Lecture 6 - CNS brain Flashcards
Gyri and Sulci _____ the surface area of the brain
Increase
2 main gyri
Pre-central gyrus
Post-central gyrus
Pre-central gyrus
Immediately anterior to the central sulcus
Motor cortex
The tracts that leave here descend (pyramidal tracts or corticospinal tracts)
Post-central gyrus
Immediately posterior to the central gyrus
Sensory cortex
Spinothalamic tracts and spinocerebellar tracts
Major fissures of the brain (4)
Longitudinal cerebral fissure
Transverse fissure
Lateral sulci/fissure
Central sulcus
Separates partially two cerebral hemispheres
Deep sulcus
Occupied by the falx cerebri which is a double-folded dura mater membrane
Longitudinal cerebral fissure
Lies between the occipital lobe and the cerebellum
Dural membrane, tentorium cerebelli, lies here
Transverse fissure
Dural extension that separates the 2 cerebellar hemispheres is called the ____ ____
Falx cerebelli
In embryo, a neural tube is formed from which 3 cavities or sections will develop?
- Prosencephalon (forebrain) = telencephalon, diencephalon
- Mesencephalon (midbrain)
- Rhombencephalon (Hindbrain) = metencephalon, myelencephalon
Cerebrum (4)
- Part of prosencephalon (telencephalon)
- Divided in the sagittal plane into two halves: the right and the left hemisphere
- Each hemisphere controls activities of the opposite side of the body
- Hemispheres are mirror images of one another in many ways but there are functional distinctions
In most people, development and use of language are located in the ____ hemisphere
Left
Areas that govern three-dimensional visualization and artistic creations are located in the ___ hemisphere
Right
4 lobes of the hemisphere
Frontal
Temporal
Parietal
Occipital
A 5th lobe lies deep to the cortex and medial to the temporal lobe
Insula
Grey matter: location and content
Cerebral cortex (conscious mind) Unmyelinated (axons)
White matter : content
Myelinated axons
The internal white matter contains myelinated fibers (tracts) extending in 3 major directions
- Commissural tracts
- Association tracts
- Projection tracts
Commissural tracts
Link the 2 sides (left and right)
Association tracts
Connects 2 different parts of the same region
Projection tracts
Connecting 2 different regions
3 structures of the basal ganglia
Caudate nucleus
Amygdala
Lentiform nucleus (globus pallidus, putamen)
Basal ganglia (3)
- Relay station for motor impulses
- Control large unconscious (autonomic) movements of skeletal muscles
- Control initiation, termination and intensity
2 prominent structures of the diencephalon
Thalamus
Hypothalamus
2 endocrine glands of the diencephalon
Pineal gland
Pituitary gland
Thalamus (6)
Two masses of grey matter
Connected by intermediate mass
Surrounds 3rd ventricle
Principle relay station for sensory (afferent) impulses travelling to cerebral cortex
Also relay for involuntary motor (efferent) impulses travelling outward
Early conscious recognition of sensations related to survival
Forms part of the roof of the 3rd ventricle
Secretes at least one hormone, melatonin, but its function remains in doubt
Pineal gland
Hypothalamus (4)
Lies below thalamus
Partially housed in the sella turcica (well protected)
Controls many involuntary body activities
Control center of the ANS
6 main functions of the hypothalamus
- control of the ANS
- production of hormones (oxytocin, ADH)
- regulation of emotional & behavioral patterns
- regulation of eating and drinking
- control of body/blood temperature
- regulation of awakening and sleep patterns
Projections from the hypothalamus include
Mammillary bodies Pituitary gland (hypophysis)
Mammillary bodies (2)
Lie at the base of the brain & hypothalamus-2 round masses
Associated with smell
Pituitary gland (3)
Extends from mammillary bodies
Tuber cinerium
Pituitary stalk
Midbrain/mesencephalon
Between diencephalon and pons
Cerebral peduncles
Corpora quadrigeminna (sup & inf colliculi)
Superior colliculi associates with
Sight
Inferior colliculi associates with
Hearing
Rhombencephalon (hinbrain) is divided in two parts
- Metencephalon
- Myelencephalon
Metencephalon (content)
Pons and cerebellum
Myelencephalon (content)
Medulla oblongata
Pons - “bridge”
Consists of white matter and scattered masses of nuclei (grey matter)
Connection between the spinal cord and brain as well as parts of the brain with each other
Associated with CN V, VI, VII, VIII
Cerebellum (content)
- Two hemispheres
- Cerebellar cortex
- Arbor vitae
Cerebellum (characteristics)
“Automatic pilot” for motor responses
Cerebellar peduncles
MAIN REGION FOR POSTURE AND BALANCE
Carry sensory information from sensory organs in muscles, joints and the inner ear
Enable brain to determine status of voluntary motor activities, equilibrium and balance
Coordinate and provide precision to skeletal muscle contraction initiated by cerebrum
Cerebellar peduncles
Inferior to pons, extends down until s.c
Outside- white matter, inside - grey matter
White matter consists of all ascending (sensory) and descending (motor) nerve fibers extending between brain and spinal cord
Pyramids
Gray matter - reflex centers play a role in visceral reflexes, consciousness and arousal
Medulla oblongata
Medulla oblongata is associated with which nerves?
CN VIII, IX, X, XI, XII
3 reflex centers
Cardiac center
Vasomotor center
Respiratory center
3 things that protect the brain
Skull, CSF, Meninges
3 layers of meninges
Pia mater
Arachnoid layer
Dura mater
Similar to spider web
Arachnoid layer
Tough mother
Dura mater
Gentle mother
Pia mater
Cerebrospinal fluid (characteristics)
- Produced within ventricles
- Foramen of Monroe (interventricular foramen)
- Cerebral aqueduct
CSF is formed by _____ ____
Filtration of blood plasma through dense networks of capillaries called choroid plexus (CP)
Capillary wall of the CP and supporting neuroglia form part of ______ ____ _____
Blood brain barrier (BBB)
