The Brain and Nervous System Review

Flashcards generated from lecture notes on brain anatomy, neurobiology, and the endocrine system.

What components make up the central nervous system (CNS)?

The brain and spinal cord.

What does the peripheral nervous system (PNS) consist of?

The nerves in the body that are connected with the CNS.

What is the primary function of afferent nerves?

They are sensory nerves that bring sensory information towards the CNS.

What is an example of an afferent nerve function?

Detecting that something is hot when you touch it with your skin.

What is the primary function of efferent nerves?

They are motor nerves that carry signals away from the CNS.

What is an example of an efferent nerve function?

Your brain telling you to move your hand.

What is the primary function of the autonomic nervous system?

It controls many automatic and internal functions.

Which branch of the autonomic nervous system is responsible for the 'fight or flight' response?

The sympathetic nervous system.

What is an example of the sympathetic nervous system in action?

Preparing your body to react when facing stress or danger, such as being chased by a dog.

What is the role of the parasympathetic nervous system?

It helps return the body to its resting state ('rest and restore').

What is the skull?

The hard bone around the brain.

What is cerebrospinal fluid (CSF) and what is its function?

Fluid surrounding the brain and spinal cord that helps protect them.

How many meninges cover the central nervous system?

3 meninges (membranes).

What is the Dura matar?

The tough outer membrane of the meninges.

What are the characteristics of the arachnoid membrane?

It is like webs and located in the middle layer of the meninges.

What is the Pia matar?

The meningeal layer that unites to the CNS surface.

Look at the attached diagram of the meninges. Which layer lies directly beneath the skull and above the arachnoid mater?

Dura mater

Look at the attached diagram of the nervous system. What two main divisions are shown?

Central nervous system (Brain, Spinal cord) and Peripheral nervous system (Peripheral nerve).

What two means does the nervous system use to send and receive messages?

Both electrical and chemical means.

What are neurons?

Cells that receive and transmit electrochemical signals.

What is contained within the cell body of a neuron?

The nucleus, which controls the cell's activity and contains genetic materials.

What is the structural appearance and function of an axon?

It looks like a long tail and transmits messages away from the cell.

What is the structural appearance and function of dendrites?

They look like branches of trees and receive messages.

What are neurotransmitters?

Chemicals sent by neurons to communicate with each other.

What is a synapse?

A tiny space or gap between the axon and dendrites.

What is the general function of glial cells?

They are cells that support and help neurons to function.

What two types of glial cells are specifically named in the notes?

Astrocytes and oligodendrocytes.

Look at the attached neuron diagram. What structure transmits electrical impulses away from the cell body toward other neurons?

Axon

Look at the attached neuron diagram. What central structure contains the nucleus and branches into dendrites?

Cell body

What are action potentials?

Electrical signals generated by neurons that allow information to travel quickly over long distances.

On average, how many neurons does the human brain contain?

An average of 86 billion neurons.

By what factor do glial cells outnumber neurons in the human brain?

By a factor of ten.

How do glial cells protect neurons?

By protecting them from chemicals that would harm the neuron.

How do glial cells assist migrating or growing neurons?

They guide neurons to their destination.

What structural covering do glial cells provide around axons?

Myelin sheaths.

What have scientists discovered regarding the active role of glial cells in neural communication?

Glial cells can respond to neural activity and influence communication between neurons.

What basic survival functions are managed by the older brain system in vertebrates?

Breathing, resting, and feeding.

Which brain structures are part of the older brain system, such as in a reptile's brain?

Brainstem, Thalamus, Reticular formation, and Cerebellum.

Which structures belong to the newer, more complex brain system in mammals like humans?

Neocortex and Forebrain.

What is the average weight of an adult human brain?

Approximately 3 pounds.

What percentage of the adult brain is made of fat?

60% of fat.

What four substances make up the remaining 40% of the brain?

Water, protein, carbohydrates, and salts.

Is the brain a muscle, and what tissue elements does it contain?

No, it is not a muscle; it contains blood vessels, nerves, neurons, and glial cells.

What are the three major divisions of the brain?

Hindbrain, Midbrain, and Forebrain.

Look at the attached brain structure diagram. Which section includes both the Telencephalon and Diencephalon?

Forebrain

What is the scientific term for the midbrain shown in embryonic division diagrams?

Mesencephalon

What is the brainstem?

One of the oldest and innermost (deep) brain regions.

What vital functions are controlled by the medulla?

Heartbeat and breathing.

What is the main function of the pons?

Helps coordinate movement.

What is the reticular formation?

A nerve network running through the brainstem and thalamus.

How is arousal defined in the context of brainstem functions?

Your level of alertness.

What functions are controlled or coordinated by the cerebellum?

Voluntary movement, balance, posture, motor learning, procedural learning, timing, cognition, and emotional regulation.

Look at the attached hindbrain diagram. Which structure lies superior to the medulla and anterior to the cerebellum?

Pons

Look at the attached brainstem diagram. What column-like nerve structure passes through the pons and medulla?

Reticular formation

Which brain regions correspond to the metencephalon and myelencephalon?

Metencephalon contains the pons and cerebellum; Myelencephalon contains the medulla.

What two regions compose the midbrain?

Tectum and Tegmentum.

What is the function of the red nucleus?

Motor coordination, especially in limb movement.

What is the function of the periaqueductal gray?

Modulates pain perception and is involved in defensive behaviour.

What neurotransmitter is produced by the substantia nigra?

Dopamine.

The degeneration of the substantia nigra is connected to which neurodegenerative disease?

Parkinson's disease.

What processes does the reticular formation in the midbrain regulate?

Regulates arousal, sleep-wake cycles, and attention.

What are the primary functions of the superior colliculi?

Visual processing and reflexive eye movement.

What are the primary functions of the inferior colliculi?

Auditory processing and locating sounds.

Look at the attached cross-section of the midbrain. Which dorsal structure includes the superior and inferior colliculi?

Tectum

In the cross-section of the midbrain, where is the substantia nigra located relative to the red nucleus?

Ventral to the red nucleus.

Where is the thalamus located and what is its main function?

Located on top of the brainstem; directs sensory messages towards the cortex and transmits replies to the cerebellum and medulla.

Where is the hypothalamus located relative to the pituitary gland?

Located above the pituitary gland.

What basic physiological functions does the hypothalamus regulate?

Body temperature, sleeping, hunger, thirst, and overall basic body regulation.

What additional functions does the hypothalamus play a role in?

Roles in memory and emotions.

What is the alternative name for the pituitary gland, and how large is it?

Master gland; it is a pea-sized gland.

Where is the pituitary gland located in the head?

Deep in the brain behind the bridge of the nose.

Which specific glands does the pituitary gland regulate?

Flow of hormones from the thyroid, adrenal glands, ovaries, and testicles.

From where does the pituitary gland receive chemical signals?

From the hypothalamus.

How do the hypothalamus and pituitary gland interact to regulate hormones?

The hypothalamus sends chemical messages to control pituitary function and provide hormonal instructions, while the pituitary helps carry out hormonal instructions.

What is the shape and location of the amygdala?

Small almond-shaped structures located under each half hemisphere of the brain.

What processes is the amygdala involved in?

Emotion, memory, reward-related processes, stress, fight or flight responses when threat, and processing fear/threat.

What is the shape and location of the hippocampus?

A curved seahorse organ on the underside of each temporal lobe.

What larger structure is the hippocampus a part of?

The hippocampal formation.

What functions are supported by the hippocampus?

Memory, learning, navigation, and spatial perception.

From where does the hippocampus receive information?

From the cerebral cortex.

What disease might the hippocampus play a role in?

Alzheimer disease.

What is the cerebral cortex?

The outermost layer of the brain.

What tissue primarily constructs the cerebral cortex?

Grey matter.

How thick is the cerebral cortex, and how much of total brain mass does it represent?

It is only a few millimeters thick, but consists of half of the total brain mass weight.

Why does the cerebral cortex have a wrinkled appearance?

To allow an increased number of neurons.

What functional importance is attributed to the cerebral cortex?

It is related to our highest mental capabilities and acts like a control center.

What structure separates the right and left hemispheres of the cerebral cortex?

A large sulcus called the medial longitudinal fissure.

Look at the attached top-view image of the brain. What feature is highlighted in red down the midline?

Medial longitudinal fissure

Look at the attached diagram of brain lobes. Which lobe is highlighted at the front in blue?

Frontal lobe

Where is the frontal lobe located and what functions is it responsible for?

Located behind the forehead; responsible for thinking, planning, memory, and making judgment.

Where is the parietal lobe located and what is it responsible for?

Located in the middle–back region; responsible for processing information about touch.

Where is the occipital lobe located and what does it process?

Located at the very back of the skull; responsible for vision information and visual processes.

Where is the temporal lobe located and what is it responsible for?

Located near the ears/in front of the temporal lobe; responsible for hearing and language.

Which two brain structures form the emotional network involved in emotion regulation?

The amygdala and the prefrontal cortex.

What is grey matter mainly made of and what is its role?

Mainly made of neuron cell bodies and dendrites; its main role is to process information in the surface layer of the brain.

Where is white matter located, what is it made of, and what is its function?

Located underneath the grey matter; made of long brain cell fibers; carries messages to and from the grey matter.

What is a feedback loop in the endocrine system?

The communication from the brain → pituitary gland → endocrine gland → back to the brain.

How do signal transmission methods differ between the nervous system and the endocrine system?

The nervous system uses neurotransmitters (like a telephone signal conveying a message from sender to receiver); the endocrine system uses hormones in the bloodstream (like a radio station conveying a message to any tuned receiver).

Which body parts and glands can produce hormones according to the notes?

Pancreas, kidneys, heart, adrenal glands, gonads, thyroid, parathyroid, and thymus.

What are the specific functions of the anterior pituitary and posterior pituitary glands?

Anterior pituitary produces and releases several hormones; Posterior pituitary stores and releases oxytocin (childbirth contractions, breastfeeding milk production) and vasopressin/ADH (water balance retain in kidneys) produced by the hypothalamus.