Behavioural Biology B11: The Nervous System - CNS & PNS

Flashcards covering the organization, protection, major structures, and functions of the Central and Peripheral Nervous Systems based on lecture notes.

Central Nervous System (CNS)

Consists of the brain and spinal cord; integrates incoming information and coordinates all voluntary and involuntary nervous functions.

Peripheral Nervous System (PNS)

Consists of ganglia and the nerves that branch from the CNS; keeps the CNS in contact with the rest of the body.

Somatic Nervous System

Directs voluntary movements by stimulating skeletal muscles.

Autonomic Nervous System

Regulates involuntary bodily activities, such as heart rate and breathing rate, and controls muscles in the heart, smooth muscle in internal organs, and glandular secretions.

Parasympathetic Nervous System

Governs bodily activities during restful conditions ('rest and digest' response).

Sympathetic Nervous System

Prepares the body for stressful or emergency situations ('fight or flight' response).

Neurons (nerve cells)

Excitable cells that generate and transmit messages.

Neuroglial Cells (glial cells)

Provide structural support, growth factors, and insulating sheaths around axons; outnumber neurons by 10 to 1.

Nerve

Bundles of myelinated axons, predominant structures in the PNS.

Meninges

Three connective tissue membranes that protect the brain and spinal cord (dura mater, arachnoid, pia mater).

Cerebrospinal Fluid

Cushions the brain and spinal cord, provides shock absorption, support, nourishment, and waste removal.

Blood-brain Barrier

Formed by tight junctions in capillaries, protects the CNS by selecting substances that can enter the cerebrospinal fluid from the blood.

Cerebrum

The thinking, conscious part of the brain, separated into two hemispheres by the longitudinal fissure.

Cerebral Cortex

A thin outer layer of gray matter (cell bodies of neurons) on each cerebral hemisphere.

Gray Matter

Includes neuroglial cells, nerve cell bodies, and unmyelinated axons.

White Matter

Consists mostly of myelinated axons, allowing for communication between brain areas and between the brain and spinal cord.

Corpus Callosum

A band of white matter that connects the two cerebral hemispheres.

Frontal Lobe

A lobe of the cerebral cortex involved in aspects like reasoning, planning, and voluntary movement.

Parietal Lobe

A lobe of the cerebral cortex involved in processing sensory information, particularly touch, temperature, and pain.

Temporal Lobe

A lobe of the cerebral cortex involved in processing auditory information and memory formation.

Occipital Lobe

A lobe of the cerebral cortex primarily responsible for visual processing.

Limbic System

A system of brain structures that produce emotions and memory, including the hippocampus and amygdala.

Thalamus

Serves as the relay station of the brain for all sensory information except smell, and directs motor activity, cortical arousal, and memory.

Hypothalamus

Maintains homeostasis by regulating blood pressure, heart rate, breathing, digestion, body temperature, and also regulates emotions.

Reticular Activating System (RAS)

An extensive network of neurons that filters sensory input and keeps the cerebral cortex in an alert state.

Cerebellum

Integrates information from the motor cortex and sensory pathways to produce smooth, well-timed voluntary movements, and controls equilibrium and posture.

Brain Stem

Includes the medulla oblongata, midbrain, and pons, connecting the cerebrum and cerebellum to the spinal cord.

Medulla Oblongata

Contains reflex centers to regulate breathing rhythm, heartbeat, and blood pressure, and serves as a pathway for sensory and motor messages.

Pons

A 'bridge' that connects the spinal cord and cerebellum with the cerebrum, thalamus, and hypothalamus, also assisting in regulating respiration.

Spinal Cord

Connects the brain to nerves throughout the body, protected by vertebrae, and contains white and gray matter involved in transmitting signals and reflexes.

Dorsal Root Ganglion

Houses cell bodies of sensory neurons outside of the spinal cord.

Sensory Receptors

Specialized structures or dendritic ends of sensory neurons that respond to changes in the internal or external environment (stimuli).

Mechanoreceptors

Sensory receptors that respond to touch, pressure, vibration, and stretch.

Nociceptors

Sensory receptors sensitive to pain-causing stimuli.