Flashcards
The Nervous System
Flashcards do conjunto (19)
- 1Complete the sentences: The nervous system is made up of a complex network of cells called __________. All neurones have a ______ _______ with a nucleus (plus cytoplasm and all other organelles you usually find in a cell).The nervous system is made up of a complex network of cells called NEURONES. All neurones have a CELL BODY with a nucleus (plus cytoplasm and all other organelles you usually find in a cell)
- 2Complete the sentences: The cell body has extensions that connect to other neurones - __________ and _________carry nerve impulses towards the cell body, and _______ carry nerve impulses away from the cell bodyThe cell body has extensions that connect to other neurones - DENDRITES and DENDRONS carry nerve impulses towards the cell body, and AXONS carry nerve impulses away from the cell body
- 3What are the 3 main types of neurones?Sensory
Motor
Relay - 4Describe the structure of sensory neuronesSensory neurones have short dendrites and one long dendron to carry nerve impulses from receptor cells to the cell body, and one short axon that carries nerve impulses from the cell body to the CNS
- 5Describe the structure of motor neuronesMotor neurones have many short dendrites that carry nerve impulses from the CNS to the cell body, and one long axon that carries nerve impulses from the cell body to effector muscles
- 6Describe the structure of relay neuronesRelay neurones have many short dendrites that carry nerve impulses from sensory neurones to the cell body, and many short axons that carry nerve impulses from the cell body to motor neurones
- 7Outline the neural pathway from the stimulus to the response1. A stimulus is detected by receptor cells and a nerve impulse is sent along a sensory neurone
2. When a nerve impulse reaches the end of a neurone, chemicals called neurotransmitters take the information across the synapse to the next neurone, which then sends a nerve impulse
3. The CNS processes the information, decides what to do about it and sends impulses along motor neurones to an effector - 8Complete the sentence: Sensory receptors act as ____________ (they convert the energy of stimuli into __________ impulses - nerve impulses)Sensory receptors act as TRANSDUCERS (they convert the energy of stimuli into ELECTRICAL impulses - nerve impulses)
- 9What happens when sensory receptors are in their resting state?In its resting state, there's a potential difference across the membrane
Resting potential is generated by ion pumps and ion channels - 10What is resting potential?The potential difference when a cell is at rest
- 11What is generator potential?The change in potential difference due to a stimulus
- 12What happens to the sensory neurone when a stimulus is detected?When a stimulus is detected, the cell membrane is excited and becomes more permeable - more ions move in and out of the cell, altering the potential difference
- 13TRUE OR FALSE: A bigger stimulus excites the membrane moreTRUE
A bigger stimulus means a bigger movement of ions and a bigger change in potential difference (a bigger generator potential is produced)
- 14What is an action potential?Electrical impulses (nerve impulses)
- 15What happens to a sensory neurone if a generator potential is big enough?If a generator potential is big enough, it'll trigger an action potential (nerve impulse) along a neurone
- 16TRUE OR FALSE: If the stimulus is too weak, an action potential could still be producedFALSE
An action potential is ONLY triggered if the generator potential reaches a certain level called the threshold level. If the stimulus is too weak, the generator potential won't reach the threshold, so there's no action potential - 17What are Pacinian corpuscles?Pacinian corpuscles are mechanoreceptors found in the skin
- 18Describe the structure of Pacinian corpusclesPacinian corpuscles contain the end of a sensory neurone (sensory nerve ending), wrapped in lots of layers of connective tissue called lamellae
- 19How do Pacinian corpuscles work as mechanoreceptors?When a Pacinian corpuscle is stimulated, the lamellae are deformed and press on the sensory nerve ending. This causes deformation of stretch-mediated Na⁺ channels in the sensory neurone's cell membrane.
The Na⁺ channels open and Na⁺ diffuse into the cell, creating a generator potential. If the generator potential reaches a threshold, it triggers an action potential
Informações
- Descrição
- O usuário eliminou as informações de disciplina FlashCards sobre The Nervous System, criado por Usuário eliminado em 05-03-2018.
- Criado por
- Usuário eliminado
- Visualizações
- 32
- Histórico
-
- Criado por Yinka F · 14 fev 2018
- Copiado por Yinka F · 5 mar 2018
- Avaliação