HUMAN FUNCTIONING NEURO Flashcards
What are the four lobes of the brain?
Temporal, parietal, occipital and frontal
What are meninges?
3 layers of protective covering called meninges surrounding the brain and the spinal cord.
Outermost - dura - thick and tough. Periosteal layer lines the inner dome of the skull and the mineingeal layer is beneath that. Space between allows passage of veins and arteries for blood supplu.
Arachnoid matter - thin, connective tissue. Below is the cerebrospinal fluid. This fluid cushions the entire central nervous system.
Pia matter - thin membrane that hugs the surface of the brain.Rich with veins and arteries.
Briefly summarise the anatomy of the brain
2 hemispheres connected by corpus callosum.
4 lobes
Each hemisphere recieves sensory and sends motor commands to the opposite side of the body
Gyri - bumps/ridges in the cerebral cortex (grey matter) and increase the brain’s surface area so more neurones can be packed.
Sulci depression/grooves in cerebral cortex that help increase surface area.
The sulci form brain divisions by creating boundaries between lobes (dividing into 2 hemispheres)
What is the anterior/ posterior cingulate gyrus?
It is a component of the limbic system.
Anterior - Emotionl processing and the vocalisation of emotions. Amygdala (processes emotions - anterior). Anterior part is more linked to speech (Broca’s area)
Posterior - Process information relating to spatial orientation of objects (the posterior part)
What is the precentral gyrus?
The primary motor centre of the brain
Excecuting voluntary movements
Works by controlling the motor movement of the body’s contralateral side (opposite side to where it is located in the brain)
What is the superior temporal gyrus?
Contains the auditory cortex, processing of sounds.
What is the central sulcus?
Separates the parietal and the frontal lobes. Defines boundary between primary motor cortex and primary somatosensory cortex
What is the parieto-occipital sulcus?
Separates the parietal and occipital lobes of the brain
What is the lateral sulcus?
Seperates the parietal and temporal lobes.
What is the cerebral cortex?
An outer layer of tissue organised in 2 cerebral hemispheres, and composed of 4 distinct lobes
What is the frontal lobe?
Controls motor activity and tasks associated with the dopamine system (memory, attention)
Problem solving
Speech production (broca’s area)
What is the parietal lobe?
Touch sensation and spaital navigaton
Body orientation
What is temporal lobe?
Auditory processing and language comprehension
Memory/information retrieval
What is the occipital lobe?
Visual processing and sight perception.
What is the cerebellum?
Coordinates unconscious motor functions eg balance and movement coordination
Vision
Motor learning
What is the brain stem?
Posterior part of the brain connecting to the spinal cord.
Includes the pons, medulla oblongata and the midbrain.
The brainstem (via the medulla) controls the automatic and involuntary activities eg breathing, swallowing.
What is the hypothalamus?
Functions to maintain homeostasis via coordination of the nervous and endocrine systems
Also produces some hormones directly which are secreted by the posterior pituitary
What is the pituitary gland?
Considered the master gland - it produces hormones that regulate other glands are target organs
Anterior lobe: FSH, LH, growth hormone
Posterior lobe: ADH and oxytocin
What is the corpus calosum?
Bundle of nerve fibres that connects the 2 cerebral hemispheres.
White matter structure
If damaged, prevents info exchange between left and right
What is the medulla oblongata?
Connection between the brainstem and the spinal cord
Comprised of cardioresp regulation system, descending motor tracks, ascending tracts, craial nerves
Motor neurons cross from left motor cortex to right side of the spinal cord in the medulla.
What is the limbic system?
Located in the cerebrum of the brain.
Processing and regulating emotion, forming and storing memories, sexual arousal and learning.
Part of the brain involved in behavioural and emotional responses, especially when it comes to behaviour for survival. Body’s response to stress.
Cells in the limbic system are arranged in fewer layers, or more jumbled than in the cerebral cortex.
What is the hippocampus? LIMBIC SYSTEM
2 hippocampi located in each hemisphere.
Memory centres.
Episodic memories are formed here, and then filed away into long-term storage in other areas.
Spatial navigation and learning and emotions.
Damage can lead to memory impairments eg spatial memory, navigation, learning, memory
What is the amygdala? LIMBIC SYSTEM
Emotional responses, also key for formation of new memories. Workswith the hippocampus by attaching emotional content to memories.
Linked with fight or flight response by creating fearful memories.
Damage may result in more aggression, loss of control of emotions, and loss of ability to recognize fear.
Damage to both sides can result in fewer feelings of shame about breaking social rules.
Explain the cingulate gyrus in relation to the LIMBIC SYSTEM
Rgeulation of emotions, behaviour and pain. Control of autonomic motor function.
Damage can result in emotions being inappropriate, lack of fear, learning impairments
Explain the hypothalamus in relation to the LIMBIC system?
Homeostasis
Autonomic functions eg hunger, thirst, temp, bp, hr, sexual activity
Interface between endocrine system and nervous system
Response to stress
Damage:
Linked with mental health disorders eg hyperactivity linked to increased anxiety and agitation.
Explain the basal ganglia in relation to the LIMBIC system?
Main functions are to regulate voluntary movements, and help with balance as well as posture.
Areas of the basal ganglia involved in limbic system is cognitive and emotional behaviours and have a role in rewards and reinforcements.
Damage:
Tremors, involuntary muscle movements, abnormal posture and links to movement disorders.
What is the circle of Willis?
Part of the cerebral circulation and is a connection of arteries:
- anterior cerebral artery
-anterior communicating artery
-internal carotid artery
-middle cerebral arteries
-posterior communicating artery
Provides collatteral blood flow between the anterior and posterior circulations of the brain.
Prevents against ischemia in the event of vessel disease or damage.
What is the spinothalamic tract? ascending tract
The lateral spinothalamic tract carries information about pain and temperature. Whilst the anterior spinothalamic tract carries information about crude touch.
What is the dorsal column medial lemniscal pathway? ascending tract
Neural pathway, one of the ascending tracts, by which sensory information from the peripheral nerves is transmitted to the cerebral cortex. Conveys proprioception, light touch, vibration.
Transmitted through the dorsal column, and transmitted through the medial lemniscus.
What is the spinocerebellar tract?
Carry unconscious proprioceptive information (pain, touch and temperature) from the muscle spindles, golgi tendon organs and joint capsules in the cerebellum.
Cell bodies that bring this information are in the dorsal root ganglia.
Posterior spinocerebellar tract: from lower limbs to the cerebellum.
Cuneo cerebellar tract: upper limbs to cerebellum.
Anterior spinocerebellar tract: from lower limbs, decussate twice and terminate in the cerebellum.
Rostral spinocerebellar tract: from upper limbs to the cerebellum.
There are 3 spinocerebellar tracts.
How can motor tracts in the spinal cord be grouped?
Pyramidal: conscious control of muscles from the cerebral cortex to the muscles of the body and face
Extrapyramidal: unconscious, reflexive or responsive control of muscles from various brainstem structures to postural or anti-gravity muscles.
Describe the tracts in the extrapyramidal tracts?
All originate in the brainstem and do not pass through the pyramids. Allow for unconscious, relfexive or responsive movement of muscles to control balance, locomotion, posture and tone.
The reticulospinal tract:
Descending, white matter, locootion, postural control
Vestibuluspinal tract: 2
increases antigravity muscle tone in response to head tilting to one side.
Rubrospinal tract:
Descending, regulates activity of motor neurones.