LAB 2 Flashcards
what is the function of the brain?
- to receive and integrate vast majority of sensory stimuli
- to coordinate appropriate responses
- site of intelligence, emotions, complex thinking, and formation of memories
what are the four major sections of the adult brain?
- cerebrum
- cerebellum
- diencephalon
- brainstem
- brainstem is continuous w/ spinal cord
- diencephalon superior to brainstem
- cerebrum superior to diencephalon
- cerebellum posterior to brain stem
how is the brain protected?
- enclosed by cranial meninges
- protected from physical damage by cranium’s bones
what is the cranial dura mater?
- two layers fused tgt/ except where they enclose the venous sinuses
- also has extensions that separate major brain structures (falx cerebri)
what are the venous sinuses?
vessels that drain blood from the brain to the internal jugular veins
what is the falx cerebri?
an extension of the dura mater that separates the two cerebral hemispheres
- extends into longitudinal cerebral fissure
- attaches to the crista galli of the ethmoid bone
is there an epidural space in the brain?
NO, no epidural space btwn cranial dura mater and the bones of the skull
what are arachnoid granulations?
extensions of arachnoid mater that project into the venous sinuses
- where CSF is reabsorbed into the blood
what are venous sinuses?
endothelial-lined venous channels that drain venous blood from the brain and deliver it back into internal jugular veins
what is the cerebrum?
most superior portion of the brain, highly developed in humans and other primates
- divided into L/R cerebral hemispheres
- contains the lateral ventricles
- can be divided into 4 lobes
what are the cerebral hemispheres?
left and right halves of cerebrum, allows for hemispheric lateralization because of slight asymmetry btwn the hemispheres
what are the 4 lobes that can be found in each cerebral hemisphere?
- frontal lobe
- parietal love
- occipital lobe
- temporal lobe
what is a fissure?
deep grooves found on the surface of the cerebrum
what is a sulcus?
shallow groove found on the surface of the cerebrum
the surface of the cerebrum has what kinds of convolutions in the tissue?
sulci, fissures, gyri
what is a gyrus?
bulge of tissue found on either side of a sulcus on the surface of the cerebrum
what is the central cerebral sulcus?
a prominent sulcus found on the cerebral surface that separates the frontal and parietal lobes of the cerebrum
what is the lateral cerebral sulcus?
shallow groove that separates frontal lobe from occipital lobe
what is the parieto-occipital sulcus?
shallow groove that separates the occipital lobe from the parietal lobe
what is the frontal lobe?
lobe of cerebrum found directly below the frontal bones, contains the primary motor cortex, Broca’s area, prefrontal cortex
what is the parietal lobe?
lobe of cerebrum found directly below parietal bones, contains the primary somatosensory cortex and somatosensory association area
what is the temporal lobe?
lobe of cerebrum found directly below the temporal bones, contains the primary auditory cortex, and facial recognition association area
what is the occipital lobe?
lobe of cerebrum found below the occipital bones, contains the primary visual cortex, and visual association area
what is the precentral gyrus?
the gyrus found anterior to the central cerebral sulcus, contains the primary motor cortex
located on frontal lobe
what is the postcentral gyrus?
the gyrus found posterior to the central cerebral sulcus, contains the primary somatosensory cortex
located on parietal lobe
what is the longitudinal cerebral fissure?
the fissure found on the cerebral surface that separates the right and left hemispheres
what is the transverse fissure?
groove that separates cerebellum from cerebrum
what is the insula?
triangular area of cerebral cortex, lying deep within the lateral cerebral fissure
what is the cerebral white matter?
region of cerebrum directly deep to the grey matter cerebral cortex, contains myelinated axons
what is the cerebral cortex?
grey matter surface of the cerebrum, highly convoluted and contains billions of neurons
what is the cerebellum?
the 2nd largest portion of the brain, found posterior to the brain stem that evaluates how well the movements initiated by cerebral motor areas are actually being carried out
- regulates posture, balance, coordination
- highly convoluted, contains nearly half of the neurons found in the brain
- has superficial grey cortex and deep white matter
what is the arbor vitae?
the cerebellar white matter, its structure resembles a tree
what are the three major structures found in the brainstem?
- midbrain
- pons
- medulla oblongata
what do the midbrain and pons do together?
forms important relay center in the brain, transmitting sensory and motor input from spinal cord to the cerebral hemispheres to be processed
what is the medulla oblongata?
structure found on brainstem found immediately superior to and merges w/ the spinal cord
- regulates heartbeat, blood vessel diameter, breathing rhythm
- controls reflexes for vomiting, swallowing, coughing, etc.
- most of the large motor tracts descending from cerebrum cross over in medulla so skeletal muscle fibers on right side of body controlled by left side of brain
what is the pituitary gland?
endocrine gland located inferior to hypothalamus
what are some hormones secreted by pituitary gland?
- growth hormone
- antidiuretic hormone
- oxytocin
- follicle-stimulating hormone
- thyroid-stimulating hormone
- prolactin
what is the infundibular stalk (infundibulum)?
stalk-like structure that attaches pituitary gland to hypothalamus
what is the midbrain?
- reflex centers for certain visual activities
- relays impulses from receptors for hearing in inner ear to brain
- reflex centre for startle reflex
- involved in release of dopamine
what is the pons?
- bridge, connects areas of brain w/ each other
- has ventral and dorsal region
- ventral: coordinates, maximizes efficiency of voluntary motor output throughout body
- dorsal: has both ascending and descending tracts, acts as bridge btwn brain and SC
what is the spinal cord?
long stalk that is part of CNS that connects brain to the rest of the body
what is the diencephalon?
central region of brain that contains many important structures (hypothalamus, thalamus, pituitary gland) that can only be seen in sagittal section as they are enclosed by cerebrum, cerebellum, and brainstem
- inferior to cerebrum, superior to brainstem, anterior to cerebellum
what is the corpus callosum?
broad band of white matter immediately inferior to cerebrum that contains axons which connect right and left cerebral hemispheres
what is the thalamus?
major sensory relay station that transmits motor info from cerebellym to cerebrum, plays role in maintaining consciousness
- forms lateral walls of diencephalon and encloses the third ventricle
what is the interthalamic adhesion?
region of grey matter that connects the left and right thalamus regions
what is the hypothalamus?
the floor of the diencephalon that acts as major regulator for homeostasis
- monitors osmotic pressure, blood glucose, hormone levels, blood temperature
- connected w/ pituitary gland to produce hormones
- controls ANS, regulates emotions and behaviour patterns