brain development and anatomy and division of cellular type and labour in organisms: vasculature

Question 1

what parts of anatomy are part of neuroanatomy?

Answer 1

• spinal cord
• brain stem
• cerebellum
• diencephalon
• cerebral cortex

Question 2

what is the anatomy of the neuron?

Answer 2

• cell body
• dendrite
• axon
• synapse
• (spine)

Question 3

what does the ectoderm give rise to?

Answer 3

the neural plate

Question 4

what is the neural plate?

Answer 4

its the precursor of the central and peripheral nervous systems

Question 5

how does the nervous system form during development?

Answer 5

first it forms the neural plate, then the neural groove then the neural tube

Question 6

what are the underlying molecular mechanisms for the development of the nervous system?

Answer 6

BMP signalling

Question 7

what is neural induction?

Answer 7

its the folding proccess in vertebrate embryos, which includes the transformation from neural plate to neural tube

Question 8

how does the neural ectoderm form?

Answer 8

it forms when BPM signalling pathways are suppressed

Question 9

what are the different types of patterning in the nervous system?

Answer 9

• rostocaudal patterning
• dorsoventral patterning
• forebrain patterning

Question 10

what is dorsalventral patterning?

Answer 10

• the ventral neural tube is patterned by sonoc hedgehog protein which is secreted by the notochord and floor plate
• the dorsal neural tube is patterned by bone morphogenetic proteins

Question 11

what molecules are involved in forebrain patterning and what do they do?

Answer 11

FGF8- establishes the rostocaudal pattern of the cerebral cortex
Pax6 and Emx2- mutually repress each others’ expression

Question 12

what is the ‘cortex’?

Answer 12

• its the ‘higher’ part of the brain involved in complex cognitive processes and ‘thinking’ and ‘planning’ and ‘remembering’
• its highly folded in humans to give it more surface area

Question 13

what happens during brain development in the embryo?

Answer 13

• during brain development, new neurons migrate along radial glia from the ventricles to form the cortex layers
• ## this movement is called ‘inside-out’: inner layers of cells are created first, then outer layers of cells

Question 14

what causes morphological changes in the brain during lissencealphy?

Answer 14

• anything ehich inhibits the migration of neurons along the glia from the ventricles to form the cortex layers

Question 15

what is a ‘neurodevelopment disaster’?

Answer 15

its mutations affecting the function of microtubules alter the ability of cells to move from, and migrate to their correct destination during the formation of the brain

Question 16

what is lissencealphy?

Answer 16

its a smooth brain caused by mutations in the neurodevelopmental pathway

Question 17

what other neurodevelopment problems are there?

Answer 17

• microcephaly
• autism
• psychiatric disorders such as schizophrenia

Question 18

what brain dosorders are caused by a loss of neurons (neurological diseases)?

Answer 18

• alzheimers disease
• parkinsons disease
• stroke

Question 19

what brain disorders are based on changes in neural circuit (neuropsychiatric diseases)?

Answer 19

• schizophrenia
• depression
• addiction
• autism spectrum disorder

Question 20

what are the main factors that influence blood pressure?

Answer 20

• cardiac output (CO)
• peripheral resistance (PR)
• blood volume

Question 21

how do you work out blood pressure?

Answer 21

=CO x PR

Question 22

what does maintainingblood pressure require?

Answer 22

• cooperation of the heart, blood vessles and kidneys

- supervision of the brain

Question 23

what is cardiac output determined by?

Answer 23

• venous return and neural and hormonal controls

Question 24

what is resting heart rate controlled by?

Answer 24

• the cardioinhibitory centre via the vagus nerves
• stroke volume is controlled by venous return
• under stress, the cardio-acceloratory centre increases the heart rate and stroke volume

Question 25

what are the properties of muscualr arteries and arterioles?

Answer 25

muscualr arteries- distal to elastic arteries, they deliver blood to body organs, they have thick tunica media with more smooth muscle and less elastic tissue

arterioles - they’re the smallest arteries which lead to capillary beds, they control flow into capillary beds via vascodilation and constriction

Question 26

what are the properties of elastic arteries?

Answer 26

theyre thick-walled arteries near the heart; the aorta and its major branches

• large lumens allow low-resistance conduction of blood
• they contain elastin in all three tunics
• withstand and smooth out large blood pressure fluctuations
• allow blood to flow fairly continuously through the body

Question 27

what are the properties of capillaries?

Answer 27

their primary function is to permit the exchange of nutrients and gases between the blood and tissue cells

• capillaries are the smallest blood vessels
• the walls consist of a thin tunica internal, one cell thick
• they allow only a single red blood cell to pass at a time
• pericytes on the outer surface stabilise their walls
• the three structural types of capillaries are: continuous, fenestrated and sinusoids

Question 28

what are the properties of veins?

Answer 28

• theyre formed when venules converge
• they’re made of three tunics, with a thin tunica media and a think tunica external made up of collagen fibres and elastic networks
• capacitance vessels (blood resivoirs) that contain 65% of the blood

Question 29

what is pressure (P)?

Answer 29

• the heart generates P to overcome resistance
• absolute pressure is less important than pressure gradient
• the pressure gradient is circulatory pressure (delta P)

Question 30

what is delta P?

Answer 30

its the difference between pressure at the heart and pressure at the peripheral capillary beds

Question 31

what is intrinsic control?

Answer 31

contraction: control of local blood flow, vascular smooth muscle intrinsic myogenic tone, stimulates smooth muscle one in response to pressure
vascodilation: vascular endothelium, relaxes smooth muscle