Term 3: Cognition

Question 1

What is “sensing”? Is it involuntary, voluntary or both?

Answer 1

It is being able to detect abnormalities within our internal/external environment with the use of sensory receptors. The message is then sent to the brain. This can be voluntary with the use of eyes/ears/skin etc or involuntary like changes to BP.

Question 2

Describe the process of sensory input, integration and motor output.

Answer 2

Sensory input - sensory receptors pass message on to the brain via afferent/sensory neurons. Integration - information is received by brain or spinal cord and action is determined. (Memory often plays a part here, how did the body previously respond?) Motor output - the action determined by integration. The outgoing message/response sent via efferent/motor neurons.

Question 3

What are the two subdivisions of the nervous system and what are the main parts they consist of and their function?

Answer 3

Central Nervous System (CNS) - brain and spinal cord. Most active are the cerebral regions. Function is to receive information and interpret it. Peripheral Nervous System (PNS) - consists of receptors which detect change, and nerves which carry information. It branches off in to somatic (sensors in eyes/ears/skin etc.) and autonomic (sensors in organs) Autonomic then branches off to sympathetic (fight or flight response) and parasympathetic (rest and digest).

Question 4

What is the outermost layer of brain cells called? What happens here?

Answer 4

The cortex. This is where thinking and voluntary movements begin.

Question 5

Where is the brain stem and what functions does it control?

Answer 5

The brain stem is between the spinal cord and the rest of the brain. Basic functions like breathing and sleep are controlled here.

Question 6

There is a cluster of structures in the centre of the brain. They coordinate messages between multiple other brain areas. What are they called?

Answer 6

Basal ganglia.

Question 7

Where is the cerebellum and what is it responsible for?

Answer 7

The cerebellum is at the base and the back of the brain. The cerebellum is responsible for coordination and balance.

Question 8

What lobes is the brain divided in to and what is the function?

Answer 8

• frontal lobes: problem solving, judgement and motor function
• parietal lobes: sensation, handwriting, body position.
• temporal lobes: hearing and memory
• occipital lobes: visual processing system

Question 9

Define meninges?

Answer 9

Connective tissue membrane protecting the skull and spinal cord.

Question 10

What are the three layers of the meninges of the brain?

Answer 10

Dura mater - this is the outermost layer connecting to inside of cranial bones. It consists of two layers, and blood vessels are located between them.

Arachnoid - this is under the dura mater and below this is the subarachnoid space. In this space lies fibres that further stabilise the brain and vertebrae, cerebrospinal fluid and most of the blood vessels are located here.

Pia mater - this is the innermost layer. Pia mmater translates to “gentle mother” it is the delicate layer that clings tightly to the brain and spinal cord’s surface.

Question 11

What is CSF and what is the function?

Answer 11

Cerebrospinal fluid.

• made up of mostly water, adults have approx. 150ml but produce 500ml per day to maintain pressure.
• cushions the brain and spinal cord, contributes with movement of substances within the blood.

Question 12

Brain capillaries are extremely permeable, true or false? Why/why not?

Answer 12

FALSE. Brain capillaries are not very permeable and this plays a protective function stopping unwanted substances entering the brain tissue. This is called the blood-brain barrier.

Some that can enter include fat soluble sunbstances such as nicotene, alcohol, blood gases, caffiene and some bacteria eg. the bacteria that causes meningitis.

Question 13

What are the three types of neurons?

Answer 13

• sensory neurons
• interneurons
• motor neurons

Question 14

What are the three parts of a neuron and what does each part do?

Answer 14

Neurons carry electrical signals.

• cell body: integrates information
• dendrites: recieve information
• axon: transmits information

Question 15

When looking at the pathways of messaging via neurons we describe their pathway as either afferent/efferent. What is the difference?

Answer 15

• Afferent – information that is coming from the periphery into the nervous system
• Efferent – information that is going away from the nervous system to the periphery

Question 16

How do neurons communicate?

Answer 16

• Communication involves the generation and movement of an electrical impulse down the neuron
• The electrical impulse derives from the establishment of an action potential.
• The action potential results from the movement of Na, K & Ca ions across the cell
• Separating each neuron from each other is a synaptic gap

Question 17

What is membrane potential?

Answer 17

• Ions have an electrical charge in different concentrations across a cell membrane. This means there will be a difference in electrical potential across the cell membrane.
• This is called Membrane Potential It is measured in millivolts

Question 18

What is a resting neuron potential?

Answer 18

The voltage across the membrane when a neuron or muscle cell is not producing an action potential

-70 millivolts

Question 19

Describe action potential.

Answer 19

• Stimulus to neuron(eg heat to thermo receptor)
• Stimulus causes Na+ channels in neuron cell membrane to open.
• Resting Membrane potential changes and depolarisation occurs
• Na+ channels close and K+ channels open and repolarisation occurs

Question 20

What is the difference between the absolute refractory period and the relative refractory period?

Answer 20

• Absolute refractory period: during sodium entry (depolarisation ) the neuron is unable to respond to a stimulus.
• Relative refractory period: after sodium channels are shut (repolarisation) it is difficult but not impossible to respond to another stimulus.

Question 21

What is a synapse?

Answer 21

• Neurons don’t meet. The small space between them is called the synapse
• Synapses are essential to nervous system communication
• Impulses are transmitted across a synapse by chemical messengers

Question 22

What is the role of the neurotransmitters?

Answer 22

• They are chemicals that enable signals to be transmitted across the synapse
• In this process, calcium needs to enter the cell to allow neurotransmitters to be released
• Neurotransmitter binds to receptors but can only bind to a specific receptor

Question 23

How many cranial nerves are there and what do they do?

Answer 23

• Extending from the brain are 12 pairs of nerves
• These are responsible for motor and sensory messages between the brain and the body.

They are numbered using a roman numerical system, named based on the area of the body they are responsible for.

Question 24

What is the role of the spinal cord? (two points)

Answer 24

• Provides pathways to and from the brain both ascending (up the cord) and descending (down the cord)
• Produces reflexes without input from the brain that require no conscious effort (involuntary) in response to pain

Question 25

How many spinal nerves are there and what do they contain?

Answer 25

• Emerging from each side of the spinal cord are 31 pairs of nerves called spinal nerves
• Spinal nerves contain motor and sensory nerve fibres to and from all parts of the body

Question 26

What are some things that need to be considered when assesing a person’s cognition and perception?

Answer 26

• movement and orientation
• hearing
• vision
• smell
• touch
• taste
• pain
• memory
• reasoning
• judgement
• decision making
• impact on ADLs
• how a person compensates for change eg. hearing loss

Question 27

Why is it important to find out about a patient’s cultural, educational background, values, beliefs, life experiences as well as mental and emotional status?

Answer 27

• These are all factors that could impact on individuals responses
• Help gather information about the way the person thinks and behaves

(how appropriate are their emotions and ideas?)

Question 28

When doing a cognitive assesment, why would you ask about medication?

Answer 28

Metabolic disorders (Vit B12 & Fe) & medications can cause cerebral dysfunction – sedatives, diuretics change electrolyte levels, alcohol (korsokoffs)

Question 29

What are some examples of objective data used to assess cognition?

Answer 29

• Mini mental state examination (MMSE)
• Addenbrooke’s cognitive examination (ACE-II)
• Neurological assessment: assess levels of consciousness, pupil size & response to light, movement of limbs, sensation, vital signs
• Glasgow Coma Scale (GCS)

Question 30

When talking about assesment of neurological function, what does AVPUC and PERRLA stand for?

Answer 30

*A – is the person alert?

*V – does the person respond to voice?

*P – does the person respond to pain?

*U – Is the person unresponsive?

*Consider pupils, do they respond to light. If pupils are equal, round, reactive to light, & accommodation (PERRLA)

Question 31

What two major parts is the Periferal Nervous System (PNS) divided in to? What do they then branch in to?

Answer 31

PNS divides in to somatic and autonomic.

Somatic divides in to motor (efferent) and sensory (afferent) (AWARE/CONSCIOUS)

Autonomic divides in to parasympathetic (fight or flight) and sympathetic (rest and digest) (associated with being below our awareness)

Question 32

What are three main points associated with the somatic nervous system?

Answer 32

• Voluntary/conscious muscle movement associated with motor and sensory.
• Carry information from somatic and special receptors to somatic integration centres in the brain and spinal cord (afferent)
• Information is then carried back via efferent somatic pathways to somatic effectors in skeletal muscle resulting in muscle movement.

Question 33

What does the autonomic nervous system do?

Answer 33

• Part of peripheral nervous system.
• Regulates the function of internal organs (the viscera) such as the heart, stomach and intestines.
• Functions involuntary and reflexively. For example we have no idea when blood vessels change diameter to facilitate BP
• Regulates muscles in the skin (around hair follicles; smooth muscle), around blood vessels (smooth muscle), in the eye (the iris; smooth muscle), in the stomach, intestines and bladder (smooth muscle) of the heart (cardiac muscle)
• It divides further into the sympathetic and parasympathetic systems

Question 34

What is the sympathetic nervous system associated with?

Answer 34

• Sympathetic nervous system allows the body to function under stressful situations which often gets referred to as “fight or flight”.
• It enables the body to increase its heart rate, breathe faster, dilates the pupils, decrease salivation and so on to help the body cope with the stressful situation

Like the accelerator in a car - speeds it up.

Question 35

What are gial cells or neuroglia?

Answer 35

“Glue” to support, insulate and protect the neurons.

Question 36

What is the blood-brain barrier?

Answer 36

A protective barrier working to maintain a stable internal chemical environment. The capillary walls of the brain are mostly impermeable, generally only allowing nutrients keeping harmful substances out with some exceptions.

Question 37

What is aphasia?

Answer 37

The inability to use language. Can be expressive (problems with language production) or receptive (problems with language comprehension)

Question 38

What is dysarthria?

Answer 38

Speech disorder resulting from distrurbance in muscular control due to damage in nervous system.