central nervous system- lecture 8

Question 1

peripheral nervous system

Answer 1

stimulus detected by sensory receptors- stage 1 (detection) turns this into sensory info, stage 2 (recognition) sends to spinal cord, stage 3 (decision) turns into motor commands to either somatic or autonomous nervous system, stage 4 (execution) e.g. in skeletal muscles

Question 2

anatomical directions

Answer 2

When describing the CNS we use directional terms described relative to an imaginary line drawn through the spinal cord and the front of the brain (neuraxis)

Question 3

ventral

Answer 3

toward front of body or towards the bottom of the head

Question 4

dorsal

Answer 4

towards the back of the body or towards top of head

Question 5

anterior/rostal

Answer 5

nose end

Question 6

prosterior/caudal

Answer 6

tail end

Question 7

lateral

Answer 7

towards the sides

Question 8

medial

Answer 8

towards the middle

Question 9

bilateral

Answer 9

on both sides of the body or head

Question 10

ipsilateral

Answer 10

on the same side of the body or head

Question 11

contralateral

Answer 11

on the opposite side of the body or head

Question 12

anatomical planes

Answer 12

1. coronal (like a slice of bread)
2. sagital (lik cutting a roll of a hot dog)
3. horizontal (like cutting a burger bun)

Question 13

resourcing the brain

Answer 13

the brain cannot store glucose

it relies on constant supply of blood for glucose and oxygen

interruption in supply uses all the brains resources

interruption causes consciousness

a few mins interruption can cause brain damage

Question 14

blood supply to CNS

Answer 14

a vast circulatory system to ensure constant supply of resources

Question 15

protecting the CNS

Answer 15

1. skull and spine
2. meninges
3. blood-brain-barrier
4. ventricular system

Question 16

skull and spine

Answer 16

brain and spinal cord are delicate and require protection

Question 17

meninges

Answer 17

between skull and brain/ spinal cord and spinal column, outer layer=thick tough and flexible, middle layer= web like sheet of tissue filled with cerebrospinal fluid, inner layer= thin with rich blood supply(infection in meninges is known as meningitis)

Question 18

blood-brain-barrier

Answer 18

the CNS cant kill viruses, BBB keeps out harmful substances (viruses, bacteria), small/uncharged molecules can pass through, active transport system pumps essentials into brain (glucose/amino acids/hormones)

Question 19

ventricular system

Answer 19

the brain floats in a bath of protective fluid (cerebrospinal fluid), CSF flows around subarachnoid space (meninges), 4 ventricles in the brain

Question 20

hind brain

Answer 20

myelencephalon and mentecephalon

Question 21

myelencephalon

Answer 21

medulla oblongata- control of vital functions- cardiovascular system, respiration, musce tone- through recieving info on heart rate, blood pressure, o2 and co2 levels

Question 22

metencephalon

Answer 22

the pons (bridge) (serves as linke between hind brain and midbrain) communicates to motor cortex and sense organs, voluntary muscle movement, maintenance of balance and equilibrium, muscle tone and posture

Question 23

mid brain

Answer 23

mesencephalon- tectum (roof) and tegmentum (covering), major pathway for sensory and motor impulses between forebrain and hindbrain- tectum- auditory and visual communication, tegmentum- sensory processes, movement, motor control (substantia nigra)

Question 24

forebrain

Answer 24

diencephalon and telencephalon

Question 25

diencephalon

Answer 25

thalamus (chamber) recieves sensory info and relays to sensory processing in cortex. hypothalamus- connected to pituitary gland- regulation of ANS and endocrine system

Question 26

telencephalon

Answer 26

(the hemispheres)- the limbic system- a group of structures involved in stress and emotion, memory storage and retrieval- 1) cingulate gyrus- control of emotional behaviour, 2) fornix (arch)- links hippocampus to hypothalamus, 3) hippocampus- involved in learning and memory and also detection of threat/emotionally charged memories 4)amygdala- emotional processing and motivation

Question 27

bumps and grooves

Answer 27

3 major grooves divide the cortex, longitudinal fissure, central sulcus, lateral fissure

the grooves form 4 major divisions (lobes)- 1) central sulcus divides frontal lobe from parietal lobe, 2) lateral fissure- divides temporall lobe from frontal, parietal and occipital lobe.

Question 28

functions

Answer 28

medulla-brainstem and cerebllum (basic functions), limbic system (behaviours essential for surivival), cerebral cortex (higher order functions)