Human Bio Exam Flashcards
1
Q
the infundibulum does what?
A
connects the hypothalamus to the pituitary
2
Q
hypothalamus does what? (function)
A
regulates basic body functions (heart rate, water balance)
3
Q
what hormones does the hypothalamus secrete?
A
oxytocin and ADH
4
Q
what does the pituitary gland do?
A
regulates basic body functions (growth, metabolism, reproductive cycles)
5
Q
what’s the pituitary gland known as?
A
master gland
6
Q
how does the pituitary release hormones?
A
nerve impulse
7
Q
where are hormones produced?
A
anterior lobe-pituitary
8
Q
how does the anterior lobe release hormones
A
chemical/hormonal stimulation
9
Q
how many hormones does the anterior lobe release?
A
6
10
Q
what does the posterior lobe do?
A
stores hormones
11
Q
how are hormones transported to the posterior lobe
A
carried down axons of neurons
12
Q
what are the 6 hormones of the anterior lobe?
A
- follicle-stimulating hormone
- luteinising hormone
- growth hormone
- thyroid-stimulating hormone
- adrenocorticotropic
- prolactin
13
Q
target organ of the FSH?
A
ovaries and testes
14
Q
Main Effects of FSH
A
growth of follicles
production of sperm
15
Q
target organ of luteinising hormone?
A
ovaries and testes
16
Q
main effects of LH?
A
ovulation/maintenance of corpus luteum
secretion of testosterone
17
Q
target organ of growth hormone?
A
all cells
18
Q
main effects of the growth hormone?
A
growth and protein synthesis
19
Q
target organ of TSH?
A
thyroid gland
20
Q
main effects of TSH?
A
secretion of hormones from the thyroid
21
Q
target organ of adrenocorticotropic (ACTH)?
A
adrenal cortex
22
Q
main effects of ACTH?
A
secretion of hormones from the adrenal cortex
23
Q
target organ of prolactin?
A
mammary glands
24
Q
main effects of prolactin?
A
milk production
25
what are the hormones of the posterior lobe?
1. Antidiuretic Hormone
| 2. Oxytocin
26
target organ of the ADH?
kidneys
27
main effects of the ADH?
reabsorption of water
28
target organs of the oxytocin?
1. uterus
| 2. mammary glands
29
main effects of the oxytocin?
contractions of the uterus during childbirth
| release of milk
30
what are some other endocrine tissues?
- the stomach
- the small intestine
- the kidneys
- the heart
- the placenta
31
what is the central nervous system made up of?
- the brain
| - the spinal cord
32
what is the peripheral nervous system made up of?
- all nervous tissue besides those in the CNS
33
what is the main job of the peripheral nervous system?
to detect stimuli and send impulses to the CNS according to the stimuli
34
what is the cell body?
contains the nucleus and cellular organelles
35
what are dendrites?
branched extensions of the cytoplasm that carry nerve impulses towards the cell body
36
what is an axon?
a single extension of cytoplasm that carries impulses away from the cell body
37
what is a myelin sheath?
a fatty layer that covers the axon. it has 3 important functions
- protects the axon
- speeds up movement
- acts an insulator
38
what is the neurilemma ?
the outer most cover of the myelin sheath. Helps repair injured fibres
39
what is the node of Ranvier?
a gap that occurs at regular intervals in the myelin sheath. It allows nutrients and waste products to enter/leave the neuron
40
what are the axon terminals?
the ends of an axon that form chemical synapses. They are away from the cell body
41
what is a schwann cell?
they are cells that lay down the protective myelin sheath around the axon. Each Schwann cell protects one length of axon; around which it twists as it grows
42
what are the other parts of the neuron?
- myelinated fibres
- unmyelinated fibres
- grey matter
- white matter
43
what are the three functional types of neurons?
- interneurons
- sensory neurons
- motor neurons
44
what do sensory neurons do?
- carry messages from the sense organs to the CNS
| - they are afferent i.e. going toward the CNS from a major muscle or organ
45
what do motor neurons do?
- carry messages from the CNS to a muscle, gland or other effectors
- they are efferent i.e. going away from the CNS to a major muscle or organ
46
what are interneurons?
- connect sensory neurons to motor neurons
| - make up most of the brain and spinal cord
47
what is a receptor?
a group of cells which are sensitive to a stimulus. they change stimulus energy
48
what is an effector?
when a muscle or gland respond in different ways. Muscle contract in response to a nerve impulse whereas a gland will secrete a hormone
49
What are the three structural types of neurons?
- unipolar
- bipolar
- multipolar
50
what is a unipolar neuron?
- one extension and one axon
- the cell body is found to the side of the axon
- carry messages to the spinal cord
- found mainly in the sensory nerves of the PNS - a neuron which only a single process leaves the cell body
51
what is a bipolar neuron?
- one axon and one dendrite
- can be found in the retina of the eye and the olfactory nerve in the nose and has two processes which leave the cell body
- they take impulses from the receptor to other neurons
52
what is a multipolar neuron?
- one axon and multiple dendrites extending from the cell body
- most common neuron
- including interneurons from the brain and spinal cord and the motor neurons that carry messages to the skeletal muscles
53
what is the membrane potential?
the difference between the ion concentrations on either side of a cell membrane
54
what is the resting membrane potential?
an unstimulated nerve fibre has this type of membrane potential; usually approximately - 70mV
55
what is saltatory conduction?
conduction of a nerve impulse along a myelinated neuron; the impulse jumps from each node of Ranvier to the next
56
what is depolarisation?
reversal of electrical charge on each side of the membrane of a neuron; inside of the membrane becomes positive and the outside becomes negative; is the opposite to polarisation and is responsible for the transmission of nerve impulses
57
what is polarisation?
when the inside of the membrane of a neuron is more negatively charged than the outside
58
what is the all or nothing response?
regardless of the strength of the stimulus, a nerve impulse is transmitted at full strength or not at all
• If the stimulus exceeds the threshold potential the nerve or muscle fibre will give a complete response; otherwise there is no response
• Action potential remains the same/nerve impulse is not more intense or weaker
59
what are the features of an unmyelinated fibre?
- nerve impulse travels continuously
- show continuous conduction
- maximum speed is 2m/s
- don't have fatty myelin sheath
60
what are the features of a myelinated fibre?
- nerve impulse jumps from one node of Ranvier to the next
- show saltatory conduction (impulse jumps from one node of Ranvier to node of Ranvier)
- can conduct impulses at a speed of up to 140m/s
- covered by a sheath of myelin
61
what is the main function of the nervous system?
the function of the nervous system is to communicate, process and respond to information about the internal and external environments
62
how many pairs of cranial nerves are there?
12 pairs
63
what are cranial nerves?
- most cranial nerves are mixed nerves, carrying impulses into and out of the brain
- two cranial nerves that are not mixed are the auditory and optic nerves
64
how many pairs of spinal nerves are there?
31 pairs
65
what are spinal nerves?
- all mixed nerves
| - each is joined to the spinal cord by 2 roots (a dorsal and ventral root)
66
what is the ventral root?
contains the axons of motor neurons that have their cell bodies in the grey matter of the spinal cord
67
what is the dorsal root?
contains the axons of sensory neurons that have their cell bodies in a small swelling on the dorsal root ganglion
68
what is the automatic nervous system?
the ANS works without conscious control and is regulated by the medulla oblongata, hypothalamus, and cerebral cortex
part of the PNS
is responsible for involuntary movement, reflexes and in control our body's internal and external environment - homeostasis
69
Describe the cranium as a protective structure of the CNS
- the brain is housed by the cranium, protecting it
| - vertebrae protects the spinal cord
70
Describe the Meninges as protective structures of the CNS
outer layer = is tough, fibrous, inflexible which prevents the brain from moving
middle layer = loose mesh fibres
inner layer = more delicate layer as it contains many blood vessels
71
Describe the cerebrospinal fluid as a protective structure of the CNS
is a clear watery fluid that contains glucose, protein, urea and salts
acts as a shock absorber
supports the brain as the brain floats in the fluid
also circulates nutrients to the cells of the brain and carries wastes away
72
what is a receptor?
a receptor is a structure that is able to detect a change in the body's internal and external environment
73
what are the five main receptors?
- thermoreceptors
- osmo-receptors
- chemoreceptors
- touch receptors
- pain receptors
74
Describe a thermoreceptor
- able to respond to hot and cold
- in the skin, there are thermoreceptors that inform the brain of changes in the temperature outside the body
- skin thermoreceptors are sensitive to either heat or cold but not both
- the temperature inside the body is monitored by thermoreceptors in the hypothalamus
75
describe osmo-receptors
Located in the hypothalamus and are sensitive to osmotic pressure
They respond to very small changes in osmotic pressure and are able to stimulate the hypothalamus so that the body’s water content is maintained
76
describe chemoreceptors
* Stimulated by particular chemicals
* Chemoreceptors are sensitive to the pH of the blood and to the concentrations of oxygen and carbon dioxide
* These are involved in the regulation of the heartbeat and of breathing
* Present in nose and in mouth – due to breathing through nose
77
describe touch receptors
* Found mainly in the skin and there are a number of different types (light touch or strong pressure)
* Light touch is close to the surface of the skin
* These occur in greater concentrations in areas of the skin that are more sensitive, such as lips, fingertips, eyelids and external genitalia organs
* Strong pressure is located deeper in the skin and are sensitive to pressure and vibrations
78
describe pain receptors
* Stimulated by damage to the tissues, such as from a cut or a heavy bump, by poor blood flow to a tissue, or by excessive stimulation from stimuli such as heat and chemicals
* The receptors for pain are especially concentrated in the skin
* Occur in most organs, but not the brain
* Pain is essential for our well-being even though it's uncomfortable
* Pain warns us that damage to tissues is occurring, and we can take evasive action or seek medical help so that damage is minimized
* Pain receptors adapt little or not at all (unlike other receptors
79
what is a reflex?
- a reflex is a rapid, automatic response
| - all reflexes have four important properties
80
what are the four properties of a reflex?
1. A stimulus is required to trigger a reflex - it is not spontaneous
2. A reflex is involuntary - it occurs without any conscious thought
3. A reflex is a rapid response - only a small number of neurons are involved
4. A reflex is stereotyped - occurs in the same way each time it happens
81
what is a learning reflex?
these can include complex motor patterns during a baby's development such as chewing, sucking and following objects with their eyes
82
what is an acquired reflex?
these include motor development skills such as galloping, running, walking, hopping and catching. To be able to do these tasks they need to be repeated and learned over and over so we can achieve these reflexes
83
Describe the reflex arc
Use the book for answers
84
what is homeostasis?
the process whereby the body’s internal environment is maintained in a steady state (i.e. with normal tolerance limits)
85
what is thermoregulation?
- Any heat gained by the body must be equal to the heat lost by the body, maintaining this equal proportion is called thermoregulation
- A human body temperature remains constant at 37 degrees
- Keeping an equal body temperature of 37 degrees is needed for cellular activities, otherwise, cellular activities aren’t maintained
86
what are some factors which increase body temperature?
1. exercise/strenuous physical activity
2. women's second half of their menstrual cycle
3. sickness (fever)
4. external factors; hot or cold parts of the day
87
what contain energy in chemical bonds?
Carbohydrates, proteins, and lipids contain energy in chemical bonds - useable by humans
88
what can energy be used for?
- muscle contraction
- active transport (requires ATP)
- the building of complex molecules (anabolic/catabolic reactions)
89
what is metabolic rate?
the rate at which energy is released to the body by the breakdown of food
90
how is most energy lost?
through heat conduction, convection and radiation
91
what are the factors that may affect the metabolic rate of releasing energy from food?
- exercise
- stress
- body temperature
92
describe radiation
- the transfer of heat from one object to another without the objects being in contact
- heat will radiate from your body to cooler objects e.g. ceilings/walls
- if objects close to you are higher than body temperature, you will absorb heat from them due to the radiation process = hotter the object the more it radiates
93
describe conduction
- involves a transfer of heat from particle to particle within an object or from the particles of one object to particles of another – transferred through contact
- Heat moves from the object of higher temperature to the object of lower temperature
94
describe convection
* Convection current = when cool air makes contact with body, it becomes warm, thus less dense. It is pushed away as denser air takes its place, which in turn becomes warm and pushed away
* Faster flow of air = faster rate of heat is transferred
* Convection also helps conduction as it makes sure a cool air supply is in contact with the body
* Without convection transfer of heat via conduction between the body and air particles would be almost negligible
95
Compare hypothermia and hyperthermia
use book for answers
96
what are the major organs of excretion?
- lungs
- alimentary canal
- kidneys
- skin
97
what is excretion?
- removal of waste products from metabolism (outside the body)
- many wastes are toxic and are harmful to our health if the waste accumulates in the body
98
describe the kidneys
- bean shaped
- a dark, brown reddish colour
- 2 of them
- produce urine
99
describe the ureter
- a thin tube that is attached from the kidney to the bladder (carries urine down from kidney to bladder)
100
describe the bladder
a membranous sac or organ that stores urine
101
describe the renal artery
carries blood from aorta to kidney
102
describe the renal veil
carries filtered blood from kidney to inferior vena cava
103
what is the role of the adrenal cortex?
- stimulates the hormone (ACTH) to be secreted from the anterior pituitary
- the hormones which are secreted from the cortex are called glucocorticoids or cortisol
- cortisol regulates the carbohydrate metabolism
- this helps stimulate the conversion of glycogen to glucose to be used
- also stimulates protein breakdown in muscles and converts amino acids into glucose in the liver
104
what is the process of the conversion of glycogen to glucose?
glycogenolysis
105
what is the role of the adrenal medulla?
- Stimulates the release of adrenaline and noradrenaline
- If these hormones are released, it will increase the BSL
- It will also stimulate the breakdown of glycogen in liver and release the glucose into the blood
- Also stimulates the production of lactic acid from glycogen in muscle cells, then the lactic acid can be used by the liver to manufacture glucose
106
what is the process of breaking down lipids in adipose tissue into glucose ?
gluconeogenesis
107
what are the receptors of the pancreas responsible for?
monitoring glucose levels in the blood
108
what is the blood glucose levels our body desires?
between 70mg/dL and 110mg/dL
109
what is a blood glucose level below 70mg/dL called?
hypogylcemia
110
what is a blood glucose level above 180mg/dL called?
hypergylcemia
111
what parts of the body are involved in moving air into and out of the body?
- the intercostal muscles
- the lungs
- the diaphragm
112
define heart rate
the number of times the heart beats per minute
113
define stroke volume
the volume of blood forced from the left ventricle of the heart with each concentration
114
define cardiac output
the volume of blood leaving the ventricle of the heart every minute
115
what is the sinotrial node?
the heart's pacemaker; a group of cells in the wall of the right atrium of the heart that regulates heart beat
116
what is the atrioventricular node?
a compact mass of modified cardiac muscle cells between the heart's atria and ventricles that relay electrical impulses to the ventricles
