Module 1: Intro to Brain

Brain

Brain

Fills most of the space inside the skull and is not directly attached to it, floating in cerebrospinal fluid (CSF).

Bilateral symmetry

The brain is bilaterally symmetrical, with left and right hemispheres connected by the corpus callosum.

Thalamus

Located just above the brain stem, it relays motor and sensory signals to the cerebral cortex.

Pons

Connects the cerebrum with the cerebellum and works with the medulla for respiration.

Medulla

Responsible for involuntary functions such as respiration, vomiting, and cardiac regulation.

Temporal lobe

Contains the auditory cortex, responsible for processing sound.

Grey matter

Composed of somas and dendrites, found on the outside of the cortex.

White matter

Composed of myelinated axons, which appear white due to fatty lipids.

Cerebral cortex

A thin sheet about 2.5mm thick, crumpled to maximize surface area, forming gyri (bumps) and sulci (folds).

Ventricles

Fluid-filled spaces in the brain that make up a small part of its total volume.

Spinal cord

Major pathway for ascending and descending information between the body and brain.

Central Nervous System (CNS)

Comprises the brain and spinal cord.

Peripheral Nervous System (PNS)

Divided into afferent (sensory input) and efferent (motor output) divisions.

Autonomic nervous system

Controls involuntary movements, divided into sympathetic (fight or flight) and parasympathetic (rest and digest) systems.

Somatic nervous system

Controls voluntary movements involving motor neurons and skeletal muscles.

Primary Motor Cortex

Executes voluntary movements after coordination in the pre-motor cortex.

Somatosensory cortex

Processes touch, temperature, pain, and vestibular information.

Limbic association cortex

Involved in processing emotions and memory.

Broca's area

Responsible for speech formation; Wernicke's area is crucial for understanding speech.

Dorsal side of spinal cord

The sensory side, containing afferent axons for sensory input.

Ventral side of spinal cord

The motor side, containing efferent axons for motor output.

Neuronal doctrine

States that neurons are individual cells, the structural and functional units of the nervous system.

Action potential

An all-or-nothing electrical depolarization of the cell membrane, generated at the axon hillock.

Myelin

A fatty lipid that insulates axons, allowing for faster conduction of action potentials.

Types of neurons

Include unipolar, bipolar, multipolar, and pseudounipolar, each with distinct structures and functions.

Glial cells

Support neurons, outnumber them by 10:1, and include astrocytes, microglial cells, oligodendrocytes, and Schwann cells.

Meninges

Membranes surrounding the brain, including dura mater, arachnoid mater, and pia mater.

Cerebrospinal fluid (CSF)

Supports the brain, provides cushioning, and maintains a chemical environment.

Blood-brain barrier

Restricts permeability of brain capillaries to protect the brain from toxins.

Synapse

Contact point where neurons interact, allowing for communication through neurotransmitters.

Excitatory and inhibitory synapses

Excitatory synapses depolarize the membrane, while inhibitory synapses hyperpolarize it.

Neurotransmitters

Chemicals that transmit signals across synapses, with glutamate being the most common excitatory neurotransmitter and GABA the most common inhibitory one.

What is contained in plasma membrane?

Ion chammels and proteins

In a sodium ion channel, is the gate open or closed at resting membrane potential?

Closed

In a sodium ion channel, how does the activation gate open?

A stimulus must change the membrane potential to a positive potential