Chapter 2 Flashcards
Spinal cord is located within the
Vertebral canal
CSF is located where?
Subarachnoid space of the brain and spinal cord
Central canal (Spine)
Cavities in the brain (Ventricles)
Three layers of meninges
- Dura
- Arachnoid
- Pia mater
Outer most layer; tough dense connective tissue
Dura mater
Middle layer, resembles spider web
Arachnoid mater
Inner layer; thin and delicate, adheres to surface of spinal cord and brain, contains blood vessels
Pia mater
What spinal cord space has fat which helps protect/cushion, between the vertebrae and dura mater
Epidural space
Spinal cord extends from the medulla oblongata to:
The second lumbar vertebrae
Two grooves that divide the spinal cord into two hemispheres
- Anterior median fissure
2. Posterior median sulcus
Two bundles of axons that connect each spinal nerve to a segment of the cord
Root
Root contains sensory axons which conduct nerve impulses from sensory receptors (AFFERENT)
Posterior (dorsal) root
Root contains axons of motor neurons (autonomic and somatic) which conduct nerve impulses from the CNS to the effectors (EFFERENT)
Anterior (ventral) root
Matter that has tracts that serve as highways for nerve impulses
White matter
Matter of the spinal cord receives and integrates incoming and outgoing information and is a site for integration of reflexes
Gray matter
Contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia
Gray Matter
Horn contains cell bodies and axons of interneurons as well as axons of incoming sensory neurons
Posterior (dorsal) horn
Horns contain cell bodies of somatic motor neurons that provide impulses for contraction of muscles
Anterior (ventral) horn
Lateral gray horn is only present in what spinal segments?
Thoracic and upper lumber
What motor neurons are located on the lateral gray horn and regulates cardiac muscle, smooth muscles, and glands
Autonomic
Consists of myelinated axons and is organized into columns
White matter
Bundles of axons in the CNS are also called:
Tracts
Axons that conduct nerve impulses toward the brain (spinothalamic tract)
Sensory tract (ascending)
Axons that conduct nerve impulses away from the brain (corticospinal tract)
Motor tract (descending)
Fast, involuntary sequences of actions in response to stimuli
Reflexes
Learned sequence, such as driving a car, is what kind of reflex?
Complex
Withdrawal reflexes are also called:
Simple reflexes
Patellar reflex tests what type of reflex?
Spinal reflex (simple)
Gag reflex tests what kind of reflex?
Cranial reflex (simple)
Connects the CNS to the sensory receptors and muscles of the body
Spinal nerves
How many pairs of spinal nerves are there for each region?
8 - Cervical 12 - Thoracic 5 - Lumbar 5 - Sacral 1 - Coccyx
Sensory information goes through which root?
Dorsal Root
Motor Information goes through which root?
Anterior
Axons are wrapped is what layer?
Endoneurium
Groups of axons arranged in bundles are called?
Fascicles
Fascicles are wrapped in what?
Perineurium
What is the superficial covering over the entire nerve?
Epineurium
Spinal nerve branches join axons from adjacent nerves to form networks
Plexuses
What plexus supplies posterior head, neck, upper part of the shoulder and the diaphragm
Cervical plexus
Plexus that supplies the upper limbs, some neck and shoulder muscles
Brachial plexus
Plexus that supplies the abdominal wall, external genitals and parts of the lower limbs
Lumbar plexus
Plexus that supplies the buttocks, perineum and most of the lower limbs
Sacral plexus
What nerve innervates the diaphragm to contract?
Phrenic (C3, C4, C5)
What spinal nerves are called intercostal nerves?
T2-T11
Supply muscles of abdomen and between the ribs, skin of chest and back
What percentage of oxygen does the brain need?
20%
Brain neurons are permanently damaged from lack of oxygen after how many minutes?
4 minutes
Circulatory anastomosis that supplies blood to brain and surrounding structures; stems from the two internal carotid arteries
Circle of Willis
Protects the brain cells from harmful substances and pathogens
Blood brain barrier
Blood brain barrier can be broken down by what?
- Trauma
- Certain toxins
- Inflammation
Tightly sealed blood capillaries and astrocytes make up what?
Blood Brain Barrier
What can pass the blood brain barrier?
Lipid soluble materials like O2, CO2, alcohol, anesthesia
What carries oxygen and glucose from the blood to the brain?
CSF
CSF is produced in what plexus?
Choroid plexus located in the brain
CSF is reabsorbed into the blood through what?
Arachnoid villi
Continuous with spinal cord contains the medulla oblongata, pons, and midbrain
Brain stem
Superior to the brain stem; contains thalamus, hypothalamus, and pineal gland
Diencephalon
“Little brain”, posterior and inferior
Functions the balance and equilibrium and coordination
Cerebellum
Largest, most superior part of the brain
Cerebrum
Inferior part of the brain stem, a continuation of the spine
Medulla Oblongata
Part of the brain where gray matter contains nuclei where neurons form synapses with one another.
- Cardiovascular center regulates the rate and force of the heart and the diameter of the vessels
- Rhythmicity area regulates breathing
Medulla Oblongata
Nuclei associated with touch, pressure, vibration and proprioception lie in the posterior part of what part of the brain?
Medulla Oblongata
Nuclei associated with cranial nerves VIII-XII are found where?
Medulla Oblongata
“Bridge” for the medulla and midbrain to connect
Pons
Connects the left and right sides of brain
Pons
Contains nuclei that:
a) Motor relay from cerebrum to cerebellum
b) Helps control breathing
c) Contains nuclei associated with cranial nerves V
Pons
Connects the pons to the diencephalon
Contains nuclei associated with cranial nerves III and IV
Midbrain
Large tracts that contain axons of motor neurons from cerebrum to the rest of the brainstem and spinal cord
Cerebral peduncles (Midbrain)
Loss of these neurons related to Parkinson disease
Substantia nigra (Midbrain)
Nuclei that coordinates muscular movement
Red nuclei (Midbrain)
Colliculi involved in scanning eye movement and responses to visual stimuli
Superior colliculi (Midbrain)
Colliculi that responds to auditory input and startle reflex
Inferior colliculi (Midbrain)
Three major regions of the Diencephalon
1) Thalamus
2) Hypothalamus
3) Pineal Gland (part of the endocrine system)
Major sensory relay center, contributes to motor functions, plays role in consciousness
Thalamus (part of the Diencephalon)
Control of pituitary and hormone production
Control and integration of the ANS
Regulation of emotional and behavior patterns
Regulation of eating and drinking
Control of body temperature
Regulation of circadian rhythms, sleep and awakening patterns
Hypothalamus (part of the Diencephalon)
Secretes melatonin which promotes sleepiness and contributes to setting the body’s biological clock
Pineal Gland (part of the epithalamus region)
Location: Posterior to medulla and pons, inferior to cerebrum and attached to brain stem by cerebellar peduncles
Cerebellum
Structure:
- Two Cerebellar Hemispheres
- Cerebellar Cortex (Gray Matter)
- Tree like appearance
Cerebellum
Functions:
- Receives wide range of sensory input from muscles, joints, tendons, eyes, equilibrium receptors in ears and eyes
- Compares actual movements with intended ones
- Helps to smooth and coordinate skeletal muscle contractions
- Helps execute skilled motor activities
- Regulates posture and balance essential for skilled motor activities
Cerebellum
Structure of the Cerebrum
- Longitudinal Fissure
- Corpus Callosum
- Cerebrum Layers
What divides the Cerebrum into right and left cerebral hemispheres?
Longitudinal Fissure
Broad band of white matter containing axons that connects the right and left cerebrum spheres internally
Corpus Callosum
What assists in motor control, emotions, behavior, executive function (cognitive process)?
Basal Ganglia (located in the Cerebrum layers)
Superficial grey matter of the Cerebrum
Cortex
Folds of the cerebrum
Gyri (gyrus)
Shallow grooves of the Cerebrum
Sulci (Sulcus)
How many lobes does each hemisphere of the cerebrum have?
Four
- Frontal
- Parietal
- Temporal
- Occipital
What separates the frontal and parietal lobes of the cerebrum?
Central Sulcus
Functions:
- Sensory areas receive, input, leading to perception
- Motor areas initiate movement
- Association areas deal with integrative functions like memory, emotions, reasoning, will, judgement, personality, intelligence
Cerebral Cortex
Primary somatosensory area: Postcentral gyrus
Input sensory: Touch, proprioception, pain, itching, tickle, temperature
Cerebral cortex
Storage of memories of past sensory experiences
Somatosensory of the cerebral cortex
Area in the cerebral cortex generates nerve impulses causing a specific group of muscles to contract in a specific sequence
Promotor area of the cerebral cortex
Ring of structures on inner border of cerebrum and floor of diencephalon, called the “emotional brain.”
Plays a primary role in pain, pleasure, anger, affection and behavior
Limbic System
What controls the nervous system’s involuntary behavior related to survival?
Limbic system
Which hemisphere of the brain controls spoken and written language, numerical and scientific skills, and reasoning?
Left Hemisphere
Which hemisphere of the brain is more involved with spatial and pattern recognition, emotional content of language, generating images of sight, sound, taste, and smell?
Right Hemisphere
Memory is associated in which areas of the brain?
- Cerebrum lobes
- Limbic System
- Diencephalon
“Skill memory” is involved in which parts of the brain?
Cerebellum and Basal Ganglia
What are the 3 Deep Gray Nuclei (Basal Ganglia) called?
1) Globus Pallidus
2) Putamen
3) Caudate Nucleus