail)
2. “putamen” (Shell)
3. “globus pallidus”. (pale globe)
Involved in control of movement
Thalamus
- the dorsal part of the “diencephalon”, located near the middle of the cerebral hemisphere, medial and caudal to the basal ganglia
- it has two lobes, connected by a bridge called “massa intermedia” (grey matter)
- receive and send information
Hippothalamus
- located beneath the thalamus
- controlls the autonomic nervous system and the endocrine system and organizes behavior related to the survival of the species.
- pituitary gland attached to the base of hyppothamalus via the pititary stalk
- The hypothalamic hormones are secreted by neurpsecretory cells
- also controls “ posterior pituitary gland” and is connected to “anterior pituitary gland”
Midbrain
- ” Mesencephalon “
- sorrounds the cerebral aqueduct and consist of two major parts: “the tectum” and “the tegmentum”
Tectum
- located in the dorsal portion of the mesencephalon
- It stuctures are “superior colliculi” (visual system) and the “inferior colliculli” (audiotory system), which appear as four bumps on the dorsal surface of the brain stem
se figur 3.16 s. 82
Tegmentum
- beneath tectum
- includes the rostal end of the reticular formation, several nuclei controlling eye movements, the “periaqueductal gray matter”, the red nucleus, the “substrantia nigra”, and the ventral tegmental area.
se figur 3.16 s. 82
Reticular formation
large structure consisting of many nuclei (over 90)
receive sensory information by means of various pathways and projects axons to the cerebral cortex, thalamus, and spinal cord.
plays a role in sleep, arousal, attention, muscle tone, movement, and various vital reflexes
Periaqueductal gray matter
- cellbodies
- contains of neural circuits that control sequences of movement that constitute special-typical behaviors, such as fighting and mating.
Substances that are important components of the motor system
The red nucleus and substantia nigra
The hindbrain consists of two major divisions. What are they called?
the Metencephalon (cerebellum and the pons)
and the Myelendephalon (medulla oblongata)
Cerrebellum
“lille hjernen”
Miniversjon av cerebrum med to hemispherer. Covered by the cerebellar cortex and has a set of deep cerebellar nuclei
Receives visual, auditory, vestibular individual muscle movements being directed to the brain, and somatosensory information
Pons
“bridge”
a large bulge in the brain stem
contains som reticular formation (important for sleep,arousal) and nucleus that relays information from cerebral cortex to the cerebellum
medulla oblongata
contains part of the reticular formation, including nucleus that control vital functions
Describe the structure and functions of the spinal cord
is a long, tube-like stucture, wider at the top than the bottom
- The function are to distribute motor fibers to the effector organs of the body (kjertler og muskler) and to collect somatosensory information to be passed on to the brain.
- Sometimes it can function independently of the brain
vertebral column
(Spinal column/spine)
It’s made up of 24 individual vertebrae in the cervical (neck), thoracic (chest), and lumbar (lower back) regions, along with the fused vertebrae that form the sacral and coccygeal sections in the pelvic area. The vertebral column supports the body’s structure, protects the spinal cord, and provides flexibility and movement.
cervical
neck
lumbar
lower back
thoracic
chest
The spinal cord is protected by ….
Vertebral Column (composed by 24 “vertebral column neck, chest, lowerback”)
Spinal roots
cauda equina
Cranial nerves
nerves that have sensory and motor functions of the head and neck region.
(Apart of the PNS)
Vagus nerve
“the 10th” Cranial nerve
regulates the functions of organs in the thoracic and abdominal cavities
Olfactory bulb
A structure in the brain that receive information from the olfactory receptors in the nose (smell).
Efferent axons
means that the direction of the information is outward, away from the CNS.
Autonomic nervous system (ANS)
a part of the PNS that is concerned with the regulation of smooth muscle, cardiac muscle, and glands.
It consists of low separate systems:
- The sympathetic division
- The parasympathetic division
Somatic nervous system
a part of the PNS that receives sensory information from the sensory organs and that controls movements of the skeletal muscles
The parasympathetic division
“rest and relax”
involved with increases in the body`s supply of stored energy.
(There activities include salivation, gastric and intestinal motility, secretion of digestive juices, slow the heart rate=
The sympathetic division
“fight or flight”
involved in activities associated with the expenditure of energy from reserves that are stored in the body.
( speeds the heart rate, increase blood flow to muscles, rise blood sugar levels)
What is an anatomical plane?
Et anatomisk plan er et hypotetisk plan som brukes til å transektere kroppen, for å beskrive plasseringen av strukturer eller bevegelsesretningen.
(Saggital/medital/coronal)
