1REVIEW Flashcards
(186 cards)
1
Q
What is the main function of the nervous system?
A
To detect and respond to internal and external stimuli to maintain homeostasis.
2
Q
What are the two main parts of the nervous system?
A
Central Nervous System (CNS) and Peripheral Nervous System (PNS).
3
Q
What does the CNS consist of?
A
Brain and spinal cord.
4
Q
What does the PNS do?
A
Carries information between the body and the CNS.
5
Q
What are the two parts of the PNS?
A
Somatic (voluntary control) and Autonomic (involuntary control).
6
Q
What are the two branches of the autonomic nervous system?
A
Sympathetic and Parasympathetic.
7
Q
What does the sympathetic nervous system do?
A
Prepares the body for stress (‘fight or flight’).
8
Q
What does the parasympathetic nervous system do?
A
Restores the body to a calm state (‘rest and digest’).
9
Q
What are the three types of neurons?
A
Sensory, interneurons, and motor neurons.
10
Q
What is the role of sensory neurons?
A
Transmit information from sensory receptors to the CNS.
11
Q
What is the role of interneurons?
A
Process information in the CNS and connect sensory and motor neurons.
12
Q
What is the role of motor neurons?
A
Transmit signals from CNS to effectors (muscles or glands).
13
Q
What is a reflex arc?
A
A quick, automatic response involving sensory neurons, interneurons, and motor neurons.
14
Q
What is the resting membrane potential?
A
-70 mV.
15
Q
How is the resting membrane potential maintained?
A
By the sodium-potassium pump (3 Na+ out, 2 K+ in).
16
Q
What is depolarization?
A
When Na+ enters the neuron, making the inside more positive.
17
Q
What is repolarization?
A
When K+ leaves the neuron, restoring a negative internal charge.
18
Q
What is the refractory period?
A
Time during which the neuron cannot fire another action potential.
19
Q
What is saltatory conduction?
A
When the impulse jumps from node to node in myelinated neurons.
20
Q
What is a synapse?
A
The gap between two neurons or a neuron and an effector.
21
Q
What are neurotransmitters?
A
Chemicals that transmit signals across a synapse.
22
Q
What is acetylcholine?
A
A neurotransmitter that causes muscle contraction.
23
Q
What enzyme breaks down acetylcholine?
A
Cholinesterase.
24
Q
What can happen if neurotransmitter balance is disrupted?
A
Physical and psychological disorders (e.g., depression, high blood pressure).
25
What are the two main parts of the nervous system?
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
26
What protects the brain and spinal cord?
Skull, meninges, and cerebrospinal fluid
27
What are the three layers of meninges?
Dura mater, arachnoid layer, pia mater
28
What is the function of cerebrospinal fluid?
Cushions the brain and transports nutrients
29
Which part of the brain controls homeostasis and hormones?
Hypothalamus
30
What does the cerebrum control?
Intellect, memory, consciousness, personality, language
31
What connects the left and right hemispheres of the brain?
Corpus callosum
32
What does the occipital lobe process?
Visual information
33
What does the temporal lobe process?
Auditory information and speech comprehension (Wernicke’s area)
34
What does the parietal lobe do?
Processes sensory input and body orientation
35
What does the frontal lobe control?
Reasoning, memory, voluntary movement, speech (Broca’s area)
36
What part of the brain helps coordinate movement and balance?
Cerebellum
37
What is the role of the medulla oblongata?
Controls involuntary functions like heart rate and breathing
38
What is the somatic nervous system responsible for?
Voluntary control of muscles
39
What does the autonomic nervous system control?
Involuntary body functions
40
What are the two branches of the autonomic nervous system?
Sympathetic and Parasympathetic
41
What do photoreceptors detect?
Light
42
Where are rods and cones located?
In the retina
43
What do rods detect?
Shades of black and white, used in low light
44
What do cones detect?
Color (red, green, blue)
45
What is the fovea centralis?
Area of the retina with the highest concentration of cones for sharp vision
46
What causes the blind spot in the eye?
Lack of photoreceptors where the optic nerve exits the retina
47
What is myopia?
Nearsightedness; image focuses in front of the retina
48
What lens corrects myopia?
Concave lens
49
What is hyperopia?
Farsightedness; image focuses behind the retina
50
What lens corrects hyperopia?
Convex lens
51
What is astigmatism?
Irregular curvature of lens or cornea causing blurred vision
52
What is glaucoma?
Pressure build-up in the eye damaging the optic nerve
53
What is a cataract?
Clouding of the lens blocking light from reaching retina
54
What is accommodation in vision?
Lens changing shape to focus on near or far objects
55
What causes afterimages?
Overstimulation of photoreceptors followed by perception of opposite color
56
What is the function of the optic nerve?
Transmits visual information to the brain
57
Where in the brain is vision interpreted?
Occipital lobe
58
What is sensation?
Receiving sensory information and sending it to the cerebral cortex.
59
What is perception?
Interpretation of sensory information by the cerebral cortex.
60
What do photoreceptors detect?
Light and color (vision).
61
What do chemoreceptors detect?
Chemicals (smell and taste).
62
What do mechanoreceptors detect?
Mechanical forces like pressure and vibration (hearing, balance, touch).
63
What do thermoreceptors detect?
Heat and cold.
64
Which photoreceptor is active in low light?
Rods.
65
Which photoreceptor is responsible for color vision?
Cones.
66
Where is the sharpest vision located?
Fovea centralis.
67
What is the blind spot of the eye?
The optic disk, where there are no photoreceptors.
68
What part of the ear collects sound?
Pinna.
69
What bones amplify sound in the middle ear?
Malleus, incus, and stapes.
70
What structure equalizes pressure in the ear?
Eustachian tube.
71
What converts sound waves into nerve impulses?
Cochlea.
72
Where is the organ of Corti located?
Inside the cochlea.
73
What part of the brain receives hearing signals?
Temporal lobe.
74
What do the semicircular canals detect?
Rotational balance.
75
What does the vestibule detect?
Gravitational equilibrium (head tilt).
76
What are otoliths?
Granules in the vestibule that detect head movement.
77
What are the five main taste perceptions?
Sweet, sour, salty, bitter, and umami.
78
Where are taste buds located?
On the papillae of the tongue.
79
Which two senses are strongly linked?
Taste and smell.
80
What are olfactory cells?
Chemoreceptors in the nose that detect odor particles.
81
Which brain areas process smell?
Olfactory bulb, frontal lobe, and emotional centers.
82
Where are mechanoreceptors for touch most concentrated?
Hands, lips, and genitals.
83
What is sensory adaptation?
The brain filtering out constant or unimportant stimuli.
84
What causes pain signals to be sent?
Chemicals released by pain receptors.
85
How do painkillers work?
By blocking the chemicals that transmit pain.
86
What causes afterimages in vision?
Overstimulated photoreceptors sending weak signals.
87
What part of the eye changes shape to focus light?
The lens, with help from ciliary muscles.
88
What is the sclera?
The white, protective outer layer of the eye.
89
What is the cornea?
The transparent part of the sclera that bends light.
90
What is the choroid?
The middle layer of the eye with blood vessels.
91
What is the iris?
The colored part of the eye that controls pupil size.
92
What is the pupil?
The opening in the eye that lets light in.
93
What does the lens do?
Focuses light onto the retina.
94
What do ciliary muscles do?
Change lens shape for focusing (accommodation).
95
What is the retina?
The inner layer containing rods and cones.
96
What is the fovea centralis?
The area of sharpest vision with many cones.
97
What is the optic nerve?
Transmits visual info to the brain.
98
What is the optic disk?
The blind spot; no photoreceptors here.
99
What do rods detect?
Light intensity (brightness); used in dim light.
100
What pigment do rods contain?
Rhodopsin.
101
What do cones detect?
Color (red, green, blue); used in bright light.
102
Where are cones concentrated?
In the fovea centralis.
103
Where is visual info processed in the brain?
Occipital lobe of the cerebrum.
104
What is neural multitasking?
Brain splits sensory input across different areas.
105
What are optical illusions?
Perceptual errors caused by incomplete reintegration of sensory info.
106
What type of receptor is responsible for hearing and balance?
Mechanoreceptors.
107
What does the auditory system detect?
Sound waves (vibrational energy of air particles).
108
What converts sound waves into electrochemical energy?
Mechanoreceptors in the inner ear.
109
What are the three main parts of the ear?
Outer ear, middle ear, and inner ear.
110
What is the function of the pinna?
Collects sound.
111
What does the auditory canal do?
Carries sound to the eardrum.
112
What is the tympanic membrane?
The eardrum that vibrates with sound.
113
What are the ossicles?
Three small bones (malleus, incus, stapes) that amplify sound.
114
What is the oval window?
A membrane that connects the middle ear to the inner ear.
115
What does the Eustachian tube do?
Equalizes pressure between the middle ear and throat.
116
What structures are found in the inner ear?
Cochlea, vestibule, semicircular canals.
117
What is the cochlea's function?
Converts mechanical sound energy into nerve signals.
118
What does the vestibule detect?
Gravitational equilibrium (linear motion and head position).
119
What do semicircular canals detect?
Rotational equilibrium (head and body rotation).
120
What is the organ of Corti?
The hearing organ in the cochlea with hair cells.
121
What does the basilar membrane do?
Vibrates and bends hair cells in response to sound.
122
What is the tectorial membrane?
The membrane hair cells press against to trigger impulses.
123
What are stereocilia?
Hair-like projections that detect vibration.
124
What happens when stereocilia bend?
They trigger nerve impulses sent to the brain.
125
Where is sound processed in the brain?
Temporal lobe of the cerebrum.
126
What pathway does auditory information take?
Auditory nerve → brain stem → thalamus → temporal lobe.
127
What part of the cochlea detects high-frequency sounds?
Hair cells closest to the oval window.
128
What part of the cochlea detects low-frequency sounds?
Hair cells farthest from the oval window.
129
What can high volume sounds do?
Damage stereocilia, causing hearing loss.
130
What are otoliths?
Calcium carbonate crystals that shift to detect head position.
131
What do the utricle and saccule do?
Detect gravitational equilibrium.
132
What do proprioceptors do?
Inform brain of body position via muscles, tendons, and joints.
133
Gonadotropin-Releasing Hormone (GnRH)
HYPOTHALMUS
Target: Anterior pituitary
Action: Stimulates the release of LH and FSH
Effect: Triggers sexual development and fertility
134
Thyrotropin-Releasing Hormone (TRH)
HYPOTHALMUS
Target: Anterior pituitary
Action: Stimulates release of TSH
Effect: Increases thyroid activity → metabolism
135
Human Growth Hormone (hGH)
ANT. PIT
Target: Most body cells, especially bones and muscles
Effect: Promotes growth, protein synthesis, and fat metabolism
136
Thyroid-Stimulating Hormone (TSH)
ANT. PIT
Target: Thyroid gland
Effect: Stimulates release of thyroxine (T4) → increases metabolism
137
Adrenocorticotropic Hormone (ACTH)
ANT. PIT
Target: Adrenal cortex
Effect: Stimulates release of cortisol (long-term stress)
138
Prolactin (PRL)
ANT. PIT
Target: Mammary glands
Effect: Stimulates milk production after birth
139
Luteinizing Hormone (LH)
ANT. PIT
Females: Triggers ovulation and formation of corpus luteum
Males: Stimulates testosterone production in testes
140
Follicle-Stimulating Hormone (FSH)
ANT. PIT
Females: Stimulates egg follicle development in ovaries
Males: Stimulates sperm production in testes
141
Antidiuretic Hormone (ADH)
POST. PIT
Target: Kidneys
Effect: Promotes water reabsorption, reduces urine output
Important during: Dehydration
142
Oxytocin
POST. PIT
Target: Uterus and mammary glands
Effect: Causes uterine contractions during labour and milk ejection
Positive feedback loop
143
Thyroxine (T4)
THYROID
Target: Most body cells
Effect: Increases metabolism, body temperature, and energy use
144
Calcitonin
THYROID
Target: Bones
Effect: Lowers blood calcium by storing it in bones
145
Parathyroid Hormone (PTH)
PARA. THYROID
Target: Bones, kidneys, intestines
Effect: Raises blood calcium by:
Releasing it from bones
Reabsorbing in kidneys
Absorbing from intestines
146
Glucocorticoids (e.g. Cortisol)
ADRENAL CORTEX
Target: Liver, fat, muscle
Effect: Raises blood glucose, breaks down fat/protein, reduces inflammation
Released during: Long-term stress
147
Aldosterone (Mineralocorticoid)
ADRENAL CORTEX
Target: Kidneys
Effect: Increases sodium and water reabsorption, raises blood pressure
148
Epinephrine (Adrenaline)
ADRENAL MEDULLA
Target: Heart, lungs, muscles
Effect: Triggers fight-or-flight:
Increases heart rate and breathing
Dilates pupils
Increases blood glucose
149
Insulin (from beta cells)
PANCREAS
Target: Most body cells
Effect: Lowers blood glucose by helping cells absorb glucose
150
Glucagon (from alpha cells)
PANCREAS
Target: Liver
Effect: Raises blood glucose by breaking down stored glycogen
151
Estrogen
Target: Uterus, breasts, brain
Effect: Female secondary sex characteristics, menstrual cycle regulation. MAINTAIN UTERINE LINING
152
Progesterone
Target: Uterus
Effect: Maintains uterine lining for pregnancy
153
Testosterone
Target: Muscle, bone, reproductive organs
Effect: Male secondary sex characteristics, sperm production
154
Inhibin
Target: Anterior pituitary
Effect: Inhibits FSH, helps regulate sperm production
155
What is the function of the endocrine system?
To regulate body systems using chemical messengers called hormones.
156
What are hormones?
Chemical messengers that travel through the bloodstream to target cells.
157
How is the endocrine system different from the nervous system?
It works more slowly but controls longer-lasting processes.
158
What is a target cell?
A cell with receptors that respond to specific hormones.
159
What is a non-target hormone?
A hormone that affects many cells or tissues (e.g. insulin).
160
What is a tropic hormone?
A hormone that acts on another endocrine gland.
161
What is the master gland of the body?
The pituitary gland.
162
What does the anterior pituitary do?
Produces and releases hormones like hGH, TSH, FSH, LH, ACTH.
163
What does the posterior pituitary do?
Stores and releases hormones made by the hypothalamus (e.g. ADH, oxytocin).
164
What is negative feedback?
A process where the end product inhibits its own production.
165
What is positive feedback?
A process where the end product enhances its own production.
166
Which hormone works via positive feedback during childbirth?
Oxytocin
167
What does hGH (human growth hormone) do?
Stimulates growth, protein synthesis, and fat metabolism.
168
What happens if the body makes too much hGH?
Gigantism.
169
What happens if the body makes too little hGH?
Pituitary dwarfism.
170
What does thyroxine (T4) do?
Increases metabolism and supports growth.
171
What is needed to make thyroxine?
Iodine.
172
What happens if there's not enough iodine?
The thyroid enlarges, forming a goiter.
173
What does calcitonin do?
Lowers blood calcium by storing it in bones.
174
What does parathyroid hormone (PTH) do?
Raises blood calcium by releasing it from bones and increasing absorption.
175
What hormones are made by the adrenal medulla?
Epinephrine and norepinephrine.
176
What do epinephrine and norepinephrine do?
Trigger the short-term stress response (fight or flight).
177
What hormones are made by the adrenal cortex?
Cortisol, aldosterone, and sex hormones.
178
What does cortisol do?
Raises blood sugar during long-term stress
179
What does aldosterone do?
Raises blood pressure by increasing sodium and water reabsorption.
180
What does insulin do?
Lowers blood sugar by helping cells absorb glucose.
181
What does glucagon do?
Raises blood sugar by triggering glucose release from the liver.
182
What is Type I diabetes?
Autoimmune disease where beta cells are destroyed and no insulin is produced.
183
What is Type II diabetes?
Cells stop responding to insulin.
184
What are common symptoms of diabetes?
Fatigue, thirst, frequent urination, and long-term complications like kidney damage and blindness.
185
What is hyperthyroidism?
A condition where the thyroid gland produces too much thyroxine (T4), increasing metabolism.
186
What is hypothyroidism?
A condition where the thyroid gland produces too little thyroxine (T4), slowing down metabolism.
