Chapter 6 Flashcards
When do hollow enclosed neural tubes form?
During the first month of human development
What are the first cells in human development? What do they exhibit? What does that mean?
Neural progenitor cells.
They only exhibit symmetrical cell division.
Each cell becomes two of the same type.
When does the symmetrical cell division period end? What happens after?
It ends 40 days after conception.
Asymmetrical cell division then starts.
What happens when a neural progenitor dies during the 85 day period?
It produces one neural progenitor and either one neuron or one glial cell.
What happens after 125 after conception? What’s special? Why?
There are over 100 billion neurons in the human neurons.
This is the most neurons we ever have .
Many die before birth, seemingly because they can’t find a place in the network.
What is neurogenesis?
The production of new neurons.
What do neural progenitor cells do when they undergo asymmetrical cell division?
They produce neurons
When does human neurogenesis stop?
4 months after conception
What is apoptosis?
A process of programmed cell death that occurs in multicellular organisms.
What does apoptosis ensure?
That a dying cell does not cause problems for its neighbours.
When do neural progenitor cells undergo apoptosis?
125 days after conception
What’s in the midbrain?
Tectum and tegmentum
What is the midbrain? What does it orchestrate?
A collection of nuclei that orchestrate complex reflexive behaviours, such as species typical responses to threat and pain as well as orienting responses to sounds and lights.
How does the tectum appear?
As two pairs of bumps on the dorsal surafce of the midbrain.
What are the bumps on the tectum? What are they involved in?
Top 2 bumps: superior colliculi, involved with orienting the animal to things seen in peripheral vision.
Bottom 2 bumps: inferior colliculi, involved with orienting to unexpected sounds
What is in the tegmentum? What do they coordinate and motivate?
It includes several structures .
Coordinate and motivate complex species-typical movements.
What do some areas of the tegmentum do?
Process pain and orchestrate behavioural responses to threats
What is the hypothalamus? What does it generally do?
A bilateral structure made up of several nuclei.
It generally regulates autonomic nervous system activity.
What is the hypothalamus critically involved in? What are the four F’s?
Behaviours that directly relate to survival (the four F’s).
Feeding, fighting, fleeing and fucking
What do different hypothalamic nuclei control?
Body temperature, sleep wake cycles, hunger and social behaviour
What is the most important function of the hypothalamus?
To link the nervous system to the endocrine system (release of hormones into the blood stream) via the pituitary gloand
What is a hormone?
A chemical substance that is released by an endocrine gland and that has an effects on target cells in other organs
What is the endocrine gland?
A gland that secretes chemical signals (hormones) into the blood stream.
What is much of endocrine system controlled by?
Hormones produced by cells in hypothalamus.
What is the thalamus? What does it do?
A bilateral structure that is divided into several nuclei, many of which relay ascending sensory information to different regions of the cerebral cortex.
What has many widespread cortical projections?
Many nuclei
What is the cerebral cortex structure?
How are the neurons interconnected between layers?
What are they thought to be?
A multi layered structure.
In a way that gives rise to cortical columns
Which are thought to be partially distinct functional units
What is the cerebral cortex the largest site of?
What does it play a key role in?
Neural integration in the central nervous system.
It plays a key role in attention, perception, awareness, thought, memory, language, decision making and consciousness
What is the surface of the cerebral hemispheres?
What is it highly convoluted with?
The cerebral cortex.
Sulci (small grooves)
Fissures (large or major grooves)
Gyri (ridges between sulci or fissures)
What do convulotions do?
Increase the surface are of the cerebral cortex
What is the outermost portion of the cerebral cortex called? Why?
Gray matter.
Because of the high concentration of cell bodies there
Where is white matter? What does it have?
Beneath the gray matter
A large concentration of myelinated axons and very few neurons
What does the longitudinal fissure do?
Seperate the two hemispheres
What does the lateral fissure do?
Separates front from the temporal lobe
What does the central sulcus do?
Provides a good landmark separating the rostral and caudal divisons of the cerebral hemisphere