1
Q
What is an excitable membrane?
A
Flow of depolarisation along the axon carrying the charge
2
Q
What inactivates behind the wave of depolarisation?
A
The sodium channels, so it only moves in 1 direction
3
Q
How many sodium and potassium molecules are moved in and out the cell to reach resting potential?
A
3 sodium out, 2 potassium in
4
Q
Explain the graph of action potential
A
- Depolarisation threshold = local current reaches threshold potential ( + 30 )
- Voltage gated sodium channels open, rapid influx of sodium ions
- Proteins don’t like being open too long so close sodium channels and open potassium channels.
- Potassium channels overshoot, becoming slightly lower than resting. Channels close and normal permeability returns
Refractory period = cannot send another signal
5
Q
Explain the activation and inactivation of sodium channels
A
- Local current opens m-gate
- Sodium ions more from the cell depolarising.,
- H-gate closes
- Potassium channels open
S. Reset ready for next action potential
6
Q
Which is m and h gate?
A
M gate = the flap, external closing
H gate = the ball , internal closing
7
Q
Describe the depolarisation of the axon
A
- Action potential arrives and initiates synaptic transmission.
- Sodium channels open depolarising the axon terminal membrane
- Depolarisation of the terminal membrane causes voltage gated calcium channels to open
- Calcium enters the celland triggers fusion of acetylcholine vesicles with the presynaptic membrane.
- Acetylcholine diffuses across the cleft and binds to post synaptic membrane.
- Activated receptors open chemically gated sodium channels and depolarise the postsynaptic membrane. Spreading of depolarisation fires an action potential in the postsynaptic membrane
- Acetylcholine left in the cleft is broken down by acetylcholine stressed and components are taken back up to presynaptic membrane for resynthesis
8
Q
Sensory pathway
A
Conduct info about limb position and sensations
9
Q
Somatosensory pathway
A
Process stimuli received from receptors within skin muscles and joints
10
Q
Viscera sensory pathway
A
Process stimuli received from the visceral - soft internal organs
11
Q
Motor pathway
A
Output from the spinal cord to the muscles
12
Q
What is sensory transduction
A
Environmental changes ( light, temp ) cause a change in membrane potential if this reaches threshold it will trigger an action potential normally transmitted to the CNS so the brain can perceive the stimulus
13
Q
Where does the spinal nerves receive info from
A
From a dermatone - area of the body’s surface served by a spinal nerve
14
Q
What is a receptor field
A
Area where a stimulus is picked up by a single neuron. If there is 2 points of contact within a single receptor field it will be perceived as one.
15
Q
Different vertebrae of the spine
A
Cervical spine vertebrae ( first 5)
Thoracic spine vertebrae
Lumbar spine vertebrae
Sacrum - at the bottom
16
Q
Different parts of the spinal cord
A
Look on Goodnotes
17
Q
What are the 2 affetent somatosensory pathways to the brain
A
- Dorsal column lemniscal - fine touch and vibration
- Spinothalamic tract - crude touch, temp and pain
18
Q
What are the 2 efferent motor pathways to the muscle
A
- Dorsolateral corticospinal tract - to periphery
- Ventromedial corticospinal tract - shoulders neck trunk
19
Q
What is the cerebellum
A
Used for balance and coordination
20
Q
Basal ganglia
A
Essential for motor skills, procedural learning and habit formation
Made from
1, putamen
2. Caudate nucleus
3. Globus pallidus
21
Q
Sympathetic nervous system
A
Fight or flight
Increases heart rate and energy expenditure
22
Q
Parasympathetic nervous system
A
Rest and digest
Calming the body to conserve energy and manage digestion
23
Q
What is the PNS split into ?
A
Both somatic and autonomic nervous system
Autonomic then splits into sympathetic and parasympathetic
24
Q
Where does sound travel to in the Ear
A
The tympanic membrane
25
What is the inner ear used for
Equilibrium
26
How are the vibrations of sound carried through the ear
Passed along the tiny bones called ossicles, these make the vibrations stronger and send them to the inner ear (the cochlea ) through the oval window
27
What are the 3 parts of the inner ear
Cochlea - hearing
Vestibule - equilibrium
Semicircular canals - equilibrium
28
How does the cochlear work
When vibrations enter the cochlear the fluid inside moves.
This causes the basilar membrane to vibrate
Tiny hair cells on this membrane bend as it moves, creating an electrical signal
These signals are then sent to the brain
29
Process of the auditory pathway
Info is taken from the sensory hair cells
Goes up to the vestibulocochlear nerve
Then to the thalamus then temporal lobe
30
How much of the brain is used to process sight
Around 40% - the cerebral cortex
31
32
What is the part of the eye responsible for producing tears
Lacrimal apparatus
33
How do tears pass into the nasal cavity
Through the nasolacrimal duct
34
How many muscles control the eye
6
- 4 rectus ( straight ) muscles
- 2 oblique ( curved) muscles
35
What cranial nerves control the eye
3,4,6
Ocularmotor, trochlear, abducens
36
What is the job of the lens
Focus light on the retina
From a near source it takes a while to focus as lens become rounder to accommodate rays
37
How are images perceived
Up side down from left to right
38
Structure of the retina
Outside layer = thin and pigmented containing melanocytes preventing light scattering
Inside layer = much thicker contains neurones and receptors
39
What are rods in the eye
Allow us to see black and white
Much more sensitive to light
40
What are cone cells in the eye
High acuity in bright light
Allow us to distinguish between blue red and green
41
Where is all visual info sent
To the occipital lobe
42
What are papilla
A small rounded protuberance on the tongue
43
What does each taste bud contain
Around 50-100 epithelial cells
44
How does transduction of salty substances work
Opens sodium channels which can cause an action potential
45
How does transduction of sour / acidic substances work
Activate proton channels to start and action potentials
46
How does transduction of bitter substances work
Cause an internal release of calcium to start an action potential
47
Which nerves take taste to the brain
Facial nerve - from the front 2/3 of the tongue
Glossopharyngeal nerve - from the back 1/3 of the tongue and throat
48
What part of the nose allows you to smell
The olfactory epithelium
When you breathe the odor molecules stick to these cells and send signals to the brain
49
What is the absence of smell called
Anosmia
Caused by:
Trauma
Colds and allergies
Polyps causing blockage
Amiodarone use
50
What are the 4 categories of memory
Declarative = memory of facts
Procedural = memory of skill
Motor = motor skills
Emotional = experiences linked to emotion
51
What are the factors affecting transfer of info from the STM to LTM
- emotional state
- rehearsal
- association
- automatic memory = stored in the LTM without conscious effort
52
What is the frontal lobe responsible for
Social appropriateness, decision making
53
What would symptoms of a brain tumour in the frontal lobe look like
Personality change, aggression, apathyb
54
Where is the Broca’s area found in the brain and what is it used for
In the frontal lobe responsible
Used for speech and formulating sentences
55
What is the occipital lobe responsible for
Vision
Damage to the right side of the brain results in loss of sight in the left field of vision
56
What is the parietal lobe responsible for
Spatial mapping, sort somatosensory information and motor function
57
What is the temporal lobe responsible for
Understanding language and perception
58
What mental illness is largely associated with the temporal lobe
Schizophrenia
59
Where is wernicke’s area found and what’s it used for
Found in the temporal lobe responsible for understanding language
60
what are the types of muscle?
- smooth
- cardiac
- skeletal
61
describe the structure and role of skeletal muscle
- striated, tubular, multinucleated fibres
- usually attached to the skeleton
- is voluntary
- enables movement of limbs and other parts of the skeleton
62
Describe cardiac muscle and the role
- has striated, tubular, branched fibres
- occurs in the wall of the heart
- involuntary
- pumps blood around the circulatory system
63
Describe smooth muscle and its role
- has narrow, tapered non-rod shaped cells
- non striated uninucleated fibres
- involuntary
- in the walls of hollow organs (except heart)
64
When do muscles relax and contract
when signals are received from the nervous system
65
what is the sight of signal exchange
neuromuscular junction
66
What are the contractile units of the myofibrils
sarcomeres
67
what gives the striated appearance of the muscle
thin and thick contractile units
thin = actin
thick = myosin
68
Wha are the functions of the skeletal system
1. support
2. protection
3. movement
4. mineral storage
5. hematopoiesis = blood cell formation carried out by the myeloid tissue
69
how many bones do you have at birth vs in an adult
300 vs 206
70
bone classification
1. long - cylindrical. longer than they are wide, used of leverage
2. short - cube like, provide stability and support with some motion
3. flat - thin and curved, points of attachment and organ protection
4. irregular - complex shape, organ protection
5. sesamoid - small, round and embedded in tendons, tendon protection from compression
71
what is the medullary cavity filled with
yellow marrow
red bone marrow turns to yellow when growing - it is more fatty
72
what is the periosteum in the bone
dense white fibrous membrane that covers the bone and attached tendons firmly to the bone
essential for bone cell survival and bone formation
73
different bone cells
1. osteogenic cells = develop into osteoblasts (maintains bone tissue)
2. osteoblasts = bone formation
3. osteocytes = maintain mineral concentration of matrix (stem cell)
4. osteoclasts = bone resorption ( found on the bone surfaces and sites of old injuries)
74
describe the role of calcitonin in calcium homeostasis in the bone
- increased calcium in the blood
- thyroid glads release calcitonin
- inhibition of osteoclast activity
- stimulates calcium uptake in bone
- blood concentration restored to normal
75
what is most likely to be related when blood calcium levels are elevated?
A. thyroxine
B. calcitonin
C. parathyroid hormone
D. vitamin D
B. calcitonin
76
What occurs in advanced adulthood to the levels of osteoclasts and osteoblasts
osteoblasts decrease
osteoclasts increase
skeleton as a whole loses strength and fracture risk increases
77
what is hematopoiesis
process the body uses to make new blood cells
78
what is the yellow marrow used for
triglyceride storage in the bone for energy
79
what are some processes calcium ions are used in
- bone formation
- blood clotting
- hormone secretion
80
what is vitamin d used for in bone development and growth
calcium absorption from small intestine and unconfirmed role in bone remodelling
81
what is vitamin k used for in bone development and growth
bone remineralisation
82
how do different hormones play a role in bone development and growth
growth hormone -= increase length of long bones
thyroxine = stimulates bone growth and synthesis os bone matrix
sex hormone = promote osteoblastic activity, responsible for adolescent growth spurt
calcitrol = stimulates absorption of calcium and phosphate from digestive tract
parathyroid hormone = stimulates osteoclasts proliferation
83
what is osteogenesis
development of bone from small cartilage model to an adult bone
84
what are the 2 types of osteogenesis
intramembranous and endochondral
85
what is intramembranous ossification
- bone forms directly from connective tissue without a cartilage precursor (stem cell to bone)
- happened mostly in flat bones e.g. skull and clavicle
86
what is endochondral ossification
- bone forms by first making a cartilage model (hyaline cartilage) which is later replaced by bone
- mostly on long bones e.g. femur and humerus
- takes place much later
87
what are GAGs
unbranched polysaccharide chains
highly negatively charged which in turn causes lots of water to be sucked into the matrix
88
89
What is the integumentary system
Integumentary form the outer covering of the body and describes the skin and its appendages - hair, skin glands, nails
90
What are the 3 layers of the skin
Epidermis
Dermis
Subcutaneous layer
91
What are the cells making up the epidermis
Kertinocytes - principal component, dynamic renewal
Melanocytes - pigment producing cells
Langerhans - immune surveillance
92
What cells make up the dermis
Fibroblast - collagen producing cells
Dendritic cells - antigen presenting cells, immune surveillance
93
Where would thick and thin skin be found
Thick = on the soles and palms
Thin = mostly of the body surfaces, thinnest = eyelids
94
What does lipid signalling in the skin allow to happen
Homeostasis
Wound healing
95
Lipid associated skin diseases
Psoriasis = decrease in oxidised lipids and hyper proliferation of kertinocytes
Eczema = alteration of ceramide species
Icythosis = mutation in lipid processing
96
Dermal-epidermal junction
Space that glues the dermis and epidermis together
Blister - rub away the epidermis from the dermis and become fluid filled
97
Is there nerve endings in the epidermis
No - if you pinch the top layer of a blister it doesn’t hurt
98
What are dermal appendages
Specialized structures that are derived from the epidermis and extend into the dermis
99
What are the sensory receptors in dermal appendages
Tactile corspuscle = slight pressure, beneath epidermis
Lamellar corpuscle = deep pressure, above hypodermis
100
What are the different sweat glands
Eccrine glands = cover the body, secrete sweat, eliminated waste and maintains a constant core temp
Apocrine glands = in armpits and ear canal, begin at puberty, secrete water, uric acid
101
What does the smell come from when working out
Not the sweat, the bacteria eating what your sweat and sebaceous glands pump out
102
Sebaceous glands
Secretes sebum - triglycerides, wax esters etc
Lipid components have antifungal activity ( acts as a plug)
Found in dermis
103
What helps with reducing the number of whiteheads and blackheads
Benzoyl peroxide
104
What would be used to treat acne
Topical retinoids
105
What is the cycle of hair growth
Anagen = growth
Catagen = growth slows / stops
Telogen = rest phase
106
Different parts of the nail - top to bottom
Free edge
Nail body
Lanula
Cuticle
Nail root
107
How is melanin made and released
Formed from tyrosine by melanocytes in basal layer
Release it in packets called melanosomes
108
Types of melanin
Eumelanin = dark brown / black melanins
Phenomelanin= reddish and orange melanins
Albinism = congenital absence of melanin
Ph1124
flashcards
Decks in class (2)
# Cards
