Autonomic Nerv Sys + Brain development + Grey/White matter

Autonomic nervous system

• also called the visceral nervous system

• processes regulated below the conscious level → motor system

• initiates and transmits nerve impulses along autonomic motor neurons from the CNS to effectors → including cardiac muscle, smooth muscle, and glands

• maintaining homeostasis!!

Sympathetic vs Parasympathetic comparison

that

Sympathetic

for fight or flight responses!

• maintains homeostasis during exercise or times of stress or emergency → release of nutrients from stores

• Ex: glucose released from the liver

• exhibiting mass activation response

Parasympathetic

rest and digest

• conserving energy and replenishing nutrient stores

• ganglia are closer to organs

• long preganglionic neurons and short postganglionic neurons

Brain development comes from…

• The neural tube!

• Which is from the germ layer: ectoderm (neurulation)

→ starts at the cephalic end and continues to caudal

What happens if it doesn’t close at the caudal end?

→ Spina bifida (poor baby :( 

Brain development: 4 weeks

In the human embryo, the brain forms from the cranial (superior) part of the neural tube, which undergoes disproportionate growth rates in diff regions

• late 4th week of development, growth has formed 3 primary brain vesicles

→ forebrain: prosencephalon

→ midbrain: mesencephalon

→ hindbrain: rhombencephalon 

Brain development: 5 weeks

• Telencephalon: Cerebrum

• Diencephalon: Thalamus and Hypothalamus

• Mesencephalon: Peduncles and Colliculi

• Metencephalon: Pons and Cerebellum

• Myelencephalon: Medulla oblongata 

Organization of Neural Tissue Areas in the brain

• Gray and White matter

Gray matter

• houses motor neuron and interneuron cell bodies, dendrites, terminal arborizations, + unmyelinated axons

• outer layer: cortex → covering most of the surface of an adult brain

White matter

• derives its color from the myelin in the myelinated axons

• deep into the gray matter of cortex

• within masses of white matter in the cerebrum contains discrete internal clusters of gray matter called cerebral nuclei (oval, spherical, sometimes irregularly shapes clusters of neuron cell bodies)

Where are ganglia and nuclei located? What do they contain?

• Ganglia are clusters of nerve cell bodies located primarily in the peripheral nervous system (PNS).

→ relay points for neural signals and are involved in the processing of sensory information and coordination of motor responses.

• Nuclei are collections of nerve cell bodies found within the central nervous system (CNS), including the brain and spinal cord.

 → play a crucial role in relaying and processing information, coordinating higher-order functions such as cognition and motor control.

In summary, ganglia are located in the PNS and are involved in sensory processing, while nuclei are located in the CNS and are involved in higher-order functions.