Topic 7: Skin and Brain (HL) (Not Finished) Flashcards
7.1.2 Functions of skin
- regulation of body temperature
- protection and immunity
- sensation
- excretion
- synthesis of vitamin D
7.1.1 Annotate a diagram of the generalized structure of the skin
a) epidermis
b) dermis
c) sweat gland
d) fat/apidose tissue
e) hair
f) oil gland
g) hair follicle
7.2.1 Label the location of the principal structures of the brain
Limit to:
- the brain stem
- the diencephalon
- the two hemispheres of the cerebrum
- the cerebellum
Functions of Diencephalon (Thalamus + Hypothalamus)
Thalamus:
- Receives messages then sends the messages to the intended destination
- Perception of sensations (pain, temperature, pressure)
- Motor signal relay
- Cognition
Hypothalamus:
- Control of autonomic nervous system (ANS), heart rate, blood pressure, pituitary gland, body temperature, appetite, thirst, fluid, electrolyte balance, and circadian rhythms
Function of Brainstem
respiratory and cardiovascular control centers
Function of Cerebrum (left and right hemispheres)
- Responsible for high-level brain functions such as thinking, language and emotion, and motivation
Function is divided into three broad processes:
- sensory (receiving sensory impulses)
- association (interpreting and storing input, and initiating a response)
- motor (transmitting impulses to effectors)
Functions of Cerebellum
- Helps to smooth and coordinate sequences of skeletal muscle contractions
- Regulate posture and balance
- Makes possible all skilled motor activities, from catching a ball to dancing
Key difference between cerebrum and cerebral cortex
- Cerebrum = uppermost largest part of the brain
- Cerebral cortex = outer layer of the gray matter of cerebrum
Different lobes of the Cerebrum (5)
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
- Limbic lobe
7.2.3. Outline blood supply to the brain
- branchiocephalic trunk = the right common carotid artery
- right + left vertebral arteries = basilar artery, supply blood to posterior part of brain
- right + left carotid arteries supply blood to anterior part of brain
- internal carotid artery supply blood to anterior part of brain
- external carotid artery supply blood to face and scalp
- internal carotid artery + basilar artery are connected by circle of willis –> ensure continous blood supply to brain
Brachiocephalic trunk
- first branch of aortic branch
- supplies blood to the right arm and the head and neck
Circle of Willis
Basilar artery + Internal carotid arteries
Blood brain barrier (BBB)
- Protects brain from ‘foreign substances’ that may injure brain
- Maintains a constant environment for brain
- Protects the brain from hormones and neurotransmitters in the rest of the body
7.2.4. Describe the principal source of energy for brain cells
- Glucose is the sole fuel for the human brain, except during prolonged starvation
- Obtains energy using glucose and oxygen from blood entering the brain
- If blood entering brain has low glucose or oxygen level, can cause mental confusion, dizziness, convulsion, loss of conciousness
Frontal lobe
- Reasoning and motivation, planning, emotions and problem-solving.
- Also contains the speech and movement motor areas.
Parietal lobe
- Sensory and motor area linked to movement, body awareness, orientation and navigation
- Sense of touch, pain and temperature
- Distinguishing size, shape and color
- Spatial perception
- Visual perception
Occipital lobe
Visual sensory (vision) and association centre
Limbic lobe
- Association processes, such as emotions, behavior, motivation, and long-term memory
- “Emotional brain”, related to survival (fear, anger, sexual behavior)
Temporal lobe
- Auditory sensory and association area
- Many aspects of long-term and visual memory
7.2.2. Label the location of the principal lobes of the cerebrum
How does the skin helps to regulate body temperature?
Goosebumps:
- e.g. of vasoconstriction
- contraction of arrector pilli muscle –> trapping heat –> raise body temp
Sweating:
- e.g. of vasodilation
- heat from body passed through sweat –> evaporate
- transfering heat from body to environment
