Module 12: Nervous System (a) Flashcards
1
Q
Central Nervous System
-Components
A
- Brain
- Spinal Cord
- CSF — CSF surrounds the brain and spinal cord for protection
- BBB — The blood brain barrier separates and shields the CNS from the body’s periphery
2
Q
CNS
-Major Structures in the Brain
A
- Forebrain (Prosencephalon)
- Telecephalon
- Diencephalon — Interbrain - Midbrain (Mesencephalon) — Connects the pons to the diencephalon and includes the:
- corpora quadrigemina
- tegmentum
- Cerebral peduncles
- Connects the forebrain and the hindbrain
- Tectum is involved w/ voluntary and involuntary motor movements
- Flood of the midbrain contains the RED NUCLEUS and the SUBSTANTIA NIGRA - Hindbrain (Rhombencephalon)
- Cerebellum
- Pons
- Medulla
3
Q
CNS
-Spinal Cord
A
- Long nerve that connects the brain and body
2. Continues from the Medulla oblongata and ends between the first and second lumbar vertebrae
4
Q
PNS
-Components
A
- 12 Cranial Nerves
- 31 spinal nerves
- Somatic
- Afferent (Sensory) — Ascending pathways — Carry Impulses from PNS to CNS
- Efferent (Motor) — Descending pathways — Carry impulses from CNS to target organs like skeletal muscle - Autonomic
- Sympathetic
- Parasympathetic
5
Q
Nervous System
-Cell Types (2)
A
- Neurons
2. Neuroglia — Support the neurons of the CNS
6
Q
Nervous System Cells
-Neurons
A
- Generates and transferes nerve impulses
- Specialized cells and do not need insulin to take up glucose**
3 components
- Cell body - Located in the CNS — Cell bodies in the PNS are called ganglia
- Dendrites - Receptor portion of the neuron — Carries nerve impulses toward cell body
- Axons - carry nerve impulses AWAY from cell body — Typical neuron has 1 axon wrapped in myelin sheath — made of Schwann cells
7
Q
Nervous System Cells
-Neuroglia Cells
A
- 2 Types of Myelinating Cells
- Oligodendroglia — Form Myelin sheath around axons in the brain and spinal cord
- Schwann Cells — Form Myelin sheath around axons in the PNS - Non-Myelinating Schwann Cells
- Provide metabolic support (Ex: astrocytes which are essencial components of BBB) —
- Micróglia — Remove cellular debris - Nodes of Ranvier — Where tight Schwann cells are pinched to create gaps — Improves speed of conduction of nerve impulse
8
Q
Neurotransmitters
-Examples of substances
A
- Amino acids — GABA, Glyceine, Glutamate, aspartate
- Neuropeptídes — Endorphins
- Monoamines — Nor-epinephrine, serotonin, dopamine & histamine
9
Q
Neurotransmitters
-Summation Definition
A
- Brings membrane closer to Threshold potential
10
Q
Forebrain Functions
-Telencephalon
A
- The telencephalon consists of
- Cerebral cortex
- Basal Ganglia - The Cerebrum makes up the forebrain — Divided into right and left hemispheres by the longitudinal fissure
- Cerebral cortex — Outer layer of the cerebrum and is made up of gray matter
- White matter lies beneath the cortex and contains myelinated axons - The Cortex can be further divided into functional lobes:
11
Q
Forebrain Functions
-Telencephalon Functional Lobes
A
- The Frontal Lobe
- Prefrontal area — Responsible for Goal-directed behavior, Short term memory, complex thought
- The rest of the frontal lobe coordinates motor movements
- Broca’s area — Speech and language interpretation — Motor speech — Inferior portion of frontal lobe - Parietal lobe — Somatic Sensory input
- Occipital lobe — Visual cortex which receives input from the retinas
- Temporal lobe — Primary auditory cortex, equilibrium, emotion, & memory
- WERNICKE’s area —Speech and language interpretation — Speech interpretation - Limbic Structures — Control emotions, short-term memory
- Nuclei of the basal ganglia — Masses of gray matter that are involved in the initiation and planning of learned motor activities.
12
Q
Forebrain Functions
-Diencephalon
A
Second part of the forebrain and is the land of THALMUS
- Epithalmus — Pineal body — secretes melatonin
- THALMUS — Relays motor and sensory signals to the cortex — Integrates afferent impulses and interprets info such as auditory, visual, tactile and taste
- Hypothalamus — Responsible for Maintenence of the internal environment - Regulates autonomic nervous system Ex: body temp,endocrine function, emotional expression and control of the pituitary gland
- Subthalamus — Part of the basal ganglia and connects to the substantia nigra of the midbrain
—Subthalmus plays large role in extrapyramidal system which is important for FINE MOTOR MOVEMENT
13
Q
Forebrain Functions
-Limbic System
A
1. Consists of an arc of structures between the telencephalon and the diencephalon Structures include the -Amygdala -Hippocampus -Fórnix -Hypothalamus -Autonomic Nuclei
- Limbic system function — Involvement in primitive behavioral responses such as emotion, fear, anger, pleasure, feeding, biological rhythms and sense of smell
14
Q
Midbrain
-Components
A
- Tectum — Visual & Auditory motor movements
- Tegmentum
- Red Nucleus — Receives sensory information from the cerebellum and sends it to the cervical spinal cord
- Substantia nigra — Synthesizes dopamine - Cerebral Peduncles — Contain white matter tracts that contain EFFERENT nerves that relay signals between cortex and brain stem
15
Q
Hindbrain
-Components
A
- Cerebellum — Responsible for regulation & coordination of movement, posture, and balance — Finger nose or heel shin test
- Controls conscious and unconscious muscle synergy required for maintaining balance and posture
- Does not initiate movement, just helps coordinate it - Pons — Transmits information from cerebellum to the brainstem
- Important for the control of RESPIRATION**
- Nuclei of the 5th and 8th cranial nerves are located in the pons - Medulla Oblongata — lowest portion of the brainstem and is responsible for various reflex activities
—Ex: Heart rate, respiration, BP, coughing, sneezing, swallowing, vomiting
