Topic 2, topic 7, topic 8 Flashcards
principal sources of energy for brain
Glucose and oxygen which pass rapidly from the blood to the brain cells used to make ATP, supply is limited so there must be continuous supply
Outline blood supply to the brain
left and right carotid arteries and left and right vertebral arteries
Carotid arteries
External: supply blood to the face and scalp
Internal: supply blood to most of the cerebrum
Brachiocephalic trunk: artery that supplies blood to the right arm, head and neck
Blood-Brain-Barrier
protects the brain from foreign substances that may injure the brain, maintains a constant environment for the brain
it is a highly selective barrier that separates the circulating blood from the brain extracellular fluid in the CNS
small molecules like antidepressants and alcohol can slip through endothelial cells, large molecules such as glucose and insulin are transported through proteins
principal source of energy for brain cells
The brain obtains energy using glucose and oxygen, which pass rapidly from the blood to the brain cells
Glucose and oxygen are used to make ATP inside the brain by the process of aerobic respiration
Carbohydrate storage in the brain is limited, so the supply of glucose must be continuous
If blood entering the brain has low glucose or oxygen levels, mental confusion, dizziness, convulsions and loss of conciousness may occur
Brain stem function
respiratory and cardiovascular control centres
Includes:
Diencephalon - Thalamus (perception of sensations cognition)
Hypothalamus (control ANS, Hr, blood pressure, pituitary gland)
cerebrum function
high-level brain functions such as thinking, language and emotion, and motivation. 3 broad processes
1-sensory (receiving sensory impulses)
2- association (interpreting and storing input, and initiating a response)
3- motor (transmitting impulses)
Frontal lobe
Motivation, reasoning and planning
Parietal lobe
Somatic sensory orientation
Occipital lobe
visual sensory and association centre
Temporal lobe
long-term memory
Limbic lobe
emotions and feelings
Cerebellum
maintain balance and posture
smooth out skeletal muscle contractions
motor activities
Circulating hormones
travel around the body in the blood (adrenaline and testosterone)
Local hormones
act on neighbouring cells without entering the bloodstream and are usually inactivated quickly. (glucagon and serotonin)
Hormones
secreted by the endocrine glands to regulate and coordinate a range of bodily functions. Most hormones are released in short bursts, although some are secreted over longer periods of time to stimulate permanent changes in the body.
Hormones affect only specific target cells by (chemically) biding to specific receptors
How circulating hormone levels are regulated
complex feedback loops that may be influenced by
-signals from the nervous system, such as adrenaline
-Chemical changes in the blood, such as insulin
-Other hormones like growth hormones
functions of the conducting airways
low resistance pathway for airflow
defence against chemicals and other harmful substances that are inhaled
Warming and moistening the air
Pulmonary ventilation
Inflow and outflow of air between the atmosphere and the lungs (breathing)
Total lung capacity
Volume of air in the lungs after a maximum inhalation (VC + RV)
Vital capacity
Maximum volume of air that can be exhaled after a maximum inhalation (TV+ERV+IRV)
Tidal volume
Volume of air breathed in and out in any one breath
Expiratory reserve volume
Volume of air in excess of tidal volume that can be exhaled forcibly
Inspiratory reserve volume
Additional inspired air over and above tidal volume
Residual volume
Volume of air still contained in the lungs after a maximal exhalation
Accessory muscles
Abdominals, scapula and pectoralis major
Inspiration
Diaphragm contracts and lowers
External intercostal muscles contract raising the rib cage (internal intercostal muscles contract antagonistic pairs)
Volume of lungs increases
Pressure decreases below atmospheric pressure
Gas always wants to go to a place with less pressure
Air flows in
Expiration
Diaphragm relaxes becoming dome-shaped
Internal intercostal muscles contract lowering the rib cage
Volume of lungs decreases
Pressure increases above atmospheric pressure
Gas is forced out because it wants to go to a place with less pressure
Air flows out
role of hemoglobin in oxygen transportation
98.5% of oxygen is transported by hemoglobin as oxyhemoglobin within red blood cells
Process of gas exchange in the alveoli
Oxygen moves into the alveolus which causes it to have a high concentration of oxygen
Oxygen diffuses (because the capillaries have low concentration of blood) through the cell membrane of alveolus (this membrane is 1 cell thick) This means that it is a short distance to the capillary
Inside the capillary if diffuses into red blood cells
Haemoglobin turns into oxyhemoglobin
Red blood cells carry deoxigenated blood and turns then into oxygenated blood
Carbon dioxide leaves the capillary and diffuses to the alveolus
CO2 leaves the alveolus
Composition of blood
Erythocytes: Transport O2 and CO2
Leucocytes:Part of the immune system (fight infections)
Platelets(thrombocytes) - clot the blood
Plasma - liquid (mostly water) transport other cells, nutrients, vitamins and everything in the blood
Functions of skin
Regulation of body temperature (sweat production by sweat glands evaporates)
Protection and immunity (from impact or substances)
Sensation (nerve endings and receptors)
Excretion (of salts, water, organic waste)
Synthesis of Vitamin D (epidermal cells produce when exposed to UV radiation)
Hypothalamus and Pituitary gland
Responsable for homeostasis
Hypothalamus is the part of the brain that controls the pituitary gland
Neurohormones (GHRH and Somatostatin) directly influence the pituitary gland
Nervous impulses from hypothalamus also stilulate the pituitary gland
Pituitary gland secretes hormones such as ADH and GH that help regulate the body functions such as growth, water and temperature regulations
Nervous and chemical controls of ventilation during exercise
Ventilation increases as a direct result of increases in blood acidity levels (low pH) due to the increase in carbon dioxide content of the blood detected by the respiratory centre. This results in an increase in the rate and depth of ventilation during exercise. The muscles use more oxygen so there is more CO2 as a byproduct
Neural control of ventilation includes lung strtch receptors, muscle proprioreceptors and chemoreceptors
Four chambers of the heart
left and right atrium (upper chambers)
left and right ventricals (lower chambers)
4 valves and major blood vessels
Aorta Valves, Tricuspid valve, Bicuspid Valve and Mitral valve Vena Cava, pulmonary vein, aorta and pulmonary artery
Through the coronary arteries
The heart has its own blood supply
Pulmonary circulation
Carries deoxygenated blood away from the heart to the lungs and returns oxygenated blood back to the heart
Systemic circulation
Carries oxygenated blood away from the heart to the body and returns deoxygenated blood back to the heart
Parasympathetic and Sympathetic
The parasympathetic nervous system restores the body to a calm and composed state and prevents it from overworking. Rest+ Digest (relaxing) The sympathetic nervous system, on the other hand, prepares the body for fight and flight response. (fight or flight)
Describe the intrinsic and extrinsic regulation of the heart rate and the sequence of excitation of the heart muscle
Extrinsic: its own pacemaker that signals it when to beat and is controlled by the ANS and by adrenaline (also increases glycogen and lipid breakdown)
Intrinsic: Electrical impulse generated at the SA node and travels across the atria to the AV ode to the ventricals
Stimulation of the heartbeat
Information from the Nervous system (how fast to beat/a lot of adrenaline or not not)
Sino-Atrial Node receives this information
SAN contracts the Atria
Atrio-Ventricular Node takes information from the contraction to the Parkinjee Fibres that cause a contraction
The contracts the ventricles –»Apex Final culmination of the heartbeat
principle structure of the ventilatory system
Nose Mounth pharynx Larynx Trachea Bonchi Bronchioles Lungs Alveoli
Relationship between cardiac output, heart rate and stroke volume at rest and during exercise
Cardiac output = stroke volume times heart rate
Stroke volume expands and heart rate increases during exercise
Analyse cardiac output, stroke volume and heart rate data for different populations at rest and during exercise
Cardiac output
At rest: CO lower in females due to differences in body size and composition
Trained individuals higher because cardiovascular adaptations
During exercise: Female is still lower but both increase
Trained exhibit more increase
Stroke volume
At rest: lower in females
Trained larger because improvements in cardiac function
During exercise: trained greater
Heart rate
At rest: higher in females
Trained have lower due to increased cardiac efficiency
During exercise: trained reach a lower maximal due to increased stroke volume
Cardiovascular drift
increased body temperature results in lower venous return to the heart, a small decrease in blood volume from sweat. A reduction in SV causes the heart rate to increase to maintain cardiac output. Blood is more viscous
systolic and diastolic blood pressure
Systolic: the force exerted by blood on arterial walls during ventricular contraction
Diastolic. the force exerted by the blood on the arterial wall during ventricular relaxation
cardiac output
Quantity of blood pumped by the heart in a given period of time 8litres per minute)
Stroke volume
volume of blood pumped out of the left ventricle of the heart during each systolic cardiac contraction (expands during exercise)
HR
number of beats per minute
Diastolic VS systolic
systolic is almost double diastolic
Systolic increases way more from rest to exercise then diastolic
response of systolic and diastolic to dynamic and static exercise
Static exercise: there is no relaxation of the arterial walls because the muscles are constantly contracted
In dynamic exercise there are periods of relaxation which means that the arterial walls are not constantly under pressure
Compare distribution of blood at rest and redistribution of blood during exercise
At rest
blood flow to muscles at rest is lower then during exercise. It also goes to other organs like the brain, heart, and kidneys. Resting skeletal muscles do not require as much oxygen and nutrients as they do during physical activity.
During exercise
Increase in blood flow to the active muscles (oxygen and nutrient supply). Oxygen is essential for aerobic respiration, providing energy for muscle contractions. Nutrients support energy production during exercise
The sympathetic nervous system is activated during exercise, leading to the release of norepinephrine.
Cardiovascular adaptations resulting from endurance exercise training
Hypertrophy to ventricular volume resulting in an increase stroke volume and lower resting and exercising heart rate
Increased capillarization which leads to more blood going to the muscles
Icreased oxygen difference (difference between the oxygen in the arteries and the veins
Higher VO2 max
maximal oxygen consumption (VO2 max)
Maximum oxygen uptake that quantifies the maximum rate that an individual can take in and use oxygen (amount of oxygen someone can use)
VO2 Max (males vs females, young vs old, trained vs untrained)
Trained has higher because they have more muscle, bigger left ventricle and more capillarization
During child years it increases as you grow but it reaches a peak at early 20s for males and late teens for females. then it decreases with age
Lower in females because of hemoglobin concentration and body composition (15% more body fat which doens´t cappilarize)
generalized structure of the skin
Epidermis
Peridermis
endodermis
Fat
Sweat glands
oil glands
Hair follicles
Relationship between the hypothalamus and the pituitary gland
hypothalamus and pituitary gland are responsible for homeostasis
Hypothalamus is the part of the brain that controls the pituitary gland
Neurohormones such as GHRH and somatostatin from the hypothalamus influence the pituitary gland as well as nerve impulses
Pituitary gland secretes ADH and GH that help regulate a wide range of bodily functions including growth and water and temperature regulations
Label the endocrine organs
Hypothalamus
pituitary gland
pineal gland
thyroid gland
adrenal
pancreas
ovaries and testes
Discuss the variability of maximal oxygen consumption with different modes of exercise
Cycling vs running vs arm ergometry - more amount of muscle groups involved the higher the VO2 max
