Exam 2 Flashcards
1
Q
What are the two ways hormones deliver messages?
A
- Endocrine: hormones travel through blood to distant targets. 2. Neuroendocrine: neurons release hormones into the blood.
2
Q
What four factors affect hormone levels in the blood?
A
- Secretion rate 2. Metabolism/excretion rate 3. Transport proteins 4. Plasma volume changes
3
Q
What is upregulation?
A
- Increase in number of receptors due to chronically low concentration of hormone
- Results in hyperactivity of receptors when hormone is available
4
Q
What is downregulation?
A
- decrease in number of receptors due to chronically high concentration of hormone
- results in decreased hormonal response
5
Q
How do hormones act on target cells?
A
Steroid hormones enter cells and change gene expression. Non-steroid hormones use surface receptors and second messengers like cAMP.
6
Q
What are insulin and glucagon, and what do they do?
A
Insulin lowers blood sugar; glucagon raises blood sugar.
7
Q
What do epinephrine and norepinephrine do during exercise?
A
Increase heart rate, blood flow to muscles, and fuel mobilization.
8
Q
What are the main divisions of the nervous system?
A
CNS (brain & spinal cord) and PNS (sensory and motor pathways including somatic and autonomic systems)
9
Q
What are the parts of a neuron?
A
Dendrites (receive), Cell body (processes), Axon (sends), Synsapse
10
Q
How does synaptic transmission work?
A
AP arrives → calcium enters terminal → neurotransmitters released → bind to next cell’s receptors.
11
Q
What is the difference between EPSP and IPSP?
A
EPSP excites (brings closer to threshold); IPSP inhibits (moves further from threshold).
12
Q
What is a motor unit and what is the size principle?
A
Motor unit = neuron + muscle fibers. Size principle: smaller units activate before larger ones.
13
Q
Sympathetic vs. Parasympathetic nervous system?
A
Sympathetic = fight/flight (↑HR); Parasympathetic = rest/digest (↓HR).
14
Q
What are the layers of muscle connective tissue?
A
Epimysium (whole muscle), Perimysium (fascicles), Endomysium (fibers)
15
Q
What is the sarcomere and its function?
A
Basic contractile unit; uses actin and myosin to shorten and contract muscle.
16
Q
Sliding filament Theory Steps
A
- Motor neuron triggers ACH release
- ACH triggers calcium release
- Calcium binds to troponin which removes the tropomyosin from covering the active sites
- Myosin heads bind to active sites
- Power stroke used to pull myosin and actin close together
- Repeated until relaxation, exhaustion or no more space to contract
17
Q
What are the 3 types of muscle contractions?
A
Concentric (shortens), Eccentric (lengthens), Isometric (no change)
18
Q
What influences how much force a muscle produces?
A
Motor unit recruitment, firing rate, muscle length, contraction speed.
19
Q
What is sarcopenia vs. cachexia?
A
Sarcopenia = age-related muscle loss; Cachexia = disease-related wasting.
20
Q
What are the main functions of the CR system?
A
Deliver oxygen, remove waste, regulate pH, temp, and fluid balance.
21
Q
What is the path of blood through the heart?
A
RA → RV → lungs → LA → LV → body
22
Q
What are systole and diastole?
A
Systole = contraction; Diastole = relaxation
23
Q
What is mean arterial pressure (MAP)?
A
MAP = DBP + 1/3(SBP - DBP)
24
Q
What changes in the CR system occur during exercise?
A
Increased HR, SV, CO, and blood flow to muscles.
25
Adrenocorticotropic Hormone (ACTH)
- released from Anterior Pituitary
- stimulates release of cortisol from adrenal glands
26
Luteinizing Hormone (LH
stimulates production of estrogen and testosterone
27
What hormones does the anterior pituitary gland release
ACTH
FSH
LH
MSH
TSH
GH
Prolactin
28
Hypothalamus
- provides hormones for release from posterior pituitary gland
- stimulates release of hormones from anterior pituitary gland by Releasing factors/hormones
29
Mechanisms of Hormone Actions
- Gene activation to alter protein synthesis
- Activating 2nd messengers via G-protein
- Altering membrane transport
30
Gene activation to alter protein synthesis
- Steroid hormones diffuse easily through cell membrane and bind to protein receptors on cytoplasm
- activates genes that lead to synthesis of mRNA which is carried to synthesize a specific protein
31
Thyroid Stimulating Hormone (TSH)
- released from Anterior Pituitary Gland
- Controls release of thyroid hormone from
32
Growth hormone functions
- Spare plasma glucose
- Stimulate release of insulin like growth factors (IGF)
- Essential for growth of all tissues
33
How growth hormone spares
- Opposes insulin action (anti-insulin effect), reduces the use of plasma
glucose.
- Increases gluconeogenesis.
- Mobilizes fatty acids from adipose tissue.
34
How growth hormone leads to essential growth of all tissues
- Amino acid uptake and protein synthesis
- Long bone growth.
35
IGF 1
- Released by growth hormone
- responsible for muscle growth
36
Neuron Structure
Cell body
Dendrite
Axon
Synapse
37
Cell Body
contains nucleus
38
Dendrite
Sends action potential towards cell body
39
Axon
Sends action potential away from cell body
Schwann cells form myelin sheath for rapid transport
40
Synapse
Point of contact between an axon of 1 neuron and dendrite of another
41
Irritability
Ability to respond to a stimulus and trigger a neural impulse
42
Conductivity
Transmitting a neural impulse down the length of the neuron
43
All or None Law
If an impulse is created, it will travel the length of the neuron
44
Excitatory Post Synaptic Potentials (EPSP)
- Promotes depolarization
- Temporal Summation
- Spatial Summation
45
Temporal Summation
- Multiple EPSPs produced from one presynaptic neuron
Additive because it results in many open ion channels
46
Spatial Summation
- EPSPs come from different presynaptic neurons
- Come together at one postsynaptic neuron
47
Inhibitory Post Synaptic Potentials (IPSP)
- Promotes hyperpolarization
- Neurons with most negative membrane potential resist depolarization
- Ratio of EPSP to IPSP determines if neuron reaches threshold
48
Process of Action Potential
- Polarized at -70
- Reaches threshold at -55 for depolarization where sodium channels open
- Once depolarized, sodium channels close, potassium channels open
- Hyperpolarizes, and slowly returns back to resting membrane potential of -70
- Refractory period between hyperpolarization and resting potential where impulses cannot be formed
49
Proprioceptors
Tell CNS about position of body
50
Free Nerve Endings
- Joint proprioceptor
- Detect touch and pressure
- High stimulation at start of exercise but adapts to have low consistent stimulus during
51
Golgi Type Receptors
- Joint proprioceptor
- In ligaments and around joints
- Same function as free nerve ending
52
Pacinian Corpuscles
- Joint proprioceptor
- In tissues around joints
- detects rate of joint rotation
- Quick response to movement initiation
53
Muscle Proprioceptors
- Detect length change and force development
- Send information about movement patterns to brain
- Afferent information sent to cardiovascular and respiratory centers to regulate exercise response
54
Muscle Spindle
- Muscle proprioceptor
- Detects length and rate of shortening
- Composed of intrafusal fibers, sensory nerve endings, gamma motor neurons
- Stretch reflex
55
Stretch Reflex
1. Muscle spindles detect stretch
2. Sensory neurons conduct action potentials to spinal cord.
3. Sensory neurons synapse with alpha motor neurons.
4. Stimulation of alpha motor neurons causes muscle to contract and resist
being stretched
56
Golgi Tendon Organ
- Muscle Proprioceptor
- In tendon
- Detect force development
57
Golgi tendon organ process
1. Detect tension on tendon
2. Send impulse to spinal cord
3. Synapse to create IPSP
4. IPSP causes relaxation relieving tension
58
Motor Unit
motor neuron and all muscle fibers it innervates
59
Somatic Motor Recruitment
Progressive recruitment of more motor units recruits more muscle fibers, increasing strength of contraction
60
Size Principle of Motor Recruitment
- Motor units recruited based on function if their size
- During exercise small motor units are recruited first and then larger units are recruited if more strength is needed
61
Cerebrum
- Large dome with 2 hemispheres
- Complex movement, learned experiences, receives sensory info, motor cortex
62
Cerebellum
- Behind pons and medulla
- coordinate and monitor complex movement
- Initiate fast movements
- Damage causes poor movement control and tremor
63
Brain Stem
- In base of skull above spinal cord
- Medulla, pons, midbrain, reticular formation
- Cardio control, metabolic functions, complex reflexes, eye movement, muscle tone, equilibrium, posture
64
Spinal Cord Motor Functions
- Refines detail of movement
- Withdrawal reflex: remove limb from source of pain
- Spinal tuning
65
Spinal Tuning
Neural networks within spinal cord refine voluntary movement after receiving messages from brain
66
Autonomic Nervous System
- Homeostasis
- Operates below conscious level
- Smooth muscle, cardiac muscle, glands
- Sympathetic and Parasympathetic
67
Sympathetic
- Cell bodies of preganglionic neurons in the thoracis and lumbar regions of spinal cord
* Releases norepinephrine (NE)
* Norepi binding to alpha or beta receptor on effector organ
- NE removed from synapse or broken down
- Fight or Flight
68
Parasympathetic
- Cell bodies in brain stem and the sacral portion of the spinal cord.
* Releases acetylcholine (ACh).
* Acetylcholine binds to receptors.
* Acetylcholine degraded by acetylcholinesterase.
- Rest and digest
69
Aldosterone
- Adrenal cortex
- potassium secretion and sodium reabsorption
- regulation of blood volume and pressure
- stimulated by:
• exercise (sweat, high intensity)
• high potassium concentration
• low blood volume
70
Insulin
- promotes uptake of glucose and storage of FFA
- pancreas
- decreased response following training
- increased level after meal
- decreased concentration during exercise
71
Glucagon
- mobilizes FFA and glucose
- pancreas
- decreased response following training
- concentration increases during exercise
72
Norepinephrine and epinephrine
- adrenal medulla
- maintain plasma glucose levels
- mobilizes muscle glycogen, liver glucose, FFA
- disrupts uptake of glucose in tissues
- increases during exercise
73
Norepinephrine and epinephrine response to submaximal exercise
Decreased response following training
74
Norepinephrine and epinephrine response to supramaximal exercise
Higher plasma concentration in trained individuals
75
76
Epinephrine and Norepinephrine Function
- Fast acting
- Maintain plasma glucose
- Increases mobilization of free fatty acids, muscle glycogen, and liver glucose
- Disrupts glucose uptake by tissues
77
Epinephrine and Norepinephrine exercise response
- increased due to high heart rate and blood pressure
- secreted by adrenal medulla
78
Insulin
- Secreted by pancreas
- increases uptake and storage of glucose and free fatty acids
- increased following meal
- secretion influenced by catecholamines
79
Insulin Exercise Response
- Plasma insulin concentration during exercise decreases
- Decreased insulin response following exercise
80
Glucagon
- secreted by pancreas
- mobilizes glucose and free fatty acids
- secretion influenced by catecholamines
81
Glucagon Exercise Response
- mobilizes glucose and free fatty acids
- increased plasma concentration during exercise
- decreased response following training
82
Catecholamines
Epinephrine, norepinephrine, dopamine
83
Sarcopenia
Progressive loss of muscle due to age
• related to immobility
84
Cachexia
Involuntary loss of weight and muscle
85
Types of muscle contraction
Concentric- shortening
Eccentric- lengthening
Isometric- not moving
86
Cortisol
- adrenal cortex
- maintains plasma glucose
- stimulate glucose synthesis
- mobilize FFA
- Blocks glucose uptake in cells
- Stimulated By:
• Stress (ACTH; GAS)
• Exercise
87
Systemic Circuit
- left side of heart
- Pumps oxygenated blood to body
- return deoxygenated blood to right side of heart
88
Pulmonary Circuit
- right side of heart
- pumps deoxygenated blood to lungs
-returns oxygenated blood to left side of heart
89
90
Systole
Contraction phase
- pumps 2/3 of blood per beat
- blood ejected into pulmonary and systemic circualtion
91
Diastole
- relaxation
- heart fills with blood
- filled from atria
- longer than systole during rest
92
Contraction phase
- pumps 2/3 of blood per beat
- blood ejected into pulmonary and systemic circulation
93
What are heart sounds
1st: closing of av valves
2nd: closing of aortic and pulmonary valves
94
Arterial blood pressure
