Nervous & Endocrine & Sense Organs Flashcards
What Are the two parts of the nervous system
- Central Nervous System (CNS)
2. Peripheral Nervous System (PNS)
What is the Central Nervous System
consists of the brain and spinal cord.
What is the Peripheral Nervous System (PNS)
consists of all the other nervous tissue
e.g. motor neurons, motor endplates, sensor receptors,
sensory neurons
Name the six parts of the brain
- Cerebrum
- Cerebellum
- Hypothalamus
- Pituitary gland
- Medulla oblongata
- Meninges
Name the function of the cerebrum
consciousness, intelligence, memory
language.
It’s outer layer consists of grey matter And the inner part consists of white matter
Name the function of the Cerebellum
Muscle co-ordination and balance
Name the function of the Hypothalamus
controls homeostatic
responses such as temperature and
osmoregulation
Name the function of the Pituitary gland
Master endocrine gland that Secretes many hormones
Name the function of the medulla oblongata
Regulates heart and breathing rates
Name the function of the meninges
Three protective membranes surrounding
the brain and spinal cord
What is a neuron
nerve cell specialised to generate and transmit nerve impulses
Neuron diagram labels
- Dendrites
- Cell body
- Myelin sheath
- Axon
- Schwann cell
- Axon
- Presynaptic knobs
What is the function of the cell body
o makes neurotransmitters
o Generates impulses
o Cell body of motor neuron lies inside CNS
o Cell body of sensory neuron lies in dorsal root ganglion
What is the function of the dendrites
Branched extensions of cell body, collect impulses from many neurons
What is the function of the Axon
Carries impulses away from cell body
What is the function of the Myelin sheath
Insulates axon, speeds up impulse
What is the function of the Schwann cell
Produces myelin sheath, speeds up transmission of impulse
What is the function of the Neurotransmitter Vesicles
- they are Bags of neurotransmitter
o Found in pre-synaptic knob
o Neurotransmitters carry impulse across the synapse
Name and describe the three neuron types
- Sensory Neuron
Carries impulse from receptors to CNS - Interneuron
Links sensory neuron to motor neurons
Only found in the grey matter
Forms part of Reflex Arc - Motor Neuron
Carries impulse from CNS to Effector [muscles or glands]
What is threshold
the minimum level of a stimulus above which the neuron will fire
What is the All-or-nothing law
there is either an impulse or no impulse
What is the intensity of an impulse
It is measured by frequency of impulses
What is a synapse
Connection between two nerve cells or nerve cell and target cell
Describe the process of transmitting an impulse
- Impulse arrives
- Synaptic vesicles release
neurotransmitter - Diffuses across synapse
- Neurotransmitter attaches to receptor
- Triggers impulse in post-synaptic
membrane - Neurotransmitter deactivated by
enzyme - Neurotransmitter broken down and returns to presynaptic knob to be reassembled
and repackaged
What is a reflex arc
Automatic response to stimulus not involving brain Eg: pulling away from a hot object
What is the mechanism of reflex action
a) Sensory receptor detects stimulus,
b) Impulse along sensory neuron,
c) Across interneuron,
d) Straight out through motor neuron,
e) Effector responds,
f) Brain not involved
g) Minimises injury
What is grey matter
- Consists mainly of cell bodies
2. Is located in the centre of the spinal cord and on the outside of the brain
What is white matter
Consists mainly of
Is located in the outside of the spinal cord and on the inside of the brain
Parkinson’s syndrome
Symptoms: shuffling walk and shaking uncontrolably
Cause: Lack of Dopamine,
Prevention: None
Treatment: Levodopa.
Ear diagram labels and their functions
Pinna: collects sound waves and directs it into
external auditory canal
Eardrum: vibrates with sound waves
Ossicles: hammer, anvil and stirrup amplify
vibrations
Cochlea: converts vibrations to nervous impulses
Auditory Nerve: carries (electrical) impulse to brain
Eustachian Tube: connects middle ear to pharynx to equalize pressure in middle ear
Semi-circular Canals: give information about
movement and orientation in three planes
Vestibular Nerve: carries information about movement and orientation to the brain
Name a hearing defect, its cause, and its treatment
Defect: Otitis media (Glue ear)
Cause: Fluid in middle ear (reduces hearing)
Treatment: Grommets
How does light affect the pupil
In bring light the pupil constricts and in dim light it is dilated
What are rods and cones in the retina
- Rods: black and white, only work in dim light
* Cones: see colour mainly around fovea only work in bright light
Eye labels and their functions (14)
- Retina: light sensitive cells( cones and rods )
- Blind spot: where optic nerve leaves eye
- Fovea: sharpest vision
- Choroid: prevents internal reflection
- Sclera: protects and maintains eye shape
- Ciliary body: adjusts lens shape
- Suspensory ligament: holds lens in place
- Iris: colored part of the eye
- Lens: fine focuses light
- Pupil: lets light in and controls how much light enters the eye
- Cornea: focuses light
- Optic nerve: carries information to the brain
- Aqueous humour: maintains shape of the eye
- Vitreous humour: maintains shape of the eye ( the inside)
Name and explain two sight faults
1. Long Sight Can see far objects clearly but near object blurred Light focused behind retina Correction convex lens
2. Short Sight Can see close objects clearly but far objects blurred Light focused in front of retina Correction concave lens
What is responsible for the sense of smell
Olfactory mucus membrane on top of nasal cavity. It is Full of chemoreceptors.
Skin diagram labels
- Sweat gland: produces sweat
- Sebaceous gland: produces oil to moisturizes skin and hair
- Hair
- Nerves (sensory receptors): feels touch, hot, cold, pain etc
- Erector muscle: causes piloerection
- Layer of fat: insulates heat
What are the different tastes
Salty
Sweet
Bitter
Sour
What is an endocrine gland
secretes its products directly into the
blood stream
What is an exocrine gland
What is an endocrine gland
What is a hormone
Chemical messenger produced in endocrine gland and transported in blood stimulating target tissue to change its activity
Compare hormonal action and nervous action
Nervous:
- Fast acting
- Short lived
- Electrical
Hormonal:
- Slow acting
- Long lived
- Chemical
Name different glands in the body, the hormone they secrete, and the function of that hormone
- Pineal: Melatonin ( Induces relaxation)
- Hypothalamus: GHRH or growth hormone regulating hormone (Stimulates pituitary to release growth hormone)
- Pituitary: prolactin (Stimulates milk formation in mammary glands)
- Thyroid: Thyroxine ( increases metabolic rate )
- Thymus: thymosin (Stimulates the maturation of T cells)
- Adrenal: adrenaline (Increases pulse and breathing rate)
- Pancreas Islets of Langerhans: insulin (Stimulates the uptake of glucose from blood)
- Ovary: oestrogen ( Development of secondary sexual characteristics, formation of Graffian Follicle)
- Testis: testosterone (Development of secondary sexual characteristics, sperm production)
Thyroxine disorders
Deficiency Symptoms
a) Children cretinism
b) Adult low metabolic rate and weight gain
Excess Symptoms – high metabolic rate and weight loss
Corrective Measures
a) Deficiency: give thyroxine
b) Excess: surgically removal of some or all of thyroid
Give two examples of hormonal supplements
- Insulin: to control blood sugar levels for diabetics
2. Oxytocin: to induce and speed up labour in maternity hospitals