Chapter 11 Flashcards
CNS
Brain and Spinal cord (contains brainstem)
PNS
Cranial and spinal nerves
How many neurons does the brain contain?
86 billion
How many pairs of cranial nerves?
12
How many pairs of spinal nerves?
31
Somatic nervous system movement
Body under voluntary control (moving arms and legs)
Autonomic nervous system movement
Bodies automatic control (heart, glands, digestion)
Sympathetic
fight (or flight)
Parasympathetic
fright (rest and digest)
Neurons
the building blocks of the nervous system
Dendrite
Take in information from other neurons
Cell body
Central part of neuron
Axon
The main connection from neuron to neuron (carries electrical impulses)
Myelin Sheath
Insulation surrounding the axons that promotes the impulse and makes the signal travel faster/efficiently
What cells are responsible for creating the myelin sheath in the CNS
Oligodendrocytes
What cells are responsible for creating the myelin sheath in the CNS
Schwann Cells
What is the node of ranvier?
A periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses. (the signal can travel and jump from one node to another)
Types of synapses
Axo-dendrite, Axo-somatic, Axo-axonic, Dendro-dendritic
Axo-dendrite
Axon to dendrite (Most common)
Axo-somatic
Axon to cell body (less common)
Axo-axonic
Axon to axon (rare and presynaptic inhibition)
Dendro-dendritic
Dendrite to dendrite (rare, local inhibitory feedback circuits)
What are the synapses used for inhibiting
Axo-axonic & Dendro-dendritic
Damage to neurons in the CNS
Functional regeneration of the axon is not possible if the cell body lives (brain surgery)
Damage to neurons in the PNS
Functional regeneration of the axon is possible if the cell body survives (hip surgery)
Brain meninges
The membranes covering the brain
What are the 3 layers of meninges
Dura mater (tough membrane), arachnoid mater (spidery mother), pia mater (faithful mother)
Spinal meninges
The membranes coving the spine
Occipital lobe
Vision
Parietal lobe
Sensation- Touch, taste, temperature
Frontal lobe
Executive function/motor development- last to develop (Plan and organization)
Temporal lobe
Hearing, memory, language (houses the primary auditory cortex)
Cerebellum
Balance, coordination
Brainstem
Basic functions- Breathing, heart rate, blood pressure
Coronal/Frontal
Cut into superior and inferior
Saggital
Cut into right and left
Horizontal/Transverse
Cut into anterior and posterior
How much oxygen does the brain receive?
25% used by the body
How many pounds is the brain?
3 (but depends)
Divisions of the brain
Prosencephalon, Mesencephalon, Rhombencephalon, cortex
Prosencephalon
Forebrain (contains the cerebral hemispheres)
Mesencephalon
Midbrain
Rhombencephalon
Hindbrain (Pons, cerebellum, medula)
What makes up the brainstem
Midbrain and hindbrain (pons and medula)
What is the cortex?
The surface of the brain (outermost layer)
Gray matter
(exterior) Cell bodies of neurons
White matter
(interior) Axons/myelin sheath
How many cerebral hemispheres are there?
R and L
What are the hemispheres separated by?
Longitudinal fissure
Gyri
Bumps on the cortex
Sulci
Grooves in the cortex
Arcuate fasciculus
Brocas
Speech production
Wenickes
Understanding
Primary motor cortex
Primary somatosensory cortex
Primary auditory cortex
What happens if there is brain damage to Brocas area?
struggle with producing speech
What does lateralization of brain functioning mean?
It means that the right brain controls the left body and vice versa
Precentral Gyrus
Part of brains frontal lobe that is a representation that depends upon the complexity of movement = tells us which part of the brain is responsible for a certain movement
What does the lower 1/3 of the precentral gyrus represent?
Lower parts of face and throat
What does the part on the longitudinal fissure represent?
Legs
Diencephalon
Thalamus, Hypothalamus, Basal Ganglia
Thalamus
Sensory & motor integration (directs signals to proper place in cortex)
Hypothalamus
Body temp & Emotion & Hunger & Thirst (regulator and hormones)
Basal Ganglia
Motor movement
Mesencephalon
Midbrain, Pons, Cerebellum, Medulla
Midbrain
Vision, audition, eye movement, body movement
Pons
Heart rate, breathing, blood pressure
Cerebellum
Movement, balance, posture
Medulla
Breathing, HR, reflexes
Brainstem consists of…
Midbrain, pons, medulla
What originates in the BS?
cranial nerves
How many hemispheres are in the BS?
2 (coordinate and integrate movement)
Ataxia
A neurological sign that indicates a loss of muscle coordination, which can cause clumsy movements and affect balance, speech, and eye movements
What is the ventricular system?
A network of fluid-filled cavities in the brain that produce and circulate cerebrospinal fluid
What does the choroid plexus do?
Creates & Produces the CSF - cerebral spinal fluid. (clear fluid that has nutrients, clears waste, cushions/protects)
How many ventricles are there?
4
What is the purpose of the ventricular system?
protection for brain and spinal cord, nutrition, waste removal, pressure regulation
How does blood supply get to the brain?
Through the anterior and posterior arteries
Anterior Artery
Internal Carotid artery
Posterior
Basilar Artery
What is the circle of willis?
a ring-shaped network of arteries located at the base of the brain that connects the major blood vessels supplying the brain, essentially acting as a “fail-safe” system by allowing blood flow to reach different parts of the brain even if one of the main arteries becomes blocked
Arteries vs Veins
Arteries are taking blood away from heart while veins are taking blood to the hear
Nerve I
Olfactory
Nerve II
Optic
Nerve III
Oculomotor
Nerve IV
Trochlear
Nerve V
Trigeminal
Nerve VI
Abducens
Nerve VII
Facial
Nerve VIII
Auditory/Vestibulocochlear
Nerve IX
Glossopharyngeal
Nere X
Vagus
Nerve XI
Accessory
Nerve XII
Hypoglossal
